Showing posts with label Type 2 diabetes. Show all posts
Showing posts with label Type 2 diabetes. Show all posts

Tuesday, April 20, 2010

Type 2 Diabetes Classification - A Straw Man Scale for Progression

Many people in the diabetes online community (DOC) are concerned about the label "prediabetes", its predecessor term "borderline diabetes", and its colloquial counterparts (e.g., "a touch of the sugar"). The prevailing attitude is that one either has diabetes, or one does not. This may seem counterintuitive to the general understanding that a woman who was diagnosed with gestational diabetes (GD), but whose postpartum glucose metabolism has returned to reference normal (RN), does not have Type 2 diabetes mellitus (T2DM), but is at increased risk for developing T2DM later in life. It also contrasts with the popular belief -- even espoused by some in the mainstream medical community -- that if a person diagnosed with T2DM can bring his glucose metabolism back to RN by changes to his diet and exercise regimen (D&E) without the use of antidiabetic medications, then he no longer has diabetes.

Two biases of significant note: (1) current medical understanding is that at the point of T2DM diagnosis, a person has lost 50% of beta cell function (AACE, p. 16), and (2) the diabetes online community is primarily informed by persons with Type 1 diabetes mellitus (T1DM), an autoimmune disorder for which there is currently no cure.

Based on the above attitudes and biases, the belief would be that the new mother, having been diagnosed with GD during pregnancy, would be considered to have T2DM, even if it can be mediated without frank lifestyle adjustments. Similarly, the person who was diagnosed with T2DM is considered to still have T2DM, even if it is mediated completely by D&E.

Unlike most presentations of T1DM, T2DM is currently understood to be a progressive condition. Our understanding of its progression in a given individual is informed by both quantitative and qualitative benchmarks. The most common quantitative benchmarks are the individual's fasting blood glucose level, serum fructosamine level, and amount of glycosylated hemoglobin. Other quantitative benchmarks -- such as c-peptide level -- may be useful in determining both insulin resistance and degree of remaining beta cell function. Qualitative benchmarks include signs and symptoms of known complications of diabetes at all levels of their development.

One analogy for cataloguing the degree of progression of T2DM is that used for cataloguing hypertension or cancer: a stage chart. In Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7), hypertension is categorized from consistently slightly-elevated blood pressure ("prehypertension") through progressively elevated levels, and the response of those levels to pharmacotherapy.

An initial straw man chart can be derived from the American Association of Clinical Endrocrinologists' Medical Guidelines for Clinical Practice for the Management of Diabetes Mellitus (2007) examples for initial pharmacotherapy of T2DM:

Classification of Type 2 Diabetes Mellitus (based on initial therapy algorithms)
Progression Level
HbA1c (untreated)
Stage 1 (Prediabetes)
5.7 - 6.4
Stage 2
6.5 - 7.0
Stage 3
7.0 - 8.0
Stage 4
8.0 - 10.0
Stage 5
> 10.0

Other issues that play into determining the progression of T2DM include the deterioration of endogenous insulin production, the development of complications of diabetes, and the degree to which a person's blood glucose levels and HbA1c are responsive to pharmacotherapy. A more complex table of progression might include these in a manner such as this:
Classifications of Type 2 Diabetes Mellitus (proposed)
LevelHbA1c
(Goal)1
Effective TherapyEvidence of
Complications
c-peptide
(relative)
Stage 1 (Pre-Diabetes)2< 6.03ILM. Oral medication optional for aggressive treatment.nonehigh
Stage 2< 6.5Oral medication and/or insulin sensitizer requirednonehigh
Stage 3< 7.0Combination therapy and/or insulin requiredpossible;
possible comorbid conditions
varies
Stage 4< 7.0Insulin therapy required, with or without oral medications and/or pramlintide (Symlin)probable;
possible comorbid conditions
low
Stage 5< 8.0Intensive insulin therapy required, possibly in conjunction with insulin sensitizersobvious; one or more
comorbid conditions
low
1 While the HbA1c goals at the more advanced levels of diabetes progression are high enough that complications are likely to develop or intensify, those goals may not be realistically achievable with current medical and pharmaceutical technology.
2 Includes all previous diagnoses of gestational diabetes or Type 2 diabetes in which pharmacotherapy is not currently indicated
3 More aggressive practitioners may argue for an HbA1c goal of under 5.5 for Stage 1, under 6.0 for Stage 2, and under 6.5 for later stages of T2DM. The less-aggressive goals are informed in part by the (ACCORD) study, in which the tested combination therapy suggested a higher mortality risk for intensive control.

A classification scheme of this sort may remove the ambiguity of a diagnosis of "prediabetes" and its associated laissez-faire ("It's not diabetes") attitude, as well as the popular belief that once diagnosed, one can become "undiagnosed" (or perhaps "de-diagnosed"). It can also alert a medical practitioner to the need for ongoing monitoring and assessment of a person's glucose metabolism. On the other hand, classification will add to the pool of people indicated to have diabetes those who do not consider themselves to be currently affected by diabetes -- and in an environment where a positive diagnosis can mean the denial of employment, medical insurance, or healthcare, this can have worse repercussions than living with undiagnosed or untreated Stage 1 (or even Stage 2) T2DM.

Thursday, December 4, 2008

On the Low Birth Weight Risk for Insulin Resistance

Altered PI3-Kinase/Akt Signalling in Skeletal Muscle of Young Men with Low Birth Weight
Original source: PLoS ONE 3(11): e3738
Authors: Christine B. Jensen, Malgorzata S. Martin-Gronert, Heidi Storgaard, Sten Madsbad, Allan Vaag, Susan E. Ozanne (corresponding author)
Publication date: November 17, 2008
DOI (digital document ID): 10.1371/journal.pone.0003738
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
Low birth weight (LBW), an indicator of stress or an adverse fetal environment, is associated with increased future risk of insulin resistance and type 2 diabetes. The investigators are reporting continuing research on a specific insulin signaling pathway may be altered in skeletal muscle of young adult men with LBW. This would help increase our understanding of the mechanisms of insulin resistance in this particular population.

Muscle biopsies were obtained from 20 healthy 19-yr old men who had been in the lowest 10% birth weight for full-term babies and compared them to 20 physically similar men of normal birth weight. The samples were checked for fasting blood glucose and insulin levels, and after four hours in which insulin-production was medically stimulated.

The researchers looked at several previously-unstudied proteins and pathways related to muscular function and muscular glucose metabolism to see if there was any difference between the two groups of men. They found significant differences in the levels of several proteins after insulin stimulation. Some of these differences seen in the LBW group are similar to those seen in patients with insulin-resistant Type 2 diabetes.

The authors conclude that these differences in skeletal-muscle response to insulin precede, and may contribute to, the development of whole-body insulin resistance and type 2 diabetes in men with LBW.


Reliability:
The tests were done on a small number of subjects and a small number of controls. The small sample could skew the results obtained. Also, these were spot observations. Longitudinal observation of these subjects (over a period of time) might give the researchers better information about whether or not insulin resistance progresses in this manner in these subjects.

Practical Applications:
This is one of a series in basic research of how diabetes may develop in specific populations.

In many areas, low birth weight is associated with maternal malnutrition and/or poor prenatal care -- which are further associated with low-income communities and minority communities. Type 2 diabetes is more common in these groups than in the general population. Proving a definite link and path may bring more interest in providing education, and medical and dietary services, to this high-risk group.

Ethics note:
Written informed consent was provided from all participants and approval was obtained from the regional ethics committee.

This synopsis was based on the entire article.

Saturday, November 22, 2008

Can genetic risks accurately predict Type 2 diabetes?

Clinical Risk Factors, DNA Variants, and the Development of Type 2 Diabetes
Original source: New England Journal of Medicine Volume 359, Number 21
Authors: Valeriya Lyssenko, Anna Jonsson, Peter Almgren, Nicoló Pulizzi, Bo Isomaa, Tiinamaija Tuomi, Göran Berglund, David Altshuler, Peter Nilsson, and Leif Groop
Publication date: November 20, 2008
DOI (digital document ID): not available
Requires subscription? Yes
Publicly-available abstract: Yes

Synopsis:
The aim of this paper is to determine whether environmental and clinical risk indicators, genetic factors, or both can be used to predict whether or not a person will develop Type 2 diabetes.

The authors singled out 16 specific gene markers that might be used to predict risk or development of diabetes. They tracked those, plus known environmental and clinical risk indicators, for over 16,000 Swedish patients and over 2500 Finnish patients, for a median period of 23.5 years. They studied the effect of variations of the gene markers on insulin secretion and insulin action over this period of time.

Over the observation period, approximately 11.7% of the subjects developed diabetes. Variations in 11 of the genes studied were associated with developing diabetes, independent of other risk indicators. Variants in eight of those genes were specifically associated with impaired beta cell function.

Adding the genetic risk to the clinical and environmental indicators slightly improved the long-term ability to predict whether or not an individual would develop Type 2 diabetes. This predictive ability increased with the duration of the follow-up.

Reliability:
While a large population was observed, and the medium observation time was over 20 years, the abstract does not provide insight into the distribution of follow-up duration, to let us know whether the median is a statistically-significant number. The improved prediction ability turns out to be about 1.5% better than the accuracy without the genetic information, which may not be cost-effective at the present time.

Practical Applications:
Known genetic risk is sometimes an incentive for making lifestyle changes to reduce the other risks for developing diabetes.

If the full paper shows direct correlations between insulin secretion, insulin resistance, and genetic variations, then initial pharmaceutical therapy can be better targeted to the individual's needs.

This synopsis was based on the abstract only.

Tuesday, November 18, 2008

A possible genetic component of Type 2 diabetes

Variance of the SGK1 Gene Is Associated with Insulin Secretion in Different European Populations: Results from the TUEF, EUGENE2, and METSIM Studies
Original source: PLoS ONE 3(11): e3506.
Authors: Björn Friedrich, Peter Weyrich, Alena Stančáková, Jianjung Wang, Johanna Kuusisto, Markku Laakso, Giorgio Sesti, Elena Succurro, Ulf Smith, Torben Hansen, Oluf Pedersen, Fausto Machicao, Silke Schäfer, Florian Lang, Teut Risler, Susanne Ullrich, Norbert Stefan, Andreas Fritsche (corresponding author), Hans-Ulrich Häring
Publication date: 5 November 2008
DOI (digital document ID): 10.1371/journal.pone.0003506
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
The authors used a "classical candidate-gene approach" to examine genes that play a role in insulin secretion and their potential roles in the development of insulin-resistant diabetes. The gene they focused on is serum and glucocorticoid inducible kinase SGK1, which is encoded by the gene SGK on chromosome 6q23. The action of this gene is increased in the presence of corticoids and insulin, among other things, and seems to provide a molecular link between electrolyte activation and glucose stability. It also appears to play a role in both insulin signalling and insulin secretion and blood pressure.

The investigators looked at genetic variance in SGK, and potential associations with insulin secretory function, in two specific groups of people (the 725-person TUEF cohort and the 634-person EUGENE2 participants) whose diabetes risks had been examined for insulin secretion traits among those who were prediabetic. These were compared with the results of a study on an older, genetically-similar population (the 4457-person METSIM cohort) to determine whether their hypothesis was correct.

Insulin sensitivity and insulin production were measured using oral glucose tolerance tests (OGTT), measuring c-peptide levels or plasma insulin levels to determine insulin secretion, along with blood glucose levels to determine insulin sensitivity. BMI and waist-hip ratio were also measured in these populations. The patients were correlated to specific variations of one of four tagged alleles (rs9402571) of the SGK-1 gene.

There was no association of the specific tagged alleles with insulin sensitivity in either the TUEF screening population or in the EUGENE2 study, but the authors suggest that this expression of the gene's expression is based on BMI. They mention that the spot in which the SGK1 gene sits has been "associated with BMI progression in participants of the Framingham Heart Study."

On the other hand, the TUEF and EUGENE2 studies did report an increase in insulin secretion in lean patients with one specific variation of the rs9402571 allele. METSIM participants with this variation had a lower incidence of Type 2 diabetes. The authors suggest that this variation may protect against Type 2 diabetes, but that its effect may become blocked or blurred in overweight or obese individuals.

Their analysis suggests that the rs9402571 allele of the SGK1 gene is associated with altered insulin secretion and with Type 2 diabetes.


Reliability:
The authors are associated with accredited medical institutions and the results were published in a peer-reviewed journal. The subsets of the TUEF and EUGENE2 participants' data analyzed in the paper are relatively small. The correlation with an older population of similar genome poses a good initial check on the original hypothesis; the ongoing nature of the TUEF study (Tübingen Family Study) suggests that a more definitive correlation will be possible at some time in the future.

Practical Applications:
The developing discipline of genomics suggests that we might one day be able to base our healthcare on how our own particular genes work.

This synopsis was based on the entire article.

Friday, November 7, 2008

Are moderate-protein diets better than low-protein diets for people with metabolic syndrome?

Moderate carbohydrate, moderate protein weight loss diet reduces cardiovascular disease risk compared to high carbohydrate, low protein diet in obese adults: A randomized clinical trial

Original source: Nutrition & Metabolism 2008, 5:30
Authors: Denise A Walker Lasker (corresponding author), Ellen M Evans, and Donald K Layman
Publication date: 7 November 2008
DOI (digital document ID): 10.1186/1743-7075-5-30
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
This study compares the effectiveness of the standard USDA Food Pyramid diet with a higher-protein, lower-carbohydrate diet for weight loss in general, for fat loss in particular, and for lowering the blood-based indicators of cardiovascular risk and insulin resistance. A total of 50 people completed the testing, split between the two dietary approaches.

Both diets under test had the same amount of calories, with about 30% of total calories coming from fats. Carbohydrates supplied about 55% of the Food Pyramid diet group's caloric intake, and protein, the remaining 15%. The people assigned to this group were instructed to eat whole grains for their bread products. About 30% of the high-protein group's calories came from protein, with the remaining 40% coming from carbohydrates. (This is the same protein-carbohydrate-fat distribution advocated by the Zone Diet.) This group was instructed to eat primarily "high quality protein", including lean meats, dairy, and eggs. Both groups had similar amounts of fruits and vegetables in their daily diets. All subjects were instructed on portion sizes, dietary substitutions, how to weigh foods, and how to keep a food diary. There was no difference in exercise between the two groups.

Baseline measurements (weight, body fat percentage, cholesterol, and postprandial insulin) were taken at the start of the experiment. The subjects followed their assigned diet plans for four months, at which time the same measurements were repeated.

  • The moderate-protein group lost about 5 pounds more per person than the USDA group, and more of their weight loss was from fatty tissues.
  • Fasting glucose levels were unchanged, but fasting insulin levels decreased in the moderate protein group, while it increased in the USDA group. In addition, postprandial insulin levels dropped 85% for the protein group, but only 50% for the Food Pyramid group. (High plasma insulin levels are indicative of insulin resistance, which is often a predecessor to Type 2 diabetes.)
  • There was a greater drop in total cholesterol in the USDA group than in the protein group. LDL ("bad") cholesterol dropped in the USDA group but rose in the protein group; on the other hand, HDL ("good") cholesterol dropped in the USDA group but rose in the protein group. The protein group also showed greater improvement in triglyceride levels than the USDA group. (High triglyceride levels are associated with increased risk of heart attack.)

Reliability:
The study was small scale, with only 50 people completing the four-month study. While the two groups of subjects were selected to be closely-matched, there is still opportunity for the results to be skewed. An initial run-in period put all subjects on as close to an even footing as possible before the trial started.
The authors are associated with an accredited university; the paper was published in a peer-reviewed journal.
Longer-term studies of larger groups may be needed to determine the long-term safety and effectiveness of high-protein diets.

The principal investigator (Denise A Walker Lasker) received funding from the National Cattleman’s Beef Association, The Beef Board and Kraft Foods. Both Beef associations have a vested interest in increasing protein consumption (in the form of beef).
The investigators have made no comparison between a higher-fat restricted-carbohydrate diet and a higher-protein restricted-carbohydrate diet.

Practical Applications:
The 30/40/30 protein/carb/fat (PCF) ratio is the basis of the Zone Diet. While this diet is higher in protein than traditionally advised for people with diabetes, recent publications suggest that this is not as high a risk as formerly perceived.

For further reading:
WebMD evaluates the Zone Diet
Wikipedia entry on the Zone Diet

This synopsis was based on the entire article.

Tuesday, November 4, 2008

Effects of adding a second drug to Metformin

Outcomes of adding second hypoglycemic drug after metformin monotherapy failure among type 2 diabetes in Hungary
Original source: Health and Quality of Life Outcomes 2008, 6:88
Authors: Gyorgy Jermendy, Diana Erdesz, Laszlo Nagy, Don Yin, Hemant Phatak, Sudeep Karve, Samuel Engel and Rajesh Balkrishnan (corresponding author)
Publication date: 31 October 2008
DOI (digital document ID): 10.1186/1477-7525-6-88
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
The authors' goal is to determine how well patients' blood glucose levels are controlled, and how the patients felt about their quality of life with diabetes, when metformin was not sufficient to control their diabetes and a second drug was added. The medical records of patients who had been on two oral diabetes drugs for at least a year were followed back for at least one year when they were on the two drugs, and going back as far as six months before the second drug was added. Other medical conditions that might affect the choice of medications, or that might need different medications, were tagged.

The goal of diabetes care was to achieve an HbA1c of under 6.5%. HbA1c is a long-term measure of average blood glucose levels; it is believed that sustained high blood glucose levels are the cause of many of the complications of diabetes. One issue that complicates this goal is that the HbA1c level includes the effects of unusually or dangerously low blood glucose -- hypoglycemia.

414 patients, average age 60 years, participated in this survey, in which they were asked about hypoglycemic incidents, satisfaction with their treatment, and overall health-related quality of life (HRQoL).

Hypoglycemic episodes were ranked as mild (little disruption to activities), moderate (requiring the to interruption of normal activities), or severe (requiring immediate medical assistance). The patients were also asked to report any swelling, weight gain, and digestive discomfort that might have occurred since starting the second drug. They were also given a standardized questionnaire to determine whether or not they took one, or both, drugs as prescribed.

27 percent reported hypoglycemic incidents, one third of that group reporting at least one moderate or severe hypoglycemic incident. Three-quarters of the patients did not meet their HbA1c goal after a year of therapy; many blamed their weight for this, though the surveys suggest it is more likely that this failure was because they were not taking their medications correctly. Reasons for not taking medications included side effects and the belief that the medications would cause them to gain weight. Patients who did not get their HbA1c below 6.5% were as a whole heavier than those who reached the goal, and they were less likely to be satisfied with the change in treatment. The participants felt that hypoglycemic incidents reduced their health-related quality of life; also, the longer they had diabetes, the lower their self-reported HRQoL.

Reliability:
The group of patients examined was relatively small, and because the individuals reported their issues themselves, it is possible that some did not admit to not using their drugs correctly, or to other issues that might affect the results of their care.

The results were published in a peer-reviewed journal, and the effectiveness of oral diabetes drugs is a hot issue. This study shows some possible reasons for why dual-drug therapy is not always successful.

It is important to note that all but one of the authors works for Merck, either as a direct employee or a paid consultant. Merck is the manufacturer of sitagliptin (Januvia), which is in a different class of oral diabetes drug from those used in the study (DP-4 inhibitors). The failure rates of both sulfonylurea and thiazolidinedione drugs used in the study could be used to build a case for the preferential use of Merck drugs Januvia and Janumet (Januvia plus Metformin) for diabetes management, which would be very profitable for Merck. Merck paid for the study.

Practical Applications:
The care protocols recently issued by both the American Diabetes Association and the European Association for the Study of Diabetes suggest either adding a sulfonylurea (a class of drug which helps the pancreas make more insulin) or moving directly to insulin injections if metformin by itself does not provide effective results. While some second-tier drugs such as Actos and Byetta were mentioned, the use of these and other classes of oral diabetes drugs (including DP-4 inhibitors such as Januvia) were considered more expensive and not as well-tested.

Another issue to consider is that the time-frames for changing ineffective therapy are much shorter in the current recommendations than those followed by the doctors in this study. Since diabetes is a progressive disease, it is possible that by the time the second medication was added, the disease had progressed too far for that medication to be effective.

For further reading:
New Major Changes in Recommendations for the Treatment of Type 2 Diabetes by ADA and EASD -- a synopsis of the new treatment recommendations from Diabetes In Control
Medical management of hyperglycaemia in type 2 diabetes mellitus: a consensus algorithm for the initiation and adjustment of therapy -- the abstract of the new treatment protocols, as published in Diabetologia

This synopsis was based on the entire article.

Primary Care Physicians as point-of-care for Type 2 diabetes

Family physician and endocrinologist coordination as the basis for diabetes care in clinical practice
Original source: BMC Endocrine Disorders 2008, 8:9
Authors: Alejandra Duran, Isabelle Runkle, Pilar Matía, Maria P de Miguel, Sofia Garrido, Emilio Cervera, Maria D Fernandez, Pilar Torres, Tomas Lillo, Patricia Martin, Lucio Cabrerizo, Nuria Garcia de la Torre, Jose R Calle, Jose Ibarra, Aniceto L Charro, and Alfonso L Calle-Pascual (corresponding author)
Publication date: 31 July 2008
DOI (digital document ID): 10.1186/1472-6823-8-9
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
The investigators looked at diabetes patients with peripheral circulation and capillary circulation issues and sought to find out whether there was any measurable difference in the results whether the patient was treated by a primary care physician (PCP) or an endocrinologist.

One of the issues surrounding diabetes care in Spain is that primary care physicians (PCPs) may not be as aggressive in treating multiple risk factors and signs of complications of diabetes as a hospital-based endocrinology team. A program in which PCPs are trained to address all these factors and to consult with the hospital-based team was instituted. This study attempts to evaluate the effectiveness of this program.

In the "Area 7" section of Madrid, Spain, 126 patients with Type 2 diabetes and peripheral circulation issues were studied over a 30-month period. After an initial three-month period of treatment by the Diabetes team at St Carlos Hospital, the patients were broken up into two groups: one to continue care at St Carlos, the other to return to their program PCPs for diabetes care. Nine patients moved out of district over the period of the study, leaving 117 patients from which to evaluate this program.

The investigators looked at the folloiwng markers as indicators of care effectiveness: HbA1c (%); Total Cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides; blood pressure; albumine-to-creatinine excretion ratio (ACR); body mass index (BMI) and waist circumference (WC); anti-aggregation treatment; and smoking status.

At the end of the follow up, no differences were found between the groups for the following counters:
  • more than 37% of diabetic patients achieved a HbA1c <>
  • more than 50% a ACR <>
  • more than 80% reached low risk values for cholesterol, LDL cholesterol, triglycerides, and diastolic blood pressure
  • more than 80% were on aspirin therapy against platelet aggregation
  • 12% remained smokers.
On the other hand,
  • less than 45% achieved a systolic blood pressure <>
  • only 49% of the men and 30% of the women had a waist circumference of low risk.
The largest difference between the groups is that while 23% of the patients cared for by the diabetes care team achieved a BMI less than 25, less than 12% of the patients cared for by family physicians achieved this level. Neither of these results was considered satisfactory and were attributed to focus on risk factors other than overweight.

The investigators concluded that good metabolic control can be achieved at the primary care level, if the PCP coordinates patient care with the endocrinologist. This will result in better results than being treated by an untrained primary care physician without endocrinological support.

Reliability:
The study was small enough that it could be a pilot project -- evaluation of a small-scale implementation before bringing this program to all of Madrid, or to all of Spain. The follow-up time was 2.5 years, which is an intermediate timeframe. Two of the authors work at the St Carlos hospital and clinic; the third is associated with the evaluation of primary care in the "Area 7" section of Madrid. The research was published in a peer-reviewed journal, which suggests a level of reliability to the results.

Practical Applications:
Moving Type 2 diabetes follow-on care out to the primary care practitioner can simplify care delivery from the patient's point of view. It also allows the PCP to do a better job of treating the entire patient, rather than a single aspect of that patient's care. In addition, teaching PCPs more about diabetes, and giving them consultation access to endocrinologists, can improve both initial diagnosis and ongoing diabetes care.


This synopsis was based on the entire article.

Monday, November 3, 2008

How "Bedside Manner" affects Self Care in Type 2 diabetes

The emotional context of self-management in chronic illness - A qualitative study of the role of health professional support in the self-management of type 2 diabetes
Original source: BMC Health Services Research 2008, 8:214
Authors: John Furler (corresponding author), Christine Walker, Irene Blackberry, Trisha Dunning, Nabil Sulaiman, James Dunbar, James Best, Doris Young
Publication date: 17 October 2008
DOI (digital document ID): 10.1186/1472-6963-8-214
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
One role of health-care professionals is to support patients with regard to both the clinical and emotional aspects of living with diabetes. The authors of this study tried to find approaches to make these professionals more effective at this task. They asked patients with Type 2 diabetes how they took care of their diabetes and how their relationships with their support teams affected this. They looked at groups who had been telephoned by nurses in the patients' general practitioners' offices to "coach" them about their diabetes and encourage them to become more actively-engaged their own health care and in their relationship with their family doctors. Their goal is to make these nurses more effective in this mission.

A total of 52 patients, ranging in age from 50-80, were split into four focus groups. Most of the participants were either unemployed or retired, and had had at least one visit with a diabetes educator. There were two English-language focus groups, plus one in Arabic and one in Turkish -- the two main languages of lower-income immigrants in the Melbourne, Australia urban area.

The groups focused on the role of personal control of diabetes and how one's relationships with one's healthcare team influenced this.

The investigators found that overall, the English speakers tended to see diabetes as life-limiting, almost punitive, and requiring self discipline. Dietary changes were viewed in terms of sacrifice -- for example, "having to give up" one's favorite foods. They looked at their entire care team as separate but equally important entities. They were more likely to "shop around" to find professionals who would give them "the right answers"; they needed information to be able to exert control their conditions.

Arabic and Turkish speakers saw diabetes as an integrated part of life, possibly indicative of stress. They saw self-management techniques as part of an integrated effort to restore personal calm. Dietary changes were put in a positive light -- using higher-quality foods rather than lesser quality ones, for example. They also relied primarily on their relationship with their General Practitioner, expecting him to provide them with all the information necessary to care for themselves. When they attended education sessions, or saw specialists, it was only upon the strong recommendation of their primary care physicians.

The investigators saw in the English-speakers the emerging concept of "patienthood", and doctor-patient relationships evolving to the ideal of the actively-engaged patient. (This is the model that is fostered by medical professional societies and by health insurers.) In contrast, they felt there was a potential danger in being completely uncritical of one's primary care physician, with the potential for insufficiently aggressive care and poorer long-term outcomes. The authors believe their findings suggest that a patient will see better results if his or her health-care professionals take the time to understand their patients' social, cultural, and emotional contexts and work from there to help them develop an effective approach to self care.

Reliability:
The study size was very small. The authors note that several aspects of its design could have skewed the results, and their specific results are not applicable outside of the particular community studied. The authors are a multidisciplinary group of professionals in medical practice, medical education, public health, and patient advocacy. The research was published in a peer-reviewed journal. The information should be considered more as a start-off point for your own relationships with your health-care team -- or if you are a practitioner, your patients.

Practical Applications:
There are many reasons that one's social and cultural background can either help or hinder self-care. I've often stated -- and even blogged -- that being willing to learn about the beliefs and cultural contexts of others, and by using those contexts as a starting point, the information or discussion you provide will be more easily understood, more appropriate to that other person, and where health information is concerned, more likely to get a positive response. I am encouraged to see this approach, and hope that it will improve diabetes care not just in Melbourne, but throughout the world.

This synopsis was based on the entire article.

Saturday, November 1, 2008

One theory of increased colon cancer risk in Type 2 diabetes

Lack of association of colonic epithelium telomere length and oxidative DNA damage in Type 2 diabetes under good metabolic control
Original source: BMC Endocrine Disorders 2008, 8:12
Authors: Deepak Kejariwal (corresponding author), Karolina M Stepien, Tracy Smith, Hugh Kennedy, David A Hughes, and Mike J Sampson
Publication date: 10 October 2008
DOI (digital document ID): 10.1186/1472-6823-8-12
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
People with Type 2 diabetes are at greatly increased risk for developing colon cancer, but the reasons for this are not clear. One possible reason may be DNA damage and oxidative stress, which may or may not be related to high blood glucose levels. Telomeres are DNA repeat sequences at the ends of chomosomes that get shorter each time a cell divides. After a certain point, they become non-functional. This causes a chemical signal to go out to kill the cell, preventing the growth of tumors. If the chemical signal is missing, the cells will continue to divide and the chromosomes will become unstable. Eventually this instability and continued cell division can result in tumors. The loss of this signal is found in many cancers, including about half of all colorectal cancers.

Under oxidative stress, telomeres may shorten more quickly, and less accurately, than they might otherwise. The authors believed that the telomeres of people with Type 2 diabetes are more prone to the effects of oxidative stress than those without diabetes, and that the cells from their colons would show evidence of shorter telomeres, which would kick off a series of events leading to colorectal cancer.

People with lower-intestinal and colon disease were excluded from this study, as were those who took vitamins or fish oil. The patients controlled their diabetes by taking metformin, a sulfonylurea drug, both of those, or insulin. A total of 32 people were examined between the people with diabetes and the non-diabetic controls. None of the subjects were smokers. The diabetic subjects had A1c under 6.9% but were dealing with known complications of diabetes. Tissue samples were taken from the lower colon and examined for oxidative damage and telomere shortening.

There were no appreciable differences in telomere length between the two groups. However, the groups were small, and the greater number of people with diabetes taking aspirin, ACE inhibitors (anti-hypertension medication), and/or statins (to reduce high cholesterol levels) may have provided some level of protection. Other reasons a difference was not seen could be that the diabetic subjects were in good control of their blood glucose levels, and that 6.5 years may not be a long enough time with diabetes for the effects of oxidative stress and increased colon cancer risk to be measurable.

Reliability:
Two of the investigators associated with a University hospital. The research was published in a peer-reviewed journal. The sample size was extremely small, and though steps were taken to minimize its effects, this small a sample could cause a skewed set of results. The authors do suggest that further research is necessary to confirm or rule out their theory.

Practical Applications:
More research is needed to find out exactly why people with Type 2 diabetes are at higher risk of developing colon cancer, and ways of minimizing that additional risk.

This synopsis was based on the entire article.

Are adverse effects of some diabetes drugs related to their suppression of sex hormones?

Are the adverse effects of glitazones linked to induced testosterone deficiency?
Original source: Cardiovascular Diabetology 2008, 7:30
Authors: M. Carruthers (corresponding author), T. R. Trinick, E. Jankowska, and A.M. Traish
Publication date: 15 October 2008
DOI (digital document ID): 10.1186/1475-2840-7-30
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
The authors pose a theory that the various adverse effects of diabetes drugs in the class called "glitazones" -- including rosiglitazone (RGZ -- brand name Avandia) and pioglitazone (PGZ -- brand name Actos) -- may be related to a separate known action of these drugs -- their suppression of sex hormones. These side effects include heart disease, swelling, weight gain, and anemia.

Glitazones act on sex hormones by reducing the levels to which they are released and by making the body less sensitive to them. These sex hormones are responsible for directing new cell growth to become blood vessels, skin, muscle, and other types of structural cells, rather than fat cells. This might give further weight to an existing theory of how obesity might cause diabetes (called "Ungar's theory of the 'Lipocentric Pathway to Hyperglycemia'"(1)). The authors note evidence that low testosterone levels in men can cause a number of the same side effects that are being observed in diabetes patients treated with glitazones; furthermore, that diabetes and/or cardiovascular disease are often seen to develop where testosterone production has been suppressed in order to treat prostate cancer. Much of this can be tied to the abdominal weight gain related to low testosterone levels. Treatment with testosterone in these cases has been shown to reduce the side effects and lower the statistical occurrence of cardiovascular disease among patients showing a number of these metabolic symptoms.

The authors note a number of known effects of rosiglitazone and troglitazone (Resulin, which has been removed from the US market) on sex hormones and on the development and maturation of new body tissues.

The authors suggest that this hypothesis might be tested by double-blind, placebo-controlled clinical studies examining the endocrine profiles, and levels of sex hormones, in people with Type 2 diabetes both before and while/after being treated with a glitazone. Additionally, studies on treating diabetic men with testosterone might show us whether this might counteract (or at least lessen) the adverse effects of glitazones. They also suggest further research into exactly how glitazones inhibit sex hormones.

Reliability:
The authors are associated with a number of universities and medical research institutes throughout the world. The hypothesis was published in a peer-reviewed journal. The authors are posing a theory, rather than a statement of fact, and suggesting ways that others could determine whether or not their theory is correct.

Practical Applications:
If the theory is correct, and if administering testosterone to men can completely counteract the adverse effects of Avandia and similar medications, that would make Avandia a relatively safer choice to treat Type 2 diabetes than it is now.

For further reading:
(1) Roger H. Unger, MD Reinventing type 2 diabetes: pathogenesis, treatment, and prevention. Journal of the American Medical Association (JAMA), 2008;299(10):1185-1187.
Full text requires paide subscription.
First 150 words available free.

"Evidence-Based Medicine", Patient Pages, Journal of the American Medical Association (JAMA)

This synopsis was based on the entire article.

Merck analyzes Januvia safety studies

Safety and tolerability of sitagliptin
Original source: BMC Endocrine Disorders 2008, 8:14
Authors: Debora Williams-Herman, Elizabeth Round, Arlene S. Swern, Bret Musser, Michael J. Davies, Peter P. Stein, Keith D. Kaufman and John M. Amatruda
Publication date: 27 October 2008
DOI (digital document ID): 10.1186/1472-6823-8-14
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
The authors are trying to assess the safety and of sitagliptin (Januvia) by combining the results of 12 separate double-blind human trials of up to 2 years in duration. (Double-blind trials are ones in which neither the investigators nor the patients know who is getting the drug under test and who is getting an alternate therapy or no drug therapy. This helps keep the results unbiased.)

A total of 6139 patients were involved in the studies; 3415 were either given 100 mg Januvia per day or the equivalent dose of another oral anti-diabetic pill; 2724 were given a placebo (a pill that has no drug action to it). The shortest study ran 18 weeks (about 4 months) and the longest ran 2 years. The patients were either given sitagliptin (Januvia) alone, or with metformin (similar to Janumet), or as addition to other antidiabetic drugs such as metformin (Glucophage), sulfonylurea, pioglitazone (Actos), and/or rosiglitazone (Avandia). The patients not getting the Januvia were getting either a placebo or one or more of the above antidiabetic drugs.

A number of known adverse reactions and side effects were examined in both the sitagliptin groups and the various control groups. According to the abstract, the only significant side effect was an increase in patient-reported hypoglycemic events among those patients who were also taking sulfonylurea drugs. The definition of "hypoglycemia" was somewhat loose, not requiring the patient to test his blood glucose and add it to the report. The authors do examine the frequency of reports of nausea and stomach pain, pancreatitis, immune system suppression, nose and throat discomfort, skin reactions (hives, discoloration, redness, etc.), and swelling in the heart and chest. These adverse reactions were considered to be similar in frequency between those taking Januvia and those who were not. The reasons for other studies reporting different results were discussed and discounted. (In at least one case, it was one of the longer-term studies that was looking specifically for adverse effects.)

The authors conclude that Under most circumstances, sitagliptin is safe and effective compared to other oral antidiabetic medications.

Reliability: The research was published in a peer-reviewed journal. One of the authors is a medical doctor.

All of the authors work for Merck, or worked for Merck during the period the research was being done. Merck manufactures Januvia, so the authors have a bias towards proving this medication safe and effective.

While a large number of patient experiences were collated into this analysis, most of the component studies were very small in scale.

Since most of the studies aggregated in this analysis only went on for four to six months, it is easy to misinterpret the data as indicating the drug is as safe over two years as it is over four months. People taking drugs to manage Type 2 diabetes are likely to stay on the same drug for much longer than the two-year longest studies examined -- so there is a possibility that there will be side effects from long-term use that have not yet shown up in laboratory and clinical studies.


Practical Applications:
Based on the authors' analysis, Januvia -- for the short-term and intermediate term -- is as safe as other drugs used to manage Type 2 diabetes.

However, because the severe reactions and deaths that have been tied to other new drugs* didn't start showing up in the media until the drugs were out in the marketplace for more than five years, and being taken by tens of thousands of patients, it is probably premature to say that Januvia is safe to be taken by the everyone covered by the prescribing instructions for the entire length of time one might expect it to be used. As with any medication, discuss the pros and cons with your doctor, as well as any additional concerns and risk factors you might have. Untreated Type 2 diabetes can cause serious complications up to and including death.

*Avandia (rosiglitazone), made by Glaxo Smith Kline, is the most recent drug with this sort of safety issue.

For further reading:
Januvia prescription information for doctors: http://www.merck.com/product/usa/pi_circulars/j/januvia/januvia_pi.pdf
Januvia site for consumers: http://www.januvia.com/sitagliptin/januvia/consumer/index.jsp
Merck website: http://www.merck.com/
Drugs.com consumer information for Januvia: http://www.drugs.com/cdi/januvia.html
Drugs.com professional information for Januvia: http://www.drugs.com/pro/januvia.html

This synopsis was based on the provisional (online preprint) article.

Thursday, October 30, 2008

Discovering and Preventing Type 2 Diabetes in New Mothers

Gestational diabetes mellitus: postpartum opportunities for the diagnosis and prevention of type 2 diabetes mellitus

Original source: Nature Clinical Practice Endocrinology & Metabolism (2008) 4, 552-558
Authors: Rhonda Bentley-Lewis (corresponding author), Sue Levkoff, Alison Stuebe and Ellen W Seely
Publication date: 9 September 2008
DOI (digital document ID): 10.1038/ncpendmet0965
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
This Continuing Medical Education (CME) course is aimed at obstetrician/gynecologists and primary care physicians, who take care of women before, during, and after childbirth. A woman who has had gestational (pregnancy) diabetes is at increased risk of developing Type 2 diabetes. The aim of this course is to look at the need to monitor these women in order to prevent, or to quickly diagnose, Type 2 diabetes following childbirth. This requires screening for diabetes at one or more points after delivery.

In current medical practice, there are a number of conflicting guidelines for diabetes screening after delivery: while the American Diabetes Association (ADA) suggests either fasting blood glucose measurement or an Oral Glucose Tolerance Test at 6-12 weeks after delivery, with follow-ups every three years if the tests are normal, or every year if the test indicates impaired glucose tolerance. The World Health Organization (WHO) suggests a single follow-up six weeks or longer after delivery. The American College of Obstetricians and Gynecologists has no specific recommendation for diabetes screening after delivery. As a result, many women who have had gestational diabetes do not get follow-up screening.

Beyond the differing guidelines, the authors suggest several reasons that women may not be receiving appropriate postpartum diabetes screening. These include confusion as to whether this should be done by the obstetrician or the woman's primary care physician, whether or not she had a postpartum visit with the obstetrician, and whether or not she was instructed to get this screening.

The authors suggest several known methods for minimizing the risk of developing Type 2 diabetes after childbirth, including diet and exercise, weight loss, breastfeeding, and the preventative use of oral antidiabetes medications.

The authors suggest both monitoring new mothers who have had GDM 6-12 weeks after birth, and continuing to monitor them regularly thereafter.

Reliability: The authors are medical doctors with additional qualifications in public health, women's health, and psychiatry, and are associated with top-name institutions. The course is presented in conjunction with a peer-reviewed publication; the information is well-documented and the source publications are also peer-reviewed.

Practical Applications: The goal of CME courses is for doctors to keep up with current research and medical practice, with the end result of improving their ability to keep their patients healthy. Vigilant screening and attention to other diabetes risk factors will keep these mothers healthier for longer periods of time, lessen their risk of complications of diabetes, and potentially provide healthier role models for their children.

For further reading: The article's bibliography section has a number of online sources for follow-on reading.

This synopsis was based on the CME version of the complete article.