Metformin and Radiological Contrast Medium

Page changed: The Truth about Oral Diabetic Drugs

Added information from updated Metformin prescribing information explaining that metformin should be discontinued at the time of or slightly before radiological procedures involving injected dye and not taken for the next 2 days. After that kidney function should be evaluated with a serum creatinine test before metformin is started again. The latter recommendation is courtesy of a radiologist who pointed me to these updated guidelines.

In rare cases in people with marginal kidney function the use of contrast dyes may cause kidney failure if a dose of metformin is taken after the dye is used. It is also possible to develop lactic acidosis when this happens. This is rare, but because many people with poorly controlled diabetes have significant kidney damage, it is important for people taking metformin to be aware of this.

These recommendations have changed from what they were a few years ago.

Stop it or you'll go blind: Actos Definitely Linked to Increased Blindness in Well Controlled Diabetics

Page changed: Actos and Avandia - Dangerous Diabetes Drugs

Cited brand new study published in an Opthalmology journal--not read by family doctors, alas, that demonstrated dramatically that Actos and Avandia both raise the risk of vision loss dramatically.

Glitazone Use Associated with Diabetic Macular Edema Donald S. Fong. Am J OphthVolume 147, Issue 4, Pages 583-586.e1 (April 2009)

This study analyzed the records of 170,000 people with diabetes treated by Kaiser Permanente Southern California. The researchers found that

In 2006, there were 996 new cases of ME. Glitazone users were more likely to develop ME in 2006 (odds ratio [OR], 2.6; 95% confidence interval [CI], 2.4 to 3.0). After excluding patients who did not have the drug benefit, did not have an eye exam, and had a HgA1c <7.0, glitazone use was still associated with an increased risk of developing ME (OR, 1.6; 95% CI, 1.4 to 1.8).

This means you are 60% more likely to develop retinal swelling leading to vision loss even with well controlled blood sugars if you take Actos or Avandia than if you don't.

It's worth noting, too, that the Science News report of this study adds, "Most of the glitazone users in the study were taking pioglitazone (Actos)."

Since the whole point of lowering blood sugar in diabetes is to avoid blindness, this study makes it crystal clear that no person with diabetes should be taking Actos or Avandia.

PRINT OUT THE ABSTRACT OF THIS STUDY AND GIVE IT TO YOUR FAMILY DOCTOR AT YOUR NEXT APPOINTMENT. YOU COULD SAVE SOMEONE'S VISION.

Benfotiamine May Not Live up to Claims: Cheaper Thiamine May Be Equivalent

Page changed: Helpful Supplements for Diabetes

Added link to study calling into question whether Benfotiamine is really lipid soluble as claimed and whether it has any advantages over much cheaper, regular thiamine supplements.

Benfotiamine, a synthetic S-acyl thiamine derivative, has different mechanisms of action and a different pharmacological profile than lipid-soluble thiamine disulfide derivativesMarie-Laure Volvert et al. BMC Pharmacology 2008, 8:10doi:10.1186/1471-2210-8-10

New Web Page Added: Dementia and Diabetes - A Confusing Relationship

Page Added: Dementia and Diabetes - A Confusing Relationship

This page pulls together information previously scattered through several posts on the Diabetes Update blog. It discusses various research studies that have been cited in the press as linking Diabetes and Alzheimer's Disease or dementia. It also cites research pointing to other, stronger, and often avoidable risk factors for dementia that should be of interest to people with diabetes.

Study: Diabetes that Starts with IGT Different From That Which Starts with IFG

Page Changed: The Patterns in Which Diabetes Develops

Added this information: The Inter99 Study was a five year study. 3,145 subjects who started out with normal glucose tolerance but developed some form of abnormal blood sugar who were given glucose tolerance tests and Insulin sensitivity index (ISI), homeostasis model assessment of insulin sensitivity (HOMA-IS), early-phase insulin release (EPIR), and insulin secretion relative to insulin action (disposition index) were estimated. The researchers conclude,

A stationary reduced insulin secretion followed by a decline in primarily hepatic insulin sensitivity characterizes the transition from N[ormal] G[lucose] T[olerance] to i-I[impaired]F[asting]G[lucose]. In contrast, low whole-body insulin sensitivity with a secondary lack of ß-cell compensation is associated with the development of i-I[mpaired]G[lucose]T[olerance]. Thereby, i-IFG and i-IGT appear to result from different underlying mechanisms, which may have implications for the prevention and treatment of the diabetes that succeeds them.

Natural History of Insulin Sensitivity and Insulin Secretion in the Progression From Normal Glucose Tolerance to Impaired Fasting Glycemia and Impaired Glucose Tolerance: The Inter99 Study.
Kristine Færch, et al. Diabetes Care, 32:439-444, 2009.

Actual Statistics on Prevalence of Diabetes and Prediabetes in the U.S. Population

Page Changed: The Patterns in Which Diabetes Develops

Added citation to a journal article published in Diabetes Care which analyzes data from the 2006 NHANES survey give an accurate idea of what the actual incidence of diabetes and prediabetes are in the American population.

Full Accounting of Diabetes and Pre-Diabetes in the U.S. Population in 1988–1994 and 2005–2006. Catherine C. Cowie et al. Diabetes Care 32:287-294, 2009.

This study reports,

In 2005–2006, the crude prevalence of total diabetes in people aged ≥20 years was 12.9%, of which ~40% was undiagnosed. In people aged ≥20 years, the crude prevalence of impaired fasting glucose was 25.7% and of impaired glucose tolerance was 13.8%, with almost 30% having either. Over 40% of individuals had diabetes or pre-diabetes. Almost one-third of the elderly had diabetes, and three-quarters had [either] diabetes or pre-diabetes.

Though the incidence of diagnosed diabetes had increased, the increase was slightly over 2% which may be due to better diagnosis, not more diabetes.

I take the high incidence of "prediabetes" compared to the modest prevalence of full fledged diabetes--much of it occurring in the elderly--as an indication that most people with "prediabetes" are not likely to become fully diabetic, though they may experience blood sugar related hunger and weight gain.

Only those with the underlying genetic flaws that prevent beta cell mass to expand or limit insulin secretion are likely to go on to become fully diabetic.

New Evidence that Post-Challege Glucose Not Fasting Plasma Glucose Accurately Predicts Future Diabetes

Page Changed: What is a Normal Blood Sugar?

Research first published in 2008 that was based on studying a group of 2,442 subjects who were free of type 2 diabetes at the beginning of the study found that fasting glucose tests were a very poor predictor of who in this group would develop diabetes.

The researchers found that people whose one hour glucose tolerance test results were over 155 mg/dl and who had markers for metabolic syndrome--such as a concentration of fat around the belly and high blood pressure were those who were more accurately predicted to be likely to develop diabetes.

Fasting Versus Postload Plasma Glucose Concentration and the Risk for Future Type 2 Diabetes Muhammad A. Abdul-Ghani et al. Diabetes Care 32:281-286, 2009 DOI: 10.2337/dc08-1264