NHANES: Retinopathy Incidence Rises Steeply At 5.5% A1c

Page Changed: Research Connecting Organ Damage with Blood Sugar Level

Added analysis of 2005-2006 NHANES data which was published in October 2009. The study looked at 1,066 individuals with or without diabetes aged 40 years or more. "A1C, FPG, and 45° color digital retinal images were assessed."

This study found a prevalence of retinopathy of 11% in those diagnosed with diabetes and 36% in those with diabetes diagnoses.

Most significantly, this study found that

The steepest increase in retinopathy prevalence occurs among individuals with A1C equal to or greater than 5.5% and FPG equal to or greater than 5.8 mmol/l [104 mg/dl]. A1C discriminates prevalence of retinopathy better than FPG.

Association of A1C and Fasting Plasma Glucose Levels With Diabetic Retinopathy Prevalence in the U.S. Population: Implications for diabetes diagnostic thresholds Yiling J. Cheng et al. Diabetes Care November 2009 vol. 32 no. 11 2027-2032. doi: 10.2337/dc09-0440

Sulfonylurea Drugs Linked to Hemolytic Anemia Especially with Certain Genetic Condition

Page Changed: Amaryl, Glyburide, Prandin, Starlix: Drugs that Stimulate Insulin Secretion

Added information on new FDA Safety Alert.

An FDA safety Alert published Auguest of 2009 reports:

Treatment of patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency with sulfonylurea agents can lead to hemolytic anemia. Because Glynase PresTab belongs to the class of sulfonylurea agents, caution should be used in patients with G6PD deficiency and a non-sulfonylurea alternative should be considered. In post marketing reports, hemolytic anemia has also been reported in patients who did not have known G6PD deficiency.

Hemolytic anemia is a condition where the body stops making red blood cells. It can become an emergency. Symptoms of hemolytic anemia include Dark urine, Enlarged spleen, Fatigue, Paleness, Rapid heart rate, Shortness of breath, Yellow skin color (jaundice).

Because the G6PD deficiency is often only discovered when people react badly to a drug, it would be a good idea to get your blood count tested shortly after starting a sulfonylurea drug.

FDA Safety Alert for Glynase (micronized glyburide) tablets

Metformin Fights Heart Disease by Improving Endothelial Function

Page changed: Metformin

Added section discussing the latest studies documenting Metformin's ability to prevent heart disease by improving endothelial function.

This idea has been floating around for years, though there wasn't definitive proof of it. A relatively small study published in March 2009 supports the idea.

Long-term Effects of Metformin on Metabolism and Microvascular and Macrovascular Disease in Patients With Type 2 Diabetes Mellitus. Kooy et all. Archives of Internal Medicine, 169 (6), 616-625 DOI: 19307526

A presentation at the 2009 European Association for the Study of Diabetes (EASD) described research which may point to why metformin is so effective.

You can read about it here:

Diabetes in Control: Metformin Improves Endothelial Function in Type 2 Diabetes

This study examined a series of factors associated with endothelial function--i.e. the function of the linings of the blood vessels. It demonstrated significant improvements in the 196 patients who took metformin over a period of up to 4.3 years.

Compared to those on placebo plus insulin those on metformin experienced highly significant drops in plasma levels of von Willebrand factor (vWf), soluble vascular adhesion molecule-1 (sVCAM-1), tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor-1 (PAI-1), C-reactive protein (CRP), and soluble intercellular adhesion molecule-1 (sICAM-1).

The drop in C-Reactive Protein--a measure strongly linked to the risk of inflammation-related heart attack was 17%.

Since all the other oral drugs prescribed for diabetes have either been linked to increased heart attacks (sulfonylureas) or produce heart failure (Avandia and Actos) this data should reinforce the idea that metformin is the safest of the oral diabetic drugs and the one most likely to improve health outcomes long term.