Glycated Hemoglobin, Diabetes, and Cardiovascular Risk in Nondiabetic Adults
Selvin, E., Steffes, M.W., Zhu, H., Matsushita, K., Wagenknecht, L., Pankow, J., Coresh, J., Brancati, F.L. (2010). Glycated Hemoglobin, Diabetes, and Cardiovascular Risk in Nondiabetic Adults. The New England Journal of Medicine 362 (9): 800-11.
Scientific Literature Reviews
Reviewed by: Catherine Hudson, DPM
Residency Program: Central Alabama Veterans Health Care System
Diabetic patients at an increased risk of morbidity and mortality comprise a large portion of podiatric patients. 17.9 million people in the United States are currently diagnosed with diabetes and this does not include the estimated 5.7 million people who remain undiagnosed.This study hypothesizes that glycated hemoglobin is superior to fasting glucose as an indicator of risk of developing diabetes and cardiovascular disease.
This prospective cohort study measured the glycated hemoglobin in 11,092 white or black adults who did not have a history of diabetes or cardiovascular disease. The prognostic value of glycated hemoglobin was compared to that of fasting glucose to identify adults at risk of diabetes and cardiovascular disease over a 15 year period. Participants were excluded who characterized themselves as other than white or black, had self-reported diabetes or used diabetes medications, or had a history of cardiovascular disease. Adjusted hazard ratios and confidence intervals were estimated using Cox proportional-hazards models. The three models are as follows, Model 1 adjusted for age, sex, and race; Model 2 for age, sex, race, LDL, HDL, BMI and other social and family history factors; Model 3 for all variables in Model 2 plus either the baseline fasting glucose level (3a) or baseline glycated hemoglobin value (3b).
Participants who had a glycated hemoglobin value of <5% (A); 5-5.5% (B); 5.5-6% (C), 6-6.5% (D); and >6.5% (E) had an incidence of diagnosed diabetes 6% (A), 12% (B), 21% (C), 44% (D), and 79% (E) respectively. Significant trends with increasing risk of coronary heart disease and ischemic stroke were observed with higher levels of baseline glycated hemoglobin and persisted even after adjustment for fasting glucose.
The study found that people with a glycated hemoglobin value of 6.0% or higher are at increased risk for developing diabetes even after adjustment for other risk factors and independently of baseline fasting glucose levels. It was also observed that glycolated hemoglobin levels in the normal range can identify those at increased risk for cardiovascular disease, stroke and death before the diagnosis of diabetes.