Are Hemoglobin Levels Elevated in Type 1 Diabetes?

OBJECTIVE — While lower hemoglobin is generally associated with adverse events in dia-betes, we have recently observed in type 1 diabetes that those with overt nephropathy had hemoglobin levels as high as 18.8 g/dl. We thus explored whether hemoglobin concentrations are generally higher in type 1 diabetes. RESEARCH DESIGN AND METHODS — Baseline (1986–1988) hemoglobin levels from the Pittsburgh Epidemiology of Diabetes Complications Study (EDC) of type 1 diabetes were compared with general population data from the National Health and Nutrition Examina-tion Survey (NHANES) III in the same age range as the EDC population (aged 8–48 years). RESULTS — Both male and female EDC study participants had significantly higher hemoglo-bin levels than their NHANES III counterparts (men: 16.0 vs. 15.1 g/dl, P 0.0001; women: 14.1 vs. 13.3 g/dl, P 0.0001). The difference between the two populations was greatest in adolescent female subjects. CONCLUSIONS — Hemoglobin levels may be higher in type 1 diabetes than in the general population, which may have important clinical implications. Diabetes Care 33:341–343, 2010 A lthough low hemoglobin is gener-ally associated with adverse eventsin diabetes (1) and kidney disease (2), we have recently observed relatively high hemoglobin levels (as high as 18.8 g/dl) among individuals with type 1 dia-betes and overt nephropathy (3) com-pared with the general renal disease population (4). This led us to question whether hemoglobin levels are generally elevated in type 1 diabetes. We therefore assessed 652 individuals from the Pitts-burgh Epidemiology of Diabetes Compli-cations Study (EDC) of type 1 diabetes and compared the hemoglobin levels ob-served with those of the general Nationa