Are Hemoglobin Levels Elevated in Type 1 Diabetes?

OBJECTIVE: While lower hemoglobin is generally associated with adverse events in diabetes, 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 Examination 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 hemoglobin 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.