The association of glycemia and cause-specific mortality in a diabetic population.

BACKGROUND: The purpose of this study was to investigate the association of glycemia with cause-specific mortality in a diabetic population.
METHODS: The study was a cohort design based in a primary care setting. Participants were all younger-onset diabetic persons (conditions diagnosed when they were younger than 30 years old and taking insulin, N = 1210) and a random sample of older-onset diabetic persons (conditions diagnosed when they were 30 years or older, N = 1780). Glycosylated hemoglobin levels were obtained at baseline examinations in 1980 to 1982 in which 996 younger-onset and 1370 older-onset persons participated. Median follow-up was 10 years in younger-onset and 8.3 years in older-onset persons; four younger-onset and two older-onset persons were unavailable for follow-up. The main outcome measure was cause-specific mortality as determined from death certificates.
RESULTS: In the younger-onset group after controlling for other risk factors in proportional hazards models and considering underlying cause of death, glycosylated hemoglobin was significantly associated with mortality from diabetes (hazard ratio [HR] for a 1% change in glycosylated hemoglobin, 1.25; 95% confidence interval [CI], 1.13 to 1.38) and ischemic heart disease (HR, 1.18; 95% CI, 1.00 to 1.40). In the older-onset group, glycosylated hemoglobin was significantly associated with mortality from diabetes (HR, 1.32; 95% CI, 1.21 to 1.43), ischemic heart disease (HR, 1.10; 95% CI, 1.04 to 1.17), and stroke (HR, 1.17; 95% CI, 1.05 to 1.30), but not cancer (HR, 0.99; 95% CI, 0.88 to 1.10). Results for any mention of specific causes of death were similar.
CONCLUSION: These results suggest possible benefit to the control of glycemia with respect to death due to vascular disease and diabetes.