Glycosylated hemoglobin and the risk of death and cardiovascular mortality in the elderly.

BACKGROUND AND AIMS

Glycosylated hemoglobin (HbA(1c)) has been associated with incident cardiovascular disease (CVD), but the findings are inconsistent. We tested the hypothesis that HbA(1c) may be associated with an increased risk of death and cardiovascular mortality in older adults.

METHODS AND RESULTS

We evaluated the association between HbA(1c) with all-cause and cardiovascular mortality in 810 participants without a history of diabetes in a sub-study of the Cardiovascular Health Study (CHS), a community cohort study of individuals > or =65 years of age. Glycosylated hemoglobin was measured at baseline and all-cause and cardiovascular mortality was assessed during the follow-up period. The relation between baseline HbA(1c) and death was evaluated with multivariate Cox proportional hazards regression models. After a median follow-up of 14.2 years, 416 deaths were observed. The crude incidence rates of all-cause mortality across HbA(1c) groups were: 4.4% per year, 4.3% per year and 4.6% per year for tertile 1 (< or =5.6%), tertile 2 (5.61-6.20%) and tertile 3 (> or =6.21%), respectively. In unadjusted and fully adjusted analyses, baseline HbA(1c) was not associated with all-cause mortality and cardiovascular mortality (hazard ratio: 1.16 [95% confidence interval 0.91-1.47] and hazard ratio: 1.31 [95% confidence interval 0.90-1.93], respectively for the highest HbA(1c) tertile compared with the lowest).

CONCLUSION

These results suggest that HbA(1c) does not significantly predict all-cause and cardiovascular mortality in non-diabetic community-dwelling older adults.