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

Abstract

Background and aimsGlycosylated hemoglobin (HbA1c) has been associated with incident cardiovascular disease (CVD), but the findings are inconsistent. We tested the hypothesis that HbA1c may be associated with an increased risk of death and cardiovascular mortality in older adults. Methods and resultsWe evaluated the association between HbA1c 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 ≥65years 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 HbA1c and death was evaluated with multivariate Cox proportional hazards regression models. After a median follow-up of 14.2years, 416 deaths were observed. The crude incidence rates of all-cause mortality across HbA1c groups were: 4.4% per year, 4.3% per year and 4.6% per year for tertile 1 (≤5.6%), tertile 2 (5.61–6.20%) and tertile 3 (≥6.21%), respectively. In unadjusted and fully adjusted analyses, baseline HbA1c 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 HbA1c tertile compared with the lowest). ConclusionThese results suggest that HbA1c does not significantly predict all-cause and cardiovascular mortality in non-diabetic community-dwelling older adults.