Diabetes, myocardial infarction and stroke are distinct and duration-dependent predictors of subsequent cardiovascular events and all-cause mortality in older men.

Abstract

The impact of older age and duration of diabetes mellitus on macrovascular complications is unclear. We tested the hypothesis that in older men, diabetes duration predicts incident cardiovascular events and death, differently from prior myocardial infarction (MI) or stroke. This was a longitudinal cohort study of 11 728 community-dwelling men aged ≥ 65 years in Perth, Western Australia, recruited in 1996-1999. We assessed all-cause mortality, and deaths or hospital admissions with MI or stroke between recruitment and December 2010, analyzing age-specific hazard and adjusting for smoking, education, alcohol, exercise, BMI, hypertension, and hypercholesterolemia. Among 1433 (12.2%) men with diabetes, 208 (14.5%) reported age of onset of diabetes < 55 years, 451 (31.5%) 55-64 years, 679 (47.4%) 65-74 years with 95 (6.6%) > 74 years. Diabetes independently predicted increased all-cause mortality with hazard ratio (HR) of 1.37 (95% confidence interval [CI] = 1.15-1.62) for a duration of 5-9 years, 1.35 (1.18-1.55) for 10-14 years, 1.42 (1.22-1.66) for 15-19 years, and 1.75 (1.45-2.11) for 20-24 years. Mortality from MI was increased for diabetes duration up to 25 years, while stroke-specific mortality increased progressively with diabetes duration. Prior MI or stroke predicted increased risk of subsequent events peaking after 10-20 years. In older men, increasing duration of diabetes predicts stable increases in all-cause and MI-related mortality and a progressively higher risk of stroke deaths. Prior MI was associated with increased risk of subsequent MI, and prior stroke with subsequent stroke, particularly in the 10-20 years following the first event. Diabetes is a duration-dependent risk factor for cardiovascular events which influences outcomes differently from prior vascular disease.