The association of severe hypoglycemia with incident cardiovascular events and mortality in adults with type 2 diabetes

OBJECTIVE There is suggestive evidence linking hypoglycemia with cardiovascular disease, but fewdata have been collected in a community-based setting. Information is lacking on individual cardiovascular outcomes and cause-specific mortality. RESEARCH DESIGN AND METHODS We conducted a prospective cohort analysis of 1,209 participants with diagnosed diabetes from the Atherosclerosis Risk in Communities (ARIC) study (analytic baseline, 1996-1998). Severe hypoglycemic episodes were identified using first position ICD-9 codes fromhospitalizations, emergency department visits, andambulance calls through 2013. Cardiovascular events and deaths were captured through 2013. We used adjusted Cox regressionmodelswith hypoglycemia as a time-varying exposure. RESULTS There were 195 participants with at least one severe hypoglycemic episode during a median fellow-up of 15.3 years. After severe hypoglycemia, the 3-year cumulative incidence of coronary heart disease was 10.8% and of mortality was 28.3%. After adjustment, severe hypoglycemia was associated with coronary heart disease (hazard ratio [HR] 2.02, 95% CI 1.27-3.20), all-causemortality (HR 1.73, 95%CI 1.38-2.17), cardiovascular mortality (HR 1.64, 95% CI 1.15-2.34), and cancer mortality (HR 2.49, 95% CI 1.46-4.24). Hypoglycemia was not associated with stroke, heart failure, atrial fibrillation, or noncardiovascular and noncancer death. Results were robust within subgroups defined by age, sex, race, diabetes duration, and baseline cardiovascular risk. CONCLUSIONS Severe hypoglycemia is clearly indicative of declining health and is a potentmarker of high absolute risk of cardiovascular events and mortality.