Severe Hypoglycemia and Incident Heart Failure among Adults With Type 2 Diabetes.

CONTEXT The effect of severe hypoglycemia on the incidence of heart failure (HF) is unclear. OBJECTIVE We evaluated the association of severe hypoglycemia with incident HF among individuals with type 2 diabetes. METHODS We included participants with type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. Severe hypoglycemia episodes were assessed during the initial 24 months following randomization and defined using two methods: symptomatic, severe hypoglycemic event requiring medical assistance (first definition) or requiring any assistance (second definition). Participants without HF at baseline and during the first 24 months of the study were prospectively followed for incident HF hospitalization. Multivariable Cox regression was used to generate adjusted hazard ratios (HR) for the association of severe hypoglycemia and incident HF. RESULTS Among 9,208 participants (mean age 63 years, 38% female, 62% White), 365 had ≥ 1 episode of severe hypoglycemic. Over a median follow-up of 3 years, there were 249 incident HF events. After multivariable adjustment for relevant confounders, participants with severe hypoglycemia requiring medical assistance had a 68% higher relative risk of incident HF (HR 1.68, 95% CI 1.06-2.66), as compared to individuals who never experienced any episode of hypoglycemia. Severe hypoglycemia requiring any assistance was also associated with a 49% higher relative risk of HF (HR 1.49, 95% CI 1.01-2.21). CONCLUSION In a large cohort of adults with type 2 diabetes, severe hypoglycemia was independently associated with greater risk of incident HF.