Risk Factors for Severe Hypoglycemia in Black and White Adults With Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE Severe hypoglycemia is a rare but important complication of type 2 diabetes. Few studies have examined the epidemiology of hypoglycemia in a community-based population. RESEARCH DESIGN AND METHODS We included 1,206 Atherosclerosis Risk in Communities (ARIC) Study participants with diagnosed diabetes (baseline: 1996–1998). Severe hypoglycemic events were identified through 2013 by ICD-9 codes from claims for hospitalizations, emergency department visits, and ambulance use. We used Cox regression to evaluate risk factors for severe hypoglycemia. RESULTS The mean age of participants was 64 years, 32% were black, and 54% were female. During a median follow-up period of 15.2 years, there were 185 severe hypoglycemic events. Important risk factors after multivariable adjustment were as follows: age (per 5 years: hazard ratio [HR] 1.24; 95% CI 1.07–1.43), black race (HR 1.39; 95% CI 1.02–1.88), diabetes medications (any insulin use vs. no medications: HR 3.00; 95% CI 1.71–5.28; oral medications only vs. no medications: HR 2.20; 95% CI 1.28–3.76), glycemic control (moderate vs. good: HR 1.78; 95% CI 1.11–2.83; poor vs. good: HR 2.62; 95% CI 1.67–4.10), macroalbuminuria (HR 1.95; 95% CI 1.23–3.07), and poor cognitive function (Digit Symbol Substitution Test z score: HR 1.57; 95% CI 1.33–1.84). In an analysis of nontraditional risk factors, low 1,5-anhydroglucitol, difficulty with activities of daily living, Medicaid insurance, and antidepressant use were positively associated with severe hypoglycemia after multivariate adjustment. CONCLUSIONS Poor glycemic control, glycemic variability as captured by 1,5-anhydroglucitol, kidney damage, and measures of cognitive and functional impairments were strongly associated with increased risk of severe hypoglycemia. These factors should be considered in hypoglycemia risk assessments when individualizing diabetes care for older adults.