Hypoglycemia in patients with type 2 diabetes mellitus

Background: Although hypoglycemia is the most common complication of intens ive diabetes therapy, there is little information about risk factors for hy poglycemia in patients with type 2 diabetes mellitus. Objective: To determine the prevalence and predisposing factors for hypogly cemia in patients with type 2 diabetes. Methods: Retrospective, cross-sectional analysis set in an outpatient speci alty diabetes clinic. We included those patients who had baseline and follo w-up visits from April 1 through October 31, 1999. Hypoglycemia was defined as typical symptoms relieved by eating, and/or blood glucose level of less than 60 mg/dL (<3.3 mmol/L). Univariate and multivariate logistic regressi on were used to determine the contributions to hypoglycemia of age, sex, di abetes duration, body mass index (calculated as weight in kilograms divided by the square of height in meters), fasting plasma glucose level, glycosyl ated hemoglobin (HbA(1c)) level, type of therapy, and previous episodes at the follow-up visit. Results: We studied 1055 patients. Prevalence of hypoglycemic symptoms was 12% (9/76) for patients treated with diet alone, 16% (56/346) for those usi ng oral agents alone, and 30% (193/633) for those using any insulin (P < .0 01). Severe hypoglycemia occurred in only 5 patients (0.5%), all using insu lin. Multiple logistic regression analysis demonstrated that insulin therap y, lower HbA(1c) level at follow-up, younger age, and report of hypoglycemi a at the baseline visit were independently associated with increased preval ence of hypoglycemia. There were no significant predictors of severe hypogl ycemia. Conclusions: Mild hypoglycemia is common in patients with type 2 diabetes u ndergoing aggressive diabetes management, but severe hypoglycemia is rare. Concerns about hypoglycemia should not deter efforts to achieve tight glyce mic control in most patients with type 2 diabetes.