Abstract

Objective: To explore if hypoglycaemic episodes during hospitalisation influence the subsequent prognosis in patients with diabetes and acute myocardial infarction.

Design, setting and patients: Within the framework of the clinical trial DIGAMI 2 hypoglycaemic episodes (blood glucose <3.0 mmol/l with or without symptoms) were recorded in 1253 patients (mean age 68 years; 67% males) with type 2 diabetes and myocardial infarction. The patients were followed during a median of 2.1 years. A total of 947 patients were randomised to an initial insulin infusion while 306 received routinely used glucose lowering therapy.

Main outcome measures: Unadjusted and adjusted (age, sex, smoking, previous infarction, heart failure, renal function, diabetes duration, coronary interventions, pharmacological treatment and B-glucose at hospital admission) hazard ratios (HR) and 95% confidence intervals (CI) for total mortality and cardiovascular events (death, re-infarction or stroke) were related to hypoglycaemic episodes during the index hospitalisation.

Results: During the first 24 hours hypoglycaemic episodes were noted in 111 (12%) insulin-treated (symptomatic 23%) and three (1.0%) routinely treated patients (symptomatic 33%). Symptomatic hypoglycaemia related to mortality (unadjusted HR 1.99; 95% CI 1.20 to 3.29; p = 0.0074) but this difference disappeared following adjustment (HR 1.09; 95% CI 0.64 to 1.87; p = 0.7403). Body weight (OR 0.97; 95% CI 0.95 to 0.98; p<0.0001) and diabetes duration (OR 1.03; 95% CI 1.01 to 1.05; p = 0.0085) were independent predictors of hypoglycaemia

Conclusions: Hypoglycaemia during the initial hospitalisation was not an independent risk factor for future morbidity or mortality in patients with type 2 diabetes and myocardial infarction. Such episodes were, however, more prevalent in patients at high risk for other reasons.