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 ± 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, reinfarction or stroke) were related to hypoglycaemic episodes during the index hospitalisation.

Results: During the first 24 hours hypoglycaemic episodes were noted in 111 (12%) of insulin-treated (symptomatic 23%) and 3 (1.0%) of routinely treated patients (symptomatic 33%). Symptomatic hypoglycaemia related to mortality (unadjusted HR 1.99; 95%CI 1.20-3.29; p=0.0074) but this difference disappeared following adjustment (HR 1.09; 95%CI 0.64-1.87; p=0.7403). Body weight (OR 0.97; 95%CI 0.95-0.98; p<0.0001) and diabetes duration (OR 1.03; 95%CI 1.01-1.05; 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.