Prevalence and characteristics of diabetic patients in a chronic heart failure population

Background Previously, estimates of the prevalence of diabetes mellitus (DM) in patients with chronic heart failure (CHF) have solely been based on history in retrospective studies. The aim of this study was to investigate the prevalence of DM and glucose abnormalities in patients with CHF in accordance with the modern diagnostic criteria of DM. A second aim was to characterize patients with DM with respect to severity of CHF. Methods and results A prospective study including patients with systolic CHF admitted to a heart failure clinic. Fasting blood glucose (FBG) levels were measured on two occasions, for classification of DM. Severity of CHF was assessed by NYHA class, echocardiography, 6 min walk test and plasma NT-proBNP levels. A total of 195 consecutive patients were included in the study, of these 188 were eligible for classification of DM. A total of 21% had DM by history, 11% of the patients without known DM had FBG≥6.1 mmol/l, and a diagnosis of DM was confirmed in half of these patients. There were no differences in severity of heart failure between patients with DM by definition and non-DM patients; however, high body mass index was related to worse CHF symptoms. Conclusion Twenty six percent of the patients had DM by definition, 20% of these were undiagnosed at the time of admission. One single measurement of FBG is not sufficient to establish a diagnosis of DM. Diabetes was not related to CHF symptoms or to a degree of left ventricular dysfunction.