The incidence of diabetes mellitus in congestive heart failure (CHF) varies widely between studies depending on patients’ age, the etiology and severity of CHF, and the definition of diabetes mellitus. In the large-scale trials with angiotensin-converting enzyme (ACE) inhibitors, 20% to 25% of patients are diabetic. However, this may be an underestimate as most trials have age restrictions and exclude patients such as those with renal failure or peripheral vascular disease, both of which are common in diabetes. In the NETWORK study (Network of General Practitioners and Hospital Physicians Involved in the Study of Low vs High Doses of Enalapril in Patients with Heart Failure), which was designed to be representative of CHF in the community, 10% of patients had diabetes. In the (RE) Studies Of Left Ventricular Dysfunction (RESOLVD) study, 27% of patients were diabetic at randomization; by including a screening fasting blood glucose, the investigators detected 8% with previously unrecognized diabetes mellitus, 9% with impaired glucose tolerance, and a total of no less than 43% with abnormal glu-
Amato L, Paolisso G, Cacciatore F, et al. Congestive heart failure predicts the development of non-insulin-dependent diabetes mellitus in the eldeHy. The Osservatorio Geriafrico Regione Campania Group. Diabetes Metab. 1997; 23:213-218.
Chae CU, Glynn RJ, Man son JE, et al. Diabetes predicts congestive heart failure risk in the elderly. Circulation. 1998;98(suppl l):721.
Norhammar A, Malmberg K. Heart failure and glucose abnormalities: an increasing combination with poor functional capacity and outcome. Eur Heart J. 2000;21:1293-1294.
cose metabolism. In a US study of patients hospitalized for CHF, Reis et al found that no fewer than 38% had diabetes requiring drug therapy. In a cross-sectional Italian study of CHF in the elderly, 30% were diabetic; the association was independent of age, gender, blood pressure, body mass index, and family history of diabetes; of the patients who were nondiabetic at study entry, 29% became diabetic over the following 3 years vs 18% of matched controls. Multivariate analysis identified CHF as an independent predictor of type 2 diabetes.
A possible explanation for the relationship is that the increased adrenergic drive caused by CHF increases free fatty acid oxidation and insulin resistance, thereby decreasing glucose oxidation and precipitating type
2 diabetes. The presence of diabetes mellitus, or of insulin resistance in nondiabetics, is associated with greater symptom severity and poorer functional performance in CHF, despite relative preservation of the left ventricular ejection fraction and a smaller left ventricular volume in both diabetics and insulin-resistant nondiabetics.
Reis SE, Holubkov R, Edmundowicz D, et al. Treatment of patients admitted to the hospital with congestive heart failure: speciality-related disparities in practice patterns and outcomes. J Am Coll Cardiol. 1997;30:733-738. Solang L, Malmberg K, Ryden L Diabetes mellitus and congestive heart failure. Further knowledge needed. Eur Heart J. 1999;20:89-795.
Suskin N, McKelvie RS, Bums RJ, et al. Glucose and insulin abnormalities relate to functional capacity in patients with congestive heart failure. Eur Heart J. 2000;21:1368-1375.
diabetes; insulin resistance; prevalence; prognosis; risk factor