Insulin resistance in chronic heart failure

The objective of this study was to investigate the existenceof abnormalities of insulin sensitivity in patients with chronicheart failure. Glucose metabolism and insulin resistance wereassessed in 10 male patients with severe, chronic heart failureand in 10 matched control subjects. Glucose, insulin and C-peptideconcentration profiles were measured following a 0.5g. kg^–1intravenous glucose tolerance test. Insulin sensitivity (inverselyrelated to insulin resistance) was estimated by minimal modellinganalysis of the glucose and insulin profiles. Heart failure patients had similar mean fasting plasma glucoseconcentration to controls but a significantly greater mean fastingplasma insulin concentration (P=0.002) and C-peptide concentration(P=0.02). Plasma glucose response profile was similar in thetwo groups but the incremental plasma insulin response profileof the heart failure group was significantly greater (P=0.004).Mean insulin sensitivity was 73% lower in the heart failurepatients (P=0.003). These findings show that patients with severe chronic heartfailure are hyperinsulinaemic and insulin resistant comparedwith a matched healthy group. This insulin resistance and hyperinsulinaemiamay contribute to the progressive deterioration in myocardialfunction and associated clinical features of fatigue and reducedexercise tolerance seen in heart failure. Interventions designedto overcome or reduce insulin resistance warrant further investigation.