Does physical training increase insulin sensitivity in chronic heart failure patients?

To determine the effect of training on insulin sensitivity (IS) and how this relates to peak 02 (peak oxygen uptake) in CHF (chronic heart failure), 77 CHF patients (New York Heart Association class, II/III; men/women, 59/18; age, 60 +/- 9 years; body mass index, 26.7 +/- 3.9 kg/m(2); left ventricular ejection fraction, 26.9 +/- 8.1%; expressed as means +/- S.D.) participated in the study. Patients were randomly assigned to a training or control group (TrG or CG respectively). Sixty-one patients completed the study. Patients participated in training (combined strength and endurance exercises) four times per week, two times supervised and two times at home. Before and after intervention, anthropometry, IS (euglycaemic hyperinsulinaemic clamp) and peak 02 (incremental cycle ergometry) were assessed. Intervention did not affect IS significantly, even though IS increased by 20% in TrG and 11% in CG (not significant). Peak (V)over dot O-2 increased as a result of training (6% increase in TrG; 2% decrease in CG; P <0.05). In both groups (TrG and CG), the change in IS correlated positively with the change in peak (V)over dot O-2 (r = 0.30, P <0.05). Training resulted in an increase in peak (V)over dot O-2, but not in IS. Whether physical training actually increases IS in CHF patients remains unclear.