Knee extensor muscle strength and index of renal function associated with an exercise capacity of 5 metabolic equivalents in male chronic heart failure patients with chronic kidney disease.

BACKGROUND

The goal of the present study was to determine knee extensor muscle strength (KEMS) and degree of renal dysfunction associated with an exercise capacity of ≥5 metabolic equivalents (METs) in male chronic heart failure (CHF) patients with chronic kidney disease (CKD).

METHODS

In this cross-sectional study of 75 male CHF patients with CKD (65.3 ± 11.6 years), we measured clinical characteristics, peak [Formula: see text], estimated glomerular filtration rate (eGFR), and KEMS. Patients were divided into two groups by exercise capacity: ≥5 METs group (n = 41) and <5 METs group (n = 34). Cutoff values for KEMS and eGFR resulting in an exercise capacity of ≥5 METs were selected with ROC curves. Patients were divided into four groups according to cutoff values, and numbers of patients attaining an exercise capacity of ≥5 METs were compared between groups.

RESULTS

Age was significantly higher although eGFR, Hb, and KEMS were lower in the <5 METs versus ≥5 METs group (P < 0.001). Multiple logistic regression analysis revealed a positive significant relation between KEMS and eGFR and exercise capacity of ≥5 METs. Exercise capacity of ≥5 METs was associated with KEMS of approximately 1.69 Nm/kg and an eGFR of 45.7 mL/min/1.73 m(2). The number of patients attaining an exercise capacity of ≥5 METs in the patients who did not reach both cutoff values was significantly lower than that in any other patients (P < 0.001).

CONCLUSION

KEMS and eGFR may be useful indices for predicting attainment of exercise capacity of ≥5 METs in male CHF patients with CKD.