Determinants of Physical Activity in Chronic Heart Failure

Abstract

Background: Patients with chronic heart failure (CHF) have reduced exercise capacity but little is known on the pattern and determinants of their physical activity (PA). PURPOSE: In ambulatory patients with CHF, we evaluated: 1) the prevalence of PA; 2) self-reported and accelerometer measured PA; and 3) the determinants and correlates of PA. METHODS: 52 patients with stable CHF had medical history, maximal cardiopulmonary exercise test, echocardiogram, as well as measurement of inspiratory muscle strength, hand grip strength, and flexibility (Flexitest). Self-reported PA was estimated by the International Physical Activity Questionnaire (IPAQ) and PA was measured by accelerometer monitoring, during 4 days. PA was expressed as the proportion of the international recommendation of 150 min per week in moderate and vigorous activities. Determinants of PA were evaluated by multiple linear regression analysis. RESULTS: The prevalence of active patients was 10% according to accelerometer measurements, and 77% according to IPAQ. Self-reported of PA was not associated with accelerometer-measured moderate and vigorous PA (r = 0.15; p = 0.32). There was a week association with borderline significance between self-reported PA and light accelerometer-measured PA (r = 0.28; p= 0.056). Significant determinants of self-reported PA were age and flexibility (r2 = 0.325 P=0.001). Only number of drugs was inversely associated with time spent in light PA (r2 = 0.295; P=0.003). Only level of education was a significant determinant of time spent in moderate plus vigorous accelerator-measured PA (r2 = 0.211; P=0.05). CONCLUSION: In ambulatory patients with CHF: 1) prevalence of moderate to vigorous accelerometer-measured PA is low; 2) there is poor association between self-reported and accelerometer-measured PA; 3) the determinants of self-reported PA are different from those of accelerometer-measured PA. Since only about 30% of the variance in PA can be accounted by the variables here evaluated, further studies should be conducted to identify other determinants of PA in this patient population. This study received financial support from Hospital de Clínicas de Porto Alegre.