Dose-response relationship between physical activity and health-related quality of life in cardiac patients

Abstract

Background: Higher levels of health-related quality of life (HRQL) are associated with physical activity in healthy people as well as in patients with ischemic heart disease (IHD). The aim of this analysis was to determine if there is a dose-response relationship between physical activity and HRQL in patients with angina, myocardial infarction, or heart failure. Methods: In this sub-study of the international HeartQoL project with cross-sectional and longitudinal phases, physical activity data were provided by 6143 patients with IHD (angina: N=2033; myocardial infarction: N=2266; ischemic heart failure: N=1844). One validated generic (SF-36) and three validated IHD-specific HRQL questionnaires (MacNew, MLHF, SAQ) were used to analyse differences in HRQL by physical activity in total (active vs. inactive) and level (not active vs. 1-2, 3-5, or >5 times/week active) with t-tests, analyses of variance and HRQL score difference calculations for dose-response effects. Findings: Regular recreational physical activity or sport was associated with significantly better HRQL regardless of diagnosis, questionnaire, or if patients were categorised as being active, inactive or by physical activity level. However, a dose-response effect was observed in each diagnosis as patients who identified themselves as minimally physically active (1-2 times/week), achieved 85% of the largest HRQL difference between active and inactive patients. Conclusions: Physically active patients with IHD, regardless of diagnosis or type of HRQL questionnaire, reported better HRQL which also is consistent with a dose-response relationship between physical activity and HRQL.