Self-reported Physical Activity and Cardiovascular Events in Adults With CKD: Findings From the CRIC (Chronic Renal Insufficiency Cohort) Study

Abstract

Rationale & objective: In the general population, there is an association between higher levels of physical activity and lower risk for cardiovascular events and mortality, but this relationship has not been well evaluated in chronic kidney disease (CKD). We investigated the association between self-reported physical activity and outcomes in a CKD cohort.

Study design: Prospective cohort study.

Setting & participants: 3,926 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study.

Exposure: Time-updated self-reported physical activity assessed by (1) quartile of moderate-to-vigorous physical activity (MVPA) and (2) meeting guideline-recommended level of physical activity (categorized as active, meeting guidelines; active, not meeting guidelines; or inactive).

Outcome: Atherosclerotic events (myocardial infarction, stroke, or peripheral artery disease), incident heart failure, and all-cause and cardiovascular death.

Analytical approach: Cox proportional hazards regression.

Results: At baseline, compared with the lowest MVPA quartile, those in the highest quartile were more likely to be younger, male, not have prevalent cardiovascular disease, and have higher estimated glomerular filtration rate. Overall, 51% met the physical activity guidelines; of those who did not, 30% were inactive. During the median follow-up period of 13.4 years, there were 772 atherosclerotic events, 848 heart failure events, and 1,553 deaths, and 420 cardiovascular deaths. Compared with the participants in the lowest MVPA quartile, the highest quartile had a lower risk of atherosclerotic events (HR, 0.64 [95% CI, 0.51-0.79]), incident heart failure (HR, 0.71 [95% CI, 0.58-0.87]), and all-cause and cardiovascular death (HRs of 0.54 [95% CI, 0.46-0.63] and 0.47 [95% CI, 0.35-0.64], respectively). The findings were similar for analyses evaluating recommended level of physical activity.

Limitations: Self-reported physical activity may result in some degree of misclassification.

Conclusions: Higher self-reported physical activity was associated with lower risk of cardiovascular events and mortality in CKD patients, which may have important implications for clinical practice and the design of interventional studies.

Plain-language summary: In this long-term study of 3,926 adults with chronic kidney disease, we found that individuals with higher levels of physical activity were less likely to experience an atherosclerotic event (for example, a heart attack, stroke, or peripheral arterial disease), new-onset heart failure, and death as compared with those with lower levels of physical activity. The findings were similar for the analyses evaluating adherence to guideline-recommended level of physical activity (that is, for more than 150 minutes per week), and they strengthen the evidence supporting the current guideline recommendations.

Keywords: Atherosclerotic events; cardiovascular death; chronic kidney disease (CKD); exercise; health-related behavior; heart failure (HF); metabolic equivalents of task (MET); modifiable risk factor; myocardial infarction (MI); peripheral artery disease (PAD); physical exercise; stroke.

Figure 1.

Cardiovascular events stratified by baseline MVPA quartile (Figure 1a) and by baseline guideline-recommended physical activity category (Figure 1b). All-cause and cardiovascular mortality rates by baseline MVPA quartile (Figure 1c) and by baseline guideline-recommended physical activity category (Figure 1d).

Figure 2.

Association of physical activity level with cardiovascular events. Hazard ratios are adjusted for clinical center, sex, age, race/ethnicity, education level, marital status, employment status, household income, smoking status, BMI, systolic BP, diabetes, CVD, ACE inhibitor/ARB use, antiplatelet medication, statin, beta-blocker, log CRP, eGFR, and log urine protein/creatinine ratio. Event rate is based on baseline physical activity classification, expressed per 100 person-years. Abbreviations: HR, hazard ratio; CI, confidence interval; MVPA, moderate-to-vigorous physical activity.

Figure 3.

Association of physical activity level with death. Hazard ratios are adjusted for clinical center, sex, age, race/ethnicity, education level, marital status, employment status, household income, smoking status, BMI, systolic BP, diabetes, CVD, ACE inhibitor/ARB use, antiplatelet medication, statin, beta-blocker, log CRP, eGFR, and log urine protein/creatinine ratio. Event rate is based on baseline physical activity classification, expressed per 100 person-years. Abbreviations: HR, hazard ratio; CI, confidence interval; MVPA, moderate-to-vigorous physical activity.