Date Published: February 6, 2019
Publisher: Public Library of Science
Author(s): Stephanie Thompson, Natasha Wiebe, Raj S. Padwal, Gabor Gyenes, Samuel A. E. Headley, Jeyasundar Radhakrishnan, Michelle Graham, Gianpaolo Reboldi.
Management of hypertension in chronic kidney disease (CKD) remains a major challenge. We conducted a systematic review to assess whether exercise is an effective strategy for lowering blood pressure in this population.
We searched MEDLINE, EMBASE, the Cochrane Library, CINAHL and Web of Science for randomized controlled trials (RCTs) that examined the effect of exercise on blood pressure in adults with non-dialysis CKD, stages 3–5. Outcomes were non-ambulatory systolic blood pressure (primary), other blood pressure parameters, 24-hour ambulatory blood pressure, pulse-wave velocity, and flow-mediated dilatation. Results were summarized using random effects models.
Twelve studies with 505 participants were included. Ten trials (335 participants) reporting non-ambulatory systolic blood pressure were meta-analysed. All included studies were a high risk of bias. Using the last available time point, exercise was not associated with an effect on systolic blood pressure (mean difference, MD -4.33 mmHg, 95% confidence interval, CI -9.04, 0.38). The MD after 12–16 and 24–26 weeks of exercise was significant (-4.93 mmHg, 95% CI -8.83, -1.03 and -10.94 mmHg, 95% CI -15.83, -6.05, respectively) but not at 48–52 weeks (1.07 mmHg, 95% CI -6.62, 8.77). Overall, exercise did not have an effect on 24-hour ambulatory blood pressure (-5.40 mmHg, 95% CI -12.67, 1.87) or after 48–52 weeks (-7.50 mmHg 95% CI -20.21, 5.21) while an effect was seen at 24 weeks (-18.00 mmHg, 95% CI -29.92, -6.08). Exercise did not have a significant effect on measures of arterial stiffness or endothelial function.
Limited evidence from shorter term studies suggests that exercise is a potential strategy to lower blood pressure in CKD. However, to recommend exercise for blood pressure control in this population, high quality, longer term studies specifically designed to evaluate hypertension are needed.
Hypertension is a key determinant of both cardiovascular (CV) events and progressive renal dysfunction.[1–5] For those with moderate to severe chronic kidney disease (CKD), the burden of hypertension is high, with a prevalence of 53% to 95%.[6,7] Although treating hypertension is one of the main priorities in CKD management, control remains suboptimal with less than half of patients attaining recommended blood pressure (BP) targets.[6,8] Medication with or without dietary counseling is the mainstay of blood pressure treatment in CKD; however, antihypertensive drugs are often only partially effective, are costly, frequently confer side effects, and contribute to pill burden. With recent recommendations for tighter control, additional strategies to better manage hypertension in this population are needed.
This systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
Overall, we found that regular exercise was not associated with a significant mean difference in non-ambulatory systolic BP in people with non-dialysis CKD. Exercise was associated with a significant BP-lowering effect at 24 weeks of follow-up, but this difference was not observed at 52 weeks. In the two trials that measured BP using 24-hour ABPM, the overall effect of exercise on systolic BP was also not significant compared to no exercise. Similarly, there was an antihypertensive effect of exercise at 24 weeks that was not detected at 48 weeks. In the interpretation of these findings, it is important to note that the direction and the magnitude of the overall effect of exercise on SBP favoured the intervention. However, our confidence in this finding is limited by the high risk of bias in all of the included trials. Furthermore, the effect moved toward the null when the outlying trial was excluded, and heterogeneity resolved.