Effects of adding exercise to usual care on blood pressure in patients with hypertension, type 2 diabetes, or cardiovascular disease: a systematic review with meta-analysis and trial sequential analysis

Introduction:Exercise is the most recommended lifestyle intervention in managing hypertension, type 2 diabetes, and/or cardiovascular disease; however, evidence in lowering blood pressure is still inconsistent and often underpowered.Method:We conducted a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials adding any form of trialist defined exercise to usual care versus usual care and its effect on systolic blood pressure (SBP) or diastolic blood pressure (DBP) in participants with hypertension, type 2 diabetes, or cardiovascular disease searched in different databases from inception to July 2020. Our methodology was based on PRISMA and Cochrane Risk of Bias-version1. Five independent reviewers extracted data and assessed risk of bias in pairs.Results:Two hundred sixty-nine trials randomizing 15 023 participants reported our predefined outcomes. The majority of exercise reported in the review was dynamic aerobic exercise (61%), dynamic resistance (11%), and combined aerobic and resistance exercise (15%). The trials included participants with hypertension (33%), type 2 diabetes (28%), or cardiovascular disease (37%). Meta-analyses and trial sequential analyses reported that adding exercise to usual care reduced SBP [mean difference (MD) MD: -4.1 mmHg; 95% confidence interval (95% CI) -4.99 to -3.14; P < 0.01; I² = 95.3%] and DBP (MD: -2.6 mmHg; 95% CI -3.22 to -2.07, P < 0.01; I² = 94%). Test of interaction showed that the reduction of SBP and DBP was almost two times higher among trials from low-and middle-income countries (LMICs) as compared to high-income countries (HICs). The exercise induced SBP reduction was also higher among participants with hypertension and type 2 diabetes compared to participants with cardiovascular disease. The very low certainty of evidence warrants a cautious interpretation of the present results.Conclusion:Adding any type of exercise to usual care may be a potential complementary strategy for optimal management of blood pressure for patients with hypertension, type 2 diabetes, or cardiovascular disease, especially, in LMICs.PROSPERO registration number CRD42019142313.