Effect of exercise on functional capacity and body weight for people with hypertension, type 2 diabetes, or cardiovascular disease: a systematic review with meta-analysis and trial sequential analysis.

BACKGROUND: Hypertension, type 2 diabetes, and cardiovascular disease affect the activities of daily living at varying degree. While the effects of aerobic exercise on functional capacity are well-documented, the extent of change for different types of exercise in these chronic conditions remains unexplored. Additionally, there is conflicting evidence regarding the role of exercise in reducing body weight.

METHODS: We conducted systematic review with meta-analysis and trial sequential analysis and searched various databases from inception to July 2020. We included randomised clinical trials adding any form of trialist defined exercise to usual care versus usual care in people with either hypertension, type 2 diabetes, and/or cardiovascular disease irrespective of setting, publication status, year, and language. The outcomes assessed were i) functional capacity assessed through different scales separately i.e., Maximal Oxygen Uptake (VO2 max), 6-min walk test (6MWT), 10-m walk test (10MWT), and ii) body weight.

RESULTS: We included 950 studies out of which 444 trials randomising 20,098 participants reported on various functional outcomes (355 trials) and body weight (169 trials). The median follow-up was 3 months (Interquartile ranges (IQR): 2.25 to 6). Exercise added to the usual care, improved VO2 max (Mean Difference (MD):2.72 ml/kg/min; 95% Confidence Interval (CI) 2.38 to 3.06; p < 0.01; I2  = 96%), 6MWT (MD: 42.5 m; 95%CI 34.95 to 50.06; p < 0.01; I2  = 96%), and 10MWT (MD: 0.06 m/s; 95%CI 0.03 to 0.10; p < 0.01; I2  = 93%). Dynamic aerobic and resistance exercise showed a consistent improvement across various functional outcomes, whereas body-mind therapies (MD: 3.23 ml/kg/min; 95%CI 1.97 to 4.49, p < 0.01) seemed especially beneficial for VO2 max and inspiratory muscle training (MD: 59.32 m; 95%CI 33.84 to 84.80; p < 0.01) for 6MWT. Exercise yielded significant reduction in body weight for people with hypertension (MD: -1.45 kg; 95%CI -2.47 to -0.43; p < 0.01), and type 2 diabetes (MD: -1.53 kg; 95%CI -2.19 to -0.87; p < 0.01) but not for cardiovascular disease with most pronounced for combined exercise (MD: -1.73 kg; 95%CI -3.08 to -0.39; p < 0.05). The very low certainty of evidence warrants cautious interpretations of the results.

CONCLUSION: Exercise seemed to improve functional capacity for people with hypertension, type 2 diabetes, and/or cardiovascular disease but the effectiveness seems to vary with different forms of exercise. The potentially superior improvement in VO2 max and 6MWT by body-mind therapies and inspiratory muscle training calls for further exploration. Additionally, prescribing exercise for the sole purpose of losing weight may be a potential strategy for people with hypertension and type 2 diabetes. The extent of improvement in functional capacity and body weight reduction differed with different exercise regimens hence personalised exercise prescriptions tailored to individual needs may be of importance. PROSPERO REGISTRATION: PROSPERO registration number: CRD42019142313.