Hypoxic exercise with dietary advice for cardiometabolic risk reduction in overweight and obese older adults: a systematic review and meta-analysis

Background Elevated blood pressure is an important factor in the mortality of older adults. This study explored the effects of hypoxic exercise on blood pressure and cognitive function among overweight and obese older adults. Methodology A search for eligible studies was conducted through four databases, followed by screening. The inclusion criteria were as follows: (1) Participants were older adults aged 60 and above; (2) Eligible studies were randomized controlled trials; (3) The intervention group received hypoxic exercise, while the control group received normoxic exercise; (4) Pre- and post-test were conducted, which included systolic blood pressure (SBP), diastolic blood pressure (DBP), and cognitive function. The Cochrane bias risk assessment tool was used to evaluate the quality of the selected study. Results Thirteen RCTs (195 hypoxic-exercise, 191 normoxic-exercise participants) were included. Hypoxic exercise reduced SBP by a mean difference of −4.30 (95% CI: −7.38 to −1.23; n = 6) and DBP by −3.67 (95% CI: −6.06 to −1.27; n = 6) mmHg versus normoxic exercise. Cognitive function improved (SMD = 0.46, 95% CI: 0.11 to 0.80; n = 4). There was no clear evidence of additional benefit on fat mass (SMD = −0.47, 95% CI: −1.27 to 0.33), BDNF (SMD = −0.02, 95% CI: −0.53 to 0.48), or CRP (SMD = 0.15, 95% CI: −0.28 to 0.57). Sensitivity analysis indicated that the SBP estimate was not robust to exclusion of the largest trial. Subgroup analyses by oxygen content and dietary advice were exploratory, and formal tests for subgroup differences did not establish that dietary advice conferred additional benefit. Conclusion Hypoxic exercise, compared with normoxic exercise, may produce modest additional reductions in SBP and DBP and may improve cognitive function in overweight and obese older adults. Evidence for fat mass, BDNF, and CRP was inconclusive. Given the small number of trials, the instability of the SBP result, and the exploratory nature of the subgroup analyses, these findings require confirmation in larger, adequately powered trials. Systematic review registration PROSPERO , CRD420251180073.