Intermittent high-intensity exercise for pre- to established hypertension: A systematic review and meta-analysis.

OBJECTIVE: To determine the impact of intermittent high-intensity exercise training ([IHIE], including high-intensity interval training [HIIT] and recreational team sports [RTS]) on systolic (SBP) and diastolic blood pressure (DBP) in adults with pre- to established arterial hypertension. DATA SOURCES: MEDLINE, Cochrane Library, Embase, and SPORTDiscus. ELIGIBILITY CRITERIA: Randomized controlled trials (RCTs) comparing the impact of IHIE on BP versus a non-exercise control. DATA COLLECTION AND ANALYSIS: Two authors independently conducted all procedures. Mean differences were calculated using random-effects model. The certainty of the evidence was assessed with GRADE. RESULTS: Twenty-seven RCTs (18 HIIT and 9 RTS) were analyzed, with median duration of 12 weeks. Participants' (n = 946) median age was 46 years. Overall, IHIE decreased SBP (-3.29 mmHg; 95% CI: -5.19, -1.39) and DBP (-2.62 mmHg; 95% CI: -3.79, -1.44) compared to the control group. IHIE elicited higher decreases in office SBP and DBP of hypertensive subjects (SBP: -7.13 mmHg, [95% CI: -10.12, -4.15]; DBP: -5.81 mmHg, [95% CI: -7.94, -3.69]) than pre-hypertensive (SBP: -2.14 mmHg, [95% CI: -4.36, -0.08]; DBP: -1.83 mmHg, [95% CI: -2.99, -0.67]). No significant differences were found between HIIT (SBP: -2.12 mmHg, [95% CI: -4.78, -0.54]; DBP: -1.89 mmHg, [95% CI: -3.32, -0.48]) and RTS (SBP: -4.18 mmHg, [95% CI: -7.19, -2.43]; DBP: -4.04 mmHg, [95% CI: -6.00, -2.09]). These findings present low/very low certainty of evidence. No adverse cardiovascular events were reported. CONCLUSIONS: IHIE appears to be safe and to promote substantial decreases in BP, particularly in patients with hypertension. However, the certainty of evidence was low/very low. PROTOCOL: CRD42020163575.

Statistical heterogeneity in meta-analysis of hypertension and exercise training: A meta-review.

We aim to evaluate the prevalence of reporting and the extent of statistical heterogeneity of systematic reviews with meta-analyses (SRMAs) of exercise training for hypertension and to provide practical recommendations for dealing with statistical heterogeneity. We systematically searched on four databases (from 2002 to September of 2023) for SRMAs comparing exercise interventions vs. a non-exercise control on blood pressure (BP) control in adults with hypertension. Fifty-nine SRMAs, with a median of 14 studies, were analysed. Cochran's Q (41%), I2 (24%), forest plots (44%), and particularly τ2 (54%) and prediction intervals (96.6%) frequently were not reported for the hypertension subgroup. The recalculated prediction intervals were discrepant (i.e., crossed the null effect) of significant 95% confidence intervals of most meta-analyses (systolic BP: 65%; diastolic BP: 92%). This suggests substantial heterogeneity across studies, which was often not acknowledged by authors' conclusions (78%). Consequently, downgrading the certainty of the available evidence may be justified alone due to heterogeneity across studies. Finally, we illustrate areas for improving I2 interpretation and provide practical recommendations on how to address statistical heterogeneity across all stages of a SRMA.