Walking and resting blood pressure: An inter-individual response difference meta-analysis of randomized controlled trials

Whether true inter-individual response differences (IIRD) exist with respect to walking training and chronic changes in resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults is not known. To address this gap, data from a meta-analysis representing up to 5060 normotensive and high normal/hypertensive (SBP ≥ 130 and/or DBP ≥ 85 mmHg) participants 16 to 84 years of age (2881 walking, 2179 control) nested in 73 randomized controlled trials were included. Walking and control group change outcome standard deviations treated as point estimates for both resting SBP and DBP were used to calculate true IIRD from each study. The inverse variance heterogeneity (IVhet) model was used to pool IIRD as well as traditional pairwise results. Both 95% confidence intervals (CI) and prediction intervals (PI) were calculated. While statistically significant reductions in resting SBP ( [Formula: see text] , −3.9 mmHg, 95% CI, −5.4 to −2.3 mmHg) and DBP ( [Formula: see text] , −1.4 mmHg, 95% CI, −2.5 to −0.3 mmHg) were found, true IIRD were neither statistically significant nor clinically important for both SBP ( [Formula: see text] , −1.4 mmHg, 95% CI, −2.0 to 2.8 mmHg) and DBP ( [Formula: see text] , 0.9 mmHg, 95% CI, −2.5 to 2.8 mmHg). The 95% prediction interval for true IIRD was −2.1 to 2.8 mmHg for SBP and −3.2 to 3.4 mmHg for DBP. CONCLUSIONS: While walking is associated with reductions in resting SBP and DBP, a lack of true IIRD exists, suggesting that factors other than training response variation (random variation, physiological responses associated with behavioral changes that are not the result of walking) are responsible for the observed variation in resting SBP and DBP.