Effect and Moderator of Isometric Resistance Training (IRT) on Blood Pressure for Pre-to Established Hypertension: A Systematic Review and Meta-Analysis

Xue Wang † ¹ Zengyu Zhang † ^2* Jiamin Chen † ^3* Jian SONG ⁴ Xu Zhang ^1*

• ¹ Jilin Sport University, Changchun, China
• ² Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, Shanghai Municipality, China
• ³ College of Integrated Traditional Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan Province, China
• ⁴ School of Physical Education and Health, East China Normal University, Shanghai, Shanghai Municipality, China

Objective to (1) systematically review the effect of isometric resistance training (IRT) on blood pressure (SBP [systolic blood pressure], DBP [diastolic blood pressure], and MAP [mean arterial pressure]) for pre-to established hypertension, and (2) explore the effect on blood pressure moderator with IRT. Methods The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations. Studies using a between-group design involving pre-to established hypertension and assessing the effect of IRT on blood pressure were included. The Cochrane Collaboration's risk of bias (RoB) tool was used to aid in assessing the RoB in individual studies, while the methodological design and quality of the included studies underwent review. Pooled effects for each outcome were summarized using mean difference (MD) and SMD (Hedge's g) using DerSimonian and Laird random effects models. A meta-analysis on blood pressure was conducted, and the observed heterogeneities were explored through subgroup, regression, and sensitivity analyses. Results Eighteen studies with a total of 756 subjects (46.1% female, average age and BMI of 57 years and 28.2 kg/m 2 ) were included in this meta-analysis (IRT, n=388; Control, n=368). IRT displayed a statistically significant reduction on SBP (MD = -7.25 mmHg, 95% CI [-9.68, -4.82], p < 0.0001; I 2 = 52%), DBP (MD = -4.69 mmHg, 95% CI [-6.27, -3.11], p < 0.0001; I 2 = 35%), and MAP (MD = -7.61 mmHg, 95% CI [-9.42, -5.81], p < 0.001; I 2 = 0%) for pre-to established hypertension compared to no-training. Sensitivity analyses showed that the above-pooled results were stable. Subgroup analyses revealed that health condition, status of medication, intervention supervised/unsupervised, and training mode all significantly moderated IRT on SBP, and BMI and interval duration might have significantly moderated trends. Regression analyses did not find a significant association between any other variables of training and the effects or dose-response of IRT on SBP and DBP. Conclusion IRT was efficacious in the reduction of resting blood pressure for pre-to established hypertension.