Experiences, acceptability and feasibility of an isometric exercise intervention for stage 1 hypertension: embedded qualitative study in a randomised controlled feasibility trial.

BACKGROUND: Healthy lifestyle changes for patients with stage 1 hypertension are recommended before antihypertensive medication. Exercise has antihypertensive benefits; however, low adoption and high attrition are common. Patients need easily adoptable, effective and manageable exercise interventions that can be sustained for life. We present participant and stakeholder perceptions of an isometric exercise intervention for stage 1 hypertension delivered in the National Health Service (NHS, UK). METHODS: An embedded qualitative study within a randomised-controlled feasibility study included intervention arm participants (n = 10), healthcare professionals from participating NHS sites (n = 3) and non-participating NHS sites (n = 5) taking part in semi-structured interviews to explore feasibility of delivering an isometric exercise intervention within the study design and an NHS context. Data was analysed using reflective thematic analysis. RESULTS: Three themes were identified: study deliverability; motivators and barriers; support for study participation. Findings indicated that the study was well designed. Health benefits, unwillingness to take medication, altruism and interest in the study helped motivation and adherence. Study support received was good, but healthcare professionals were insecure in intervention delivery with regular training/supervision needed. Perception of health improvement was mixed, but, in some, uptake of wider lifestyle changes resulted from participation. Stakeholders felt that current service challenges/demand would make implementation challenging. CONCLUSIONS: Despite participant positivity, delivery of an isometric intervention in an NHS setting was considered challenging given the current service demand, although possible with robust effectiveness evidence. Findings support further effectiveness data and implementation development of the isometric exercise intervention. TRIAL REGISTRATION: ISRCTN, ISRCTN13472393 . Registered 18 September 2020.

Effects of isometric resistance training on resting blood pressure: individual participant data meta-analysis.

BACKGROUND: Previous meta-analyses based on aggregate group-level data report antihypertensive effects of isometric resistance training (IRT). However, individual participant data meta-analyses provide more robust effect size estimates and permit examination of demographic and clinical variables on IRT effectiveness. METHODS: We conducted a systematic search and individual participant data (IPD) analysis, using both a one-step and two-step approach, of controlled trials investigating at least 3 weeks of IRT on resting systolic, diastolic and mean arterial blood pressure. RESULTS: Anonymized individual participant data were provided from 12 studies (14 intervention group comparisons) involving 326 participants (52.7% medicated for hypertension); 191 assigned to IRT and 135 controls, 25.2% of participants had diagnosed coronary artery disease. IRT intensity varied (8-30% MVC) and training duration ranged from 3 to 12 weeks. The IPD (one-step) meta-analysis showed a significant treatment effect for the exercise group participants experiencing a reduction in resting SBP of -6.22 mmHg (95% CI -7.75 to -4.68; P < 0.00001); DBP of -2.78 mmHg (95% CI -3.92 to -1.65; P = 0.002); and mean arterial blood pressure (MAP) of -4.12 mmHg (95% CI -5.39 to -2.85; P < 0.00001). The two-step approach yielded similar results for change in SBP -7.35 mmHg (-8.95 to -5.75; P < 0.00001), DBP MD -3.29 mmHg (95% CI -5.12 to -1.46; P = 0.0004) and MAP MD -4.63 mmHg (95% CI -6.18 to -3.09: P < 0.00001). Sub-analysis revealed that neither clinical, medication, nor demographic participant characteristics, or exercise program features, modified the IRT treatment effect. CONCLUSION: This individual patient analysis confirms a clinically meaningful and statistically significant effect of IRT on resting SBP, DBP and mean arterial blood pressure.