Estimating the efficacy of isometric handgrip training to lower resting blood pressure in patients with stage 1 hypertension in Eastern Uganda compared to standard of care: study protocol for a randomized controlled trial.

BACKGROUND

Hypertension (HTN) is a major non-communicable disease worldwide, including in Uganda. Studies have estimated HTN prevalence in Uganda between 19 and 33% among adults, with only 7-9% controlled within clinical target ranges. Isometric handgrip training (IHT), a form of resistance training that consists of performing multiple static forearm contractions separated by brief rest periods on a handgrip dynamometer or stress ball, is a promising simple, time-efficient, and low-cost intervention. This randomized controlled trial (RCT) aims to determine the efficacy of 12 weeks of IHT compared to standard of care on resting blood pressure (BP) levels in a population of hypertensive patients at the Soft Power Mukagwa Allan Stone Community Health Clinic (Kyabirwa, Uganda).

METHODS

This study consists of a two-arm, parallel, randomized controlled, superiority trial. Patients having (1) a diagnosis of stage 1 HTN (BP > 140-159/90-99 mmHg), (2) not currently taking HTN medication, (3) not having been on HTN medication in the past 3 months, and (4) aged ≥18 years will be recruited. A total of 250 participants will be randomized with equal allocation to intervention and control arms. The control arm will receive standard care for HTN for a duration of 12 weeks, as per clinic standard practice. In addition to standard care, the intervention arm will perform IHT sessions three times a week for a duration of 12 weeks. IHT sessions will consist of four 2-min isometric handgrip contractions, using alternate hands with 1-min rest periods between contractions (total: 12 min). The primary outcome is the mean resting systolic BP at 12 weeks. Data collection will be conducted at baseline, 1, 2, and 3 months and will include measurements of BP levels and administration of questionnaires.

DISCUSSION: This RCT will provide evidence on the efficacy of IHT, a promising and cost-efficient therapy for blood pressure control in a Ugandan context. We anticipate that our results will inform treatment strategies for hypertensive patients in Uganda and in other high-burden LMIC contexts.

TRIAL REGISTRATION: Retrospectively registered. ISRCTN Registry; ISRCTN46005092 ; 31/10/2024.