Effect of a physical activity promotion intervention based on the transtheoretical model on blood pressure in patients with hypertension attending primary care: a randomized controlled trial

Hypertension is a major public health concern, affecting an estimated 1.28 billion people worldwide. Although physical activity is a key component of non-pharmacological treatment, only a small proportion of adults achieve the recommended levels. This study aimed to assess the effect of a physical activity promotion intervention, that included a specific Exercise Program and grounded in the Transtheoretical Model, on blood pressure among patients with hypertension attending a primary care center in Aguascalientes, Mexico. A randomized controlled trial was conducted with 440 patients aged 40 to 70 years diagnosed with hypertension. Participants were randomly assigned to either an intervention or control group. The intervention group had access to a six-month exercise program and attended six workshops, one per month. The first two workshops covered general recommendations on physical activity for adults, information on hypertension, and dietary guidelines for people with hypertension. The following four workshops focused on promoting physical activity using the Transtheoretical Model. The control group had usual care and attended the first two workshops. The primary outcomes were the differences in the changes between the groups in blood pressure levels, and in the proportion of blood pressure control. Blood pressure was measured at baseline and after six months. Participants were also asked about their stage of change and self-efficacy for exercising regularly, adherence to pharmacological treatment, and physical activity performed. The study was conducted between August 2022 and December 2023. Compared with the control group, the intervention group showed: (1) a greater change in blood pressure, with an average decrease of 3.9 mm Hg [95% CI: 0.87, 6.88] in systolic pressure and 3.2 mm Hg [95% CI: 1.2, 5.2] in diastolic pressure; (2) 14.8% [95% CI: 5.3, 24.3] more participants achieving controlled blood pressure; and (3) greater progression through the stages of readiness to adopt regular exercise. This physical activity promotion intervention had positive effects on blood pressure levels, blood pressure control, and progression through the Transtheoretical Model stages of change. Primary care services should implement physical activity promotion programs as part of hypertension management. ClinicalTrials.gov, ID NCT05680025. Registered on December 26, 2022.