Effects of lifestyle-related interventions on blood pressure in the low and middle income countries: systematic review and meta-analysis

Abstract

Background: Despite a plethora of evidence supporting the efficacy of antihypertensive agents, hypertension remains poorly controlled worldwide, and in Low and Middle Income Countries (LMICs) in particular. In this context, it is unclear if non-pharmacological lifestyle-based interventions are effective to help maintain optimum blood pressure levels in the LMICs. Methods: We performed a systematic review and meta-analysis of available clinical trials, based in the LMIC and published before June 2012, which assessed effects of any lifestyle-related intervention on blood pressure. We identified relevant studies by systematically searching multiple electronic databases. Interventions were grouped into behavioral counseling, dietary modification, physical activity and multiple interventions. We calculated and pooled effect estimates (weighted mean difference or WMD in mm Hg between the post- and pre-intervention measurements) with random-effects models. Where appropriate, subgroup and meta-regression analyses were employed to evaluate origins of heterogeneity. Findings From the initial 6211 references identified, 52 studies were included, comprising a total of 6,779 non-overlapping participants. The changes (and corresponding 95% CI) in the WMD expressed as mm Hg achieved for systolic blood pressure were -5.39 (-10.73, -0.05) for behavioral counseling, -3.48 (-5.45, -1.50) for dietary modification, -11.37 (-16.06, -6.68) for physical activity and -6.09 (-8.87, -3.32) for multiple lifestyle interventions. Findings were generally consistent for diastolic blood pressure. Nonetheless, heterogeneity was generally high across these studies, which was partly explained when studies were grouped according to sample size, duration of follow-up and analytical approach used. Interpretation: Available data indicate that lifestyle-related interventions are effective in lowering blood pressure in the LMIC. The potential of cost-effective, easily scalable lifestyle interventions is attractive in the resource-poor settings as a complementary approach to help shape preventive guidelines. Nonetheless, further investigations with sufficient power and scientific rigor would be required to more reliably quantify these effects.