Intragenerational Social Mobility and Changes in Blood Pressure: Longitudinal Analysis From the ELSA-Brasil Study.

Abstract

During the past 4 decades, the highest worldwide blood pressure (BP) levels have shifted from high-income countries to low- and middle-income countries. We investigated the association of intragenerational social mobility with changes in BP and also with the incidence of hypertension over a 4-year follow-up. Data for 6,529 baseline participants from ELSA-Brasil born between 1938 and 1975 were used. Based on a social mobility matrix, occupational social mobility was defined as the change in occupational social class between participants' first occupation and current occupation (stable high; upward; downward; stable low). Incident hypertension was defined as systolic blood pressure (SBP) ≥ 140 mm Hg or diastolic blood pressure (DBP) ≥ 90 mm Hg or use of antihypertensive medication. Hypertensive participants at baseline were excluded. Mixed effects regression models were used. Compared to the stable high group, the downwardly mobile group showed a higher increase over time in both SBP (β = 1.49, 95% CI 0.60; 2.37) and DBP (β = 0.96, 95% CI 0.32; 1.59) after adjustments for background characteristics and also proximal risk factors such as health-related behaviors and body mass index as time-dependent covariates, and diabetes. In contrast, upward mobility had no influence on BP changes (β = 0.67, 95% CI -0.07; 1.41 for SBP, and β = 0.47, 95% CI -0.05; 1.00 for DBP). Social mobility was not associated with the incidence of hypertension. We showed socioeconomic inequalities in BP progression over the life course. The longitudinal changes in BP varied by social mobility groups in the context of low- and middle-income countries, where high BP has become most prevalent.