Blood pressure, socio-economic status and health in the Lothian 1921 birth cohort: A longitudinal study

SummaryObjectivesTo test whether socio-economic status and disease burden influence blood pressure in older adults.Study designLongitudinal cohort study of community-resident people born in 1921 and assessed at mean ages of 79, 83 and 87 years.MethodsSitting and standing systolic and diastolic blood pressures (BP) were measured at each wave of attendance. Socio-economic status was assessed by years of full-time education and occupational social class. History of disease, medication use, smoking status and alcohol use were recorded. Deaths were ascertained prospectively by flagging from the General Registrar’s Office, Scotland. Mixed general linear models were fitted to examine the effects of predictor variables on BP over all three waves; change in BP over time; and differential effects on systolic, diastolic, sitting and standing BP.ResultsIn total, 549 participants were assessed at Wave 1, 321 at Wave 2 and 209 at Wave 3. Significant effects on BP across all waves were found for social class (P = 0.003), heart disease (P < 0.001) and number of drugs (P = 0.049). The mean BP of participants from social class I was 5.4 [95% confidence interval (CI) 1.7–9.7] mmHg higher than that of the participants of social class V. Participants with heart disease had lower mean BP over all measures (113 mmHg, 95% CI 110–115) than those without heart disease (120 mmHg, 95% CI 118–121).ConclusionsSocio-economic status had a persistent effect on BP in this cohort born in 1921. Unlike other cardiovascular risk factors at younger ages, people from social class I had significantly higher mean BP than people from social class V.