Hypertension prevalence, control and survivorship in an Afro-Caribbean population

Objective: To evaluate the prevalence, distribution, awareness, treatment and control of hypertension in an Afro-Caribbean population, and their relationship to 4-year survival. Design: Population-based prospective cohort study. Setting and participants: Simple random sample of Barbados-born citizens (4709 persons; 84% participation), with 4-year follow-up. Interventions: None. Main outcome measures: Hypertension prevalence, awareness, treatment and control were evaluated at baseline. Four-year cumulative mortality was assessed by the product-limit method and relative risk of mortality by the Cox proportional hazards method. Results: Mean systolic (SBP) and diastolic (DBP) blood pressure were higher among black than white participants. In the black population, age-specific prevalence of hypertension increased from 32.7% in men and 34.0% in women at 40-49 years of age to 63.4% in men and 85.5% in women at ages 80 years and older, with an overall prevalence of 55.4%. Hypertension awareness, treatment and control rates were 62.5, 53.8 and 18.5%, respectively. Compared to DBP < 80 mmHg, the presence of a DBP between 80 and 84 mmHg, 100-109 mmHg and ≥ 110 mmHg was associated with adjusted death rate ratios of 1.6, 1.7 and 2.0, respectively. Systolic blood pressure was not related to the risk of cardiovascular mortality, after adjustment for age or other potential confounders. Hypertensives were at modestly increased risk of 4-year cardiovascular mortality [RR = 1.4; 95% confidence inteval (CI) (1.0, 2.0)], while treated uncontrolled hypertensives were at increased risk of all cause [RR = 1.4; 95% CI (1.0, 1.9)] and cardiovascular [RR = 1.6; 95% Cl (1.1, 2.5)] mortality. Conclusions: High rates of hypertension in this population coexist with conservative levels of treatment and low rates of blood pressure control. In contrast to other reports, elevated SBP was not independently associated with increased risk of cardiovascular mortality. The modest impact of elevated blood pressure might partly explain the comparatively lower hypertension-related mortality rates in populations of Caribbean-origin. Treated uncontrolled hypertensives are at increased risk of early mortality, signaling the need for strict blood pressure control in this group.