High prevalence of hypertension and high-normal blood pressure: findings from a large population-based survey of young adults in Zimbabwe

Background Most cardiovascular mortality is due to hypertension and onset may be in youth. We investigated the prevalence of and risk factors for elevated blood pressure (BP) (hypertension (≥140/90mmHg) and high-normal BP (130-139/85-89mmHg)) among youth in Zimbabwe. Methods A population-based survey of randomly sampled 18-24 year olds from 24 communities in three provinces was conducted, with standardised questionnaires to collect socio-demographic, behavioural and clinical data. Height, weight and BP were recorded. The association of potential risk factors with elevated BP was examined using multivariable logistic regression. Findings Of 17,682 participants recruited (98% of those eligible), 17,637 had complete data. The median age was 20 (IQR: 19-22) years and 60.7% were female. After excluding pregnant women (N=754), the prevalence of hypertension and high-normal BP was 7.4% (95% CI:7.0-7.8) and 12.2% (95% CI:12.7-13.7), respectively. Prevalence of hypertension was higher in men (8.7% (95% CI:8.2-9.6) vs 6.6% (95% CI:6.0-6.9) in men and women, respectively) but with age increased to equivalent levels among women (at 18y 7.3% (95% CI:6.2-8.6) and 4.3% (95% CI:3.5-5.2); at 23-24 years 10.9% (95% CI:9.3-12.5) and 9.50% (95% CI:8.4-10.7) in men and women, respectively). After adjusting for confounders, male sex ((aOR) 1.53 (95% CI:1.36-1.74)), increasing age (19-20 years aOR:1.20 (1.00-1.44); 21-22 years aOR:1.45 (95% CI 1.20-1.75); 23-24 years aOR 1.90 (95% CI:1.57-2.30), vs 18 years) and obesity (aOR 1.94 (95% CI:1.53-2.47)) were associated with hypertension. Being underweight (aOR 0.79 (0.63-0.98)) and living with HIV (aOR 0.71 (95% CI:0.55-0.92)) were associated with lower odds of hypertension. Interpretation Prevalence of elevated BP is high among youth in SSA and rises rapidly with age. Further research is needed to understand drivers of BP elevation and the extent of target organ damage in youth in SSA, to guide implementation of prevention and management strategies. Funding Wellcome Trust.