School-based blood pressure measurement and its association with left ventricular mass index among adolescents in urban Tanzania

BACKGROUND: High blood pressure (BP) among adolescents is increasingly common in sub-Saharan Africa, yet evidence of its association with left ventricular mass index (LVMI) - a key marker of early cardiovascular risk remains limited. We aimed to assess the association between school-based BP measurements and LVMI. METHODS: We conducted a cross-sectional study among 210 adolescents in Mwanza City, Tanzania. BP was measured at two visits approximately one week apart. High BP was defined as BP ≥ 120/80 mmHg, according to the 2017 American Academy of Pediatrics guideline. Having high BP at both visits was referred to as sustained high BP. RESULTS: Prevalence of high BP at one and two visits were 18.6%. and 11.9% respectively. Mean (SD) LVMI for participants with normal BP, high BP at one visit, and sustained high BP were 52.9(11.9) g/m2, 57.0(16.5) g/m2 and 60.8(14.9) g/m2 respectively. Sustained high BP was associated with higher LVMI of 6.4 (95% CI: 1.4,11.4) g/m² after adjusting for confounders. Similarly, participants with high BP at only one visit had a 4.5 (95% CI: 0.4,8.6) g/m2 higher LVMI. High sugar consumption (≥ 6 teaspoons/day) was also associated with higher LVMI of 5.4 (95% CI: 0.1,10.7) g/m². Conversely, adequate consumption (≥ 5 servings/day) of fruits and vegetables was associated with lower LVMI of 3.7 (95% CI:0.1, 7.2) g/m². CONCLUSION: High BP was associated with higher LVMI among apparently healthy Tanzanian adolescents, while fruit, vegetable, and sugar consumption were associated with differences in LVMI, highlighting potential targets for future interventions.