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.