Associations of general and abdominal adiposity with incident elevated blood pressure among Tianjin adolescents: a school-based longitudinal study
摘要
Because elevated blood pressure during adolescence often persists into adulthood and increases the risk of cardiovascular diseases, early identification of modifiable risk factors for elevated blood pressure is critical for timely prevention. This study compared the predictive performance of body mass index (BMI) and waist-to-height ratio (WHtR) in identifying incident elevated blood pressure among Tianjin adolescents.
MethodThis longitudinal analysis included 4,694 students aged 11–18 years from the 2023–2024 National Student Common Diseases and Risk Factors Surveillance in Tianjin, China. Modified Poisson regression with false discovery rate (FDR) correction and restricted cubic splines (RCS) were used to assess associations of BMI and WHtR with incident elevated blood pressure, stratified by sex. Predictive performance was evaluated using area under the receiver operating characteristic curves (AUC), integrated discrimination improvement (IDI), calibration plots, and decision curve analysis (DCA).
ResultsDuring the one-year interval, 13.2% of girls and 13.5% of boys developed elevated blood pressure. Adjusting for sociodemographic and lifestyle factors, both general and abdominal obesity were significantly associated with incident elevated blood pressure in girls (general obesity: RR 2.25 [95% CI: 1.75–2.88]; abdominal obesity: 1.92 [1.57–2.36]) and boys (general obesity: 2.07 [1.59–2.71]; abdominal obesity: 1.83 [1.48–2.25]). RCS revealed linear associations except for WHtR in girls. AUCs for BMI (girls: 0.640; boys: 0.669) and the combination with WHtR (girls: 0.641; boys: 0.670) were comparable in both sexes; both were similar to WHtR in girls (0.633) but slightly higher than WHtR alone in boys (0.641; DeLong’s test p < 0.05). Adding BMI to the basic model improved discrimination more than adding WHtR (IDI: girls 0.0272 vs. 0.0222; boys 0.0242 vs. 0.0179), while including both indices provided no additional improvement. All expanded models showed good calibration and higher net benefits than the basic model, with no additional clinical advantage observed for the combined model.
ConclusionBoth BMI and WHtR were associated with incident elevated blood pressure and showed comparable discriminative ability. However, BMI provided a greater incremental improvement in risk prediction than WHtR across sexes, with no additional incremental value from combining both indices.