Moderating Effect of Physical Activity and Body Mass Index on the Relationship Between Sedentary Behavior and Cardiometabolic Markers in Adolescents: A Longitudinal Analysis

OBJECTIVE: We examined the moderating effect of moderate to vigorous physical activity (MVPA) and body mass index (BMI) on the association between sedentary behavior (SB) and cardiometabolic markers (CMM) in adolescents. METHODS: In this 3-year longitudinal study (2014, 2015, and 2017), we collected and analyzed data from 136 adolescents (10-13 y) from João Pessoa, Paraíba, Brazil. We collected SB data using an ActiGraph GT3X+ accelerometer and calculated total sedentary time (in hours per day), also classifying participants into 2 exposure patterns: "Low SB" (≤8 h/d) and "High SB" (>8 h/d). We evaluated CMM including: glucose, total cholesterol (TC), triglycerides (TG), high-density (HDL-C) and low-density lipoprotein cholesterol non-HDL-C, TC/HDL-C, TG/HDL-C, BMI, waist circumference, and systolic and diastolic blood pressure. We applied Generalized Estimating Equations to test whether time spent in MVPA and BMI moderated associations between SB and CMM. RESULTS: The Generalized Estimating Equation identified significant interactions between SB and MVPA, as well as between SB and BMI, for several CMM (P < .05). Among adolescents with low SB exposure (≤8 h/d), those who accumulated more MVPA (>50 min/d) showed more favorable lipid profiles, including TC, LDL-C, non-HDL-C, and TC/HDL-C ratio. The combination of high SB exposure (>8 h/d) and excess weight was associated with less favorable TG, TC/HDL-C, TG/HDL-C, HDL-C, waist circumference, and systolic blood pressure values. Even under low SB exposure, excess weight corresponded to less favorable TC/HDL-C, TG/HDL-C, HDL-C, and waist circumference levels. CONCLUSION: MVPA moderated associations with CMM only at low sedentary exposure, whereas excess body weight amplified adverse associations across multiple cardiometabolic outcomes during adolescence.