Association Between Obesity, Digital Screen Time, and Early-Onset Hypertension in Adolescents: A Prospective Cohort Study.

Objective This study aimed to assess the associations between obesity, digital screen time, and early-onset hypertension in adolescents. Specifically, it examined the independent and combined effects of these factors on blood pressure (BP) regulation. Methods A prospective cohort study was conducted among 350 adolescents (N = 350) aged 10-18 years, with an equal distribution of obese (n = 175, 50.0%) and non-obese (n = 175, 50.0%) participants. Digital screen time was categorized into recreational and educational use, with excessive screen time defined as >3 hours/day. BP was measured three times per participant using a validated oscillometric device, following the American Academy of Pediatrics (AAP) guidelines. Hypertension was defined as BP ≥ 95th percentile for age, sex, and height. Multivariate logistic regression was employed to assess the association between obesity, screen time, and hypertension, adjusting for physical activity, socioeconomic status (SES), family history of hypertension, and dietary factors. Results A total of 82 participants (23.4%) were hypertensive, with a significantly higher prevalence in obese adolescents (n = 64, 36.6%) compared to non-obese adolescents (n = 18, 10.3%) (p < 0.001). Excessive screen time (>3 hours/day) was an independent predictor of hypertension (adjusted odds ratio (aOR) = 2.58, 95% CI: 1.73-3.86; p < 0.001). Recreational screen time (>3 hours/day) was more strongly associated with hypertension (aOR = 3.12, 95% CI: 2.10-4.02) compared to educational screen time (aOR = 1.75, 95% CI: 1.21-2.44). Adolescents with both obesity and excessive screen time had the highest hypertension prevalence (52.4%), significantly exceeding those with either risk factor alone. The combined risk group had an aOR = 5.14 (95% CI: 3.28-7.56), suggesting a potential interaction effect, though formal mediation analysis was not performed. Low physical activity (Physical Activity Questionnaire for Older Children (PAQ-C) score < 2.33) was also associated with hypertension (aOR = 1.62, 95% CI: 1.04-2.51; p = 0.033). Conclusion Obesity and excessive screen time are independently and jointly associated with early-onset hypertension in adolescents. These findings emphasize the need for targeted interventions, including routine BP screening for high-risk adolescents, school-based digital wellness programs, and structured physical activity initiatives. While this study establishes associations, not causality, further longitudinal research is required to explore the causal pathways and potential interaction effects between obesity, screen time, and hypertension.