The interplay of adolescent obesity and smoking on hypertension in early adulthood: insights from TLGS.

BACKGROUND

Hypertension (HTN) increasingly originates in childhood and adolescence, with obesity and smoking as modifiable risk factors. However, longitudinal evidence on their independent and joint effects on HTN risk into early adulthood remains limited in non-Western populations.

METHODS

Using data from the Tehran Lipid and Glucose Study (TLGS), we followed 985 adolescents (mean age 15.01 years) for a median of 15.05 years. Adolescent overweight/obesity was defined using national BMI percentiles, and smoking status was self-reported. Incident adulthood HTN was defined as blood pressure ≥ 140/90 mmHg or use of antihypertensive medication. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for potential confounders.

RESULTS

Over follow-up, 95 participants developed HTN. In adjusted analyses, adolescent overweight/obesity was independently associated with higher adulthood HTN risk (HR: 1.73; 95% CI: 1.11-2.71). Adolescent smoking was not independently associated with adulthood HTN after adjustment (HR: 1.15; 95% CI: 0.63-2.09). In joint exposure analyses, overweight/obese non-smokers had a higher risk than normal-weight non-smokers (HR: 1.77; 95% CI: 1.10-2.84), whereas smokers did not show statistically significant excess risk regardless of weight status. The obesity-smoking interaction suggested a possible synergistic effect on HTN risk in adulthood.

CONCLUSIONS

Adolescent overweight/obesity is an independent predictor of adulthood HTN. Although smoking was not independently associated after adjustment, the potential interaction between obesity and smoking merits further study. Prevention efforts should prioritize adolescent weight management to reduce long-term cardiovascular risk.

CLINICAL TRIAL NUMBER: Not applicable.