Self-rated Health in Youth with Different Screen Time in Their Adolescence: Tehran Lipid and Glucose Study

BACKGROUND

The long-term effects of childhood screen time on health-related quality of life (HRQoL) are still unclear. This study aimed to investigate the relationship between screen time during adolescence and sex-specific HRQoL in early youth.

METHODS

We studied the data from 642 adolescents aged 13-19 years, who participated in the Tehran Lipid and Glucose Study from 2005 to 2011 (baseline) with complete data on HRQoL in their early adulthood (22-28 years at the last follow-up). Physical and Mental HRQoL were assessed using the Iranian version of the short-form 12-item health survey version 2 (SF-12v2). Screen time and leisure-time physical activity were evaluated using the Iranian Modifiable Activity Questionnaire (MAQ). All analyses were conducted in Stata (version 14); MI used the mi impute command.

RESULTS

The mean±SD of age, body mass index (BMI), and physical activity in childhood were 16.33±1.27, 23.27±4.63 and 13.77±16.07, respectively. Overall, 35% of boys and 34% of girls had high screen time (HST) in childhood. In general, the HRQoL scores in male participants were higher than in females in both the mental and physical domains. HST in males in childhood was associated with decreased mental health (β=-6.41, 95% CI: -11.52, -1.3 and P=0.014), social functioning (β=-5.9, 95% CI: -11.23, -0.57 and P=0.03) and mental component summary (MCS) (β=-2.86, 95% CI: -5.26, -0.45 and P=0.02). The odds of poor MCS were significantly higher in those with HST compared to their counterparts with low screen time (LST) after adjusting for all potential cofounders.

CONCLUSION

The results of the present study showed the negative effect of screen time during adolescence on HRQoL in early youth. This effect was observed in men, mainly in the mental dimension. Investigating the long-term consequences of screen-time behaviors on self-assessed health in other populations with the aim of effective primary prevention is also suggested.

The association between leisure-time physical activity and blood pressure changes from adolescence to young adulthood: Tehran Lipid and Glucose Study

The effectiveness of long-term leisure time physical activity (LTPA) on blood pressure (BP) changes is still under debate. Since adolescence lifestyle behaviors shape the adulthood health profile, this study aimed to investigate the sex-specific impact of LTPA on BP changes from adolescence to young adulthood. This longitudinal study uses the data of 1412 adolescents (52% females) aged 12-18 years through a median follow-up of 12.2 years in the Tehran Lipid and Glucose Study (TLGS) framework. LTPA was calculated using the reliable and valid Iranian version of the modified activity scale (MAQ), and BP was measured at least twice by trained physicians. The linear mixed model was used to examine the study variables, considering individual and intrapersonal differences during the study. The majority of participants consistently demonstrated insufficient LTPA throughout the follow-up assessments, ranging from 54.7 to 67.1% for males and 77.7-83.4% for females. Despite a declining trend in LTPA (β = - 2.77 for males and β = - 1.43 for females), an increasing trend was noticeable in SBP, DBP, and BMI (β = 1.38, β = 1.81, β = 0.97 for males, and β = 0.10, β = 0.20, β = 0.97 for females, respectively). The unadjusted model revealed a significant trend in all variables for both sexes, except for female BP (P = 0.45 for SBP and P = 0.83 for DBP). Using the adjusted model, no significant association was observed between LTPA and changes in BP over time in both sexes. Our study indicates no association between LTPA and BP changes from adolescence to young adulthood. Insufficient LTPA levels, particularly among Iranian females, are likely the primary factor. Further research is crucial to identify appropriate LTPA levels to promote cardiovascular health and implement targeted interventions to achieve optimal LTPA levels in the Iranian population.