Cumulative accelerometer-based sedentary time from childhood through young adulthood with progressive left ventricular remodelling in British youth: a 13-year longitudinal study
Authors: Agbaje A O 
Published: November 2023

Abstract

Background
Questionnaire-based sedentary time and behaviour has been associated with worse cardiometabolic profiles such as adiposity, insulin resistance, and blood pressure, in the pediatric population. However, objectively measured sedentary time has not been consistently associated with poor cardiometabolic health. Till date, there is no evidence of the cumulative effect of time spent sedentary assessed with an accelerometer and cardiac structural changes in youth.

Purpose
To investigate the longitudinal association of cumulative sedentary time from childhood through young adulthood with structural cardiac changes during growth from adolescence through young adulthood.

Methods
From the Avon Longitudinal Study of Parents and Children (ALSPAC), UK birth cohort, 766 children aged 11 years who had at least two follow-up time-points accelerometer-measured sedentary time over 13 years follow-up, and complete cardiac structural measures at age 17 years clinic visit were included. Sedentary time was assessed with ActiGraph accelerometer worn for 4-7 days at the 11-, 15-, and 24-year clinic visits. Repeated echocardiography measured left ventricular mass indexed for height2.7 (LVMI2.7) and relative wall thickness (RWT) were available at baseline and follow-up. Multivariable adjusted associations were examined using generalized linear mixed-effect models and adjusted for sex, and time-varying covariates measured at both baseline and follow-up such as age, insulin, high-sensitivity C-reactive protein, heart rate, systolic blood pressure, glucose, fat mass, lean mass, smoking status, family history of hypertension/diabetes/high cholesterol/vascular disease, socioeconomic status, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, light physical activity, and moderate to vigorous physical activity,

Results
Among 766 children (mean [SD] age, 11.75 [0.24] years; 422 [55.0%] females]) males spent on average 360, 467, and 527 minutes/day sedentary at ages 11, 15, and 24 years, respectively. Females spent 364, 481, and 535 minutes/day sedentary at ages 11, 15, and 24 years respectively. LVMI2.7 was significantly higher among males than females with an average difference of ∼4g/m2.7 both at ages 17 and 24 years but no significant sex differences in RWT. In a fully adjusted model, a 1-minute increase in sedentary time from ages 11 – 24 years was associated with progressively increased changes in LVMI2.7 (effect estimate 0.004g/m2.7 [CI 0.001 – 0.006] p=0.002) from ages 17 – 24 years in the total cohort and females (effect estimate 0.009g/m2.7 [CI 0.005 – 0.012] p&lt;0.0001). There was no statistically significant longitudinal association between cumulative sedentary time and changes in RWT in the total cohort, males, and females.

Conclusion
Cumulative increase in sedentary time during growth from childhood through young adulthood was associated with progressive left ventricular structural remodelling.