👤 Keith Godfrey

Current evidence is unclear due to methodological limitations. We bridge critical knowledge gaps by quantifying the longitudinal changes in movement behaviours and their correlates from early childhood through adolescence. Longitudinal observational cohort study. General healthy child and adolescent sample in Singapore. Growing Up in Singapore Towards healthy Outcomes study participants. We used wrist-worn accelerometry and proxy-reported data to examine movement behaviours (sleep, inactivity, light physical activity (PA; LPA) and moderate-to-vigorous PA (MVPA) and screen-viewing) at ages 5.5, 8, 10 and 12 years and the sociodemographic and maternal lifestyle-related correlates using linear regression models with generalised estimating equations. Among 837 children, sleep, LPA and MVPA declined by 3% (from 9.1 to 8.8 hours/day), 24% (from 5.8 to 4.4 hours/day) and 44% (from 71.3 to 40.1 min/day), respectively, while inactivity and screen viewing increased by 26% (from 8.0 to 10.1 hours/day) and 155% (from 1.8 to 4.6 hours/day), respectively, from ages 5.5 to 12 years. The greatest annual increase in inactivity (0.6 hour/annum) and screen-viewing (0.8 hour/annum) and decrease in LPA (0.3 hour/annum) and MVPA (10.4 min/annum) occurred from ages 8 to 10 years. Girls of Malay ethnicity and lower socioeconomic status, and whose mothers had less favourable movement behaviours, had significantly less sleep, higher inactivity and screen-viewing and/or lower PA. Maternal PA levels and/or sitting time were associated with children's sleep, inactivity and MVPA up to age 8 years, while maternal sitting and screen-viewing behaviours were associated with children's screen-viewing at all ages. Using contemporaneous datasets relevant to the present day, we confirmed that children become less physically active and have longer screen-viewing as they transition into adolescence and highlighted characteristics to be prioritised in future interventions. Show less

Movement behaviours, including moderate-to-vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), sedentary behaviour (SB), and sleep, influence childhood adiposity. However, their collective impact on adiposity from a sex-specific perspective remains underexplored. Our research examined the sex-specific longitudinal associations of 24-h movement behaviours with body mass index (BMI) and abdominal adiposity among children. In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study, we repeatedly measured 24-h movement behaviours using wrist-worn accelerometers (ActiGraph GT3x) and assessed adiposity (BMI, abdominal circumference, and MRI-based abdominal fat volumes) at three time points (ages 5.5-6, 7.5-8, and 10-10.5 years) within the same children in a longitudinal design. Compositional multivariable linear mixed-effect modelling and isotemporal substitution were used to estimate the associations. 531 children (49.5% girls) were included in the analysis. Significant interactions between movement behaviours and sex were observed across all outcomes. In girls, higher MVPA relative to other behaviours was linked to lower BMI [-0.8 (-1.5, -0.1) kg/m²] and total abdominal adiposity [-225.5 (-451.6, -2.5) mL], while in boys, longer sleep duration was associated with lower BMI [-1.6 (-3.2, -0.1) kg/m²] and total abdominal adiposity [-624.2 (-1225.6, -31.3) mL]. The isotemporal substitution model showed that replacing 30 min of LPA/SB with MVPA reduced BMI and abdominal circumference by 1-2% and MRI-measured abdominal adiposity by 6-9% in both sexes. However, replacing LPA/SB with sleep reduced BMI and abdominal circumference by 1% and MRI-measured adiposity by 3-6% only in boys, with no changes in girls. These associations were pronounced on visceral adiposity. This study highlights sex-specific associations of movement behaviours with adiposity in school-aged children, with stronger associations observed in MRI-derived measures compared to conventional adiposity indices. Replacing LPA/SB with MVPA reduced BMI and abdominal adiposity in both sexes, with particularly pronounced effects on visceral adiposity. However, sleep replacement benefits were observed only in boys, suggesting the need for gender-sensitive approaches in lifestyle interventions. Show less

In randomized trials, supplementation of n-3 (ω-3) long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy has resulted in increased size at birth, which is attributable to longer gestation. We examined this finding by using a Mendelian randomization approach utilizing fatty acid desaturase (FADS) gene variants affecting LC-PUFA metabolism. As part of a tri-ethnic mother-offspring cohort in Singapore, 35 genetic variants in FADS1, FADS2, and FADS3 were genotyped in 898 mothers and 1103 offspring. Maternal plasma n-3 and n-6 PUFA concentrations at 26-28 wk of gestation were measured. Gestation duration was derived from an ultrasound dating scan in early pregnancy and from birth date. Birth length and weight were measured. Eight FADS variants were selected through a tagging-SNP approach and examined in association with PUFA concentrations, gestation duration among spontaneous labors, and birth size with the use of ethnicity-adjusted linear regressions and survival models that accounted for the competing risks of induced labor and prelabor cesarean delivery. Maternal FADS1 variant rs174546, tagging for 8 other variants located on FADS1 and FADS2, was strongly related to plasma n-6 but not n-3 LC-PUFA concentrations. Offspring and maternal FADS3 variants were associated with gestation duration among women who had spontaneous labor: each copy of rs174450 minor allele C was associated with a shorter gestation by 2.2 d (95% CI: 0.9, 3.4 d) and 1.9 d (0.7, 3.0 d) for maternal and offspring variants, respectively. In survival models, rs174450 minor allele homozygotes had reduced time to delivery after spontaneous labor compared with major allele homozygotes [HR (95% CI): 1.51 (1.18, 1.95) and 1.51 (1.20, 1.89) for mothers and offspring, respectively]. With the use of a Mendelian randomization approach, we observed associations between FADS variants and gestation duration. This suggests a potential role of LC-PUFAs in gestation duration. This trial was registered at http://www.clinicaltrials.gov as NCT01174875. Show less