Physical Activity, Not Sedentary Time, Predicts Dual-Energy X-ray Absorptiometry–measured Adiposity Age 5 to 19 Years

Abstract

Purpose To examine the associations among physical activity (PA), sedentary time (SED), and TV viewing (TV) with fat mass (FAT) and visceral adipose tissue mass (VAT) from childhood through adolescence (5–19 years). Methods Participants in the Iowa Bone Development Study (n = 230 males and 233 females) were examined at ages 5, 8, 11, 13, 15, 17 & 19 years. Accelerometers measured moderate- or vigorous-intensity PA (MVPA; min/day), light-intensity PA (LPA; min/day), and SED (h/day). Parent-proxy report (5 & 8 years) and child-report (11, 13, 15, 17, & 19 years) measured TV (h/day). DXA scans measured FAT (kg) and VAT (g). Sex-specific growth models were used to create FAT and VAT growth curves for individual participants (level 1), and to test the effect of MVPA, LPA, SED, & TV (level 2) after adjusting for weight, height, linear age, non-linear age, and maturity. Results Growth models indicated that low levels of MVPA were associated with high levels of FAT and VAT for males and high levels of FAT for females. TV was positively associated with FAT and VAT for males and females. LPA was positively associated with FAT in males. SED was not associated with FAT or VAT for males or females (p > 0.05). Conclusion This study supports current PA guidelines focusing on MVPA rather than SED. The contribution of high TV, but not high SED, to high levels of adiposity suggests that TV’s contribution to obesity is not just a function of low energy expenditure.

Physical activity modulates arterial stiffness in children with congenital heart disease: A CHAMPS cohort study

“…5 Therefore, children with CHD are more prone to increased arterial stiffness, but the role of physical activity on arterial stiffness has not been previously investigated. We extend prior reports by demonstrating that physical activity volume may help modulate Low physical activity increases overweight and obesity risk, 19 and these factors adversely contribute to arterial stiffness in children. 20 Sakuragi et al 6 CHD may be more causally attributed to physical activity levels, rather than established anthropometric determinants of arterial stiffness.…”

“…Low physical activity increases overweight and obesity risk, and these factors adversely contribute to arterial stiffness in children . Sakuragi et al found that BMI, waist circumference, and % body fat were all independently and positively associated with arterial stiffness in healthy children, and more so than exercise capacity.…”

Hepatic fat content and bone mineral density in children with overweight/obesity

“…6 In fact, the majority of the studies objectively measuring sedentary time found no relationship with BMC or BMD in pediatric populations, which concurs with our findings. 6,28 It should be noted that the association of hepatic fat content with BMD was independent of physical activity in the current report.…”

“…In addition, experimental evidence supports a complex network between the bone, the liver, and adipose tissue regulating bone remodeling, liver metabolism, and glucose homeostasis through the secretion of pro-/anti-inflammatory cytokines and hormones. 26 On the other hand, physical activity, 27 particularly MVPA, 28,29 has positive effects on bone metabolism and bone accrual in childhood and adolescence. Sedentary behavior, on the contrary, is related to higher risk of cardiovascular disease and mortality, 30 while its influence on bone health is controversial.…”

Identification of and Associations among Low, Middle, and High Body Composition Trajectories from Age 5- to 17-Years

“…Data used in the current prospective cohort analyses were collected as part of the longitudinal Iowa Fluoride (IFS) and Iowa Bone Development Studies (IBDS), Clinical Trial Registration: NCT03547128, which investigated fluoride exposures, dietary intakes, oral health, and bone measures [ 9 , 10 , 11 , 12 , 13 ]. Mothers ( n = 1882) were recruited at the time of their children’s births for participation in the IFS, and IFS participants active at age 5 (approximately 800) were invited to participate in the IBDS.…”