1.
Associations between adiposity, hormones, and gains in height, whole-body height-adjusted bone size, and size-adjusted bone mineral content in 8- to 11-year-old children.
Dalskov, S, Ritz, C, Larnkjær, A, Damsgaard, CT, Petersen, RA, Sørensen, LB, Ong, KK, Astrup, A, Michaelsen, KF, Mølgaard, C
Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. 2016;(4):1619-1629
Abstract
UNLABELLED We examined fat-independent associations of hormones with height and whole-body bone size and mineral content in 633 school children. IGF-1 and osteocalcin predict growth in height, while fat, osteocalcin, and in girls also, IGF-1 predict growth in bone size. Leptin and ghrelin are inversely associated with bone size in girls. INTRODUCTION Obesity causes larger bone size and bone mass, but the role of hormones in this up-regulation of bone in obesity is not well elucidated. We examined longitudinal associations between baseline body fat mass (FM), and fat-independent fasting levels of ghrelin, adiponectin, leptin, insulin, insulin-like growth factor-I (IGF-1), osteocalcin, and intact parathyroid hormone, and subsequent changes in height and in whole-body height-adjusted bone area "BAheight" and size-adjusted bone mineral content "BMCsize" in 8- to 11-year-olds. METHODS Analyses were carried out separately for boys (n = 325) and girls (n = 308) including data from baseline, 3 and 6 months from OPUS School Meal Study. RESULTS In both sexes: gain in BAheight was positively associated with baseline FM (≥2.05 cm(2)/kg, both p ≤ 0.003). Furthermore, gain in height was positively associated with baseline IGF-1 (≥0.02 cm/ng/ml, p = 0.001) and osteocalcin (≥0.13 cm/ng/ml, p ≤ 0.009); and gain in BAheight was positively associated with baseline osteocalcin (≥0.35 cm(2)/ng/ml, p ≤ 0.019). In girls only, gain in BAheight was also positively associated with baseline IGF-1 (0.06 cm(2)/ng/ml, p = 0.017) and inversely associated with both baseline ghrelin (-0.01 cm(2)/pg/ml, p = 0.001) and leptin (-1.21 cm(2)/μg/ml, p = 0.005). In boys, gain in BMCsize was positively associated with osteocalcin (0.18 g/ng/ml, p = 0.030). CONCLUSIONS This large longitudinal study suggests that in 8- to 11-year-old children, IGF-1 and osteocalcin predict growth in height, while FM, osteocalcin, and in girls also, IGF-1 predict growth in BAheight. Fat-independent inverse associations of leptin and ghrelin with BAheight in girls' are contrary to proposed growth-stimulating effects of leptin. Osteocalcin in boys predicts gain in BMCsize.
2.
Sleep duration modifies effects of free ad libitum school meals on adiposity and blood pressure.
Hjorth, MF, Sjödin, A, Dalskov, SM, Damsgaard, CT, Michaelsen, KF, Biltoft-Jensen, A, Andersen, R, Ritz, C, Chaput, JP, Astrup, A
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2016;(1):33-40
Abstract
Insufficient sleep can potentially affect both energy intake and energy expenditure, resulting in obesity and reduced cardiometabolic health. The objective of the study was to investigate if habitual sleep duration of 8- to 11-year-olds modifies the effect of free ad libitum school meals on cardiometabolic markers, body composition, dietary intake, and physical activity. For 2 consecutive 3-month periods, this cluster-randomized, controlled, cross-over trial provided 530 children with school meals or usual lunch brought from home. Dietary intake, activity, and sleep were measured simultaneously for 7 consecutive days using dietary records and accelerometers. Short- and long-sleeping children were defined as lower and upper tertile of sleep duration. Body composition, blood pressure, blood lipids, and homeostatic model assessment of insulin resistance (HOMAIR) were measured/calculated. Overall, school meals compared with lunch from home had positive effects on physical activity and blood pressure in long-sleeping children and negative effects on body fat in short-sleeping children. Short-sleeping children increased fat mass compared with long-sleeping children by 0.21 (95% confidence interval 0.03-0.38) kg, android fat mass by 0.02 (0.001-0.04) kg, waist circumference by 0.73 (0.23-1.24) cm, blood pressure by 1.5 (0.4-2.6) mm Hg, fat intake by 1.1 (0.2-2.0) percentage of energy, and decreased total physical activity by 7.2 (1.6-12.7) % (all P ≤ 0.04), while HOMAIR and blood lipids were not modified by sleep duration (all P ≥ 0.32). In conclusion, the susceptibility to increase abdominal adiposity and blood pressure when exposed to dietary changes can potentially be explained by too little sleep, which results in increased caloric intake and reduced physical activity.
3.
Interactions of dietary protein and adiposity measures in relation to subsequent changes in body weight and waist circumference.
Ankarfeldt, MZ, Angquist, L, Jakobsen, MU, Overvad, K, Tjønneland, A, Halkjaer, J, Astrup, A, Sørensen, TI
Obesity (Silver Spring, Md.). 2014;(9):2097-103
Abstract
OBJECTIVE To investigate if dietary protein and degree of adiposity interacts in relation to change in body weight and waist circumference (WC) in the general population. METHODS In total 22,433 middle-aged individuals with dietary assessment at baseline and anthropometry at baseline and at follow-up about 5 years later were analyzed with multiple linear regression and dietary macronutrient substitution models. Interactions between dietary protein and baseline body mass index (BMI) and baseline WC adjusted for BMI (WCBMI ) (divided in tertiles; nine groups total), were analyzed in relation to changes in body weight (BW) and changes WC adjusted for change in BW. RESULTS Baseline intake of protein was not significantly associated with changes in weight or waist circumference. Across the nine groups of baseline BMI and WCBMI there were no distinct trends in the associations between dietary protein, whether replacing carbohydrate or fat, and weight change. However, individuals in the highest tertile of baseline BMI (irrespective of baseline WCBMI ) had significantly inverse change in waist circumference when protein replaced carbohydrate, but not when protein replaced fat. CONCLUSION Replacing carbohydrate with protein in the diet may prevent a relative increase in WC in individuals with a greater BMI.