Dietary Zinc Intakes Are Associated With Skeletal Muscle Mass and Strength in Children and Adolescents: Zinc and Muscle in Children.

The purpose of this study was to evaluate the relationship between dietary zinc intakes and skeletal muscle mass and strength in children and adolescents. A retrospective study was conducted using data on United States adolescents aged 8 to 19 years. Data were extracted from the National Health and Nutrition Examination Survey 2011-2014 cycles. Subjects were divided into 3 groups based on the tertiles of dietary zinc intakes. The levels of appendicular skeletal muscle mass divided by weight (ASM/Wt, %) and grip in subjects with the highest tertile were higher than those in subjects with the middle and lowest tertiles (P < .05). Dietary zinc intakes were positively correlated with ASM/Wt (r = .221, P < .001) and grip (r = 0.169, P < .001). After a multivariate analysis, dietary zinc intakes were still significantly associated with ASM/Wt (ß = 0.059, P < .001) and grip (ß = 0.245, P < .001). The present study demonstrates that dietary zinc intakes were positively associated with skeletal muscle mass and strength in children and adolescents.

The relationship between obesity and bone mineral density in children and adolescents: analysis of the National Health and Nutrition Examination Survey.

Childhood and puberty are important period for the skeleton grows. Fat mass, especially visceral adipose tissue, was negatively correlated with areal bone mineral density in children and adolescents. The present study suggests that fat mass, especially visceral adipose tissue, has a slightly negative association with bone development in children and adolescents. PURPOSE: This study observed the relationship between fat mass and distribution, and areal bone mineral density (aBMD) in children and adolescents. METHODS: A retrospective study was conducted on US children and adolescents aged 8-19 years. Whole body (less head) aBMD was evaluated. Height (Ht) adjusted Z-scores for aBMD were calculated. RESULTS: After controlling for age, gender, race, and lean body mass index (LBMI) Z-score, there were significant negative associations between fat mass index (FMI) Z-score and aBMD Ht-Z-adjusted Z-score (ß = - 0.272, P < 0.001, R2 = 0.033). In the linear regression models with aBMD Ht-Z-adjusted Z-score as the dependent variable, the regression coefficients of android fat mass were - 0.241 (P < 0.05, R2 = 0.002), - 0.473 (P < 0.001, R2 = 0.036), and - 0.474 (P < 0.001, R2 = 0.038) for healthy weight, overweight, and obesity group, respectively. The regression coefficients of visceral adipose tissue (VAT) mass were - 0.218 (P > 0.05, R2 = 0.001), - 2.025 (P < 0.001, R2 = 0.044), and - 1.826 (P < 0.001, R2 = 0.039), and the regression coefficients of subcutaneous adipose tissue (SAT) mass were - 0.467 (P < 0.001, R2 = 0.004), - 0.339 (P < 0.01, R2 = 0.024), and - 0.347 (P < 0.001, R2 = 0.018) for healthy weight, overweight, and obesity group, respectively. CONCLUSIONS: The present study suggests that fat mass has a slightly negative association with bone development in children and adolescents. Trunk fat accumulation, especially visceral adipose tissue, was correlated with the lower level of aBMD. This association was obvious in overweight and obese children.

The relationship between metabolic syndrome and bone mineral density in adolescents: analysis of the National Health and Nutrition Examination Survey.

OBJECTIVES: The purpose of this study was to observe the relationship between metabolic syndrome (MetS) and height (Ht) adjusted Z-scores for areal bone mineral density (aBMD) in adolescents. METHODS: A retrospective study was conducted on the United States adolescents aged 12-17 years. Data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2011-2012, 2013-2014 and 2015-2016 cycles. Ht adjusted Z-scores for aBMD were calculated. RESULTS: A total of 969 adolescents (493 boys and 476 girls), aged 14.5 ± 1.7 years were enrolled in this study. After control for age, gender, race, 25-hydroxyvitamin D [25(OH)D], and lean body mass index (LBMI) Z-score, adolescents with MetS had significantly lower levels of total body (less head) aBMD Ht-Z-adjusted Z-score than adolescents with one, two components of MetS and without component of MetS (p<0.05) and significantly lower levels of lumbar spine aBMD Ht-Z-adjusted Z-score than adolescents with one component of MetS and without component of MetS (p<0.05). There were significantly negative associations between total body (less head) aBMD Ht-Z-adjusted Z-score and waist circumference (WC) (ß=-0.027, p<0.001, R2=0.057) and homeostasis model assessment insulin resistance (HOMA-IR) (ß=-0.225, p<0.001, R2=0.016). There were significantly negative associations between lumbar spine aBMD Ht-Z-adjusted Z-score and WC (ß=-0.039, p<0.001, R2=0.058) and HOMA-IR (ß=-0.251, p<0.001, R2=0.008). CONCLUSIONS: The present study demonstrates that MetS may have a negative effect on bone mineral density in adolescents. Abdominal obesity and insulin resistance play a major role on the decline of aBMD in adolescents.