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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) (β=−0.027, p<0.001, R2=0.057) and homeostasis model assessment insulin resistance (HOMA-IR) (β=−0.225, p<0.001, R2=0.016). There were significantly negative associations between lumbar spine aBMD Ht-Z-adjusted Z-score and WC (β=−0.039, p<0.001, R2=0.058) and HOMA-IR (β=−0.251, p<0.001, R2=0.008). Conclusion 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.

Abstract-Mobile ad-hoc network (MANET) is a set of movable hosts established without existing network infrastructure and can be self-organized dynamically. MANET protocols have faced big challenges due to dynamic changing network topology and asymmetric network link. In this paper, we simulate AODV, DSDV, DSR routing protocols in network simulator NS-2 and evaluate and compare the performance metrics for each routing protocol using packet delivery ratio, average end to end delay of packets and normalized routing overhead. We conduct the simulation by varying the sending rate of source node (2 packets/s and 4 packets/s) with different pause time using node movement model and cbr source traffic model.

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 ( β = 0.059, P < .001) and grip ( β = 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.