Evaluating Weight Status and Sex as Moderators of the Association of Serum Leptin with Bone Mineral Density in Children and Adolescents
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BACKGROUND/AIMS: Animal studies suggest that leptin may adversely affect bone mineral density (BMD). Clinical studies have yielded conflicting results. We therefore investigated associations between leptin and bone parameters in children. METHODS: 830 healthy children (age = 11.4 ± 3.1 years; 75% female; BMI standard deviation score [BMIz] = 1.5 ± 1.1) had fasting serum leptin measured with ELISA and body composition by dual-energy X-ray absorptiometry. The main effects for leptin and BMIz plus leptin's interactions with sex and BMIz were examined using hierarchical linear regressions for appendicular, pelvis, and lumbar spine BMD as well as bone mineral content (BMC), and bone area (BA). RESULTS: Accounting for demographic, pubertal development, and anthropometric variables, leptin was negatively and independently associated with lumbar spine BMC and BA, pelvis BA, and leg BA (p < 0.05 for all). Sex, but not BMIz, moderated the associations of leptin with bone parameters. In boys, leptin was negatively correlated with leg and arm BMD, BMC at all bone sites, and BA at the subtotal and lumbar spine (p < 0.01 for all). In girls, leptin was positively correlated with leg and arm BMD (p < 0.05 for both). CONCLUSION: Independent of body size, leptin is negatively associated with bone measures; however, these associations are moderated by sex: boys, but not girls, have a negative independent association between leptin and BMD.
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A Randomized Controlled Trial to Prevent Depression and Ameliorate Insulin Resistance in Adolescent Girls at Risk for Type 2 Diabetes.

BACKGROUND: Prospective data suggest depressive symptoms worsen insulin resistance and accelerate type 2 diabetes (T2D) onset. PURPOSE: We sought to determine whether reducing depressive symptoms in overweight/obese adolescents at risk for T2D would increase insulin sensitivity and mitigate T2D risk. METHOD: We conducted a parallel-group, randomized controlled trial comparing a 6-week cognitive-behavioral (CB) depression prevention group with a 6-week health education (HE) control group in 119 overweight/obese adolescent girls with mild-to-moderate depressive symptoms (Center for Epidemiological Studies-Depression Scale [CES-D] ≥16) and T2D family history. Primary outcomes were baseline to post-intervention changes in CES-D and whole body insulin sensitivity index (WBISI), derived from 2-h oral glucose tolerance tests. Outcome changes were compared between groups using ANCOVA, adjusting for respective baseline outcome, puberty, race, facilitator, T2D family history degree, baseline age, adiposity, and adiposity change. Multiple imputation was used for missing data. RESULTS: Depressive symptoms decreased (p < 0.001) in CB and HE from baseline to posttreatment, but did not differ between groups (ΔCESD = -12 vs. -11, 95 % CI difference = -4 to +1, p = 0.31). Insulin sensitivity was stable (p > 0.29) in CB and HE (ΔWBISI = 0.1 vs. 0.2, 95 % CI difference = -0.6 to +0.4, p = 0.63). Among all participants, reductions in depressive symptoms were associated with improvements in insulin sensitivity (p = 0.02). CONCLUSIONS: Girls at risk for T2D displayed reduced depressive symptoms following 6 weeks of CB or HE. Decreases in depressive symptoms related to improvements in insulin sensitivity. Longer-term follow-up is needed to determine whether either program causes sustained decreases in depressive symptoms and improvements in insulin sensitivity. TRIAL REGISTRATION NUMBER: The trial was registered with clinicaltrials.gov (NCT01425905).