Evaluating Weight Status and Sex as Moderators of the Association of Serum Leptin with Bone Mineral Density in Children and Adolescents
.

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.
.

Cortisol response to an induction of negative affect among adolescents with and without loss of control eating.

BACKGROUND: Adults with binge eating disorder may have an exaggerated or blunted cortisol response to stress. Yet, limited data exist among youth who report loss of control (LOC) eating, a developmental precursor to binge eating disorder. METHODS: We studied cortisol reactivity among 178 healthy adolescents with and without LOC eating. Following a buffet lunch meal adolescents were randomly assigned to watch a neutral or sad film clip. After, they were offered snacks from a multi-item array to assess eating in the absence of hunger. Salivary cortisol was collected at -80, 0, 30 and 50 min relative to film administration, and state mood ratings were reported before and after the film. RESULTS: Adolescents with LOC had greater increases in negative affect during the experimental paradigm in both conditions (ps > 0.05). Depressive symptoms, but not LOC, related to a greater cortisol response in the sad film condition (ps > 0.05). Depressive symptoms and state LOC were related to different aspects of eating behaviour, independent of film condition or cortisol response (ps > 0.05). CONCLUSIONS: A film clip that induced depressed state affect increased salivary cortisol only in adolescents with more elevated depressive symptoms. Adolescents with and without LOC were differentiated by greater increases in state depressed affect during laboratory test meals but had no difference in cortisol reactivity. Future studies are required to determine if adolescents with LOC manifest alterations in stress reactivity to alternative stress-inducing situations.

A preliminary examination of Loss of Control Eating Disorder (LOC-ED) in middle childhood.

Loss of Control Eating Disorder (LOC-ED) has been proposed as a diagnostic category for children 6-12years with binge-type eating. However, characteristics of youth with LOC-ED have not been examined. We tested the hypothesis that the proposed criteria for LOC-ED would identify children with greater adiposity, more disordered eating attitudes, and greater mood disturbance than those without LOC-ED. Participants were 251 youth (10.29years±1.54, 53.8% female, 57.8% White, 35.5% Black, 2.0% Asian, 4.8% Hispanic, 53.0% overweight). Youth were interviewed regarding eating attitudes and behaviors, completed questionnaires to assess general psychopathology, and underwent measurements of body fat mass. Using previously proposed criteria for LOC-ED, children were classified as LOC-ED (n=19), LOC in the absence of the full disorder (subLOC, n=33), and youth not reporting LOC (noLOC, n=199). LOC-ED youth had higher BMIz (p=0.001) and adiposity (p=0.003) and reported greater disordered eating concerns (p<0.001) compared to noLOC youth. Compared to subLOC youth, LOC-ED youth had non-significantly higher BMIz (p=0.11), and significantly higher adiposity (p=0.04) and disordered eating attitudes (p=0.02). SubLOC youth had greater disordered eating concerns (p<0.001) and BMIz (p=0.03) but did not differ in adiposity (p=0.33) compared to noLOC youth. These preliminary data suggest that LOC-ED youth are elevated on disordered eating cognitions and anthropometric measures compared to youth without LOC-ED. Longitudinal studies are needed to determine if those with LOC-ED are at particularly increased risk for progression of disordered eating and excess weight gain.

Metabolic characteristics of youth with loss of control eating.

PURPOSE: Preliminary data in adults suggest that binge eating is associated with greater prevalence of metabolic syndrome (MetS) components. However, there are limited data in youth, and little is known of the role of binge episode size in these relationships. METHODS: We examined the relationship between loss of control eating and metabolic characteristics in a convenience sample of 329 treatment-seeking and non-treatment-seeking adolescent boys and girls. The sample was enriched by design with adolescents who were overweight or obese and with individuals who reported episodes of loss of control over their eating (either objectively large binge episodes, OBEs or subjectively large binge episodes, SBEs, in the past month), as assessed by clinical interview. MetS components (blood pressure, lipids, glucose, and waist circumference) were the primary variables of interest. RESULTS: 46% of the cohort reported loss of control eating; among those, 53% reported SBEs only and 47% reported OBEs. Youth with loss of control eating had higher systolic blood pressure (p=.001) and higher low-density lipoprotein cholesterol (LDL-c) (p=.002) compared to those without loss of control eating, in analyses adjusted for intervention-seeking status, fat mass and sociodemographic characteristics. Youth reporting OBEs had higher LDL-c (p=.013) compared to those reporting only SBEs. CONCLUSIONS: Adolescents reporting loss of control episodes had greater dysfunction in some components of the MetS compared to youth without loss of control; episode size may contribute to metabolic dysfunction.