Differences in insulin secretion and sensitivity of Caucasian and African American prepubertal children.

OBJECTIVE: To investigate whether differences in body composition of African American children (AA) and Caucasian children (C) explain differences in insulin sensitivity and secretion. STUDY DESIGN: Prepubertal nondiabetic children (31 AA and 54 C) were studied; 84% were overweight. Participants underwent a 2-hour hyperglycemic clamp, to estimate insulin sensitivity (SI(clamp)) and secretion, and dual energy x-ray absorptiometry, to assess body composition. RESULTS: AA had greater total body fat mass (P =.01), fasting, 1st phase, 2nd phase, and steady state insulin levels (P <.05). AA and C had similar glucose disposal rates, but AA had lower SI(clamp) (P <.05). Fasting, 1st phase, and steady state C-peptide were less in C (P <.05), whereas corresponding C-peptide/insulin ratios were higher (all P <.005). Insulin levels and SI(clamp) remained different in AA and C after adjustment for body fat or lean mass differences. Analyses restricted to only overweight AA and C showed similar trends. CONCLUSION: Prepubertal African American children have higher baseline and glucose-stimulated insulin and C-peptide levels, as well as reduced insulin sensitivity that is not entirely explained by differences in adiposity. The lower C-peptide/insulin molar ratio in AA suggests that they probably have lower hepatic insulin clearance than Caucasian children.

Loss of control over eating, adiposity, and psychopathology in overweight children.

OBJECTIVE: To investigate the relationship between loss of control over eating, adiposity, and psychological distress in a nontreatment sample of overweight children. METHOD: Based on self-reports of eating episodes, 112 overweight children, 6-10 years old, were categorized using the Questionnaire of Eating and Weight Patterns-Adolescent Version into those describing episodes of loss of control over eating (LC), and those with no loss of control (NoLC). Groups were compared on measures of adiposity, dieting, and eating behavior, and associated psychological distress. RESULTS: LC children (33.1%) were heavier and had greater amounts of body fat than NoLC children. They also had higher anxiety, more depressive symptoms, and more body dissatisfaction. 5.3% met questionnaire criteria for BED. Episodes of loss of control occurred infrequently, were often contextual, and involved usual meal foods. DISCUSSION: As in adults, overweight children reporting loss of control over eating have greater severity of obesity and more psychological distress than those with no such symptoms. It remains unknown whether children who endorse loss of control over eating before adolescence will be those who develop the greatest difficulties with binge eating or obesity in adulthood.