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.
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.
Authors: Robert H Lustig; Michele L Mietus-Snyder; Peter Bacchetti; Ann A Lazar; Pedro A Velasquez-Mieyer; Michael L Christensen Journal: J Pediatr Date: 2006-01 Impact factor: 4.406
Authors: Lorrene D Ritchie; Sushma Sharma; Joanne P Ikeda; Rita A Mitchell; Aarthi Raman; Barbara S Green; Mark L Hudes; Sharon E Fleming Journal: Trials Date: 2010-05-21 Impact factor: 2.279
Authors: Kara L Marlatt; Julia Steinberger; Donald R Dengel; Alan Sinaiko; Antoinette Moran; Lisa S Chow; Lyn M Steffen; Xia Zhou; Aaron S Kelly Journal: J Pediatr Date: 2013-08-20 Impact factor: 4.406