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

Area of Science:

• Pediatric Endocrinology
• Metabolic Health
• Body Composition Research

Background:

• Differences in insulin sensitivity and secretion exist between racial groups in children.
• Body composition is a key factor influencing metabolic health.
• Understanding these differences is crucial for early identification and intervention.

Purpose of the Study:

• To determine if body composition differences explain disparities in insulin sensitivity and secretion between African American (AA) and Caucasian (C) children.
• To investigate racial differences in insulin dynamics and metabolic parameters in prepubertal children.

Main Methods:

• A hyperglycemic clamp was used to assess insulin sensitivity (SI(clamp)) and secretion in 31 AA and 54 C prepubertal children.
• Dual-energy X-ray absorptiometry (DXA) was employed to measure body composition.
• Analysis included adjustments for body fat and lean mass.

Main Results:

• AA children exhibited greater total body fat mass and higher fasting, first-phase, second-phase, and steady-state insulin levels compared to C children.
• Despite similar glucose disposal rates, AA children had lower insulin sensitivity (SI(clamp)).
• Lower C-peptide/insulin molar ratios in AA children suggest reduced hepatic insulin clearance.

Conclusions:

• Prepubertal AA children demonstrate reduced insulin sensitivity and altered insulin/C-peptide secretion profiles compared to C children.
• These metabolic differences are not fully explained by variations in adiposity.
• Reduced hepatic insulin clearance may contribute to the observed metabolic disparities in AA children.