RACIAL DISPARITY IN GLUCAGON-LIKE PEPTIDE 1 (GLP-1) AND INFLAMMATION MARKERS AMONG SEVERELY OBESE ADOLESCENTS

Abstract

Objective: Compared with Caucasians (C), obese African-American (AA) adolescents have higher risk for type 2 diabetes. Subclinical inflammation and reduced GLP-1 concentration are linked to the pathogenesis of the disease. We determined the relationship between insulin resistance, β-cell activity, and sub-clinical inflammation with GLP-1 concentrations, and whether racial disparities in GLP-1 response were present in 49 obese adolescents (14 ± 3 y, 76% AA, 71% female).

Research Design And Methods: Subjects underwent physical examination and an oral glucose tolerance test. We measured levels of high sensitivity CRP (CRP_hs), fibrinogen, glucose, GLP-1_total, GLP-1_active, and insulin. Insulin and glucose area under the curve, insulinogenic index (ΔI30/ΔG30), and composite insulin sensitivity index (CISI) were computed. Subjects were categorized by race and as inflammation-positive (INF+) if CRP_hs or fibrinogen were elevated.

Results: No racial differences were seen in mean or relative BMI. Thirty-five percent of subjects had altered fasting or 2-hour glucose levels (AA vs. C, P = NS), and 75% were INF+ (AA vs C, P = 0.046). Glucose and insulin, CISI, and ΔI30/ΔG30 values were similar; AA had lower GLP-1_totalAUC (P = 0.01), GLP-1_active at 15 min (P = 0.03), GLP-1_activeAUC (P = 0.06), and higher fibrinogen (P = 0.01) and CRP_hs (P = NS) compared with C.

Conclusion: AAs exhibited lower GLP-1 concentrations and increased inflammatory response. Both mechanisms may act synergistically to enhance obese AA predisposition to type 2 diabetes. Our findings might be relevant to effective deployment of emerging GLP-1-based treatments across ethnicities.