899-P: Body Composition and Cardiometabolic Risk in South Asian Adolescents Compared with African American and White Peers

Abstract

Background: South Asian (SA) adults have greater cardiometabolic risk (CMR) at lower BMI compared to White (W) and African American (AA) ancestry groups, thought to be due to increased visceral fat (VFAT). Few studies have examined adolescents for early ancestry differences. Objective: Examine ancestry-related differences in body composition and CMR factors in SA, AA, and W youth. Methods: SA, AA and W youth, 12-21 y, BMI ≥ 80%ile (or ≥23kg/m2 if ≥18y) had pubertal staging (PUB), whole body DXA, and measurement of CMR factors, including fasting metabolic labs. Insulin and glucose were used to calculate HOMA-IR. ANOVA or Kruskal Wallis compared groups, and linear regression adjusted for covariates (age, sex, PUB, BMI-Z) and analyzed interaction by group. Results: Participants (34 SA, 23 AA, 44 W) were similar in sex and PUB, but SA were older [median (IQR) 20.2y (18.9, 21.2)] and AA had higher BMI [37.0 kg/m2 (32.7, 39.8)] compared to SA [28.6 (25.7, 30.6)] and W [27.7 (15.2, 32.5)]. Lipid panel, glucose, BP, and VFAT were similar among groups. Insulin [SA 15.0 µIU/mL (10.2, 25.1); AA 19.3 (15.4, 33.9); W 10.9 (7.1, 16.4), p=0.0005] and HOMA-IR [SA 3.5 (2.2, 5.6); AA 4.2 (3.4, 7.2); W 2.5 (1.5, 3.4), p=0.0005] were higher in SA and AA compared to W. In adjusted models: SA and W had greater increases in VFAT with increasing BMI-Z (SA*BMI-Z p=0.006; W*BMI-Z p<0.0005) and with increasing total body fat (BF) (SA*BF p=0.007; W*BF p<0.0005) compared to AA. SA had higher fasting insulin [β 6.45, p=0.01] and HOMA-IR [β 1.56, p=0.009] compared to W, even after adjusting for BF (p=0.004) or VFAT (p=0.009). Conclusion: SA and W adolescents had greater increases in VFAT with increasing BMI-Z and with increasing BF, compared to AA. For a given BMI-Z, SA youth had higher HOMA-IR than W, even after adjustment for BF or VFAT. Further mechanistic studies are needed to understand the etiology of this higher insulin resistance in SA youth. Disclosure J. A. Manfredo: None. N. S. Anand: None. B. S. Zemel: None. A. Kelly: Consultant; Self; Vertex Pharmaceuticals Incorporated, vTv Therapeutics. S. N. Magge: None.