Obesity-Related Metabolic Risk in Sedentary Hispanic Adolescent Girls with Normal BMI

Abstract

Hispanic adolescent girls with normal BMI frequently have high body fat %. Without knowledge of body fat content and distribution, their risk for metabolic complications is unknown. We measured metabolic risk indicators and abdominal fat distribution in post-pubertal Hispanic adolescent girls with Normal BMI (N-BMI: BMI < 85th percentile) and compared these indicators between girls with Normal BMI and High Fat content (N-BMI-HF: body fat &ge; 27%; n = 15) and Normal BMI and Normal Fat content (N-BMI-NF: body fat < 27%; n = 8). Plasma concentrations of glucose, insulin, adiponectin, leptin and Hs-CRP were determined. Insulin resistance was calculated using an oral glucose tolerance test. Body fat % was measured by DXA and subcutaneous, visceral and hepatic fat by MRI/MRS. The N-BMI-HF girls had increased abdominal and hepatic fat content and increased insulin resistance, plasma leptin and Hs-CRP concentrations (p < 0.05) as compared to their N-BMI-NF counterparts. In N-BMI girls, insulin resistance, plasma insulin and leptin correlated with BMI and body fat % (p < 0.05). This research confirms the necessity of the development of BMI and body fat % cut-off criteria per sex, age and racial/ethnic group based on metabolic risk factors to optimize the effectiveness of metabolic risk screening procedures.

Keywords: BMI; Hispanic; abdominal fat; body fat; insulin resistance.

Figure 1

Pearson correlation analysis between BMI (black bar) and body fat % (striped bar), respectively, and metabolic risk indicators. Significant correlation (r) between BMI or body fat % with metabolic risk indicators. * p ≤ 0.05; ** p ≤ 0.01.

Figure 2

Pearson correlation analysis between homeostasis Model Assessment Insulin Resistance (HOMA-IR; black bar) and Whole Body Insulin Sensitivity Index (WBISI; striped bar) with metabolic risk indicators. Significant correlation (r) between HOMA-IR or WBISI with metabolic risk indicators. * p ≤ 0.05 ** p ≤ 0.01.