Sex differences in the associations of visceral adiposity, homeostatic model assessment of insulin resistance, and body mass index with lipoprotein subclass analysis in obese adolescents.

BACKGROUND

The relationship of lipoprotein particle subclasses to visceral adipose tissue area (VAT-area) in obese children has not been examined previously.

OBJECTIVES

The study aims were to compare the relationships of VAT-area, homeostatic model assessment of insulin resistance (HOMA-IR), and body mass index (BMI) with lipids and lipoprotein subclasses in obese adolescents and to determine whether these relationships vary by sex.

METHODS

This cross-sectional study of obese adolescents (BMI ≥ 95th percentile), aged 12 to 18 years, measured VAT-area by dual-energy X-ray absorptiometry, BMI, fasting lipids, lipoprotein subclasses, and HOMA-IR. Linear regression models evaluated the associations of VAT-area, HOMA-IR, and BMI with lipid cardiometabolic risk factors. Sex-stratified analyses further explored these associations.

RESULTS

Included were 127 adolescents (age = 14.4 ± 1.5 years; 53.5% female; 88.2% African-American), mean BMI = 34.0 ± 5.1 kg/m(2). VAT-area was negatively associated with low-density lipoprotein particle (LDL-P) size (β = -0.28, P = .0001), high-density lipoprotein particle (HDL-P) size (β = -0.33, P < .0001), and large HDL-P concentration (β = -0.29, P < .0001) and positively associated with small LDL-P concentration (β = 0.23, P = .0005) and small HDL-P concentration (β = 0.25, P = .05). When VAT-area, HOMA-IR, and BMI associations were compared, VAT-area had the strongest associations with most of the lipoprotein subclasses. After sex stratification, the associations of VAT-area with HDL cholesterol, LDL-P size, and large LDL-P concentration were significant only for females (all P < .05).

CONCLUSIONS

In a cohort of largely African-American obese adolescents, VAT-area was associated with a more atherogenic lipoprotein subclass profile. When compared with HOMA-IR and BMI, VAT-area had the strongest associations with most lipoprotein subclasses. The relationships between VAT-area and certain lipoprotein subclasses are significantly different in males vs females.