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.