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

Abstract

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 if these relationships vary by sex. Methods This cross-sectional study of obese adolescents (BMI≥95th percentile), ages 12-18y, measured VAT-area by dual energy x-ray absorptiometry (DXA), 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/m2. VAT-area was negatively associated with LDL particle (−P) size (β=−0.28, p=0.0001), HDL-P size (β=−0.33, p<0.0001) and large HDL-P concentration (β=−0.29, p<0.0001), and positively associated with small LDL-P concentration (β=0.23, p=0.0005) and small HDL-P concentration (β=0.25, p=0.05). 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<0.05). Conclusions In a cohort of largely African-American obese adolescents, VAT-area was associated with a more atherogenic lipoprotein subclass profile. When compared to 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 versus females.

Lipoprotein‐subclass particle numbers in children with abdominal obesity

“…Another finding of the present study was the sex differences in LDL-and HDL-subclass PN profiles. In a previous study in obese adolescents, 24 the positive association between VAT and small HDL-PN was shown in males, but not in females, which is compatible with our results. Another study in healthy children demonstrated that insulin sensitivity is a determinant of small HDL-PN in black boys and girls, however, only in white boys.…”

Cardiometabolic risk in obese children

“…Increased ectopic fat deposition (liver and visceral compartments) are strong predictors of glucose intolerance and type 2 diabetes. Many, but not all studies 91,92 , indicate that ectopic fat accumulation in visceral and hepatic compartments is a more significant determinant of cardiometabolic health than overall BMI in adolescents 93,94 and adults 95 with obesity. Visceral and intra-peritoneal adipose depots may increase hepatic insulin resistance through the release of localized inflammatory mediators or as a direct substrate for the release of free fatty acids 90 .…”

Total urinary polyphenols and ideal cardiovascular health metrics in Spanish adolescents enrolled in the SI Program: a cross-sectional study

“…Gender differences have also been described in fatty acid metabolism, with women being more sensitive to the antilipolytic effects of insulin than men, resulting in a greater release of free fatty acids that contribute to the production of TG and TC 39 . This could explain the higher triglyceride levels found in girls, although TC levels did not differ from those of boys.…”