Impaired ApoB-Lipoprotein and Triglyceride Metabolism in Obese Adolescents With Polycystic Ovary Syndrome.

Abstract

Adolescents with polycystic ovary syndrome (PCOS) have atherogenic dyslipidemia and increased cardiovascular disease (CVD) risk, and this is exacerbated in obesity. To determine and compare fasting and nonfasting lipid and apolipoprotein (Apo)B-lipoprotein metabolism in 3 groups of adolescent girls: healthy-weight controls, obese without PCOS (obese-control), and obese with PCOS (obese-PCOS). Participants aged 12 to 17 years were recruited for this cross-sectional study from a pediatric weight management clinic and the local community in Alberta, Canada. Plasma lipids and ApoB lipoproteins, including triglycerides (TGs) and ApoB100- and ApoB48-lipoproteins, were measured in the fasted and postprandial state following a high-fat meal. Obese-control (n = 12) and obese-PCOS (n = 18) groups had twofold higher concentrations of fasting plasma TG and ApoB100- and ApoB48-lipoprotein remnants compared to healthy-weight controls (n = 10) (ApoB48-lipoproteins: 19.32 ± 2.10, 24.02 ± 4.28, and 8.95 ± 1.05 μg/mL, respectively; P < 0.001). The obese-PCOS group had 50% higher fasting plasma TG level compared to the obese-control group. The postprandial response was higher in both obese-controls and obese-PCOS subjects compared with healthy-weight controls in plasma TG area under the curve (AUC) (1028.0 ± 83.67, 1587.01 ± 259.6, and 615.42 ± 76.42 μg/mL⋅h, respectively; P < 0.01) and ApoB48(AUC) (191.30 ± 19.06, 238.8 ± 37.73, and 96.58 ± 9.17 μg/mL⋅h, respectively; P < 0.0001). Nonfasting plasma TG(AUC) and ApoB48(AUC) were positively correlated with free testosterone (r = 0.38; P < 0.001 and r = 0.33; P < 0.05, respectively), and these relationships were highly associated with insulin and body mass index. Adolescent girls with obesity and PCOS have elevated fasting and postprandial plasma TG and ApoB-lipoprotein remnants, providing evidence of early subclinical CVD risk, and these indices are highly associated with impaired insulin metabolism and hyperandrogenemia.