Gestational Insulin Resistance and Lipid Metabolism in Pregnant Women With Polycystic Ovary Syndrome

Abstract

Objective To study insulin resistance and lipid metabolism in pregnant women with polycystic ovary syndrome (PCOS). Methods One hundred and two women with PCOS diagnosed pregnant from September 2007 to February 2009 in the Second Affiliated Hospital, Sun Yat-sen University were divided into early pregnancy group (n=50, 8th-13th pregnant week), second trimester pregnancy group (n=38, 24th-28th pregnant week), and third trimester group (n=14, 32nd-36th pregnant week). One hundred and fourteen pregnant women without PCOS were selected as control group; 48 in early pregnancy group, 50 in second trimester and 16 in third trimester respectively. People was excluded with PCOS, diabetes mellitus and serious medical disease and so on. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of the Second Affiliated Hospital of SUN Yat-sen university. Informed consent was obtained from each patient. All groups were examined with fasting plasma glucose(FPG), fasting insulin(FINS) and lipid level including cholesterol (CHOL), triglyceride (TG), high density lipo-protein cholesterol (HDL) and low density lipoprotein cholesterol (LDL). Oral glucose tolerance test (75 g dextrose) was also performed to examine plasma glucose and insulin level on 1 h/2 h/3 h. HOMA-IR, HOMA-β and ISI were calculated. All subjects were followed up and pregnancy outcome were recorded. Results ①As gestational age of patients with PCOS developed, 2 h glucose of the second trimester increased than that of the first trimester (7.99±2.00 vs. 7.10 ± 1.92). About insulin level, plasma fasting insulin, indexes of HOMA-IR, HOMA-β increased, while ISI decreased (7.81±4.65 vs. 5.71±2.76; 1.65±1.08 vs. 1.17±0.63; 169.47±119.40 vs. 124.64±66.99; 0.04±0.03 vs. 0.05±0.02). And the levels of CHOL, TG, HDL in the second trimester group and third trimester group were higher than those in the first trimester group (5.85±1.27 vs. 4.67±1.14; 3.21±1.40 vs. 1.75±1.05; 1.82±0.27 vs.1.52±0.34 and 6.02±1.74 vs. 4.67±1.14; 4.10±2.00 vs. 1.75±1.05; 1.75±0.32 vs. 1.52±0.34). All of the differences above were significant(P<0.05). ②As to the level of glucose, plasma glucose on 1 h and 2 h after dextrose intake and AUCglu were higher in patients with PCOS during the first trimester than those in control group(8.45±2.61 vs. 7.47±1.35; 7.10±1.92 vs. 6.18±1.00; 20.48±2.70 vs. 18.12±1.31)(P<0.05); during the second trimester, plasma glucose on 1 h and 2 h after dextrose intake, AUCglu in PCOS group were higher than those in control group(9.27±1.95 vs. 7.57±1.64; 7.99±2.00 vs. 6.75±1.33; 22.43±2.47 vs. 16.60±1.81)(P<0.05). Besides, in the first trimester, plasma insulin levels including fasting stage, 2 h after dextrose intake and AUCins, HOMA-IR, HOMA-β of patients in PCOS group were higher than those in the control group, while the level of ISI were lower than that of control group(5.71±2.76 vs. 4.51 ± 1.79; 86.67 ± 62.54 vs. 61.59 ± 28.90; 190.67 ± 60.47 vs. 146.61 ± 28.17; 1.17±0.63 vs. 0.91±0.40; 124.64±66.99 vs. 93.21±66.12; 0.05±0.02 vs. 0.06±0.02)(P<0.05). In the second trimester, insulin level on 1 h and 2 h after dextrose intake and AUCins were higher than those in the control group (93.33 ± 48.56 vs. 66.09 ± 39.87; 98.59±57.99 vs. 57.96 ± 34.17; 222.21 ± 63.74 vs. 144.09 ± 44.53)(P<0.05). In the third trimester, fasting insulin level of PCOS group was higher than that in the control group(9.05±4.11 vs. 6.20±2.98; P<0.05). As to lipid metabolism, in patients with PCOS during the first trimester, plasma TG and LDL were higher than those in control group( 1.75±1.05 vs. 1.14±0.57; 2.84±0.95 vs. 2.37±0.54)(P<0.05). During the second trimester, plasma TG was higher while HDL was lower in patients with PCOS than control subjects(3.21±1.40 vs. 2.25±0.70; 2.84±0.95 vs. 2.37±0.54)(P<0.05). Conclusion As early as the first trimester of pregnancy, patients with PCOS developed insulin resistance. Insulin resistance aggravated while insulin sensitivity decreased as the gestational weeks increased, which was significant during the second trimester. Overall fasting plasma lipid level was elevated during pregnancy of patients with PCOS, which was more obvious for TG than other sorts of lipid. Key words: polycystic ovary syndrome (PCOS); insulin resistance; pancreatic βcell function; lipid level