Visceral Fatness and Insulin Sensitivity in Women With a Previous History of Gestational Diabetes Mellitus SOO LIM, MD 1 SUNG HEE CHOI, MD 1 YOUNG JOO PARK, MD 1 KYONG SOO PARK, MD, PHD 1 HONG KYU LEE, MD, PHD 1 HAK C. JANG, MD, PHD 1 NAM H. CHO, PHD 2 BOYD E. METZGER, MD 3 OBJECTIVE — The purpose of this study was to investigate the insulin sensitivity and visceral fatness in women with previous gestational diabetes mellitus (GDM), who are prone to develop type 2 diabetes. RESEARCH DESIGN AND METHODS — A 75-g oral glucose tolerance test (OGTT) performed 1 year postpartum identified 21 GAD - women with previous GDM and impaired glucose tolerance (GDM-IGT). Sixty age- and BMI-matched women with normal glucose toler- ance (GDM-NGT) were selected by 1:3 matching to the GDM-IGT group. Another 18 women with normal glucose metabolism during a previous pregnancy and no family history of diabetes were recruited as the normal control group. Age and BMI matching was performed using a range of 1.0 years and 1.0 kg/m 2 , respectively. Total body fat was measured by tetrapolar bioel- ectrical impedance, and visceral fat was determined using a single cut of a computed tomography scan. Insulin sensitivity was determined by the minimal model technique using the frequently sampled intravenous glucose tolerance test. RESULTS — One year postpartum, visceral fat was greater in the GDM-IGT group than in the age- and BMI-matched GDM-NGT or normal control groups. The insulin sensitivity index was lower in the GDM-IGT group than in the GDM-NGT or normal control groups. -Cell function, as measured by the acute insulin response to glucose, was also lower in GDM-IGT. CONCLUSIONS — High body fat content, especially visceral fat content, and a low insulin response to glucose seem to contribute simultaneously to the development of impaired glucose metabolism in Korean women with previous GDM. Diabetes Care 30:348 –353, 2007 G estational diabetes mellitus (GDM) is defined as carbohydrate intoler- ance of variable severity first recog- nized in pregnancy (1). GDM may complicate as many as 5– 8% of all preg- nancies in North America (2). Recent re- ports have shown that the prevalence of GDM has been increasing in multiethnic populations (3,4). Although the reported prevalence of GDM seems to be slightly lower in Asian countries (5,6), adverse outcomes are similar in these two regions. Women with GDM have an increased risk of later development of type 2 diabetes (7). Studies in Western populations have found conversion rates of 3–38% within the 1st year postpartum (8 –10). Al- though a limited number of studies have been performed in Asian countries, the prevalences of impaired glucose metabo- lism in the early postpartum period have been reported to be 20% in Hong Kong and 38.3% in Korea (11,12). Several reports have identified clini- cal factors at antepartum testing or during pregnancy that predict the development of future diabetes in women with GDM. However, few reports have focused on postpartum metabolic characteristics as a risk factor for future diabetes. More than two decades ago, Ward et al. (13) showed that women with previous GDM had in- sulin-secretion defects and that only obese women with GDM had a lower in- sulin sensitivity index (S I ) and higher waist-to-hip ratio than their obese coun- terparts when tested postpartum. Since then, several studies have revealed that women with previous GDM have greater insulin resistance and lower insulin re- sponses than women with no history of GDM (14 –17). Buchanan et al. tested 30 clinical parameters to discriminate between women with previous GDM who have a high and low risk for type 2 diabetes, and they found that the postpartum oral glu- cose tolerance test (OGTT) provides the best discrimination (18). Women who develop diabetes have a lower acute insu- lin response to glucose and lower dispo- sition index than women who remain free of diabetes (19). To our knowledge, few reseachers have investigated both insulin sensitivity and body composition, especially the amount of visceral fat at the postpartum evaluation, as contributors to the devel- opment of impaired glucose metabolism after GDM. Many studies showed that Asians have a higher percentage of body fat compared with Caucasians with the same BMI (20,21). The prevalence of obe- sity is lower in Asian women than in their Western counterparts, but the GDM prev- alence is not lower in Asian women than in Western women (11,22). We have re- ported previously that most women in Korea who develop GDM are not obese before pregnancy according to the usual body weight criteria for obesity (11). In- creased visceral fat deposition plays an ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● From the 1 Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea; the 2 Department of Preventive Medicine, Ajou University Medical School, Suwon, Korea; and the 3 Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Med- icine, Chicago, Illinois. Address correspondence and reprint requests to Hak C. Jang, MD, PhD, Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi- dong Bundang-gu, Seongnam-city, South Korea 463-707. E-mail: janghak@snu.ac.kr. Received for publication 8 July 2006 and accepted in revised form 24 October 2006. Abbreviations: AIRg, acute insulin response to glucose; CT, computed tomography; GDM, gestational diabetes mellitus; IGT, impaired glucose tolerance; NGT, normal glucose tolerance; OGTT, oral glucose tolerance test. A table elsewhere in this issue shows conventional and Syste `me International (SI) units and conversion factors for many substances. DOI: 10.2337/dc06-1405 © 2007 by the American Diabetes Association. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Cardiovascular and Metabolic Risk O R I G I N A L A R T I C L E 348 DIABETES CARE, VOLUME 30, NUMBER 2, FEBRUARY 2007