Association of insulin resistance and β-cell function with macrosomia among pregnant women with gestational diabetes mellitus

Abstract

Objective To investigate the associations of insulin resistance and β-cell function with macrosomia among pregnant women with gestational diabetes mellitus (GDM). Methods Totally 165 women with GDM were enrolled from January 2017 to June 2017 in the Nutrition Clinic of Beijing Obstetrics and Gynecology Hospitals of Capital Medical University, and they were followed-up until delivery. These GDM women were divided into macrosomia group (birth weight≥4 000 g) and control group (birth weight 2 500-3 999 g) according to their infants′ birth weight. Homeostasis model assessment of insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were estimated. Multivariable logistic regression was conducted to analyze the risk factors of macrosomia. Results Compared to control group, macrosomia group had higher gestational weeks and body mass index (BMI) before pregnancy, gestational weight gain, fasting plasma glucose levels during both 24-28 and 28-32 weeks of gestation, and HOMA-IR. Multivariable logistic regression showed that the risk of macrosomia was associated with BMI before pregnancy (OR=1.41, 95%CI 1.14-1.75, P<0.01), gestational weight gain (OR=1.50, 95%CI 1.26-1.79, P<0.01) and fasting blood glucose during the 28-32 week period of gestation (OR=6.56, 95%CI 1.15-37.27, P<0.05). In addition, BMI before pregnancy was positively correlated to birth weight (r=0.21, P<0.01), HOMA-IR(r=0.46, P<0.01), and HOMA-β(r=0.26, P<0.01). Conclusion Fasting plasma glucose levels during 28-32 weeks of gestation are associated with the risk of giving birth to macrosomia in pregnant women with GDM independent of maternal BMI before pregnancy as well as gestational weight gain. Key words: Gestational diabetes mellitus; Insulin resistance; Islet β-cell function; Macrosomia