Associations between maternal visceral fat in mid-pregnancy and subsequent gestational diabetes mellitus in a Chinese population: a cohort study

Abstract

Background: Maternal obesity is an established risk factor for gestational diabetes mellitus (GDM). This study aimed to investigate the association between ultrasound-measured visceral adipose tissue and GDM risk in lean Chinese pregnant women.

Methods: A prospective cohort study of pregnant women aged 18-45 years with a singleton pregnancy was conducted in Shenzhen Nanshan Maternity and Child Healthcare Hospital, China, between May 2022 and October 2022. Ultrasound measurements of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) depth were performed at 21-23 weeks' gestation. GDM diagnosis was performed using 75 g oral glucose tolerance test (OGTT) at 24-28 weeks' gestation. After adjustment for maternal age, parity, family history of diabetes, educational level, and pre-pregnancy body mass index (BMI), log-binomial model was used to analyze the associations of ultrasound measurements of VAT and SAT with GDM. A receiver-operating characteristic (ROC) curve analysis was conducted to assess the predictive value of VAT and SAT for new-onset GDM.

Results: Among 550 women included, 141 subjects (25.6%) developed GDM. The mean maternal age (32.9 ± 4.8 vs. 30.7 ± 4.2 year, P < 0.001) and the mean pre-pregnancy BMI (22.05 ± 2.95 vs. 20.76 ± 2.46 kg/m², P < 0.001) were significantly higher in women who developed GDM than those who did not. Ultrasound measurements of VAT depth, but not SAT depth, were significantly associated with increased risk for GDM, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) after adjustment for potential confounders. Compared with the bottom tertile, the risk ratio (RR) and 95% confidence interval (95% CI) in the highest tertile of ultrasound measurements of VAT depth for GDM, IFG and IGT were 2.04 (1.24-3.37), 10.86 (1.37-85.80) and 2.03 (1.22-3.39), respectively. The receiver-operating characteristic (ROC) curve analysis for diagnosis of GDM showed a higher area under the curve (AUC) for VAT than SAT or pre-pregnancy BMI. In stratified analysis, the association of VAT depth with fasting glucose was more profound in women with normal weight before pregnancy than those with overweight or obesity (P - interaction = 0.009).

Conclusions: Ultrasound-measured abdominal VAT during mid-pregnancy is a potential clinical tool for improving sensitivity of early risk stratification for GDM in non-obese pregnant women.

Keywords: Chinese pregnant women; Gestational diabetes; Maternal visceral obesity; Ultrasound.

Fig. 1

Flowchart of inclusions and exclusions in the present cohort

Fig. 2

Ultrasound measurement of subcutaneous adipose tissue (SAT) depth, which was defined as the distance from the skin line to the anterior edge of the linea alba, 1 cm above the umbilicus, on the mid-sagittal plane. The SAT in the above-mentioned figure was 7.9 mm

Fig. 3

Ultrasound measurement of preperitoneal adipose tissue (a representative of visceral adiposse tissue, VAT) depth, which was defined as the distance from the posterior edge of the linea alba to the anterior surface of the left lobe of the liver, approximately 1.5 cm under the xipho, on the mid-sagittal plane. The VAT in the above-mentioned figure was 9.8 mm

Fig. 4

Receiver operating characteristic curve for visceral adipose tissue (VAT) depth, subcutaneous adipose tissue (SAT) depth, and pre-pregnancy body mass index (BMI), and their respective associations with developing gestational diabetes mellitus