Abstract
OBJECTIVE: To evaluate the association between neck circumference (NC) measured during pregnancy and markers of glucose metabolism measured 2-6 months postpartum in women with overweight/obesity with and without gestational diabetes (GDM). SUBJECTS AND METHODS: This prospective study enrolled 100 pregnant women (including 50 with GDM) with pregestational body mass index (BMI) ≥ 25 kg and < 40 kg/m². The cohort was stratified according to NC tertiles during pregnancy. Glucose metabolism was assessed in the postpartum period. The association between NC during pregnancy and markers of glucose metabolism postpartum was tested using linear regression analysis. RESULTS: Participants with NC in the third tertile, compared with those with NC in the second and first tertiles, had higher levels of glycated hemoglobin (HbA1c; 5.6 ± 0.4% versus 5.4 ± 0.3% versus 5.3 ± 0.2%, respectively, p = 0.006), fasting insulin (13.2 ± 6.6 µIU/mL versus 11.1 ± 5.8 µIU/mL versus 9.5 ± 4.9 µIU/mL, respectively, p = 0.035), homeostasis model for insulin resistance (HOMA-IR; 3.1 ± 1.7 versus 2.5 ± 1.3 versus 2.1 ± 1.2, respectively, p = 0.035) and triglyceride-glucose index (TyG; 4.6 ± 0.2 versus 4.5 ± 0.2 versus 4.5 ± 0.3, respectively, p = 0.010). In crude linear regression analysis, NC measured during pregnancy was significantly associated with levels of fasting plasma glucose, 2-hour glucose, HbA1c, log HOMA-IR, and TyG index. The association remained after adjustment for age, family history of diabetes, and number of pregnancies. When adjusted for pregestational BMI and gestational weight gain, NC remained independently associated with fasting plasma glucose and HbA1c levels. CONCLUSION: The NC measured during pregnancy was positively associated with worse glucose metabolic profile in the postpartum among women with obesity/overweight with and without GDM. The NC measurement may be a feasible tool for early identification of women at a higher risk of developing type 2 diabetes mellitus.