Early-pregnancy trunk phase angle derived from bioelectrical impedance analysis for the prediction of gestational diabetes mellitus.

OBJECTIVE

To evaluate first-trimester predictors of gestational diabetes mellitus (GDM) and develop an early risk model.

METHODS

Women at 8-12 weeks of gestation who attended routine antenatal care at Hainan General Hospital between October 2023 and December 2024 were enrolled and followed until 24-28 gestational weeks for a 75-g oral glucose tolerance test (OGTT). Participants were classified into a GDM group or a normal glucose tolerance (NGT) group according to standard diagnostic criteria. General clinical characteristics, fasting biochemical parameters, and body-composition variables were collected in early pregnancy; Body composition was measured at 13 weeks using a multi-frequency bioelectrical impedance analyzer (InBody 770). Logistic regression, ROC, bootstrap validation, calibration plots, and decision curve analysis were used.

RESULTS

Of 125 women (68 GDM, 57 NGT), GDM had higher age, pre-pregnancy body mass index (p-BMI), assisted conception, family hyperglycemia, first-trimester weight gain, glucose, insulin, HOMA-IR, TyG, lipids, neutrophils, uric acid, and most body-composition indices (all P<0.05). After adjustment, 25 variables (P<0.01) were grouped into six domains. HOMA-IR, triglycerides (TG), first-trimester gestational weight gain (GWG-F), and 50-kHz trunk phase angle (trunk PhA) were selected as core predictors. The BIC-based model identified HOMA-IR (OR = 3.287), TG (OR = 2.277), GWG-F (OR = 1.150), trunk phase angle (OR = 2.615), and age (OR = 1.180) as independent risk factors. The model showed good discrimination (AUC = 0.921), calibration (Hosmer-Lemeshow P = 0.287), and net benefit.

CONCLUSION

HOMA-IR, TG, GWG-F, trunk PhA, and age are independent early GDM predictors. The combined model (AUC = 0.921) can help identify high-risk women early for timely intervention.