Non-HDL/HDL cholesterol ratio (NHHR) as a novel predictor of gestational diabetes mellitus: a NHANES-based cross-sectional study.

Purpose: To investigate the association between the non-HDL/HDL cholesterol ratio (NHHR) and gestational diabetes mellitus (GDM) risk, and assess NHHR's predictive utility as a novel biomarker in U.S. pregnant women.

Patients and methods: A cross-sectional analysis of 1590 pregnant women from NHANES (1999-2018) was conducted. GDM was defined as fasting glucose ≥5.1 mmol/L. NHHR was calculated as (total cholesterol - HDL-C)/HDL-C. Multivariable logistic regression, restricted cubic spline (RCS) models, and ROC analysis were used to evaluate associations, threshold effects, and diagnostic accuracy, incorporating NHANES sampling weights.

Results: The highest NHHR quartile was associated with 4.48-fold higher odds of GDM (95% CI: 2.72-7.39, p < 0.001) after full adjustment. A nonlinear dose-response relationship with a threshold at NHHR = 2.267 was identified; above this threshold, GDM odds rose sharply (OR = 2.6, 95% CI: 2.0-3.3). Subgroup analyses confirmed consistency across age, ethnicity, and BMI (p for interaction > 0.05). NHHR demonstrated limited standalone diagnostic accuracy (AUC = 0.549, 95% CI: 0.510-0.587).

Conclusion: While NHHR demonstrates limited standalone diagnostic accuracy (AUC = 0.549), its specificity for metabolic dysregulation suggests potential as a complementary biomarker in multi-parameter models.