The prevalence of GDM is highest in the South-East Asia Region at 25.0%, while it is 10.4% in the North America and Caribbean Region [16]. GDM is associated with increased risks of preeclampsia, macrosomia, perinatal complications, and mortality. Therefore, in East Asia, it is crucial to highlight the importance of early detection and management. Although older maternal age and specific ethnicities are known high-risk factors for GDM [17], numerous studies have shown that blood lipid levels also play a critical role in the development of GDM [18–20]. Lipid levels rise slightly in early pregnancy and significantly in later stages [21, 22], These changes in lipid metabolism promote maternal fat accumulation in early and mid-pregnancy, allow fat mobilization as an energy source in late pregnancy, and facilitate lipid transport across the placenta [23], If these adaptive changes exceed a certain threshold, GDM can develop.
Recent studies suggest that non-traditional lipid parameters may serve as simple, reliable, and cost-effective indicators for assessing metabolic diseases (MS) [14, 24]. Zhang et al. [14] found that TG/HDL-C, TC/HDL-C, LDL-C/HDL-C, and non-HDL-C were associated with MS (all P < 0.05). The odds ratios were 4.075 (0.891, 1.107), 3.121 (1.844, 5.282), 3.106 (1.734, 5.561), and 2.238 (1.302, 3.848), respectively, suggesting these are effective predictors of MS in polycystic ovary syndrome (PCOS). Similarly, Golabi et al. [25] revealed that non-traditional lipids (TG/HDL-C, TC/HDL-C) are associated with cardiometabolic risk factors in patients with T2D. Consistent with previous studies, our research showed that all the first-trimester parameters, except RC/HDL-C, were effective indicators for predicting GDM. Among the seven indicators, Non-HDL-C had the best predictive performance, with a sensitivity of 56.7% and specificity of 69.2% in predicting GDM. Although the p-value of RC/HDL-C with GDM was 0.05 after full adjustment, showing no significant difference in our study, other studies have shown that the RC/HDL-C ratio is the best lipid parameter for reflecting diabetes risk (HR: 6.75, 95% CI 2.40-18.98) [26].
The mechanisms of non-traditional lipid profiles are unclear and speculative. One hypothesis is that increased insulin resistance reduces lipoprotein lipase activity, preventing the adequate hydrolysis of very low-density lipoprotein, leading to elevated LDL and TG levels [27, 28]. This suggests that comprehensive lipid indices may better predict GDM risk than single indices. Additionally, because Non-HDL-C includes all apolipoprotein-B-containing lipoproteins, this hypothesis explains why Non-HDL-C is the best predictor of GDM among the seven parameters. Further large-scale research is needed to investigate the specific mechanisms involved.
Our investigation revealed a significant positive correlation between most non-traditional lipid parameters and fasting blood glucose levels, but no discernible association with 1-hour and 2-hour blood glucose levels. These results suggest that non-traditional lipids could potentially serve as biomarkers for isolated impaired fasting glucose (hepatic insulin resistance and inadequate insulin secretion), rather than impaired glucose tolerance.
The maternal lipid profile is associated with fetal growth and neonatal birth weight during pregnancy [29–31]. Clinck Isabel et al. [30] reported that for each 1 mmol/L increment in triglycerides, birth weight increased significantly by 81.7 g, indicating a positive correlation between TG levels and neonatal birth weight. Similarly, our study found positive correlations between LDL/HDL-C and TC/HDL-C with neonatal birth weight in the non-GDM group. Notably, in the GDM subgroup, Non-HDL-C showed a negative correlation with neonatal birth weight. This may be attributed to not excluding preterm infants and not adjusting for confounding factors such as gestational weight gain, lifestyle, and dietary control during pregnancy [32, 33].
This study has several limitations that should be considered. First, its retrospective design and restriction to a single center may limit the generalizability of the findings. Second, blood lipid levels were measured only once during early pregnancy, without subsequent monitoring, potentially missing fluctuations in non-traditional lipid parameters throughout gestation. Third, the study lacks data on lifestyle factors, economic status, dietary habits, physical activity, and sleep patterns, which could act as confounders and influence the results. Further research is needed to explore the mechanisms linking non-traditional lipid parameters and GDM, including the roles of adipokines, oxidative stress, inflammation, and insulin resistance.