Agouti signalling protein and triglyceride-glucose index in early pregnancy with gestational diabetes: a prospective cohort study

OBJECTIVE: Agouti signalling protein (ASIP) is an adipokine regulating appetite and energy balance. This study aimed to investigate the association of first-trimester serum ASIP and triglyceride-glucose (TyG) index with the development of gestational diabetes mellitus (GDM). METHODS: This prospective study enrolled 231 singleton pregnant women (GDM, n = 42; non-GDM, n = 189). Serum ASIP, the TyG index, and routine metabolic parameters were measured during the first (8-12 gestational weeks) and second (24-28 gestational weeks) trimesters. GDM was diagnosed at 24-28 weeks via a standard 75-g oral glucose tolerance test. RESULTS: Both serum ASIP levels and TyG index were significantly elevated in the GDM group compared to the non-GDM group during both trimesters (all P < 0.001). First-trimester ASIP and TyG index correlated positively with second-trimester fasting plasma glucose, 2-hour postprandial glucose, and homeostatic model assessment of insulin resistance, and inversely with quantitative insulin sensitivity check index and Bennett insulin sensitivity index (all P < 0.01). After adjustment, both ASIP and TyG index in the first trimester remained independent risk factors for GDM (ASIP: adjusted odds ratio [a OR] = 1.031, 95% confidence interval [CI] 1.015-1.047, P = 0.019; TyG: a OR = 5.445, 95% CI 1.936-15.319, P < 0.001), with consistent associations across age and body mass index subgroups (interaction P > 0.05). The combination of ASIP and TyG index in the first trimester yielded an AUC of 0.788 for GDM prediction, with a sensitivity of 76.2%, specificity of 68.8%, positive predictive value of 35.2%, and negative predictive value of 92.9%. Its predictive performance improved in the second trimester, achieving an AUC of 0.894, with corresponding values of 92.9%, 72.0%, 42.4%, and 97.9%, respectively. CONCLUSIONS: Elevated first-trimester serum ASIP and TyG index are associated with an increased risk of GDM, and correlate with increased insulin resistance and dysglycaemia during pregnancy.