The correlation between the vitamin D/insulin ratio and central precocious puberty in girls and its screening potential.

Introduction: There are still no effective biomarkers for the diagnosis of central precocious puberty (CPP), and single metabolic indicators (such as vitamin D or insulin) are susceptible to interference from metabolic interactions. We conducted a study to assess the correlation between the vitamin D/insulin ratio (VDIR) and CPP and the screening potential of the VDIR.

Methods: Case-control study in a sample of 170 girls aged 6-10 years, including 85 girls with CPP and 85 girls with normal growth and development. We collected data on growth and developmental indicators and laboratory test results for both groups. The association between the VDIR and CPP/gonadal development was assessed by means of multivariate logistic and linear regression analyses. The diagnostic value of VDIR was evaluated by means of receiver operating characteristic (ROC) curve analysis.

Results: The VDIR in the CPP group was lower than in the control group (3.45 vs 6.18). The area under the ROC curve (AUC) of the VDIR for diagnosis of CPP was 0.731, with a sensitivity of 70.59% and a specificity of 67.06%, higher compared to vitamin D alone (AUC = 0.682) or insulin alone (AUC = 0.690). The multivariate logistic/linear regression analysis revealed that for every 1-unit increase in VDIR, there was a 0.814-fold decrease in the risk of CPP and a 233.54 mm³ decrease in uterine volume.

Conclusion: By integrating the metabolic interactions between vitamin D and insulin, VDIR shows promising value in assessing the risk of CPP. As a potential biomarker, it may offer dual clinical value by enabling early screening of high-risk individuals prior to the definitive diagnosis, as well as providing guidance for personalized interventions.