Correlation between serum 25-hydroxyvitamin D levels and cardiac structure and function in children and adolescents with obesity combined with metabolic syndrome.

Objective: the aim of this study was to investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and echocardiographic indices in children and adolescents with obesity combined with metabolic syndrome (MetS). Methods: we performed a retrospective study of patients hospitalized between January 2018 and December 2022. A total of 180 patients with obesity combined with MetS were enrolled and underwent anthropometric measurements and serum 25(OH)D level detection. Spearman correlation, multiple linear regression, and binary logistic regression analyses were employed to assess the association between serum 25(OH)D levels and echocardiographic indices of cardiac structure and function in this population. Results: Serum 25(OH)D concentrations showed significant inverse correlations with end-diastolic interventricular septal thickness (IVSd; r = -0.285, p < 0.001), left ventricular posterior wall thickness in diastole (LVPWd; r = -0.168, p = 0.024), left ventricular mass (LVM; r = -0.217, p=0.004), and relative wall thickness (RWT; r = -0.247, p = 0.001). No significant correlations were found with left-ventricular end-diastolic diameter (LVEDd), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), or left ventricular mass index (LVMI). After multivariate adjustment (age, sex, BMI, season, blood pressure, lipids, uric acid, glucose), 25(OH)D remained independently and inversely associated with IVSd (β = -0.242, 95% CI: -0.382, -0.101; p = 0.001) and RWT (β = -0.241, 95% CI: -0.392, -0.091; p = 0.002), but not with LVPWd or LVM. Logistic regression identified vitamin D deficiency as an independent predictor of concentric hypertrophy, even after full adjustment. Conclusions: our findings underscore the importance of maintaining sufficient vitamin D levels in pediatric populations with obesity and MetS as a potential strategy to mitigate adverse cardiac remodeling. Vitamin D deficiency may represent a modifiable risk factor for cardiac complications in this high-risk population.