Serum FGF-23 and Vitamin D Deficiency as Predictors of Metabolic Syndrome in Chronic Kidney Disease

Background: Chronic kidney disease (CKD) is closely linked to disruptions in mineral metabolism and a high prevalence of metabolic syndrome. This study explored the relationship between serum fibroblast growth factor 23 (FGF-23), vitamin D deficiency, and metabolic syndrome in CKD patients. Methods: A cross-sectional study was conducted from June 2024 to December 2024 at Liaquat University of Medical and Health Sciences, Jamshoro. Using purposive sampling, 200 CKD patients aged 18 years or older were included. Serum FGF-23 and vitamin D levels were measured, and metabolic syndrome was defined using NCEP ATP III criteria. Data was analyzed via SPSS for measures of central tendency and correlation, with p<0.05 considered statistically significant. Results: Among 200 participants, 196 (98%) had metabolic syndrome. Serum FGF-23 levels rose significantly with advancing CKD stages (Stage 1: 120.5 ± 50.6 pg/mL; Stage 5: 680.3 ± 90.4 pg/mL, p<0.01), while vitamin D levels decreased (Stage 1: 25.6 ± 4.2 ng/mL; Stage 5: 10.2 ± 2.3 ng/mL, p<0.01). FGF-23 showed a weak positive correlation with fasting glucose (r=0.16, p=0.03), and vitamin D negatively correlated with blood pressure (r=-0.11, p=0.04). Logistic regression identified elevated FGF-23 (OR=1.05, p<0.01), low vitamin D (OR=0.95, p=0.02), and older age (OR=1.06, p<0.01) as predictors of metabolic syndrome. Conclusion: Metabolic syndrome was prevalent in 98% of CKD patients, primarily driven by elevated FGF-23 and vitamin D deficiency. Addressing these factors may help reduce cardiovascular risks and improve CKD outcomes.