Vitamin D Receptor rs7975232 (ApaI) Variant, Inflammatory Markers, and Patient-Reported Outcomes in Orthopedic Surgery

<b>Background:</b> Genetic variability in the vitamin D receptor (VDR) may influence immune regulation and systemic inflammation, factors potentially relevant for outcomes in orthopedic surgery. This study explored the association of the <i>VDR</i> rs7975232 (<i>ApaI</i>) single nucleotide variation (SNV) with inflammatory biomarkers and health-related quality of life (HRQoL). <b>Methods:</b> The study included 292 orthopedic patients and 90 controls. Genotyping was performed using real-time PCR. Laboratory analyses comprised hematological parameters, C-reactive protein (CRP), and serum 25-hydroxyvitamin D₃ [25(OH)D₃]. HRQoL was assessed with the SF-36 questionnaire. Associations between genotype, inflammation, and HRQoL were examined using regression models adjusted for age and body mass index (BMI). <b>Results:</b> Genotype (<i>p</i> = 0.023) and allele (<i>p</i> = 0.007) distributions differed between patients and controls. In multivariable models, the CC genotype was associated with higher neutrophil counts (<i>p</i> = 0.029), whereas the AA genotype was associated with elevated CRP levels (<i>p</i> = 0.025). Genotypic variation was further associated with SF-36 scores, independently of age and BMI. <b>Conclusions:</b> The <i>VDR</i> rs7975232 SNV may be associated with baseline systemic inflammation and patient-reported quality of life in orthopedic surgery. Genotyping of this variant may complement conventional biomarkers in future research aimed at improving diagnostic precision. Moreover, it could contribute to innovation in laboratory diagnostics aimed at improving perioperative outcomes.