Abstract
INTRODUCTION: Since its emergence, COVID-19 has caused a global health crisis with multi-systemic complications, particularly affecting the respiratory and cardiovascular systems. Identifying potential risk factors is important for early detection of disease and may improve patients survival. This study was carried out to evaluate inflammatory, hematological and nutritional indicators to determine the risk of COVID-19 infection. MATERIALS AND METHODS: This case-control study conducted on 234 COVID-19 cases and 160 non-COVID-19 controls from 2021 to 2023 in Maragheh, northwest of Iran. Participants were recurited from referrals to local hospitals and healthcare centers of Maragheh University of Medical Sciences. Laboratory methods were employed to measure serum vitamin D, potassium, CRP, and the hematological indices. Standard statistical analysis were performed in SPSS version 21, and a p-value less than 0.05 was considered statistically significant. RESULTS: No significant difference was observed in gender distribution between the two groups (54% vs. 52% female; p = 0.858). The median serum CRP level was significantly higher in COVID-19 patients (60.5 mg/L, IQR: 40.0–85.0) compared to the non-COVID-19 group (37.5 mg/L, IQR: 20.0–65.0, p < 0.001). Creatinine levels were significantly lower in the COVID-19 group (p = 0.033). Additionally, the median vitamin D level was significantly lower in the COVID-19 group (33.0 ng/mL, IQR: 22.0–45.0; p < 0.001). A significant protective effect of vitamin D, potassium, creatinine, and lymphocyte-to-CRP (Lym/CRP) ratio against COVID-19 was observed, while age, CRP, neutrophil-to-lymphocyte ratio (NLR) showed a positive association with increased risk of COVID-19 risk. CONCLUSION: A practical clinical approach to potentially reduce the risk of COVID-19 could be assessing inflammatory (CRP and NLR) and nutritional biomarkers (vitamin D and potassium). CLINICAL TRIAL NUMBER: Not applicable.