The Relationship Between Vitamin D Deficiency And The Main Characteristics Of Copd Patients

Introduction: The effects of vitamin D are not limited to the maintenance of calcium and bone homeostasis. Vitamin D deficiency is also known to contribute to the risk of many inflammatory diseases. Aim: to analyze the relationship between serum vitamin D level and the main characteristics of COPD patients. Materials and Methods: This cross-sectional study included 75 patients with stable COPD (63 males/12 females, mean age 67,4 ± 8,7 years). The respiratory muscle strength (maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)) were measured by body plethysmograph MasterScreen Body. The level of 25 (OH) D was assessed by chemiluminescent immunoassay on microparticles according to international standards. Results: Low levels of serum vitamin D (median 13,2 (12;18,7) ng/ml) were found in 72 COPD patients (96%): insufficient vitamin D level(≥20≤30 ng/ml) was defined in 10 patients (13,3%), vitamin D deficiency (≥10-20 ng/ml) – in 68 patients (51%) and pronounced vitamin D deficiency (˂10 ng/ml) - in 11 patients (14,7%). Although vitamin D deficiency was found in all COPD patient9s groups, the lowest levels were observed in the group D (p˂0,05). Serum vitamin D levels correlated significantly with smoking index (r=-0,34), disease duration (r=-0,42), MIP (r=0,48) and MEP (r=0,40), FEV1 (r=0,32). Patients with pronounced vitamin D deficiency have respiratory muscle dysfunction more often than patients with higher serum 25(OH)D concentration (OR = 1,6 (95% CI 1,3-1,9, p=0,01). Conclusions: Vitamin D deficiency is often observed in COPD patients and it associated with the severe airflow limitation, severity and duration of the disease, respiratory muscle strength, and smoking index.