Predictive Factors Of Vitamin D Status In Southern-Mediterranean Patients With Copd

Introduction: Vitamin D deficiency is a common public health issue in many countries worldwide. Patients with COPD represent a very specific population particularly at risk to develop it due to different factors such as aging, reduced outdoors activities, poor diet, and the use of corticosteroids. Aims and Objectives: The study aimed to explore different factors affecting vitamin D serum concentration in patients with COPD. Methods: A cross-sectional study of male individuals with COPD was conducted during February and March 2019. The study was approved by the regional ethics board. Participants gave informed consent and were asked about demographic features, sun exposure, and vitamin D dietary intake. They performed a spirometry. Symptoms were assessed using mMRC and CAT. Blood samples were taken for vitamin D measurement. Vitamin D deficiency was defined as < 12 ng/ml. Results: Forty patients were recruited. Their mean age was 67.5 ± 7.9 years. Mean vitamin D concentration was 17.4 ± 8.6 ng/ml. Deficiency was present in 9 patients (22.5%). Vitamin D levels did not follow Normal distribution, thus the variable was transformed with LN (LND). Mean LND was 2.8 ± 0.4. Dyspnea was associated to LND (p = 0.016). LND was correlated to latitude (p = 0.03, r = -0.34), CAT (p = 0.028, r = -0.35), and FVC (p = 0.04, r = 0.33). Five variables had p<0.05 after multivariate analysis: taking sea/sun baths (OR: 0.28 [0.03 ; 0.54]), latitude (OR: -0.89 [-1.49 ; -0.28]), mMRC (OR: -0.12 [-0.18 ; -0.047]), FEV1 (OR: -0.71 [-1.25 ; -0.18]), and FVC (OR: 0.47 [0.12 ; 0.82]). Conclusion: This study showed that vitamin D deficiency is associated to sun exposure, dyspnea and disease severity in patients with COPD.