Association Between Vitamin D Level and Respiratory Symptoms in Patients with Stable Chronic Obstructive Pulmonary Disease

Abstract

Chai Young Lee,1,* Sun Hye Shin,1,* Hye Sook Choi,2 Yunjoo Im,1 Bo-Guen Kim,1 Ju Yeun Song,1 Daegeun Lee,1 Hye Yun Park,1 Jun Hyeok Lim3 1Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; 2Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kyung Hee University Hospital, Seoul, Republic of Korea; 3Division of Pulmonology, Department of Internal Medicine, Inha University Hospital, Inha University School of Medicine, Incheon, Republic of Korea*These authors contributed equally to this workCorrespondence: Hye Yun Park, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea, Tel [phone], Fax [phone], Email [email protected] Jun Hyeok Lim, Division of Pulmonology, Department of Internal Medicine, Inha University Hospital, Inha University School of Medicine, Incheon, Republic of Korea, Tel [phone], Fax [phone], Email [email protected]: Vitamin D insufficiency or deficiency is prevalent in patients with chronic obstructive pulmonary disease (COPD). However, the association between vitamin D levels and respiratory symptoms in patients with stable COPD has not been fully investigated. This study evaluated the association between vitamin D levels and respiratory symptoms in patients with stable COPD.Patients and Methods: Patients with COPD who had their serum 25-hydroxyvitamin D (25-OH vitamin D) level measured within 6 months of spirometry between January 2016 and April 2020 were retrospectively included. Respiratory symptoms were assessed using the modified Medical Research Council (mMRC) scale and COPD assessment test (CAT) score.Results: Of the 329 included patients, 193, 88, and 48 were categorized as having vitamin D deficiency (< 20 ng/mL), insufficiency (20– 29 ng/mL), and sufficiency (≥ 30 ng/mL), respectively. The mean serum 25-OH vitamin D level of each group was 13.45 ng/mL, 24.61 ng/mL, and 38.90 ng/mL, respectively. Patients with vitamin D insufficiency/deficiency showed higher CAT scores than those with vitamin D sufficiency (p = 0.004). In multivariable adjusted models, vitamin D insufficiency/deficiency was significantly associated with a CAT score of 10 or more (adjusted odds ratio [aOR] = 2.41, 95% confidence interval [CI] = 1.20– 4.82, p = 0.013) and mMRC ≥ 2 (aOR = 2.39, 95% CI = 1.08– 5.32, p = 0.032). Among CAT items, the amount of phlegm (p = 0.008), chest tightness (p = 0.030), breathlessness walking upstairs (p < 0.001), home activity limitations (p = 0.002), and lack of energy (p = 0.003) were significantly associated with vitamin D insufficiency/deficiency after adjustment for age, sex, body mass index, smoking history, Charlson comorbidity index, post-bronchodilator forced expiratory volume in 1 second, and season of blood draw.Conclusion: Vitamin D insufficiency/deficiency were associated with worse respiratory symptoms in patients with stable COPD.Keywords: chronic obstructive pulmonary disease, vitamin D, respiratory symptoms, COPD assessment test, modified Medical Research Council

Keywords

• chronic obstructive pulmonary disease
• vitamin d
• respiratory symptoms
• copd assessment test
• modified medical research council