Effect of Vitamin D Supplementation and/or Physical Training on Cigarette Smoke Induced COPD in Rats

Background: Chronic obstructive pulmonary disease (COPD) is a major health problem with increasing morbidity and mortality. Vitamin D deficiency has been established as exceedingly prevalent in many of chronic lung disease populations and exercise training in COPD patients results in positive effects in dyspnea and exercise tolerance. Aim of Work: The purpose of the present study was to investigate the effect of vitamin D supplementation and/or physical training on pulmonary functions, lung inflammation, antimicrobial production and matrix degradation in a rat model of COPD. Methodology: Forty male Albino rats were used in this study and divided into 5 groups, 8 rats each: Group1: Control group, Group 2: (COPD group): COPD rats maintained untreated for the experimental period, Group 3: (Vit. D+COPD): COPD rats were treated with vitamin D injection 1, 25 (OH) D3 was administered intraperitoneally (i.p.) at dose 0.5μg/kg of body weight (BW), 3 times a week for 8 weeks, Group 4: (COPD+ Exercise): COPD rats performed daily exercise program and group 5: (COPD+Vit D+exercise) COPD rats treated with vitamin D injection (i.p.) at a dose of 0.5μg/kg, 3 times a week for 8 weeks and performed daily exercise program. After 8 weeks of treatment, pulmonary functions were tested and blood samples were withdrawn for measuring vitamin D and Ca2+ levels and the lung tissues were excised to measure interleukin 12 (IL12), tumor necrosis factor alpha (TNF alpha), metalloproteinase-9 (MMP-9) and cathelicidin. Results: Peak expiratory flow (PEF), forced vital capacity (FVC), vitamin D and Ca2+ were significantly reduced in COPD rats after 12 weeks of exposure to cigarette smoke. Vitamin D supplementation and swimming training for 8 weeks improved PEF, FVC, vitamin D and Ca2+ significantly as compared to untreated COPD. Combined vitamin D treatment and physical training significantly improved FVC level as compared with each treatment separately. The improvement was associated with significant reduction in inflammatory markers and MMP-9 as compared to COPD untreated rats. The antimicrobial cathelicidin was significantly increased in COPD rats and was further increased on vitamin D treatment but not with exercise training. Conclusion: Our results showed that COPD is an inflammatory disease and it is associated with vitamin D deficiency. Vitamin D supplement or rehabilitation by physical training each separately improved the pulmonary functions, reduced inflammation, and attenuate lung parenchymal degradation. Vitamin D in addition induced an antimicrobial protection, however vitamin D supplement had a slightly better effects as compared with exercise training. Combination of both vitamin D supplementation and exercise training had a synergistic effect and produced a significant improvement as compared to each therapy separately. We can conclude that vitamin D supplement has a beneficial effects as a therapy in cases of COPD and it is better added to rehabilitation training programs for better results.