Association Of Serum Vitamin D Levels With Acute Exacerbation Of COPD And Pulmonary Function Including FEV1/FVC% And FEV1/FVC%

ObjectiveTo compare the difference of vitamin D levels(25(OH)Vit D,25-Hydroxy Vitamin D)between the acute exacerbation stage and the stable stage in chronic obstructive pulmonary diseases(COPD)patients,evaluate the correlation between serum vitamin D levels and pulmonary function including FEV1/FVC% and RV/TLC% in different stages of COPD,explore the relationship between vitamin D levels and length of stay in patients with acute exacerbation of COPD.Vitamin D is expected to be a biomarker to identify the acute exacerbation of COPD,to evaluate the degree of COPD,and to be an adjuvant treatment for COPD.MethodA retrospective analysis about 209 cases was conducted on the visiting patients with COPD in our hospital from January 2016 to October 2019 including121 cases in acute exacerbation group(all with moderate or severe exacerbation)and 88 cases stable period group.According to 2020 GOLD guideline,the all patients which measured 25(OH)Vit D were divided into two subgroups:mild-moderate group(GOLD 1-2)91 cases(including 41 cases with exacerbation and 50 cases with stable COPD)and severe-very severe group(GOLD 3-4)118cases(including 80 cases with exacerbation and 38 cases with stable COPD);To compare the differences of sex,age,smoking index,BMI and serum 25(OH)Vit D levels between exacerbation group and stable period group in general and subgroups;To evaluate the correlation between serum 25(OH)Vit D level and FEV1 / FVC,RV / TLC ratio of pulmonary function in patients with acute exacerbation and stable phase;The correlation between the level of 25(OH)Vit D and length of stay in patients with exacerbation of COPD was also analyzed.SPSS19.0 software was used for statistical analysis.ResultsThere was no difference in the sex,age,smoking index and BMI between exacerbations group and stable COPD group patients,the serum level of 25(OH)Vit D of people in exacerbations group was lower than that in the stable COPD group,and the difference was statistically significant(46.41(36.04-58.86)nmol/L vs 61.95(55.02-72.02)nmol/L;Z =-6.635,P<0.01).The mean serum 25(OH)Vit D level of exacerbation patients in mild-moderate group was53.53±11.15nmol/L which was lower than that in stable COPD(67.81±1.70nmol/L),the difference was statistically significant(t=-4.681,P<0.01);The serum 25(OH)Vit D level of exacerbation patients in severe-very severe group was 41.01(32.15-53.21)nmol/L which was lower than that in stable COPD(57.44(50.69-61.53)nmol/L),the difference was statistically significant(Z =-4.487,P<0.01);The serum 25(OH)Vit D level of exacerbation patients and stable COPD are all positive correlated with FEV1/FVC%(rs=0.453,P<0.01;rs=0.426,P<0.01).Opposite associations were observed for RV/TLC%(rs=-0.270,P<0.01;rs=-0.300,P<0.01).The serum 25(OH)Vit D level of exacerbation patients in severe-very severe group was negative correlated with length of stay in patients(rs=-0.291,P<0.01),but there was no statistically correlation in mild-moderate group(rs=-0.200,P>0.05).Conclusion1.The serum level of 25(OH)Vit D in exacerbations group was significantly lower than that in the stable COPD group,it is the same results after they are further divided into the mild-moderate group and the severe-very severe group according to lung function.The serum level of vitamin D is expected to be a biomarker to identify the exacerbation of COPD.2.The serum 25(OH)Vit D level in patients with COPD was positive correlated with FEV1/FVC%.This suggests that serum vitamin D is related to the degree of COPD.This suggests that serum level of vitamin D is related to the degree of airflow restriction in COPD.3.The serum 25(OH)Vit D level in patients with COPD was negative correlated with RV/TLC%.Whether the serum level of vitamin D can be a new index reflecting the phenotype of emphysema in COPD needs more explorations.4.The serum 25(OH)Vit D level of exacerbation patients in severe-very severe group was negative correlated with length of stay in patients.The clinical effect of vitamin D supplementation in the treatment of acute exacerbation of COPD deserves further study.