目的 探讨湖北地区慢性阻塞性肺疾病(COPD)患者维生素D水平及其维生素D结合蛋白(GC)基因多态性.方法 对250例受检者(116例吸烟COPD患者和134例健康吸烟者)进行问卷调查,收集相关资料(吸烟史、维生素D摄入、并发症等);ELISA法检测受试者血清25-羟基维生素D(25-OHD)水平,通过Taqman探针实时荧光定量PCR对GC基因(rs4588位点和rs7041位点)进行分型;并进行肺功能检测.结果 吸烟COPD者25-OHD水平较健康吸烟者低(36.58 nmol/L比43.80 nmol/L,P<0.001).25-OHD水平吸烟COPD者第1秒用力呼气容积(FEV1)占预计值百分比≥80%者为39.43 nmol/L,FEV1占预计值百分比>50%~80%者为35.32 nmol/L,FEV1占预计值百分比>30%~50%者为32.21 nmol/L,FEV1占预计值百分比<30%者为26.25 nmol/L(P< 0.01).25-OHD水平与肺功能呈正相关(r2 =1.911,P<0.000 1).GC基因rs7041位点的TT型与25-OHD水平和COPD易感性存在关联(P<0.01;OR =2.140,95% CI1.157~3.959,P=0.015).结论 吸烟COPD者易患维生素D缺乏,且COPD气流受限程度与维生素D水平呈负相关.GC基因rs7041位点的TT型与25-OHD水平和COPD易感性密切相关,可能成为COPD易感性筛查的候选突变位点.
Objective To assess the correlation of serum 25-hydroxyvitamin D (25-OHD) levels with vitamin D-binding protein (the group-specific component,GC) gene polymorphism in chronic obstructive pulmonary disease (COPD).Methods In a cross-sectional case-control study,250participants,including 116 COPD patients with smoking history and 134 healthy smokers,were investigated.A questionnaire about smoking history,vitamin D intake and comorbidities was collected.General pulmonary function was done by routine.Serum 25-OHD levels were detected by ELISA.The genetic variants (rs4588and rs7041) were genotyped by real time fluorescence polymerase chain reaction (RT-PCR) with TaqMan probe technology.Results The COPD patients had lower serum vitamin D level than the smoker subjects (36.58 nmol/L vs 43.80 nmol/L,P <0.001).In the COPD patients,vitamin D level was 39.43 nmol/L in those with percentage of predicted forced expiratory volume in 1 second (FEV1 % pred) greater than or equal to 80%.In other groups with FEV1 % pred 50%-80%,30%-50% and lower than 30%,vitamin D levels were 35.32 nmol/L,32.21 nmol/L,26.25 nmol/L respectively (P < 0.01).Moreover,there was a significant relevance of 25-OHD levels with FEV1 % pred in both COPD patients and healthy smokers (r2 =1.911; P <0.000 1).The mean 25-OHD concentration had a negative correlation with Global Initiative for Obstructive Lung Disease (GOLD) stages.Homozygous carriers of vitamin D-binding protein gene rs7041 T allele were independently related to 25-OHD levels and susceptibility of COPD (P < 0.01 ; OR =2.140,95% CI 1.157-3.959,P =0.015 respectively).Conclusions Patients with COPD are at high risk of vitamin D deficiency and the severity of COPD is inversely correlated with vitamin D levels.Furthermore,homozygous carrier of rs7041 T allele influences 25-OHD serum levels and is related to susceptibility of COPD,which may be a potential candidate gene for screening COPD.