Association Of The SFTPA Gene Polymorphism With Severe Obstructive Sleep Apnea

Objective: The present study aimed to investigate the association of the pulmonary surfactant-associated protein A(SFTPA)gene polymorphism with severe obstructive sleep apnea(OSA).Method: In this case-control study,clinically suspicious of OSA patients older than 18 years old were consecutively selected from Sleep Monitoring Room of Hypertension Center of People's Hospital of Xinjiang,China from April to December 2016 and divided as severe OSA group(n=164)and control group(n=171)based on the evaluation of full night polysomnography.Serum surfactant protein A(SP-A)was measured by Enzyme-linked immunosorbent assay(ELISA).Kompetitive Allele Specifc PCR was performed for detection of gene polymorphisms of rs1136451,rs1059225,rs1965708 and rs1059046 of SFTPA gene.Result: There were no significant differences in the genotype,allele,dominant and recessive models of rs1136451,rs1059225,rs1965708 and rs1059046 of SFTPA gene between severe and non OSA groups in the total population.Divided by the mean(0.336pg/ml)of serum SP-A,it showed that the proportions of severe OSA was significantly greater in patients with lower serum SP-A group than in patients with higher serum SP-A group(P=0.019).The distribution of recessive model(P=0.028)of rs1059046 showed significant difference between patients with higher and lower serum SP-A levels group,even after adjustment for covariates(OR: 2.120,95% CI: 1.063-4.227,P=0.033).Moreover,the lower serum SP-A level was considered as risk factor for severe OSA after adjustment for covariates(OR: 2.164,95% confidence interval [CI]: 1.217-3.850,P=0.009).For women,the distribution of recessive model of rs1059046 showed significant difference between severe and non OSA groups(P=0.040).The logistic regression analysis showed that the AA genotype of rs1059046(OR: 2.776,95% CI: 1.027-7.504,P=0.044)was a potential risk factor for severe OSA.Furthermore,in patients with larger abdominal circumference(abdominal circumference?105cm),the distribution of dominant model of rs1059225,genotype of rs1965708 and allele model and recessive model of rs1059046 were significantly different between severe OSA and non OSA groups(P=0.041,P=0.024,P=0.046 and P=0.016,respectively).Multiple logistic regression analyses were performed that the GA+AA genotype of rs1059225(OR: 2.073,95% CI: 1.027-4.185,P=0.042),the CC genotype of rs1965708(OR: 2.732,95% CI: 1.295-5.760,P=0.008)and AA genotype of rs1059046(OR: 3.446,95% CI: 1.358-8.745,P=0.009)were remained significant even after adjustment for covariates.Conclusion: AA genotype of rs1059046 may be a potential risk factor of severe OSA via contribution to lower serum SP-A levels.Furthermore,AA genotype of rs1059046 in SFTPA gene may play as potential risk factors in women with severe OSA.GA+AA genotype of rs1059225,CC genotype of rs1965708 and AA genotype of rs1059046 in SFTPA gene may play as risk factors in larger abdominal circumference patients with severe OSA.