Objective: To investigate the relationship of an insertion/deletion (I/D) polymorphism of the angiotension-converting enzyme (ACE) gene to obstructive sleep apnea syndrome (OSAS).
Method: Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers were flanking the polymorphic region in intron 16 of the ACE gene.
Result: The distribution of the DD, ID, and II ACE genotypes was 16%, 52%, and 32% in the control subjects and 0%, 56%, and 44% in OSAS patients, respectively. The estimated frequencies of the insertion allele and the deletion allele were 58%, 42% in the control subjects and 72%, 28% in OSAS patients, respectively. The differences were statistically significant(P < 0.05). The OSAS patients with I/I genotype had significantly longer apnea time (P < 0.05), lower minimum SaO2(P < 0.05) and more severe AHI (P < 0.05) than did the OSAS patients with I/D genotype.
Conclusion: These results indicate that the II genotype and I allele might be a risk factor for OSAS in Chinese.