Angiotensin-converting enzyme gene polymorphism in north Indian population with obstructive sleep apnea

Background

A deletion of 287-bp Alu repeat of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene is associated with hypertension.

Purpose

The aim of this study is to determine the frequency of ACE (I/D) polymorphism in patients with obstructive sleep apnea (OSA).

Methods

Genotyping of ACE (I/D) gene polymorphism and estimation of serum angiotensin-converting enzyme (SACE) activity were done in 813 subjects who underwent polysomnography. Of these, 395 were apneics and 418 were non-apneics.

Results

The frequencies of II genotype (OR = 1.8, 95 % CI 1.26–2.60, p?=?0.001) and I allele (OR = 1.4, 95 % CI 1.13–1.69, p?=?0.001) of ACE gene were found to be significantly increased in patients with OSA as compared to patients without OSA. Frequency of II genotype was significantly decreased (OR = 0.46, 95 % CI 0.28–0.77, p?=?0.003) in OSA patients with hypertension. In contrast, the frequencies of ID (OR?=?1.80, 95 % CI 1.08–2.99, p?=?0.024) and DD genotypes (OR?=?2.15, 95 % CI 1.30–3.57, p?=?0.003) were significantly increased in this group. The activity of SACE was significantly decreased in the apneic group as compared to the non-apneic group (OR?=?0.99, 95 % CI 0.98–1.00, p?=?0.04).

Conclusions

The findings suggest that II genotype confers susceptibility towards development of OSA whereas DD genotype confers susceptibility towards hypertension irrespective of OSA.