Objective: To investigate the association of polymorphisms in the angiotensin system gene with obstructive sleep apnea-hypopnea syndrome (OSAHS).
Methods: The genotypes and alleles of angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) genes were identified by polymerase chain reaction-restricted fragment length polymorphism assay in 221 unrelated subjects of the north region "Han" population of China (including 121 OSAHS subjects and 100 non-OSAHS subjects). The genotypes and allele frequencies of the polymorphisms were compared between OSAHS group and non-OSAHS group. The effects of the polymorphisms in OSAHS group on body mass index (BMI), neck circumference (NC), waist/hip rate (WHR), apnea-hypopnea index (AHI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were analysed.
Results: There were significant differences in genotypes distribution in AGT polymorphism between the two groups (P = 0.009). Compared with the control group, OSAHS group had significantly higher T allele frequency in AGT polymorphism (P = 0.020). There were independent effects of AGT polymorphism on BMI, NC, WHR in OSAHS group, and carriers of the T allele of AGT polymorphism had greater BMI, NC, and WHR, while the carriers of the T allele had greater AHI, SBP, and DBP.
Conclusions: ACE polymorphism may not be correlated with central obesity and OSAHS in the population. AGT polymorphism may be involved in the development of central obesity and may be related to OSAHS and hypertension in OSAHS patients by the central obesity in male OSAHS subjects of North region "Han" population of China.