Abstract
OBJECTIVE: To investigate the relationship between angiotensin Ⅰ-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and the genetic risks for polycystic ovary syndrome (PCOS) and to evaluate the impact of ACE I/D genotypes on clinical, hormonal, metabolic and oxidative stress parameters in patients with PCOS. METHODS: This was a retrospective case-control study involving a total of 1 020 PCOS patients and 825 female controls who visited the outpatient clinic of the Department of Reproductive Endocrinology, West China Second Hospital of Sichuan University between 2006 and 2019. The ages of the subjects ranged between 17 and 44. The ACE I/D genotypes were determined by polymerase chain reaction (PCR) and gel electrophoresis. 667 PCOS patients and 527 controls were selected for an analysis of their genotypes and the hormonal, metabolic and oxidative stress parameters. RESULTS: The genotype distributions of the ACE I/D single nucleotide polymorphism was in Hardy-Weinberg equilibrium in both the PCOS group and the control group (all P>0.05), which was representative of the population. There were no statistically significant differences in genotype and allele frequencies between the PCOS and the control groups ( P>0.05). After adjusting for both age and body mass index (BMI), there was no statistically significant difference in clinical characteristics among all genotypes in either the PCOS group or the control group. In the PCOS group, compared with the II genotype subgroup, the ID genotype subgroup had lower luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio, while the DD genotype subgroup had higher homeostatic model assessment of insulin resistance (HOMA-IR) and malondialdehyde (MDA) levels. Compared with the ID genotype subgroup, the DD genotype subgroup had lower serum sex hormone binding globulin (SHBG) level, but higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels ( P<0.05). In the control group, II genotype subgroup had a higher level of total oxidant status (TOS) than that of the DD genotype subgroup. CONCLUSION: ACE I/D genetic polymorphism is not associated with risks for PCOS. The I/D variation of ACE gene may be related to insulin resistance, dyslipidaemia, hyperandrogenemia and oxidative stress in PCOS patients.