Introduction: The Pro12Ala polymorphism of the PPARγ gene affects insulin sensitivity, but its distribution in Iranian patients with polycystic ovary syndrome (PCOS) based on diabetic status has been less investigated. This study was conducted with aim to determine the frequency of Pro12Ala genotypes in diabetic and non-diabetic PCOS patients in Mashhad.
Methods: This cross-sectional study was conducted in 2020 on 200 women with PCOS based on Rotterdam criteria, including 100 diabetic and 100 non-diabetic patients. Demographic information including age and body mass index (BMI) was recorded for all participants. Genotyping was performed using PCR-RFLP method, and fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR) were evaluated. Data analysis was performed using SPSS software (version 26) with Chi-square, Fisher's exact, independent t-test, and analysis of covariance (ANCOVA). P<0.05 was considered significant.
Results: The mean age and BMI were significantly higher in the diabetic group compared to the non-diabetic group (p<0.05). The frequency of the Ala allele was significantly lower in the diabetic group (4.5%) than in the non-diabetic group (11%) (p<0.05). The odds ratio for the presence of the Ala allele in the non-diabetic group compared to the diabetic group was 2.62 (95% CI: 1.15-5.98). After adjusting for age and BMI using ANCOVA, the difference in HOMA-IR between the two groups remained significant (p=0.012). Also, carriers of the Ala allele showed lower HOMA-IR values compared to individuals with the Pro/Pro genotype, although this difference was not statistically significant (p>0.05).
Conclusion: The Pro12Ala polymorphism has a lower prevalence in PCOS patients with diabetes. The findings of this study suggest that the Ala allele may be associated with a reduced risk of developing type 2 diabetes in women with PCOS (OR=2.62; 95% CI: 1.15-5.98).