Introduction: Non-alcoholic fatty liver disease (NAFLD) is commonly associated with metabolic comorbidities including obesity, type II diabetes, and dyslipidemia. However, there is also clear epidemiologic evidence demonstrating that NAFLD can be found even in the non-obese individuals. Polycystic ovary syndrome (PCOS) is one of the common endocrine abnormality in women with reproductive age, and is characterized by chronic anovulation and hyperandrogenism. Insulin resistance (IR) is one of the core pathophysiology of this syndrome, and obesity is also prevalent in women with PCOS. Thus, NAFLD is known to be common in women with PCOS, but most of the studies investigated prevalence of NAFLD in obese PCOS patients. The aim of this study was to compare the prevalence of NAFLD in non-obese women with or without PCOS, and to assess the association between PCOS and NAFLD in non-obese Asian cohort.
Methods: PCOS was diagnosed using the Rotterdam criteria. Aftersubjects with other potential causes of chronic liver disease were excluded, 275 non-obese women with PCOS and 892 non-obese controls were enrolled for analysis. Prevalence of NAFLD on hepatic ultrasonography between non-obese women with or without PCOS was compared. Analyses with logistic regression were used to analyze the adjusted odds ratio (OR) and 95% confidence interval (CI) for NAFLD while controlling for potential confounders. All data analyses were performed using the SPSS software, and statistical significance was set at two-sided P values
Results: Non-obese women with PCOS had a significantly higher prevalence of NAFLD than those without PCOS (5.5% vs. 2.8%, respectively, P=0.027). Presence of PCOS was significantly associated with NAFLD, and OR was 2.00 [95% CI 1.04-3.85]. Even after adjustment for age and BMI, the odds that a woman has a NAFLD was 2.62 times higher (95% CI 1.25-5.48) if she has PCOS, but this association was attenuated after adjustment for insulin resistance. However, among women with PCOS, the level of androgenicity represented by free testosterone or free androgen index was associated with presence of NAFLD even after adjustment for age, obesity, lipid profile, insulin resistance or glycemic status.
Conclusion: NAFLD is more prevalent in non-obese women with PCOS than those without, and in these non-obese women with PCOS, hyperandrogenemia is an independent risk factor for NAFLD. Our result gives an evidence about characteristics which can help identifying non-obese women who are at increased risk for NAFLD.