Introduction:
Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies among women at reproductive age, but its pathology remains unknown. From epidemiological studies it is known that endogenous, mainly genetic and exogenous, environmental factors are of importance.

Objective:
The aim of the study was to compare the phenotype of women diagnosed with PCOS from urban and rural areas of Poland. According to the knowledge of the authors, this is first such study.

Material and Methods:
The retrospective study included 3,877 PCOS patients: 2511 women living in cities and 1,366 village inhabitants, aged between 18 – 45 years. Clinical data, including medical history, body mass, height and hirsutism severity was obtained from each patient. Hormones were also tested in each patient: follicle stimulating hormone, luteinizing hormone, prolactin, estradiol [E2], testosterone, dehydroepiandrosterone sulphate [DHEAS], thyroid stimulating hormone, free thyroxin, insulin [INS], 17 hydroxyprogesterone, cortisol [CORT]) and metabolic (75g oral glucose tolerance test, Chol – total cholesterol, HDL-C – high density lipoprotein cholesterol, LDL-C low density lipoprotein cholesterol, and the TG (triglicerides) profile.

Results:
PCOS women from urban areas had a higher mean serum concentration of E2 in comparison to the inhabitants of rural areas. Women from cities had a lower mean level of DHEAS, CORT, and INS measured in the morning than rural residents. Insulin-resistance, using homeostasis model assessment, was more pronounced among women from villages. The prevalence of menstrual disorders, in general, was higher in PCOS women living in rural comparing to urban areas.

Conclusions:
The clinical and biochemical indices differed significantly between women diagnosed with PCOS living in cities and villages. In general in Poland, the PCOS phenotype is more severe in women living in rural areas. This study shows that different living conditions significantly affect the PCOS phenotype.