Objective: to establish clinical and molecular features of endometrial hyperplasia in conditions of organic solvents exposure in patients with obesity. Materials and methods: postmenopausal women with endometrial hyperplasia (morphological criteria) were included to observational cross-sectional study. The main group included 140 subjects with occupational organic solvents exposure, aged 57,5 (46;64) years, of whom 70 had obesity and 70 had normal weight. Comparison group — 140 women without of occupational health risks, aged 56,5 (46;65) years, 68 with and 72 without obesity. Investigated workers were painters in machine building industry with length of service above 10 years, in post-contact period lasted for 1-5 years were 29 (20.7%) of participants. Organic solvents concentrations at the workplace’s areas were 1.5-5.5 times above occupational exposure limits. Linear and logistic regression were used to explore relationships. Level of significance p<0.05. Results: workers exposed to organic solvents had maximal percent of atypical endometrial hyperplasia: 34.3% in obesity subjects and 18.6% in those without obesity, in the comparison group 10.3% in subjects with and 6.9% in those without obesity, p=0.004. Subgroup with toxicant exposure with obesity characterized by maximal expression of Ki-67 (55,9±2,51, 51,4±4,95, 41,5±3,29 and 30,1±2,18 scores respectively), higher rate of uterine bleeding, M-echo thickness, blood interleukin 1β concentration. Atypical endometrial hyperplasia was associated with length of service (OR 1.80), maximal short-term exposure concentration of toluene (OR 2.51), waist circumference (OR 1.68), Ki-67 (OR 2,01), estrogen receptors on epithelium (OR 1.92). Conclusions: organic solvents exposure in postmenopausal women with endometrial hyperplasia contributes to development of atypical hyperplasia, systemic inflammation, Ki-67 expression, higher grades in subjects with obesity.

Introduction. Organic solvents have a hematotoxic effect, which leads to the development of anemia. Endometrial hyperplasia may also be the cause of a decrease in blood hemoglobin levels. The phenotype of anemia in combination of these diseases is still insufficiently studied. Exposure to organic solvents is associated with a carcinogenic risk, while their role in the development of precancerous conditions is little known. The study aims to research the features of anemia in patients with endometrial hyperplasia under the influence of organic solvents and depending on the obesity factor. Materials and methods. The design of the study is a single–center, single-stage observational. The researchers formed 2 groups of women with endometrial hyperplasia confirmed by histological examination, who worked under conditions of exposure to organic solvents (n=140, the main group, 70 of them obese according to WHO criteria) or who had no health risks (n=140, the comparison group, 68 of them obese). The patients of the main group are painters at a machine-building enterprise. Organic solvents concentrations at the workplace air were 1.2–5.0 times above occupational exposure limits, length of service was 21.5 (18; 28) years. Results. Scientists have registered anemia in 72.9% of obese workers, 54.2% of non-obese workers, 33.8% and 25.0% of patients in the comparison group with obesity and normal body weight, respectively, χ2=8.2, p=0.008. In contact with organic solvents, 60.7% of patients had anemia normal- or macrocytic, normal- or hyperchromic, hyporegenerative. In the subgroup of obesity and atypical endometrial hyperplasia, we have watched the minimum values of hemoglobin — 95 (90; 105) g/l and reticulocytes — 1 (0.5; 2), the maximum values of the average erythrocyte volume — 98 (92; 107) fl and the average hemoglobin content in the erythrocyte — 35(34; 38) pg. The researchers have determined the association of this variant of anemia with atypical endometrial hyperplasia by logistic regression, OR 2.51, 95% CI 1.08–5.85, p=0.033. In comparison group, all patients had iron-deficiency anemia. Limitations. The limitations of the study are related to the recruitment of patients in one center. Conclusion. Anemia in women with endometrial hyperplasia in conditions of organic solvents exposure is normo- or hyperchormic, normo- or macrocytic, hyporegenerative, most prominent in patients with obesity, and associated with atypical histological type of the disease. Ethics. The authors have carried out the study in compliance with the Ethical principles of conducting scientific medical research with human participation, set out in the Helsinki Declaration of the World Medical Association and in accordance with the Ethical norms and rules provided for by the Bulletin of the Higher Attestation Commission of the Ministry of Education of Russia No. 3 of 2002 "On the procedure for conducting biomedical research in humans". The study was approved by the Ethics Committee of the Federal State Budgetary Educational Institution of the Russian Ministry of Health.