I.A. Petrova - Junior Research Scientist of Hygiene Department, FBSI «Nizhny Novgorod Research Institute for Hygiene and Occupational Pathology». E-mail: yes-ia@mail.ru
L.A. Strakhova - Junior Research Scientist of Clinic Department, FBSI «Nizhny Novgorod research institute for hygiene and occupational pathology. E-mail: Larisa4577@yandex.ru
M.A. Sapozhnikova - Physician of Clinico-Diagnoctic Laboratory, FBSI «Nizhny Novgorod research institute for hygiene and occupational pathology»
T.V. Blinova - Dr.Sc. (Med.), Research Senior Scientist, Clinic Department, FBSI «Nizhny Novgorod research institute for hygiene and occupational pathology». E-mail: btvdn@yandex.ru
I.A. Makarov - Ph.D. (Med.), Senior Research Scientist of Clinic Department, FBSI «Nizhny Novgorod research institute for hygiene and occupational pathology»

The aim of the present study was to obtain more accurate information on role of free fatty acids (FFA) as well as their amount and ratio in insulin resistance formed among patients with occupational chronic obstructive pulmonary diseases (COPD). The insulin resistance is one of the causes of an associated diabetes mellitus. The examined persons were blue collar workers of metallurgy and engineering industries. The persons suffered from occupational COPD in combination with obesity and type 2 diabetes mellitus. Content of free fatty acids (FFA), insulin, C-peptide, glucose were analyzed in blood serum of patients. The study showed the changes of total content of FFA in blood serum of examined persons were in physiological range of concentrations. An association of FFA level in blood serum with stage of obesity and glucose concentration was found. The increase of FFA content in blood was combined with parallel increase in body mass (BM). The increase of FFA level in all patients (irrespective of glucose level) was accompanied by moderate hyperinsulinemia and increase of C-peptide level (2,2 times higher than in control group). During aggravation of obesity, the increase of FFA content was not accompanied by a considerable change of fatty acid (FA) spectrum; a directional increase of absolute content in every class of FA separately was recorded. The ratio between saturated, monounsaturated and polyunsaturated acids was practically identical with both persons with normal BM and persons with obesity of third stage. The cause of an observed invariability of ratios of aforementioned acids is unclear yet, thus, further studies to find biochemical peculiarities of formation of insulin resistance in patients with COPD associated with type 2 diabetes mellitus are required. The study suggested that FFA increase in serum without changes in their spectrum was one of the signs of formation of insulin resistance and type 2 diabetes mellitus in patients with bronchopulmonary diseases. In healthy persons, the increase of FFA in reference range is compensated by increase of glucose secretion that promotes to maintain normal level of glucose. The authors revealed three types of interaction between FFA level, insulin level and glucose concentration. In 29% of patients with bronchopulmonary diseases and excess BM, even insignificant increase of FFA content was accompanied by hyperinsulinemia and hyperglicemia that provided evidence about formation of insulin resistance and type 2 diabetes mellitus. In 17% of patients with occupational bronchopulmonary diseases combined with obesity of III stage, elevated level of FFA was accompanied by hyperinsulinemia and normal level of glucose. Apparently, this category of patients had a normal tolerance to glucose and, in spite of obesity and elevated level of FFA, had not insulin resistance and diabetes mellitus. In spite of excess BM and obesity of I stage, 60% of patients had low level of FFA accompanied by hyperinsulinemia and normal level of glucose. It supposed that absence of insulin resistance in most of patients with occupational COPD associated with obesity and diabetes mellitus caused by mechanisms involved in both regulatory functions of FFA and secretion of various active humoral factors by adipose tissue.