Objective: To evaluate the possibility of using fibroblast growth factor 21 (FGF 21) as a marker of metabolic disorders and premature aging in polymorbid cardiovascular pathology. Research methods: 199 men aged 35-55 years who were stratified into 3 groups were examined: group A - 117 patients with type 2 diabetes mellitus (type 2 diabetes), polymorbid cardiovascular disease (PCVD), obesity, androgen deficiency and anxiety-depressive disorders (ADD); group B - 55 patients with PCVD, obesity and ADD; group C - control group (n = 27). The examination of patients included a laboratory study of the level of FGF 21, indicators of carbohydrate and lipid metabolism, hormonal status, as well as daily monitoring of blood pressure and ECG. Results and conclusions. When compared with the control group, the level of FGF 21 was 3 times higher in the presence of type 2 diabetes. The most intense increase in FGF 21 levels was observed in groups of patients with several diseases. An increase in the level of FGF 21 in young and middle-aged people is probably due to a compensatory reaction to the existing androgen deficiency, disorders of carbohydrate and lipid metabolism. Strong correlations between FGF 21 and glucose, HDL cholesterol, total testosterone, ALT, and SBP during the day allow FGF 21 to be considered an early marker of cardiovascular disease and premature aging (PA) in young and middle-aged people