Objective — to assess the relationship between cortisol levels and sleep disorders in patients with hypertension (H) and type 2 diabetes mellitus (DM2).Materials and methods. The study included 107 patients with H and DM2. All patients were evaluated for sleep disorders using the Epworth Daytime Sleepiness Scale and the International Classification of Sleep Disorders Scale (International Academy of Sleep Disorders, Issue 3, 2014). Plasma lipids, blood levels of glucose and glycosylated hemoglobin as well as anthropometric parameters were measured in all patients. Prolactin was determined using immunosorbent analysis using fixed enzymes (principle conjugated by ELISA peroxidase) on an Immunochem 2100 analyzer.Results and discussion. Patients were divided into 2 groups. Group 1 included 74 patients with a combined course of H and DM2 with an average age of (59.7 ± 10.5) years. Group 2 included 33 patients with an isolated hypertension, the average age of which was (54.6 ± 9.8) years. There were no significant differences in the age of patients between the groups (p = 0.25). In the whole group, when analyzing indicators of cortisol, glucose, glycosylated hemoglobin, blood pressure and heart rate, depending on early awakenings, there were no significant differences in the level of daytime sleepiness on the basis of the Epworth scale. At the same time, it was found that early awakenings are significantly more likely to occur with high levels of cortisol. Thus, the median of cortisol in the group of patients with early awakenings was 557.23 [461.74 ÷ 655.70] nmol/l, while in the group without early awakenings it was 534.90 [435.80 ÷ 648.40] nmol/l, p = 0.05. When analyzing separately the data of patients of group 1 and group 2, depending on the presence of early awakenings and their relationship with the level of cortisol, it was found that in group 1, patients who had early awakenings, cortisol was 551.13 [452.53 ÷ 728.36] nmol/l, in patients without early awakenings — 495.79 [407.82 ÷ 557.96] nmol/l, p = 0.05; whereas in group 2 in patients who had early awakenings, cortisol was 535.4 [356.50 ÷ 631.67], in patients without early awakenings — 497.93 [448.84 ÷ 80.23] nmol/l, p = 0.90.Conclusions. A relationship was established between cortisol levels and early awakenings in patients with hypertension and type 2 diabetes. Patients with a combined hypertension and type 2 diabetes mellitus, and early awakenings have a higher level of cortisol, than patients with an isolated hypertension.