<b>Objective:</b>&nbsp;To investigate the prevalence of diabetes mellitus in comorbidity structures and its effect on the clinical course in hospitalized COVID-19 patients in south region of Kazakhstan.<br /> <b>Material and methods:</b> A retrospective analysis of data from 918 patients with COVID-19 treated at the City Clinical Infectious Diseases Hospital was carried out. Pearson's Chi-square test and Student's t-test were conducted.<br /> <b>Results:</b> In Kazakhstan, diabetes mellitus occupies the second position in the structure of comorbidities in patients with COVID-19 with a share of 20%. Diabetes mellitus in patients most often occurs in combination with cardiovascular diseases and arterial hypertension (20.3% and 16.3%, respectively). Combination of diabetes mellitus, arterial hypertension and other diseases was detected in 72.4% of patients. Combination of diabetes mellitus, cardiovascular and other diseases was detected in 32.5%.<br /> In diabetes mellitus patients, COVID-19 was more severe, the hospital stay was longer, and patients over 60 years of age suffered. These patients had a combination of diabetes mellitus with arterial hypertension, obesity, and cardiovascular diseases. Hyperglycemia, elevated blood pressure, rapid breathing, and low saturation were more common for these patients.<br /> <b>Conclusion:</b> Diabetes mellitus ranks second in the structure of comorbidities in COVID-19 in the south region of Kazakhstan and is characterized by a combination with cardiovascular diseases, arterial hypertension and obesity. In patients with diabetes, COVID-19 is more severe, which affects the length of stay in the hospital, the mortality rate and the need for transfer to the Intensive Care Unit.

Objective. To identify clinical and laboratory differences of COVID-19 in patients with hypertension (HTN), as well as to identify factors associated with its severe course in these patients. Design and methods. A retrospective analysis of case histories of 940 patients with COVID-19 was performed. Statistical analysis was carried out by the method of contingency tables using Pearson's Chi-square test with Bonferroni correction, multiple logistic regression analysis and ROC-analysis were also applied. Results. The group of patients with COVID-19 and HTN showed a number of significant differences compared with the group of patients without HTN history. The study group was characterized by higher rates of females, people over 65, patients with severe COVID-19. They were more likely to have diabetes mellitus, coronary heart disease, and chronic kidney disease. On admission, in the group of HTN patients, leukocytosis and elevated blood glucose levels were more common, as well as pneumonia, shortness of breath and low saturation (p < 0,05). Multivariate logistic regression analysis showed that the presence of coronary heart disease (odds ratio (OR) = 3,492, 95 % confidential interval (CI): 2,016-6,048), leukocytosis (OR = 1,376, 95 % CI: 1,540-7,703), thrombocytopenia (OR = 1,779, 95 % CI: 1,031-3,071) and low SpO2 saturation (OR = 3,265, 95 % CI: 1,996-5,341) were associated with severe COVID-19 in hypertensive patients. ROC-analysis showed that the combination of the identified factors increases power of their association with the severe COVID-19 in HTN patients (AUC = 0,766). Conclusions. 1. Some indicators of hospitalized COVID-19 patients with HTN are different compared to patients with no HTN history. 2. Factors associated with severe COVID-19 in individuals with HTN do not differ from those in the general population of COVID-19 patients. 3. Severe COVID-19 in patients with HTN was strongly associated with the low SpO2 saturation and the presence of concomitant coronary heart disease.