Clinical profile of patients with obstructive sleep apnea syndrome in a cardiology hospital

Relevance. Obstructive sleep apnea syndrome (OSAS) is an important medical and social problem due to its high prevalence and impact on quality of life. The relationship between OSAS and cardiovascular pathology has been proven by many studies, which confirms the necessity for early diagnosis of OSAS and its treatment for the prevention of fatal and non-fatal events.
Aim: to study epidemiological and clinical profile of the patients referred by a cardiologist to a specialized sleep laboratory to verify the diagnosis of OSAS.
Materials and methods. Object of study – 527 patients aged 56.9±12.5 years who were hospitalized to the Myasnikov Clinical Cardiology Research Institute from 2016–2018 and had OSAS risk factors. Initially, complaints, medical history, anthropometric data were collected. As a screening survey, questionnaires were conducted using questionnaire scales. Verification of the diagnosis of OSAS and determination of the severity was carried out by cardiorespiratory or respiratory monitoring. Subsequently, 4 groups were formed depending on the presence and severity of OSAS.
Results. The prevalence of OSAS among patients in a cardiology hospital referred to a verification study was 88.6%. A comparative analysis of the groups revealed a progressive increase in the values of anthropometric indicators with increasing severity of OSAS. No differences were found between the groups by gender and daytime sleepiness on the Karolinska Sleepiness Scale. The average score on the Epworth sleepiness scale was statistically significantly lower only in the group of patients without OSAS when compared with the group with a severe degree of OSAS, and is comparable with the scores in the groups of mild and moderate degrees of OSAS. In a multivariate model of logistic regression, independent predictors of OSAS were identified as: age over 45 years, indications of loud intermittent snoring, frequent nightly urination, overweight or obesity. According to the results of assessing the incidence of various cardiovascular diseases in patients referred to the sleep laboratory, no significant differences were detected. At the same time, a significant difference was found in the frequency of obesity in patients with severe OSAS compared with other groups, as well as the frequency of type 2 diabetes mellitus or impaired glucose tolerance – when compared with groups without OSAS, and with mild OSAS. In one-factor logistic regression models, it was found that the likelihood of having a severe degree of OSAS increases with increasing both comorbidity and age.
Conclusions. High prevalence of OSAS in patients of a cardiological hospital, referred to a sleep laboratory for verification study, was confirmed. Considering the data that early diagnosis and treatment of OSAS can affect the course of both nosologies, the quality of life and prognosis of these patients, it is advisable to routinely screen and verify the diagnosis of OSAS in patients with cardiovascular diseases.