Recently, the question of a causal relationship between obstructive sleep apnea syndrome and metabolic syndrome has been increasingly raised. It is possible to consider breathing disorders during sleep as one of the causes of the metabolic syndrome and its important component.

Metabolic syndrome is a complex of symptoms that combines abdominal obesity, dyslipidemia, insulin resistance and impaired glucose tolerance, increased blood pressure, and a high predisposition to thrombosis. Metabolic syndrome associated with a sedentary lifestyle, overeating and unbalanced nutrition is an actual problem of modern medicine.

The main component of the metabolic syndrome is the low sensitivity of the body to insulin, which leads to its compensatory increase in the blood. Low sensitivity to insulin largely determines the development of other metabolic and hemodynamic disorders. According to the data, patients with metabolic syndrome have a high risk of developing diabetes mellitus.

An equally important factor in the metabolic syndrome is obesity, which results from reduced tissue sensitivity to insulin, leads to even greater metabolic disorders and causes the progression of insulin resistance. Fat accumulation in the abdomen refers to visceral fat deposits, which are located near the internal organs. They are more dangerous in terms of circulatory disorders and the development of diseases of the cardiovascular system.

Changes in fat metabolism lead to dyslipidemia, which in the metabolic syndrome is manifested by an increase in the level of low density lipoproteins and a decrease in the level of high density lipoproteins. All of the above factors lead to the early development of atherosclerosis, its progression and the occurrence of cardiovascular complications.

In patients with metabolic syndrome, the prevalence of obstructive sleep apnea is 50%. Metabolic syndrome and sleep disturbances exist in parallel and mutually aggravate each other. Obesity, as one of the leading components of the metabolic syndrome, is the main risk factor for obstructive sleep apnea. The increase in the severity of obstructive sleep apnea causes the progression of visceral obesity and metabolic syndrome, since the production of hormones at night is disrupted, in particular growth hormone, which is involved in the mobilization of fat from the depot. On the other hand, sleep apnea can be an independent cause of metabolic disorders: insulin resistance, dyslipidemia, and type 2 diabetes mellitus. Hypoxia and fragmentation of sleep entail hormonal disturbances in the state of the hypothalamic-pituitary-adrenal system, due to which insulin resistance develops.

A vicious circle ensues—complications of diabetes contribute to obstructive sleep apnea, and sleep disturbances cause insulin resistance and glucose intolerance.

In this case, the correction of respiratory disorders for such patients is mandatory for effective treatment of the metabolic syndrome. The appointment of CPAP therapy , which eliminates breathing disorders during sleep, increases insulin sensitivity, improves glucose metabolism, and even contributes to weight loss. This fact also confirms a causal relationship between metabolic syndrome and obstructive sleep apnea syndrome.