Evaluation of Obstructive Sleep Apnea in Metabolic Syndrome

Background: Metabolic syndrome has become one of the most important public health problems with a growing prevalence in both developed and developing countries. Obesity is a major risk factor for obstructive sleep apnea (OSA), which is associated with significant cardiorespiratory morbidity.

Aims: The aims of this study were to find out the prevalence of OSA in patients with metabolic syndrome and to highlight the importance of assessment of OSA in these patients.

Methods: This cross-sectional analytical study was conducted on 100 subjects aged 30-60 years, comprising 50 cases of metabolic syndrome and 50 controls without metabolic syndrome. Overnight polysomnography was done in all the subjects. Prevalence and severity of OSA were assessed and compared between the two groups.

Results: Prevalence of OSA was significantly higher (66%) in patients with metabolic syndrome than in subjects without metabolic syndrome (12%). Out of 33 (66%) OSA patients with metabolic syndrome, 8 (16%) had mild OSA, 11 (22%) had moderate OSA, and 14 (28%) had severe OSA. Increasing severity of OSA was associated with higher mean levels of all the metabolic syndrome parameters except serum high density lipoprotein (HDL).

Conclusions: OSA is highly prevalent in patients with metabolic syndrome. Also, the increasing severity of OSA is associated with poorer control of diabetes, hypertension, and dyslipidemia, which are all components of metabolic syndrome. Therefore, effective treatment of metabolic syndrome can prevent and control OSA in these patients. Similarly, reducing the severity of OSA (by early diagnosis and treatment) in patients with metabolic syndrome might help to optimize control of blood sugar, blood pressure, and serum lipids, thereby reducing the risk of cardiovascular disease. Therefore, the need for screening metabolic syndrome patients for OSA has been reinforced by this study.