Sleep-disordered breathing in Asian populations is being increasingly recognized. This prospective cross-sectional study investigated the relationship of the metabolic profile or cardiovascular risk factors to obstructive sleep apnoea(OSA) in Chinese subjects in Hong Kong.
255 consecutive Chinese subjects of either sex, aged between 30-60 years old, were recruited from staff in public institutions and visitors to community centers. Demographic and anthropometric data, blood pressure, metabolic parameters(fasting blood glucose, LDL & HDL-cholesterol and triglycerides), and polysomnographic findings were collected.
The major dependent outcome variable was the apnoea-hypopnoea index(AHI), the average number of apnoeas and hyponoeas per hour of sleep. Obstructive sleep apnoea was defined as AHI≥ 5. Independnet variables were anthropometric measurement, blood pressure, serum lipoproteins, fasting blood glucose, age and sex. Significant linear relationship of AHI with age, BMI, waist circumference, systolic and diastolic blood pressure, triglycerides and HDL-cholesterol could be established. Multiple regression analysis identified age and obesity, in particular, central obesity as major determinants of AHI. OSA was also highly associated with more than one risk factor of the metabolic syndrome, as defined by clinical criterai (American Medical Association. Summary of the NECP adult treatment panel III report). JAMA 2001;285:19.
Among community-based subjects, presence of OSA is associated with a cluster of metabolic risk factors known to contribute to cardiovascular mortality or morbidity.
Are OSA and Metabolic Syndrome one disease? Are they associated in a vicious cycle: More severe OSA subjects are highly associated with Metabolic syndrome or subjects with Metabolic syndrome do suffer from OSA? We should further investigate the effects of Continuous positive pressure treatment on the metabolic profile of those OSA subjects, and look into the preventive measures.
J. Lam, None.