[Risk factors in development of sleep apnea syndrome--a large population study using a simple monitoring system].

We studied the risk factors in the development of sleep apnea syndrome (SAS) in 779 patients (705 males and 74 females) using Apnomonitor R. The apnea index (AI) significantly correlated with the body mass index (BMI), and was higher in obese patients (BMI > or = 25 kg/m2) than in non-obese patients. The prevalence of SAS increased with patient age. Obesity was less common in older than in younger patients. The AI was significantly higher in smokers than in non-smokers, as was the prevalence of SAS. The AI and the prevalence of SAS were higher in smokers than in non-smokers in both obese and non-obese patients. The AI was significantly higher in males than in females, and so was the prevalence of SAS. The AI and the prevalence of SAS were always higher in male obese patients, non-obese patients, smokers, and non-smokers than in female patients in the same categories. These results suggest that obesity, age, smoking, and gender were independent risk factors in the development of SAS.