Age- and gender-related characteristics of obstructive sleep apnea. 
The present study attempted to characterize the phenotype of men and women of different ages with a laboratory diagnosis of obstructive sleep apnea (OSA) using demographic, subjective complaints and medical history and to determine the best fitting apnea-hypopnea index (AHI) cutoff point for OSA diagnosis in each group.  Data collected from 23,806 patients examined by a whole-night polysomnography were retrospectively analyzed.  First, descriptive analysis was used to determine the gender-specific relationship between AHI and age, then binary logistic regression was used to determine the best fitting gender- and age-specific AHIs and the predictors of OSA in each age and gender group.  Of the total number of patients, 70.7% had AHI >10, and men had consistently higher AHI than women.  OSA severity rose linearly with age in normal-weight and obese women and in normal-weight men.  The best fitting AHI cutoff point increased with age in both genders.  Obesity and snoring were significant predictors of OSA in all age by gender groups, while hypertension and excessive daytime sleepiness were common to all men and the two older women groups.  Insomnia-related complaints were negative predictors of obstructive sleep apnea syndrome (OSAS) in some of the groups.  OSAS severity varies with age in both genders, while women have less severe syndrome in all ages.  Obesity, snoring, hypertension, and excessive daytime sleepiness are OSAS predictors in both genders, while insomnia-related complaints are negative predictors.