Distribution of age and apnea-hypopnea index in diagnostic sleep tests in West Texas

Obstructive sleep apnea (OSA) is a disease characterized by the collapse of the upper airway during sleep. It is debated whether increasing age is associated with an increased severity based on the apnea-hypopnea index (AHI) in OSA patients. To better characterize the distribution of age and AHI in OSA patients, a large, retrospective analysis of diagnostic sleep test results in West Texas was performed. This study analyzed 3993 adult patients (aged ≥18 years) who had either a full or a split night sleep study performed at Alpha Sleep Labs between July 1, 2009, and September 1, 2020. The distribution of age approximates a normal distribution with a mean age of 52.6 and standard deviation of 14.4 years. Compared to the US population, the study population is overrepresented by those 40 to 60 years of age and underrepresented by those 20 to 40 and ≥60 years. The degree of underrepresentation was greater for young patients than the elderly. The number of subjects vs. AHI approximated an exponential decay. Although prevalence probably contributes to the observed distributions of age and AHI, we cannot conclude that our data represent either the prevalence of OSA or AHI. The population of people undergoing diagnostic sleep testing is not representative of the total population. Interdependencies are observed between age and AHI, but the basis for these interdependencies is unclear. Future studies will need to examine these effects in greater detail.