ABSTRACT
This chapter is intended to address risk and causality for adult obstructive sleep apnea (OSA and OSAHS) in regard to three features—genetics, gender, and age. This limited set is chosen to represent reasonable examples in which to address causal pathways.
There is a distinction between risk factors like age, weight, gender, genetics, co-morbidity, etc., which are equally present during wakefulness and causal pathways leading to multiple apneas—sleep itself, the anatomy of the upper airway, the responses of the upper airway muscles and the gain of the ventilatory control system. Genetics underpins all of these pathways and examples of dominant genetic effects are better known in pediatric than in adult sleep apnea. The influence of gender is discussed in the context of born female, hormonal manipulation, and special cases found in clinical syndromes such as PCOS. Age and ageism capture different aspects of OSA across the lifetime, in which the causal impacts vary.
