Sex-related differences in the peripheral vascular response to hypoxia: Implications in health and relevance for obstructive sleep apnoea.

The incidence and presentation of obstructive sleep apnoea, as well as hypertension and cardiovascular disease, have been reported to differ by sex. It is thus reasonable to propose mechanisms contributing to subsequent pathology differ by sex. This concept is supported from a pre-pathological perspective, as sex differences have been observed in the vascular response to hypoxia both alone and during concomitant hypoxia and sympathetic activation. However, the mechanisms governing the vascular response to hypoxia in females compared to males have only recently been examined, with the preponderance of data in predominantly male or all-male cohorts. Determining the sex-specific mechanisms contributing to the foundational vascular response to hypoxia is essential to the development of targeted therapeutics. Herein we outline literature in support of vascular sex-related differences in the acute response to both intermittent and steady-state hypoxia, with an emphasis on the healthy state. However, questions remain to bridge the gap between preclinical observations to pathological conditions, such as the role of sex hormones and adrenergic receptors, with increasing adiposity, age and chronic disease (e.g., sleep apnoea).