Sex Differences in Reflex Responses to Intermittent Hypoxia

Over 35% of the US population will develop sleep apnea at some point in their life. Sleep
apnea is the most common form of sleep disordered breathing and patients with sleep apnea are
at increased risk of developing high blood pressure. Intermittent, repeated exposures to low
oxygen during sleep (intermittent hypoxia, IH) has been implicated as the primary stimulus
for increases in sympathetic nervous system activity and blood pressure with sleep apnea.
Interestingly there are some reports of a lower incidence of hypertension in women with sleep
apnea when compared to men. Results from the present study will provide information important
to the investigator's understanding of potential sex-differences in clinical outcomes for
conditions related to acute/chronic hypoxia and may have important implications for
treatments which may improve blood pressure control in patients with sleep apnea.

Inclusion Criteria:

- healthy adult men and women;

- BMI <30 kg/m2;

- non-pregnant;

- non-breastfeeding;

- non-smokers;

- premenopausal women with a normal menstrual cycle unaffected by hormonal contraceptive
use;

- taking no medications known to affect autonomic or cardiovascular function (PI
discretion).

Exclusion Criteria:

- taking any medications known to affect the cardiovascular or autonomic nervous system
(e.g. alpha-blockers, beta-blockers, etc);

- a self-reported history of hepatic, renal, pulmonary, cardiovascular, or neurological
diseases;

- stroke or neurovascular disease;

- bleeding/clotting disorder;

- sleep apnea or other sleep disorders;

- diabetes;

- smoking;

- history of alcoholism or substance abuse;

- hypertension.