ABSTRACT

1. A B C INTRODUCTION RESULTS DISCUSSION Determinants of Upper Airway Collapsibility in Polycystic Ovarian Syndrome during NREM Sleep Sankri-TarbichiAG, Ross-King M, DiamondM.Pand Badr MS John D. Dingell VA Medical Center, WSU Sleep Research Laboratory, Detroit, MI • Mechanical ventilation protocol • Nasal mechanical ventilation for 3 minutes to cause hypocapnia during NREM sleep. • Data Analysis • PETCO2 : difference in PETCO2 between control (5 breaths prior to mechanical ventilation) and the last 5 breaths of mechanical ventilation) • Plot PETCO2 v. Nadir VE (% of control), where apnea nadir VE = 0. • Apnea threshold (PETCO2 -AT) defined as the measured PETCO2 at which the apnea closest to the last hypopnea occurred (arrow in figure below). • PETCO2 -AT defined as the PETCO2 between the control and hyperventilation periods associated with the first apnea. Abstract Determinants of Upper Airway Collapsibility in Polycystic Ovarian Syndrome during NREM Sleep. AG. Sankri-Tarbichi, M. Ross-King, M.P. Diamond1 and M.S. Badr. Wayne State University and John D. Dingell VAMC, Detroit, MI, United States. Sleep disordered breathing (SDB) is highly prevalent in females with polycystic ovary syndrome (PCOS). There is a strong link between androgens and increased prevalence of SDB. Furthermore, exogenous testosterone induces sleep apnea and even decreases upper airway (UA) patency in females. Differences in hormonal states (decreased progesterone or increased testosterone) may contribute to the pathogenesis of SDB. We sought to study UA mechanics and susceptibility to collapse in patients with PCOS. Methods: We studied 10 subjects (5 pairs of PCOS and normal control, matched for age, gender and BMI). PCOS diagnosis was defined as oligomenorrhea and hyperandrogenemia. None of the patients had obstructive sleep apnea (OSA). Central apnea and /or hypopnea were induced via nasal mechanical ventilation during stable NREM sleep. The airflow (V) was measured using a pneumotachometer and the pressure (Psg) was measured using a pressure catheter positioned at the supraglottic area. Baseline UA resistance (RUA) was measured at a fixed flow of 0.2 L/s. Inspiratory flow limitation (IFL) was determined during stable NREM sleep using mathematical model of the upper airway pressure-flow relationship. Apneic threshold (AT) was defined as the change in end-tidal CO2 to reach an apnea ( PETCO2-AT). Conclusions: 1) PCOS patients are more susceptible to hypocapneic central apnea than normal females. 2) While the change in PETCO2 to apneic threshold was lower in PCOS patients, upper airway resistance was not significantly different, indicating that factors that may impose a load upon the upper airway may not influence the susceptibility to develop central apnea. ABSTRACT • Sleep disordered breathing (SDB) is highly prevalent in females with polycystic ovary syndrome (PCOS). • There is a strong link between androgens and increased prevalence of SDB. • Exogenous testosterone induces sleep apnea and even decreases upper airway (UA) patency in females. • Differences in hormonal states (decreased progesterone or increased testosterone) may contribute to the pathogenesis of SDB. PETCO2 -AT is decreased in women with PCOS (*p=0.076) compared to normal control. RUA is not different between normal women and those with PCOS (p=0.14). INTRODUCTION In patients with PCOS the PETCO2 -AT correlates strongly with BMI (r2=0.97 p=0.005) in contrast to thecontrol group (r2=-0.59 p=0.29).No correlation between age, neck circumference or RUA and PETCO2 -AT in either group. HYPOTHESES Apneic threshold is lower in PCOS patients and upper airway resistance is higher compared to matched control. SUBJECTS & METHODS • PCOS patients are more susceptible to develop hypocapneic central apnea than normal females. • Increased BMI in PCOS patients enhances the susceptibility to develop hypocapneic apnea. Pressure catheter