Hypercapnic Ventilatory Response in Patients With and Without Obstructive Sleep Apnea : Do Age, Gender, Obesity, and Daytime Paco2 Matter?

摘要

Study objective: To evaluate the relationship between obstructive sleep apnea (OSA) andnventilatory responsiveness to carbon dioxide in both men and women.nDesign: An analysis of 219 patients referred to an university-based sleep center between 1989 ton1994 was conducted (104 with OSA and 115 without OSA; 43 women and 176 men). These patientsnhad spirometry and a daytime hypercapnic ventilatory response (HCVR) test that was correctednto the patient’s ability to attain maximal ventilation. Comparisons between OSA and no-OSAngroups, as well as between men and women, were made using multivariate modeling techniques.nResults: There was no significant difference in the slope of correlated HCVR (cHCVR) betweennthose with and without OSA (1.57 6 0.57 vs 1.63 6 0.66; p 5 0.48). In men, an inverse correlationnbetween daytime PCO2 and cHCVR was observed in both crude and multivariate analyses (crudenb-coefficient 52 0.04 6 0.02, p 5 0.02; adjusted b-coefficient 5 0.07 6 0.02, p < 0.01). Al-nthough age and cHCVR did not share a significant relationship in the crude analysis (crudenb-coefficient 52 0.01 6 0.01, p 5 0.10), with adjustments for confounding variables, a signifi-ncant inverse relationship between age and cHCVR was observed (b-coefficient 52 0.02 6 0.01,np 5 0.04). On the other hand, in women, only body mass index (BMI) was positively correlatednwith cHCVR (crude b-coefficient 5 0.03 6 0.01, p 5 0.01; adjusted b-coefficient 5 0.04 6 0.01,np < 0.01).nConclusion: OSA disorder is not associated with a blunted ventilatory chemoresponsiveness toncarbon dioxide. Elevated PaCO2 and older age are significant correlates for a low cHCVR in men.nFor women only, BMI was associated with cHCVR. These findings suggest that men and womennmay have different ventilatory control mechanisms