SESSION TYPE: Sleep Posters
PRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PM
PURPOSE: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome (OSA) are frequently encountered diseases, their coexistence (overlap syndrome = OS) is due to chance and the prevalence is 0.5-1%. The literature shows that OS is associated with more severe nocturnal desaturation.
METHODS: We conducted a retrospective study, analysing two populations, each of 24 patients with smoking history, diagnosed with OSA (apnea-hipopnea index AHI >5/h),one associating COPD, matched by gender , smoking status, age and AHI, regarding anthropometric variables, Epworth scale (ESS), pack-year index (PY), daytime saturation (SaO2) and sleep study reports.Patients with central apnea syndrome, obesity-hypoventilation syndrome and restrictive ventilatory disfunction were excluded. For the analysis we used SPSS (T-test, Chi test, Pearson correlation).
RESULTS: OS patients are heavier smokers (PY=43.79±25.97vs17.79±12.33), more obese (BMI=40.3±7 vs34.3±4.93kg/m2), more sleepy (ESS=12.79±6.42 vs 8.75±6.86), have lower daytime SaO2 (91.87±5.39 vs 96.55±1.23%) compared to OSA patients, without any significant differences regarding neck circumference and ENT alterations.After CPAP, OS patients have a higher hypopnea index (23.4±14.47vs10.05±11.01/h) and greater nocturnal desaturation (67.76±25.14 vs 13.26±18.82%). Both before and after titration, OS patients have a greater hypopnea index (149.58±83.52 vs12.46±15.4, p<0.001) and smaller apnea index (13.18±13 vs 29.91±23.6,p=0.005) compared to OSA patients. Pulmonary function (FEV1) correlates with the obesity degree (r= -0.31, p=0.03), oxygen saturation (r=0.56, p<0.001), minimum nocturnal O2 level (r= 0.83, p<0.001) as was expected, and surprisingly with apnea index (r=0.44, p=0.002) and hypopnea index (r= -0.72, p<0.001).CPAP properly corrects the respiratory events in both groups of patients, but nocturnal hypoxaemia is still an issue in OS patiens.
CONCLUSIONS: Patients with OS are more obese, more sleepy and, at similar values of AHI, have less apnea and more hypopnea events compared to OSA patients; this differences persist under CPAP and are correlated with the pulmonary function. Studies are necessary to elucidate the pathophysiology of this peculiarity.
CLINICAL IMPLICATIONS: Due to these consequences of the overlap syndrome, it is recommended to actively search for its existence in COPD patients.
DISCLOSURE: The following authors have nothing to disclose: Oana Deleanu, Diana Pocora, Dan Mihaicuta, Oana Arghir, Paraschiva Postolache, Ruxandra Ulmeanu, Florin Mihaltan
No Product/Research Disclosure InformationUniversity of Medicine and Pharmacy “Carol Davila”, Bucharest, Romania