Journal of physiology and pharmacology : an official journal of the Polish Physiological Society
-
J. Physiol. Pharmacol. · Dec 2008
The influence of obesity on sleep quality in male sleep apnea patients before and during therapy.
Evidence exists that obesity, even in the absence of sleep related respiratory disorders, affects sleep negatively. In this study we examined the influence of obesity on sleep quality of male sleep apnea patients before and after breathing normalization with continuous positive airway pressure (CPAP). We compared the polysomnography from the diagnostic night, second night with CPAP, and a control night (three months later) in 13 non-obese, 13 obese, and 12 severely obese male obstructive sleep apnea patients. ⋯ In the second night under CPAP, normalization of the AHI and a rebound of REM and SWS occurred, which was more pronounced in severely obese than in the non-obese and obese group. The polysomnography recorded three months thereafter revealed no differences in sleep stages between the groups. We conclude that after the long-term CPAP therapy, no effect of obesity on sleep quality is apparent.
-
J. Physiol. Pharmacol. · Dec 2008
Significance of pulmonary vagal afferents for respiratory muscle activity in the cat.
The influence of vagal stretch receptor afferents on respiratory motor-output and respiratory changes in esophageal pressure (DeltaP(es)) was studied in anaesthetized cats. Tracheal occlusions and lung inflations were performed during hyperoxic normocapnia, during electrical stimulation of one carotid sinus nerve (CSN) or the intracranial medullary chemosensitivity (MCS), during hypercapnia or the combination of CSN and hypercapnia. Tracheal occlusions during inspiration led to increased and prolonged inspiratory muscle (IM) activity. ⋯ The sensitivity of the lung reflexes is enhanced with increasing respiratory drive. The HB-inspiration inhibitory reflex limits the depth of lung inflation, whereas the HB-expiration facilitatory reflex promotes an effective lung deflation. Both reflex mechanisms, the inspiratory and expiratory one, are present in eupnoeic breathing, but play an important role during increased chemoreflex drive and obstruction of expiration, e.g., with increased external airway resistance.