Short-term effects of continuous positive airway pressure on oxidative stress in severe sleep apnea

Sleep and Breathing - Obstructive sleep apnea (OSA) is associated with oxidative stress that is involved in the pathogenesis of cardiovascular and metabolic complications. The concentrations of...     

Short‐term effects of continuous positive airway pressure on sex hormones in men and women with sleep apnoea syndrome

Patients with sleep apnoea syndrome (SAS) suffer from symptoms of hypogonadism. Besides surgical interventions, in some cases, the standard care of SAS for most patients is continuous positive airway pressure (CPAP). Studies focusing on the long‐term effects of CPAP on testosterone levels revealed conflicting results. None of the studies included female patients with SAS. The aim of our study was to analyse and compare sex hormone levels in saliva before and after a night without and with CPAP in women and men with SAS. The results were negative. One night with CPAP did not affect the dynamics of sex hormones, neither in men nor in women. Future studies should focus on long‐term effects of CPAP in both genders.     

Oxidative and carbonyl stress in patients with obstructive sleep apnea treated with continuous positive airway pressure

Purpose  

The pathogenesis of cardiovascular complications of obstructive sleep apnea syndrome (OSAS) can be explained by oxidative and carbonyl stress due to oxygenation and reoxygenation injury during sleep. This hypothesis has yet to be proved experimentally, although several clinical observations have found increased oxidative damage in plasma. Continuous positive airway pressure (CPAP) improves symptoms and prognosis of patients with OSAS.     

Antioxidant vitamins prevent oxidative and carbonyl stress in an animal model of obstructive sleep apnea

Purpose

The aim of our study was to analyze the effects of an antioxidant treatment on markers of oxidative and carbonyl stress in a rat model of obstructive sleep apnea.

Methods

Wistar rats were randomized into six groups—according to gender and intervention—sham, intermittent hypoxia, and intermittent hypoxia with treatment by vitamins C and E. Rats underwent tracheostomy. The tracheal cannula was closed for 12 s every minute for 1 h to simulate obstructive sleep apnea-related intermittent hypoxia. In the treatment group, rats received vitamin C and E 24 h prior to surgery.

Results

The intervention had a significant effect on advanced oxidation protein products (p?=?0.008) and advanced glycation end products–specific fluorescence (p?=?0.006) but no effect on malondialdehyde. Oxidation and glycation protein products were higher in intermittent hypoxia groups than in sham and in treated groups.

Conclusions

Antioxidants alleviate oxidative and carbonyl stress in an experimental model of obstructive sleep apnea. Future studies will show whether such treatment has any clinical value regarding cardiovascular complications of sleep apnea syndrome, preferably in patients with low compliance to continuous positive airway pressure.     

Salivary markers of oxidative stress in patients with obstructive sleep apnea treated with continuous positive airway pressure

Purpose

Obstructive sleep apnea syndrome (OSAS) is characterized by elevated oxidative stress. Measurement of oxidative stress in saliva seems to be promising in long-term treatment monitoring of OSAS patients. In this study, our aim was to investigate whether short-term continuous positive airway pressure (CPAP) treatment would influence oxidative stress in saliva.

Methods

Patients with diagnosed OSAS (16 women, 28 men) underwent polysomnography during the first night and CPAP treatment during the second night. Saliva samples were taken in the evening and morning on both days. Markers of oxidative stress and antioxidant status were analyzed in saliva.

Results

Evening concentrations of the salivary thiobarbituric acid reacting substances (p?p?p?Conclusion Salivary markers of oxidative stress and antioxidant status do not change significantly after one night treatment with CPAP. On the contrary, after 1 month with CPAP therapy, reduced markers of oxidative stress were reported. Therefore, the future studies should be focused on finding the optimal sampling frequency to clarify the potential of saliva for the monitoring of OSAS treatment.     

Carotid intima-media thickness is not associated with homocysteine and vitamin D levels in obstructive sleep apnea

Obstructive sleep apnea syndrome (OSA) is associated with increased vascular morbidity. Accelerated atherosclerosis might be one of the most important mechanisms linking OSA with the development of vascular disorders. Homocysteine (HCY) and vitamin D has been associated with atherogenesis. The aim of this study was to assess a possible association between the levels of HCY and vitamin D and the carotid intima-media thickness (cIMT), which is a known marker for subclinical atherosclerosis in patients with OSA. We prospectively enrolled 110 patients with the history of snoring, who underwent standard overnight polysomnography. Clinical characteristics of the population were recorded on admission and blood samples were obtained in the fasting condition following morning. Extracranial cIMT measurements were performed according to the standardized scanning protocol. A significant correlation was found between cIMT and apnea-hypopnea index (r?=?.276, p?=?.006), age (r?=?.486, p?r?=?.377, p?r?=?.274, p?=?.006) and history of stroke (r?=?.251, p?=?.012). We failed to find any significant correlation between cIMT and the levels of HCY (r?=?.036, p?=?.724) or vitamin D (r?=?.027, p?=?.800). In conclusion, our data suggest that the association of cIMT with the severity of OSA can be influenced by multiple metabolic consequences of OSA including traditional and non-traditional risk factors. HCY and vitamin D do not seem to play a superior role in this process.