Continuous positive airway pressure affects mitochondrial function and exhaled PGC1-α levels in obstructive sleep apnea

Abstract

Purpose: Subjects with obstructive sleep apnea (OSA) exhibit systemic and upper airway oxidative stress and inflammation, which cause mitochondrial dysfunction. The intend of this study is to estimate mitochondrial function (mitochondrial DNA/nuclear DNA [Mt/N] ratio) and protein levels of peroxisome proliferator-coactivated receptor gamma co-activator 1-alpha (PGC1-α) in the exhaled breath condensate (EBC) and plasma before and after continuous positive airway pressure (CPAP) treatment. Materials and methods: Twenty healthy individuals (control) and 40 subjects with severe or moderate OSA were recruited to undergo CPAP treatment and evaluation in a sleep study. The Mt/N ratio in the EBC and blood were assayed by quantitative real-time polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the protein concentration of PGC1-α in the EBC and plasma. All experiments were performed after 3 months of CPAP treatment in subjects with OSA. Results: We observed no noteworthy differences between the control and treatment groups. Moreover, there were no differences in the Mt/N ratio in the blood and plasma levels of PGC1-α in subjects with OSA before and after treatment. However, the Mt/N ratio and protein levels of PGC1-α in the EBC of OSA subjects were higher than those in the control group and returned to normal levels after CPAP treatment. Conclusions: We successfully treated subjects with OSA by CPAP, which restored the Mt/N ratio and levels of PGC1-α in the EBC.

Keywords:

• Continuous positive airway pressure
• exhaled breath condensate
• mitochondrial DNA/nuclear DNA ratio
• obstructive sleep apnea
• PGC1-α

Disclosure statement

There are no conflict of interest.

Ethics

All methods were carried out in accordance with the approved guidelines and the Declaration of Helsinki. Ethics committee approval was received from the Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Fundation Research Ethics Committee (approval No: 08-XD-001). All subjects who participated in this study signed informed consent.

Additional information

Funding

The research reported in this publication was supported by the Ministry of Science and Technology (Grant MOST 108-2314-B-303-025).