Roles of periostin in patients with severe obstructive sleep apnea

Abstract

Background: The roles of periostin in patients with severe obstructive sleep apnea (OSA) remain unclear. Aims and objectives Serum periostin is a marker of type-2 inflammation and tends to increase in non-obese patients with asthma. Meanwhile‚ several in vitro studies suggest that impaired glycolipid metabolism, mechanical stress and hypoxia upregulate expression of periostin. Here‚ we aimed to clarify roles of periostin in patients with OSA‚ who are often obese but accompanied by these conditions. Methods: In patients diagnosed as having OSA‚ we examined associations between serum periostin levels and clinical indices‚ such as severity of OSA‚ body mass index (BMI)‚ and blood glucose and lipids. Assessments were done at baseline and after 3 months of continuous positive airway pressure (CPAP) treatment. Results: In 96 patients with OSA‚ serum periostin levels positively correlated with age and blood glucose and tended to correlate with BMI negatively (p = 0.055). When adjusted for BMI‚ severe OSA (apnea hypopnea index ≥ 30) tended to associate with elevated serum periostin (p = 0.07). Among 53 patients with severe OSA‚ patients with high serum periostin levels (highest quartile‚ ≥ 85ng⁄mL, n = 13) showed higher free fatty acid‚ fasting blood glucose and frequency of micro⁄overt albuminuria than those with severe OSA alone. In patients with severe OSA and high serum periostin‚ serum periostin and urinary albumin levels were significantly decreased after 3 months of CPAP treatment. Conclusions Serum periostin levels tend to increase in severe OSA‚ when adjusted for BMI. Elevated serum periostin in patients with severe OSA may indicate the risk of albuminuria‚ which could be reduced with CPAP treatment.