[Show abstract][Hide abstract] ABSTRACT: Obstructive sleep apnea can induce chronic intermittent hypoxia (CIH) during sleep and is associated with obesity and diabetes. Resveratrol (RSV), a polyphenolic phytoalexin, can regulate glucose metabolism, thereby reducing insulin resistance. The present study aimed to assess whether RSV attenuates CIH‑induced insulin resistance in rats and the underlying mechanisms. A total of 40 rats were randomly assigned into five groups: i) Control; ii) subjected to CIH only; iii) subjected to CIH and treated with 3 mg/kg/day of RSV; iv) subjected to CIH and treated with 30 mg/kg/day of RSV; v) subjected to CIH and treated with 60 mg/kg/day of RSV. All animals were sacrificed following 28 days of treatment. Subsequently, the blood and livers were harvested and blood insulin and glucose levels were measured. Levels of sirtuin (Sirt) 1, insulin receptor (InsR) and glucose transporter 2 (Glut2) in the liver were measured. RSV treatment was demonstrated to suppress weight gain and improve hepatic morphology. RSV treatment also significantly reduced the homeostasis model assessment estimate of insulin resistance of the rats exposed to CIH. This effect occurred in a dose‑dependent manner. RSV significantly upregulated liver Sirt1 levels and inhibited InsR and Glut2 expression in the liver. Additionally, RSV activated the phosphorylation of phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K) and AKT. The present study demonstrates that RSV prevents CIH‑induced insulin resistance in rats. Upregulation of Sirt1 and activation of PI3K/AKT signaling may be involved in this process.
Molecular Medicine Reports 10/2014; · 1.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Inflammation is involved in the mechanism of obstructive sleep apnoea syndrome (OSAS). Omentin, a newly discovered adipokine, is implicated to play an anti-inflammatory role. This study aims to determine whether serum levels of omentin-1 are associated with the presence and severity of OSAS. METHODS: This study consisted of 192 patients with OSAS and 144 healthy subjects. Serum levels of omentin-1 were measured using enzyme-linked immunosorbent assay. RESULTS: Serum omentin-1 levels were significantly decreased in OSAS patients compared with healthy controls. Multivariable logistic regression analysis revealed that serum omentin-1 levels were inversely associated with the presence of OSAS (odds ratio 0.520, 95% confidence interval 0.433 to 0.623; P < 0.001). Severe OSAS patients had significantly lower serum omentin-1 levels compared with mild and moderate OSAS patients. Spearman correlation analysis showed that serum omentin-1 levels were correlated with the severity of OSAS. Simple linear regression analysis showed that the serum levels of omentin-1 were negatively correlated with waist circumference, body mass index, systolic blood pressure, homeostasis model assessment of insulin resistance (HOMA-IR), C-reactive protein (CRP), and apnoea-hypopnoea index in patients with OSAS. Furthermore, only HOMA-IR and CRP remained inversely associated with serum omentin-1 after multiple stepwise regression analysis. CONCLUSION: Decreased serum omentin-1 levels could be considered as an independent predictive marker of the presence and severity of OSAS.
Annals of Clinical Biochemistry 04/2013; · 2.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemerin is implicated to be correlated with obesity and inflammation.
This study aims to investigate whether serum chemerin is associated with the presence of obstructive sleep apnea syndrome (OSAS).
A total of 132 patients with OSAS and 108 healthy subjects were enrolled in this study.
Serum chemerin levels were significantly elevated in OSAS patients (120.93 ± 25.84 µg/L vs. 107.51 ± 20.41 µg/L). Multivariable logistic regression analysis revealed that serum chemerin levels were an independent determinant of the presence of OSAS (OR 1.030, 95% CI 1.016-1.045; p < 0.001). Serum chemerin levels in severe OSAS patients were significantly higher compared with those in mild and moderate OSAS patients (p = 0.015 and p = 0.020, respectively). Spearman correlation analysis indicated that serum chemerin levels were correlated with the severity of OSAS (r = 0.210, p = 0.016). Serum chemerin were positively correlated with waist circumference (r = 0.164, p = 0.008), body mass index (r = 0.158, p = 0.014), systolic blood pressure (r = 0.135, p = 0.037), homeostasis model assessment of insulin resistance (r = 0.140, p = 0.031), C-reactive protein (r = 0.202, p = 0.002), and apnea-hypopnea index (r = 0.152, p = 0.022).
Elevated serum chemerin levels could be an independent predicting marker of the presence and severity of OSAS.