Endocan: a novel predictor of endothelial dysfunction in obstructive sleep apnea syndrome.

BACKGROUND AND AIMS: Obstructive sleep apnea syndrome (OSA) is an independent risk factor for endothelial dysfunction and cardiometabolic diseases. Plasma endocan levels are elevated in a large number of diseases, and is a novel surrogate endothelial cell dysfunction marker. We aimed to assess the role of serum endocan level as a potential mechanism of endothelial dysfunction in OSA patients. MATERIALS AND METHODS: This was a cohort study in which patients who had undergone a sleep study for diagnosis of OSA were recruited. Included patients were grouped according to apnea-hypopnea index (AHI) as mild, moderate and severe OSA. Patients with AHI < 5 served as control group. Endothelial function was evaluated with flow-mediated dilatation (FMD). Plasma endocan level was measured for all patients. RESULTS: One hundred twenty eight OSA patients included (15 controls, 22 with mild, 22 with moderate and 69 with severe OSA). The mean age was 51.6 ± 11.9 years and 43.8% (56/128) of the study population was female. As expected, the prevalence of hypertension, diabetes and cardiovascular disease increased as the severity of OSA increased. Endocan levels were significantly higher and FMD measurements were lower in patients with OSA compared to healthy controls. There was a positive correlation between AHI and serum endocan levels (rho = 0.826, P < 0.0001) and there was a negative correlation between AHI and FMD (rho = -0.686, P < 0.0001) In addition, we observed a strong negative correlation between serum endocan level and FMD (rho = -0.613, P < 0.0001). In linear regression analysis AHI was independently related both with endocan (P < 0.0001) and FMD (P = 0.011). CONCLUSION: Serum endocan level is strongly associated with the severity of OSA and endothelial dysfunction. Endocan might be a useful early novel marker for premature vascular endothelial system damage in OSA patients.

Obstructive sleep apnea is a risk factor for osteoarthritis.

INTRODUCTION: Obstructive sleep apnea (OSA) syndrome is closely associated with cardiovascular and metabolic disorders. Recent studies reported that osteoarthritis (OA) is associated with cardiovascular disease as well as inflammation defined as "metabolic disorder". Due to the strong association of metabolic disorders with both OA and OSA, we aimed to investigate the association between severity of OSA and osteoarthritis grade based on X-Ray. MATERIALS AND METHODS: Patients who underwent polysomnography due to suspicion of OSA were recruited in a cross-sectional study. Included patients were grouped according to apnea-hypopnea index (AHI) as mild (AHI between 5 and 14.9), moderately (AHI between 15 and 29.9), and severe OSA (AHI ≥ 30). Patients with AHI p< 5 served as the control group. Kellgren-Lawrence scoring system was used to express OA severity, which was graded as Grade 0, 1, 2, 3 and 4. RESULT: One hundred twenty patients were enrolled into the study. Mean age was 52.4 ± 11.5 years and 56% (68/120) of the patients were male. A strong correlation was present between severity of OSA and severity of OA. Among those with Grade 4 OA group (33 patients), all patients had severe OSA and this association was independent from body-mass index. In the Grade 1 OA group, none of the patients had severe OSA (p< 0.05). A positive correlation was also seen between severity of OSA, OA and hs-CRP. CONCLUSIONS: There is a strong association between OSA and OA. OSA might be a novel risk factor for the development OA. Further studies should evaluate the effect of OSA treatment on OA.

Differences in leptin, ghrelin, and glucagon-like peptide-1 levels between religious fasting and normal fasting

Background/aim: Leptin, ghrelin, and glucagon-like peptide-1 (GLP-1) affect hunger, satiety feelings, and food intake. We hypothesized that during Ramadan, if the brain knows that the body will be hungry until sunset, there may be differences between leptin, ghrelin, and GLP-1 levels in Ramadan and non-Ramadan fasting. Materials and methods: This study had two phases. In the first phase, the participants were asked to skip the dawn meal of Ramadan (suhur), so that 12 h of fasting could be achieved. Participants ceased food intake at midnight, and at noon blood was drawn. Eight participants were selected as a subgroup. These participants gave blood three times a day to detect hormonal changes during Ramadan. Six months later, in the second phase, blood samples were obtained at noon from participants after 12 h of fasting. Results: Analysis was conducted on 30 patients [19 males (63.3%) and 11 females (36.7%)]. There was a significant difference in leptin, ghrelin, and GLP-1 levels between Ramadan fasting and non-Ramadan fasting (P = 0.04, P = 0.02, and P < 0.001, respectively). In the subgroup analysis, there was no statistically significant difference in leptin, ghrelin, and GLP-1 levels over time. Conclusion: The results of this study suggest that the nervous and gastrointestinal systems may behave differently in religious fasting than in nonreligious fasting.