Correlation between endothelial dysfunction, Rho-associated protein kinase activity, C-reactive protein and obstructive sleep apnoea syndrome in male patients

Reduced Peripheral Blood Mononuclear Cell ROCK1 and ROCK2 Levels in Obstructive Sleep Apnea Syndrome

BACKGROUND/AIM

Obstructive sleep apnea syndrome (OSAS) is associated with intermittent episodes of hypoxia, endothelial dysfunction and associated cardiovascular problems. Our aim was to investigate whether OSAS-related hypoxia alters the expression of rho-associated protein kinase (ROCK), a marker of chronic hypoxia and endothelial dysfunction.

MATERIALS AND METHODS

ROCK1 and ROCK2 levels were measured by immunoblotting in peripheral blood mononuclear cells (PBMC) of 47 OSAS patients and 17 healthy controls.

RESULTS

OSAS patients showed significantly lower PBMC ROCK1 and ROCK2 levels than healthy controls in the morning, but not in the evening. ROCK1/2 levels were correlated with blood triglyceride, visceral adiposity index, minimum oxygen saturation, C-reactive protein concentration, lymphocyte levels and sleep efficiency.

CONCLUSION

Intermittent hypoxia induced by OSAS does not permanently alter ROCK protein expression levels. OSAS appears to be associated with endothelial dysfunction through inflammation and lipid metabolism pathways.

Patients with Obstructive Sleep Apnea Display Decreased Flow-Mediated Dilatation: Evidence from a Meta-Analysis

Background

Endothelial dysfunction, which can be measured by flow-mediated dilatation (FMD), is an early clinical marker of atherosclerosis, which is considered to be the main cause of the observed cardiovascular complications in obstructive sleep apnea (OSA) patients. The association between OSA and endothelial dysfunction has been reported in a number of studies; however, the findings are not entirely consistent. Our aim was to meta-analytically synthesize the existing evidence to explore the association between OSA and endothelial dysfunction.

Material/Methods

Data from PubMed, EMBASE, the Cochrane library, and Google Scholar for all trials that investigated the relationship between endothelial dysfunction and OSA were systematically reviewed. The minimum inclusion criteria for the studies were reporting of the Apnea-Hypopnea Index (AHI) and FMD measurements (as an indicator of endothelial dysfunction) for both OSA and control groups. Data from case-control studies that met the inclusion criteria were extracted.

Results

Twenty-eight studies comprising a total of 1496 OSA patients and 1135 controls were included in the meta-analysis. A random-effects model was used. The weighted mean difference in the FMD measurements was −3.07 and the 95% confidence interval was −3.71 to −2.43 (P<0.01). Meta-regression analysis showed that age, sex, body mass index (BMI), blood pressure, glucose, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol did not explain the heterogeneity.

Conclusions

This meta-analysis showed that patients with OSA have decreased FMD, which may contribute to the development of atherosclerosis.