Serum advanced glycation end products are associated with insulin resistance in male nondiabetic patients with obstructive sleep apnea

Role of gender in explaining metabolic syndrome risk factors in an Iranian rural population using structural equation modelling

Many factors can lead to an increase in the prevalence of metabolic syndrome (MetS) in different populations. Using an advanced structural equation model (SEM), this study is aimed to determine the most important risk factors of MetS, as a continuous latent variable, using a large number of males and females. We also aimed to evaluate the interrelations among the associated factors involved in the development of MetS. This study used data derived from the Fasa PERSIAN cohort study, a branch of the PERSIAN cohort study, for participants aged 35 to 70 years with 10,138 males and females. SEM was used to evaluate the direct and indirect effects, as well as gender effects of influencing factors. Results from the SEM showed that in females most changes in MetS are described by waist circumference (WC), followed by hypertension (HP) and triglyceride (TG), while in males most changes in MetS are described by WC, followed by TG then fasting blood glucose (FBG). Results from the SEM confirmed the gender effects of social status on MetS, mediated by sleep and controlled by age, BMI, ethnicity and physical activity. This study also shows that the integration of TG and WC within genders could be useful as a screening criterion for MetS in our study population.

Advances in Molecular Pathology of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common syndrome that features a complex etiology and set of mechanisms. Here we summarized the molecular pathogenesis of OSA, especially the prospective mechanism of upper? airway dilator fatigue and the current breakthroughs. Additionally, we also introduced the molecular mechanism of OSA in terms of related studies on the main signaling pathways and epigenetics alterations, such as microRNA, long non-coding RNA, and DNA methylation. We also reviewed small molecular compounds, which are potential targets for gene regulations in the future, that are involved in the regulation of OSA. This review will be beneficial to point the way for OSA research within the next decade.

Possible Preventative/Rehabilitative Role of Gliflozins in OSA and T2DM. A Systematic Literature Review-Based Hypothesis

Obstructive sleep apnoea (OSA) is characterized by frequent apnoea episodes during sleep due to upper airway obstruction. The present review summarizes current knowledge on inter-relationships between OSA and type 2 diabetes mellitus (T2DM) and suggests the former as a possible target for sodium-glucose co-transporter-2 inhibitors (SGLT-2i). Based on pathophysiological mechanisms underlying OSA onset and renal SGLT-2 effects, we suggest that SGLT-2i indications might expand beyond current ones, including glucose, lipids, uric acid, blood pressure, and body weight control as well as chronic heart failure and kidney disease prevention.

The Interaction Between Craniofacial Computed Tomographic Dimensional Parameters and BMI in Obstructive Sleep Apnea

Introduction

The impact of the dimensional parameters of the pharyngeal bony frame by its length, width and the position of the hyoid upon the severity of obstructive sleep apnea syndrome (OSAS) has not been investigated in depth. Interactions of those parameters with body mass index (BMI) and their overall reciprocal effect on OSAS severity have also not been established.

Materials and Methods

This retrospective cross-sectional study was conducted on 108 male OSAS patients followed in OSAS outpatient clinics between November 2014 and October 2015. They all underwent a polysomnography test, and an apnea-hypopnea index (AHI) was calculated. They also underwent an upper airway computerized tomographic scan in which three craniofacial parameters were evaluated: inter-pterygoid distance (IPD), hard palate-to-hyoid (HP-H) distance, and gnathion plane-to-hyoid (GP-H) distance.

Results

A longer pharynx and an inferiorly placed hyoid bone correlated with the AHI (r = 0.33, p = 0.001 and r = 0.226, p = 0.03, respectively). GP-H correlated with body mass index (BMI) (r = 0.3243, p < 0.001), while HP-H and IPD did not. We found an interaction between BMI and HP-H, but none between GP-H and BMI. IPD did not correlate with OSAS severity, but it correlates with the age of the OSAS patients (r = 0.235, p = 0.015).

Conclusion

Pharynx length and hyoid position have significant effects upon OSAS severity, and they interact differently with BMI in terms of those effects. Hard palate width increases with age but has no correlation with OSAS severity.

Interactions between and Shared Molecular Mechanisms of Diabetic Peripheral Neuropathy and Obstructive Sleep Apnea in Type 2 Diabetes Patients

Type 2 diabetes (T2D) accounts for about 90% of all diabetes patients and incurs a heavy global public health burden. Up to 50% of T2D patients will eventually develop neuropathy as T2D progresses. Diabetic peripheral neuropathy (DPN) is a common diabetic complication and one of the main causes of increased morbidity and mortality of T2D patients. Obstructive sleep apnea (OSA) affects over 15% of the general population and is associated with a higher prevalence of T2D. Growing evidence also indicates that OSA is highly prevalent in T2D patients probably due to diabetic peripheral neuropathy. However, the interrelations among diabetic peripheral neuropathy, OSA, and T2D hitherto have not been clearly elucidated. Numerous molecular mechanisms have been documented that underlie diabetic peripheral neuropathy and OSA, including oxidative stress, inflammation, endothelin-1, vascular endothelial growth factor (VEGF), accumulation of advanced glycation end products, protein kinase C (PKC) signaling, poly ADP ribose polymerase (PARP), nitrosative stress, plasminogen activator inhibitor-1, and vitamin D deficiency. In this review, we seek to illuminate the relationships among T2D, diabetic peripheral neuropathy, and OSA and how they interact with one another. In addition, we summarize and explain the shared molecular mechanisms involved in diabetic peripheral neuropathy and OSA for further mechanistic investigations and novel therapeutic strategies for attenuating and preventing the development and progression of diabetic peripheral neuropathy and OSA in T2D.

Serum from obstructive sleep apnea patients induces inflammatory responses in coronary artery endothelial cells

BACKGROUND AND AIMS

Obstructive sleep apnea (OSA) is characterized by intermittent airway obstruction and systemic hypoxia during sleep, which can contribute to an increase in reactive oxygen species, vascular remodeling, vasoconstriction and ultimately cardiovascular disease. Continuous positive airway pressure (CPAP) is a clinical therapy that maintains airway patency and mitigates several symptoms of OSA. However, it is currently unknown whether CPAP therapy also reduces the overall inflammatory potential in the circulation; to address this in an unbiased manner, we applied a novel endothelial biosensor approach, the serum cumulative inflammatory potential (SCIP) assay.

METHODS

We studied healthy controls (n = 7), OSA subjects receiving no treatment, (OSA controls) (n = 7) and OSA subjects receiving CPAP for 3 months (n = 8). Serum was obtained from OSA subjects before and after CPAP or no treatment. A battery of quantitative and functional assays was performed to assess the serum inflammatory potential, in terms of endothelial responses. For the SCIP assay, human coronary artery endothelial cells (hCAECs) were incubated with 5% serum in media from individual subjects for 4 h. qPCR was performed to assess endothelial inflammatory transcript (ICAM-1, VCAM-1, IL-8, P-selectin, CCL5, and CXCL12) responses to serum. Additionally, transendothelial resistance was measured in serum-incubated hCAECs following leukocyte challenge.

RESULTS

hCAECs exhibited significant increases in VCAM-1, ICAM-1, IL-8 and P-selectin mRNA when incubated with serum from OSA patients compared to serum from healthy control subjects. Furthermore, compared to no treatment, serum from CPAP-treated individuals was less potent at inducing inflammatory gene expression in the SCIP assay. Similarly, in a leukocyte adhesion assay, naïve cells treated with serum from patients who received CPAP exhibited improved endothelial barrier function than cells treated with OSA control serum.

CONCLUSIONS

OSA results in greater serum inflammatory potential, thereby driving endothelial activation and dysfunction.

Relationship between serum levels of endogenous secretory RAGE and blood pressure in male nondiabetic patients with obstructive sleep apnea

The interaction of advanced glycation end products (AGE) and their specific cell-surface receptor (RAGE) has an important role in the pathogenesis of cardiovascular disease and diabetic complications. Two isoforms of C-truncated RAGE, soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE), may prevent activation of RAGE signaling by acting as decoys. This study investigated whether serum esRAGE and sRAGE levels are associated with blood pressure in nondiabetic patients with obstructive sleep apnea (OSA). Male nondiabetic patients (n=139) with OSA were enrolled. Serum esRAGE and sRAGE levels were examined using enzyme-linked immunosorbent assay. Three consecutive seated systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements were obtained at 5-min intervals in the morning. In univariate analysis, there was a significant correlation between serum esRAGE and SBP or DBP, but not between serum sRAGE and SBP or DBP. Multiple regression analysis showed that SBP was independently associated with waist circumference, HbA1c, minimum SaO2 and serum esRAGE, and that DBP was independently associated with low-density lipoprotein cholesterol, apnea-hypopnea index, serum AGE and body mass index, but not with serum esRAGE. These results indicated that serum esRAGE levels were inversely associated with blood pressure, especially SBP, in male nondiabetic patients with OSA. esRAGE may have a protective role against hypertension in patients with OSA, and it may be a novel biomarker for OSA patients at high risk of developing cardiovascular diseases.