Vascular endothelial growth factor levels in patients with obstructive sleep apnea: a meta-analysis

Analysis of Macular Vascularization Using Optical Coherence Tomography Angiography in Patients with Obstructive Sleep Apnea Syndrome: A Prospective Clinical Study

Background and Objectives: Given the conflicting data available in the literature, this study aimed to investigate the impact of obstructive sleep apnea syndrome (OSAS) on the macular vascular density (VD) and perfusion density (PD). Materials and Methods: Based on the obstructive apnea-hypopnea index (OAHI), 61 prospectively recruited patients were assigned to either a control group (n = 12; OAHI < 5/h) or an OSAS group (n = 49; OAHI ≥ 5/h). The macular VD and PD of the superficial and deep capillary plexuses (SCP and DCP, respectively) were measured in the parafoveolar and perifoveolar areas using Zeiss PLEX Elite 9000 (6 × 6 mm). The values were compared between the control and OSAS groups. Results: Compared with the control group, the OSAS group demonstrated an increased VD of the DCP in the parafoveolar and perifoveolar areas and PD of the DCP in the perifoveolar area. No significant differences in either the macular VD or PD of the SCP were observed. There was no correlation between the OAHI and macular VD or PD. Conclusions: This study indicates that collateral vessel formation and possible retinal vasodilation occur in the DCP of patients with OSAS.

Potential Diagnostic and Monitoring Biomarkers of Obstructive Sleep Apnea-Umbrella Review of Meta-Analyses

Obstructive sleep apnea (OSA) is a prevalent, underdiagnosed disease that imposes a significant impact on the health and wellbeing of patients and a financial burden on individuals, their families, and society. Development of new methods of testing other than an overnight sleep study, such as measurement of serum or plasma biomarkers, may provide an easier diagnostic process to identify patients with OSA and allow earlier initiation of treatment, which might prevent serious comorbidities. We conducted a systematic review and quality assessment of available meta-analyses regarding potential diagnostic and monitoring biomarkers of obstructive sleep apnea. A total of 14 sets of candidate biomarkers displayed differences in levels or concentrations in OSA patients compared to non-OSA controls, and decreased after OSA treatment: CRP, IL-6, TNF-α, Il-8, HCY, ICAM-1, VCAM-1, VEGF, TC, LDLc, HDLc, TG, leptin, MDA, ALT, AST, IGF-1, adiponectin, and cortisol. This review summarizes the evidence for OSA-associated potential biomarkers and demonstrates that the quality of available studies, as measured by AMSTAR2, is often low and associated with a high risk of bias.

Sleep, cardiovascular risk factors, and kidney function: The Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVES

Examine the associations of sleep measures with kidney function changes over time among individuals from a community-based study.

METHODS

The sample includes 1657 participants (287 with chronic kidney disease [CKD]) in the Multi-Ethnic Study of Atherosclerosis Sleep Cohort (mean age: 57.7 years, male: 46.0%). We examined associations between a large set of sleep variables (polysomnography, actigraphy, and questionnaires) and cardiovascular disease risk factors and changes in estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio over approximately 5 years using high-dimensional regression. We investigated the modifying effect of sleep on the associations between cardiovascular disease risk factors and kidney function.

RESULTS

Sleep metrics predicted kidney function decline only among individuals with baseline CKD. Among this group, eGFR decline was associated with decreased stage N3 sleep (0.32 mL/min/1.73 m2/y per 10% decrease in N3, p < .001); increased actigraphy napping frequency (beta: -0.20 [-0.30, -0.07]); and actigraphy sleep midpoint trajectory in early morning (ref: midnight, beta: -0.84 [-1.19, -0.50]). Urinary albumin-to-creatinine ratio increase was associated with high wake bouts trajectory (ref: low, beta: 0.97 [0.28, 1.67]) and increased sleep-related hypoxemia (oxygen saturation %time<90 [≥5%], beta: 2.17 [1.26, 3.08]). Sleep metrics--N3 sleep, naps, and midpoint trajectory--significantly modified associations between hemoglobin A1C and eGFR decline.

CONCLUSIONS

Reduced deep sleep, daytime napping, increased wake bouts, delayed sleep rhythms, and overnight hypoxemia are associated with longitudinal kidney function decline, with effects most apparent in individuals with CKD. Deep sleep, napping, and sleep timing modified the association between hemoglobin A1C and kidney function.

Pathway-Specific Polygenic Risk Scores Identify Obstructive Sleep Apnea-Related Pathways Differentially Moderating Genetic Susceptibility to Coronary Artery Disease

BACKGROUND

Obstructive sleep apnea (OSA) and its features, such as chronic intermittent hypoxia, may differentially affect specific molecular pathways and processes in the pathogenesis of coronary artery disease (CAD) and influence the subsequent risk and severity of CAD events. In particular, competing adverse (eg, inflammatory) and protective (eg, increased coronary collateral blood flow) mechanisms may operate, but remain poorly understood. We hypothesize that common genetic variation in selected molecular pathways influences the likelihood of CAD events differently in individuals with and without OSA, in a pathway-dependent manner.

METHODS

We selected a cross-sectional sample of 471 877 participants from the UK Biobank, with 4974 ascertained to have OSA, 25 988 to have CAD, and 711 to have both. We calculated pathway-specific polygenic risk scores for CAD, based on 6.6 million common variants evaluated in the CARDIoGRAMplusC4D genome-wide association study (Coronary ARtery DIsease Genome wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics), annotated to specific genes and pathways using functional genomics databases. Based on prior evidence of involvement with intermittent hypoxia and CAD, we tested pathway-specific polygenic risk scores for the HIF1 (hypoxia-inducible factor 1), VEGF (vascular endothelial growth factor), NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) and TNF (tumor necrosis factor) signaling pathways.

RESULTS

In a multivariable-adjusted logistic generalized additive model, elevated pathway-specific polygenic risk scores for the Kyoto Encyclopedia of Genes and Genomes VEGF pathway (39 genes) associated with protection for CAD in OSA (interaction odds ratio 0.86, P=6×10-4). By contrast, the genome-wide CAD PRS did not show evidence of statistical interaction with OSA.

CONCLUSIONS

We find evidence that pathway-specific genetic risk of CAD differs between individuals with and without OSA in a qualitatively pathway-dependent manner. These results provide evidence that gene-by-environment interaction influences CAD risk in certain pathways among people with OSA, an effect that is not well-captured by the genome-wide PRS. This invites further study of how OSA interacts with genetic risk at the molecular level and suggests eventual personalization of OSA treatment to reduce CAD risk according to individual pathway-specific genetic risk profiles.

Evaluation of VEGF-A and CCL2 in dogs with brachycephalic obstructive airway syndrome or canine idiopathic pulmonary fibrosis and in normocephalic dogs

Brachycephalic obstructive airway syndrome (BOAS) and canine idiopathic pulmonary fibrosis (CIPF) of West Highland White Terriers (WHWTs) often cause intermittent or chronic hypoxemia. Our objective was to evaluate serum and bronchoalveolar lavage fluid (BALF) concentrations of hypoxemia-related proinflammatory mediators vascular endothelial growth factor A (VEGF-A) and chemokine (CC motif) ligand 2 (CCL2) in brachycephalic dogs (BDs) and WHWTs with and without CIPF. Additionally, effects of BOAS severity and ageing on these mediators were assessed. 114 BDs (28 English Bulldogs (EBs), 37 French Bulldogs, 49 Pugs), 16 WHWTs with CIPF, 26 healthy WHWTs, and 39 normocephalic control dogs were included. Fifty-four BDs were re-examined after two to three years. Bead-based immunoassay was used for proinflammatory mediator measurements. Compared with controls, significantly higher serum concentrations of VEGF-A were seen in EBs (P = 0.009) and of CCL2 in CIPF and healthy WHWTs (P < 0.001; P = 0.002). BALF samples were available from controls, EBs, and WHWTs. VEGF-A was significantly lower in EBs (P < 0.001) and in CIPF and healthy WHWTs (P = 0.006; P = 0.007) and CCL2 was higher in CIPF WHWTs (P = 0.01) compared with controls. Between visits, only serum VEGF-A significantly decreased in BDs (P < 0.001), but breed, BOAS severity, or its change had no significant effect. In conclusion, in EBs with BOAS proinflammatory changes in VEGF-A were detected in both serum and BALF. Ageing reduced serum VEGF-A in BDs. In WHWTs, our results confirmed earlier findings of CCL2 as an important biomarker for CIPF.

[The role of biomarkers in the detection of the OSA syndrome. A narrative review of the literature]

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common sleep-related breath disorder associated with cardiovascular and cerebrovascular complications, such as hypertension, arrhythmia, coronary artery disease and stroke. Unfortunately, OSA is underdiagnosed.

BACKGROUND

Because of its clinical and therapeutic variability, OSA could benefit a personalized medicine approach. Diagnosis with polysomnography is expensive and access is limited. Clinical scoring systems allow screening of OSA, but many limitations exist. Because of this, biomarkers could be useful for the detection of OSA.

OUTLOOK

Biomarkers specific to OSA would allow for better mass screening and more personalized treatment of the disease. This narrative review of the literature aims to summarize the biomarkers already described for the diagnosis of OSA and clarify both their advantages and limitations in daily practice.

CONCLUSIONS

Our review of the literature did not actually identify an ideal biomarker even if promising research is ongoing.

Coagulation and Fibrinolysis in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a common disease which is characterised by repetitive collapse of the upper airways during sleep resulting in chronic intermittent hypoxaemia and frequent microarousals, consequently leading to sympathetic overflow, enhanced oxidative stress, systemic inflammation, and metabolic disturbances. OSA is associated with increased risk for cardiovascular morbidity and mortality, and accelerated coagulation, platelet activation, and impaired fibrinolysis serve the link between OSA and cardiovascular disease. In this article we briefly describe physiological coagulation and fibrinolysis focusing on processes which could be altered in OSA. Then, we discuss how OSA-associated disturbances, such as hypoxaemia, sympathetic system activation, and systemic inflammation, affect these processes. Finally, we critically review the literature on OSA-related changes in markers of coagulation and fibrinolysis, discuss potential reasons for discrepancies, and comment on the clinical implications and future research needs.

Correlation between OSAHS and Early Peripheral Atherosclerosis Indices in Patients with Type 2 Diabetes Mellitus in China: A Cross-Sectional Inpatient Study

OBJECTIVE

To analyze the differences of early atherosclerosis indices in type 2 diabetes mellitus (T2DM) patients with different degrees of obstructive sleep apnea-hypopnea syndrome (OSAHS) and explore the correlation between them, so as to provide a new clinical basis for the prevention and treatment of early atherosclerosis in patients with T2DM and OSAHS. Methods. A prospective study was conducted in 312 patients with T2DM and snoring who were hospitalized in the Department of Endocrinology, Peking University International Hospital from January 2017 to January 2020. According to the monitoring results, 312 patients were divided into 4 groups including the control group (208 cases), mild OSAHS group (18 cases), moderate OSAHS group (38 cases), and severe OSAHS group (48 cases). Multivariate logistic regression analysis was used to analyze the early atherosclerosis indices including brachial-ankle pulse wave velocity (PWV) and ankle-brachial index (ABI) in patients with T2DM coexistence with different degrees of OSAHS. Results. (1) As the degree of OSAHS increased, ABI decreased gradually and was lower than that in the control group, but PWV increased and was higher than that in the control group (p < 0.05, respectively). (2) The apnea-hypopnea index (AHI) positively correlated with PWV (r = 0.36, p < 0.05) and negatively correlated with ABI (r = -0.37, p < 0.05). (3) Multivariate logistic regression showed that after adjusting for age, gender, duration, BMI, blood pressure, blood glucose, blood lipid, and other factors, OSAHS was a risk factor of lower extremity arterial disease (LEAD) in patients with T2DM. With the increase of degree of OSAHS, the risk of lower extremity atherosclerosis gradually increased. Conclusion. OSAHS is an independent risk factor of LEAD in patients with T2DM, and with the increase of AHI, the ABI and PWV have changed, which provides a new clinical basis for the prevention and the treatment of early atherosclerosis in patients with T2DM and OSAHS.

Prothrombotic Factors in Obstructive Sleep Apnea: A Systematic Review With Meta-Analysis

BACKGROUND

Previous studies revealed that the prothrombotic factors in patients with obstructive sleep apnea (OSA) remain controversial.

AIM/OBJECTIVE

The aim of the systematic review is to elucidate the relationship between prothrombotic factors and OSA.

MATERIALS AND METHODS

This systematic review was performed under the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The literature we investigated was extracted from 4 main medical databases (PubMed, Web of Science, Cochrane Library, and Chinese databases) as of February 2020. We used significant weighted mean differences (SMDs) with 95% CIs from random-effects model.

RESULTS

A total of 15 studies comprising 2190 patients were available for the meta-analysis. The pooled results showed that the levels of fibrinogen (SMD = 0.95, 95% CI = 0.26 to 1.65, P = .000), vascular endothelial growth factor (SMD = 0.37, 95% CI = -0.90 to 1.63, P = .000), and plasminogen activator inhibitor 1 (SMD = 0.61, 95% CI = 0.29 to 0.92, P = .040) increased in patients with OSA. There were no statistical differences between groups in terms of d-dimer (P = .108) and platelet counts (P = .233). Subgroup analyses demonstrated that specimen types and age could account for the heterogeneity.

CONCLUSIONS AND SIGNIFICANCE

This meta-analysis indicated the relationship between prothrombotic factors in OSA hypopnea. Obstructive sleep apnea-related effects may underline the importance of considering the dysfunction of the hemostatic system. The prothrombotic factors in OSA can influence making a choice of appropriate therapy.

Diastolic dysfunction in men with severe obstructive sleep apnea syndrome but without cardiovascular or oxidative stress-related comorbidities

Background:

We aimed to evaluate whether the severity of obstructive sleep apnea syndrome (OSAS) per se affects the prevalence of left ventricular (LV) diastolic dysfunction in patients without comorbidities.

Methods:

A total of 42 patients with first-diagnosed severe OSAS [apnea–hypopnea index (AHI) > 30] and 25 controls (AHI < 5), having been referred for snoring to the Sleep Laboratory Department of our tertiary Hospital, were enrolled in the study. Inclusion criteria were absence of any cardiovascular or oxidative stress-related comorbidities, and age between 20 and 70 years. Clinical, laboratory, echocardiographic, and polysomnographic data were recorded prospectively. Diastolic dysfunction diagnosis and grading was based on 2016 ASE/EACVI recommendations.

Results:

Severe OSAS was associated with significantly increased prevalence and degree of diastolic dysfunction (26/42; 61.9%) compared with controls (7/25; 28%) (p = 0.007). AHI ⩾ 55 (dichotomous value of severe OSAS subset) was also characterized by greater prevalence and degree of diastolic dysfunction compared with 30 < AHI < 55 patients (p = 0.015). In the severe OSAS subset, age >45 years-old, height <1.745 m, body-mass index (BMI) >27.76 kg m⁻², OSAS severity (AHI > 57.35), oxidative stress (overnight reduction of reduced to oxidized glutathione ratio < 18.44%), and BMI/height ratio > 16.155 kg m⁻³ (an index describing ‘dense’, short-heavy patients) presented significant diagnostic utility in identifying diastolic dysfunction in ROC-curve analysis (0.697 ⩾ AUC ⩾ 0.855, 0.001 ⩽ p ⩽ 0.018). In binary logistic regression model, advanced age (OR 1.23, 95% CI 1.025–1.477; p = 0.026) and AHI (OR 1.123, 95% CI 1.007–1.253; p = 0.036) showed independent association with diastolic dysfunction in severe OSAS.

Conclusions:

The present prospective study may suggest that severe OSAS is significantly associated with LV diastolic dysfunction; OSAS clinical severity exerts a positive influence on (and possibly constitutes an independent risk factor of) LV diastolic dysfunction.

The reviews of this paper are available via the supplementary material section.

Cardiotoxicity with vascular endothelial growth factor inhibitor therapy

Angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway (VSP) have been important additions in the therapy of various cancers, especially renal cell carcinoma and colorectal cancer. Bevazicumab, the first VSP to receive FDA approval in 2004 targeting all circulating isoforms of VEGF-A, has become one of the best-selling drugs of all times. The second wave of tyrosine kinase inhibitors (TKIs), which target the intracellular site of VEGF receptor kinases, began with the approval of sorafenib in 2005 and sunitinib in 2006. Heart failure was subsequently noted, in 2-4% of patients on bevacizumab and in 3-8% of patients on VSP-TKIs. The very fact that the single-targeted monoclonal antibody bevacizumab can induce cardiotoxicity supports a pathomechanistic role for the VSP and the postulate of the "vascular" nature of VSP inhibitor cardiotoxicity. In this review we will outline this scenario in greater detail, reflecting on hypertension and coronary artery disease as risk factors for VSP inhibitor cardiotoxicity, but also similarities with peripartum and diabetic cardiomyopathy. This leads to the concept that any preexisting or coexisting condition that reduces the vascular reserve or utilizes the vascular reserve for compensatory purposes may pose a risk factor for cardiotoxicity with VSP inhibitors. These conditions need to be carefully considered in cancer patients who are to undergo VSP inhibitor therapy. Such vigilance is not to exclude patients from such prognostically extremely important therapy but to understand the continuum and to recognize and react to any cardiotoxicity dynamics early on for superior overall outcomes.