Galectin-3 and neutrophil-to-lymphocyte ratio are indicative of heart remodelling and disease severity in patients with obstructive sleep apnoea

Unlocking the role of Galectin-3: Implications for sleep disorders and health

Galectin-3 is a member of the lectin family, and is an intriguing protein that is found in diverse tissues across the body. It is known for its multifaceted involvement in various physiological functions, including tissue repair, immune function and neuroinflammation in the central nervous system. It also serves as a paracrine signal, promoting the growth of certain cells and contributing to fibrosis, while higher levels of Galectin-3 in the bloodstream correlate with an increased risk of mortality and cardiovascular disease-related outcomes in the general population. Recent scientific studies have identified a potential link between Galectin-3 and sleep disorders. However, the precise mechanisms through which galectin-3 influences sleep disorders remain an active area of investigation. Although initial studies suggest a potential association between Galectin-3 and sleep disruptions, including conditions, such as insomnia, insufficient sleep time, and obstructive sleep apnea, further research is required to establish a more definitive relationship. This review explores recent findings regarding the potential connection between Galectin-3 and sleep patterns, and offers insights into the complex interplay between this protein and sleep. These discoveries present promising prospects for the development of innovative therapeutic approaches aimed at sleep disorder management, using Galectin-3 as a potential target for interventions or as a biomarker for sleep health.

Role of galectin-3 as a biomarker in obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Because obstructive sleep apnea (OSA) is a prevalent condition, biomarkers for OSA would be very useful. Galectin-3 has gained attention as a marker for several diseases. The aim of this study was to investigate the association between circulating galectin-3 levels and OSA.

METHODS

PubMed, Scopus, Embase, and Web of Science were explored to find the studies evaluating galectin-3 in OSA and controls, within different severities of OSA, or before and after continuous positive airway pressure (CPAP) treatment in cases with OSA. We used random-effect meta-analysis to calculate standardized mean differences (SMD) along with 95% confidence intervals (CI). Newcastle-Ottawa Scale was used assessment of the risk of bias in studies.

RESULTS

An initial search resulted in 289 results. After exclusion of duplicate studies, screening of titles/abstracts and assessments of full texts, six studies were included comprised of 987 cases with a mean age of 54.4 years. Meta-analysis showed that there were significantly higher galectin-3 circulating levels in patients with OSA than in healthy controls (SMD 0.80, 95% CI 0.30 to 1.31, p value < 0.01). Severe OSA was related to higher levels of galectin-3, in comparison to non-severe OSA (SMD 0.76, 95% CI 0.29 to 1.22, p value < 0.01). CPAP therapy also significantly reduced galectin-3 peripheral levels in patients with OSA (SMD - 3.55, 95% CI - 6.90 to - 0.20, p value = 0.04).

CONCLUSION

The findings suggest that Galectin-3 may have potential utility as a biomarker in patients with OSA. Further research is needed to demonstrate its role in pathophysiology, as well as its possible use in diagnosis and prognosis.

Chronic intermittent hypoxia-induced cardiovascular and renal dysfunction: from adaptation to maladaptation

Chronic intermittent hypoxia (CIH) is the dominant pathological feature of human obstructive sleep apnoea (OSA), which is highly prevalent and associated with cardiovascular and renal diseases. CIH causes hypertension, centred on sympathetic nervous overactivity, which persists following removal of the CIH stimulus. Molecular mechanisms contributing to CIH-induced hypertension have been carefully delineated. However, there is a dearth of knowledge on the efficacy of interventions to ameliorate high blood pressure in established disease. CIH causes endothelial dysfunction, aberrant structural remodelling of vessels and accelerates atherosclerotic processes. Pro-inflammatory and pro-oxidant pathways converge on disrupted nitric oxide signalling driving vascular dysfunction. In addition, CIH has adverse effects on the myocardium, manifesting atrial fibrillation, and cardiac remodelling progressing to contractile dysfunction. Sympatho-vagal imbalance, oxidative stress, inflammation, dysregulated HIF-1α transcriptional responses and resultant pro-apoptotic ER stress, calcium dysregulation, and mitochondrial dysfunction conspire to drive myocardial injury and failure. CIH elaborates direct and indirect effects in the kidney that initially contribute to the development of hypertension and later to chronic kidney disease. CIH-induced morphological damage of the kidney is dependent on TLR4/NF-κB/NLRP3/caspase-1 inflammasome activation and associated pyroptosis. Emerging potential therapies related to the gut-kidney axis and blockade of aryl hydrocarbon receptors (AhR) are promising. Cardiorenal outcomes in response to intermittent hypoxia present along a continuum from adaptation to maladaptation and are dependent on the intensity and duration of exposure to intermittent hypoxia. This heterogeneity of OSA is relevant to therapeutic treatment options and we argue the need for better stratification of OSA phenotypes.

Changes in Lipids in Granulomatosis with Polyangiitis Relates to Glucocorticoids and History of Hypertension

Granulomatosis with polyangiitis (GPA) is an ANCA-associated small-vessel vasculitis. Vessel wall inflammation induces multiple vascular damages, leading to accelerated atherosclerosis. Metabolic profile and cardiovascular risk are somewhat understood in GPA patients. Cardiovascular atherosclerotic disease (ASCVD) may represent a risk for outcomes. Our purpose is to evaluate ASCVD risk in GPA patients. Thirty-six patients received GPA diagnosis (T0) and were evaluated after 1 (T1) and 2 (T2) years follow-up. All patients were treated with high-dose glucocorticoid, one-year tapered, along with immunosuppressants. Total cholesterol significantly increased in T1 vs. T0 and T2. LDL exhibited the same trend, while triglycerides increased in both T1 and T2 vs. T0. No difference was found in HDL. A significant hsCRP decrease was detected at T1 and T2 vs. T0, but not between T2 and T1. Moreover, we found a significant reduction in ESR at T2 compared with T1 and T0 and at T1 compared to T0. Hypertensive patients presented a pronounced increase in lipids, while inflammation reduced slowly compared to normotensives. Our data suggest that the increase in cholesterol and LDL in T1 is a consequence of glucocorticoids. These data can be useful in the evaluation of both CV diseases and lipid metabolism, which are closely related to vessel inflammation.

Involvement of Galectin-3 in neurocognitive impairment in obstructive sleep apnea via regulating inflammation and oxidative stress through NLRP3

OBJECTIVE

Accumulated studies have revealed that oxidative stress and inflammation play important roles in the development of OSA related cognitive dysfunction. Galectin-3, a member of the galectin family, has been reported to be involved in the neuroinflammatory diseases. However, the relationship between Galectin-3 and cognitive impairment in OSA remains ambiguous.

MATERIALS AND METHODS

47 new diagnosed OSA patients and 18 age-, gender-, education- and body mass index-matched healthy control subjects were enrolled in the present study. All subjects underwent whole-night in-laboratory polysomnography (PSG). Montreal Cognitive Assessment (MoCA) was used to evaluated the cognitive function of OSA patients. Serum Galectin-3, interleukin (IL)-1β and IL-8 were examined by enzyme-linked immunosorbent assay (ELISA). The levels of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured to evaluate oxidative stress. Protein level of Galectin-3 and NLRP3 in peripheral blood mononuclear cells (PBMCs) and human microglial clone 3 (HMC3) cells were measured by Western Blot.

RESULTS

Serum Galectin-3 level in severe OSA patients (2.31 ± 0.43 ng/m) was higher than those in mild-moderate OSA patients (1.87 ± 0.32 ng/m, p < 0.001) and those in the healthy controls (1.56 ± 0.22 ng/ml, p < 0.001). Similarly, Galectin-3 level in PBMCs was increased with disease severity (p < 0.01). In addition, OSA patients also showed higher levels of inflammation and oxidative stress (p < 0.01). Patients with OSA scored significantly lower than healthy controls on the MoCA test after controlling for age, gender, education, and BMI. CPAP treatment for 12 weeks effectively reduced the levels of Galectin-3, inflammation and oxidative stress, as well as improved cognitive function of severe OSA patients. Closed correlations were observed between Galectin-3 with sleep respiratory parameters and cognitive dysfunction. In addition, we explored the underlying mechanism of Galectin-3 in neuroinflammation and oxidative stress. We treated HMC3 cells with LPS to mimic neuroinflammatory response in vitro. The results showed that LPS treatment led to a dose-dependent increase in Galectin-3 expression, meanwhile induced inflammation and oxidative stress. Inhibiting Galectin-3 with a specific Galectin-3 inhibitor, TD139, significantly ameliorated LPS-induced neuroinflammation and oxidative stress via suppressing NLRP3.

CONCLUSION

Current findings suggest that increased Galectin-3 might be involved in the cognitive impairment of OSA patients by promoting neuroinflammation and oxidative stress via regulating NLRP3. These results suggested that Galectin-3 inhibition may exert a protective role against the neurocognitive dysfunction associated with OSA.

Changes in Left Heart Geometry, Function, and Blood Serum Biomarkers in Patients with Obstructive Sleep Apnea after Treatment with Continuous Positive Airway Pressure

Background: Cardiovascular remodeling is essential in patients with obstructive sleep apnea (OSA), and continuous positive airway pressure (CPAP) therapy could improve these processes. Two-dimensional (2D) speckle-tracking (ST) echocardiography is a useful method for subclinical biventricular dysfunction diagnosis and thus might help as an earlier treatment for OSA patients. It is still not clear which blood serum biomarkers could be used to assess CPAP treatment efficacy. Objectives: To evaluate left heart geometry, function, deformation parameters, and blood serum biomarker (galectin-3, sST2, endothelin-1) levels in patients with OSA, as well as to assess changes after short-term CPAP treatment. Materials and Methods: Thirty-four patients diagnosed with moderate or severe OSA, as well as thirteen patients as a control group, were included in the study. All the subjects were obese (body mass index (BMI) > 30 kg/m2). Transthoracic 2D ST echocardiography was performed before and after 3 months of treatment with CPAP; for the control group, at baseline only. Peripheral blood samples for the testing of biomarkers were collected at the time of study enrolment before the initiation of CPAP therapy and after 3 months of CPAP treatment (blood samples were taken just for OSA group patients). Results: The left ventricle (LV) end-diastolic diameter and volume, as well as LV ejection fraction (EF), did not differ between groups, but an increased LV end-systolic volume and a reduced LV global longitudinal strain (GLS) were found in the OSA group patients (p = 0.015 and p = 0.035, respectively). Indexed by height, higher LV MMi in OSA patients (p = 0.007) and a higher prevalence of LV diastolic dysfunction (p = 0.023) were found in this group of patients. Although left atrium (LA) volume did not differ between groups, OSA group patients had significantly lower LA reservoir strain (p < 0.001). Conventional RV longitudinal and global function parameters (S′, fractional area change (FAC)) did not differ between groups; however, RV GLS was reduced in OSA patients (p = 0.026). OSA patients had a significantly higher right atrium (RA) diameter and mean pulmonary artery pressure (PAP) (p < 0.05). Galectin-3 and sST2 concentrations significantly decreased after 3 months of CPAP treatment. Conclusions: OSA is associated with the left heart remodeling process—increased LV myocardial mass index, LV diastolic dysfunction, reduced LV and RV longitudinal strain, and reduced LA reservoir function. A short-term, 3-months CPAP treatment improves LV global longitudinal strain and LA reservoir function and positively affects blood serum biomarkers. This new indexing system for LV myocardial mass by height helps to identify myocardial structural changes in obese patients with OSA.

Effects of chronic intermittent hypoxia on left cardiac function in young and aged mice

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular disease that is characterized by chronic intermittent hypoxia (CIH), and its impact is related to age. This study aims to assess the age-related impact of CIH on cardiac function and to further explore the mechanism. After 8 weeks of severe CIH exposure, the hearts of young mice showed slight physiological hypertrophy, decreased diastolic function, and collagen I accumulation but no obvious change in contractile function. However, the contractile function of the hearts of aged mice was severely decreased. CIH exposure promoted the fragmentation of mitochondria in the hearts of aged mice and decreased the mitochondrial membrane potential of cardiomyocytes, but these effects were not observed in young mice exposed to the same conditions. CIH induced significant decreases in basal respiration, maximum respiration and ATP production in cardiac mitochondria of aged mice compared to those of young mice. The assessment of mitochondrial-related proteins showed that young mouse hearts had upregulated adaptive nuclear respiratory factors (Nrf)1/2 sirtuin (SIRT)1/3 and transcription factor A (TFAM) expression that stabilized mitochondrial function in response to CIH exposure. Aged mouse hearts exhibited maladaptation to CIH exposure, and downregulation of SIRT1 and TFAM expression resulted in mitochondrial dysfunction.

Analysis of the Correlation of Galectin-3 Concentration with the Measurements of Echocardiographic Parameters Assessing Left Atrial Remodeling and Function in Patients with Persistent Atrial Fibrillation

Galectin-3 (gal-3) is a fibrosis marker and may play a role in fibrosis of the left atrium (LA). Left atrial wall fibrosis may influence the transition from paroxysmal to non-paroxysmal atrial fibrillation (AF). In this study, we assessed the correlation of gal-3 concentration with the main echocardio-graphic parameters evaluating dimensions, volume, compliance, and left atrial contractility during AF and after successful electrical cardioversion (DCCV). The study included 63 patients with left atrial enlargement who qualified for DCCV due to persistent AF. The procedure recovered sinus rhythm in 43 (68.3%) patients. The concentration of gal-3 was negatively correlated with the echocardiographic parameters of LA including dimensions (LA length pre, rho = −0.38; p = 0.003), volume (LAV pre, rho = −0.39; p = 0.003), compliance (LASr mean post, rho = −0.33) and contractility (pLASRct mean post, rho = −0.33; p = 0.038). Negative correlations of gal-3 concentration were also observed in relation to the volume and contractility of the left ventricle. The concentration of gal-3 significantly negatively correlates with the size, systolic function, and compliance of the LA wall in patients with persistent AF. Determining gal-3 concentration in patients with persistent AF may help in the assessment of remodeling of the LA wall.

Imaging Evaluation of Pulmonary and Non-Ischaemic Cardiovascular Manifestations of COVID-19

Coronavirus Disease 2019 (COVID-19) has been a pandemic challenge for the last year. Cardiovascular disease is the most described comorbidity in COVID-19 patients, and it is related to the disease severity and progression. COVID-19 induces direct damage on cardiovascular system, leading to arrhythmias and myocarditis, and indirect damage due to endothelial dysfunction and systemic inflammation with a high inflammatory burden. Indirect damage leads to myocarditis, coagulation abnormalities and venous thromboembolism, Takotsubo cardiomyopathy, Kawasaki-like disease and multisystem inflammatory syndrome in children. Imaging can support the management, assessment and prognostic evaluation of these patients. Ultrasound is the most reliable and easy to use in emergency setting and in the ICU as a first approach. The focused approach is useful in management of these patients due its ability to obtain quick and focused results. This tool is useful to evaluate cardiovascular disease and its interplay with lungs. However, a detailed echocardiography evaluation is necessary in a complete assessment of cardiovascular involvement. Computerized tomography is highly sensitive, but it might not always be available. Cardiovascular magnetic resonance and nuclear imaging may be helpful to evaluate COVID-19-related myocardial injury, but further studies are needed. This review deals with different modalities of imaging evaluation in the management of cardiovascular non-ischaemic manifestations of COVID-19, comparing their use in emergency and in intensive care.