Vascular Endothelial Function as a Valid Predictor of Variations in Pulmonary Function in T2DM Patients Without Related Complications

Evaluating the impact of type 2 diabetes mellitus on pulmonary vascular function and the development of pulmonary fibrosis

The increasing prevalence of type 2 diabetes mellitus (T2DM) is a significant worldwide health concern caused by sedentary lifestyles and unhealthy diets. Beyond glycemic control, T2DM impacts multiple organ systems, leading to various complications. While traditionally associated with cardiovascular and microvascular complications, emerging evidence indicates significant effects on pulmonary health. Pulmonary vascular dysfunction and fibrosis, characterized by alterations in vascular tone and excessive extracellular matrix deposition, are increasingly recognized in individuals with T2DM. The onset of T2DM is often preceded by prediabetes, an intermediate hyperglycemic state that is associated with increased diabetes and cardiovascular disease risk. This review explores the relationship between T2DM, pulmonary vascular dysfunction and pulmonary fibrosis, with a focus on potential links with prediabetes. Pulmonary vascular function, including the roles of nitric oxide (NO), prostacyclin (PGI2), endothelin-1 (ET-1), thromboxane A2 (TxA2) and thrombospondin-1 (THBS1), is discussed in the context of T2DM and prediabetes. Mechanisms linking T2DM to pulmonary fibrosis, such as oxidative stress, dysregulated fibrotic signaling, and chronic inflammation, are explained. The impact of prediabetes on pulmonary health, including endothelial dysfunction, oxidative stress, and dysregulated vasoactive mediators, is highlighted. Early detection and intervention during the prediabetic stage may reduce respiratory complications associated with T2DM, emphasizing the importance of management strategies targeting blood glucose regulation and vascular health. More research that looks into the mechanisms underlying pulmonary complications in T2DM and prediabetes is needed.

Physical exercise in patients with testicular cancer treated with bleomycin, etoposide and cisplatin chemotherapy: pulmonary and vascular endothelial function-an exploratory analysis

PURPOSE

Bleomycin, etoposide, and cisplatin combination chemotherapy (BEP) improves the survival of patients with testicular cancer, but is associated with potentially life-threatening toxicities like pneumonitis and thromboembolic events. This study explored the effects of physical exercise in patients with testicular cancer during or after BEP-chemotherapy on pulmonary and vascular endothelial toxicity.

METHODS

In this post hoc analysis of a multicenter randomized clinical trial (NCT01642680), patients with metastatic testicular cancer scheduled to receive BEP-chemotherapy were randomized to a 24-week exercise intervention, initiated during (group A) or after BEP-chemotherapy (group B). Endpoints were pulmonary function (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), lung transfer-coefficient and transfer factor for carbon monoxide (KCO, DLCO) and markers of vascular endothelial dysfunction (von Willebrand factor (vWF) and factor VIII).

RESULTS

Thirty patients were included. Post-chemotherapy, patients declined less in FVC, FEV1 and DLCO in group A compared to group B. Post-chemotherapy, vWF and factor VIII were significantly lower in group A compared to group B. After completion of exercise, started either during BEP-chemotherapy or thereafter, no between-group differences were found. At 1-year post-intervention, significant between-group differences were found in favour of group A in DLCO and KCO.

CONCLUSIONS

Patients who exercised during BEP-chemotherapy better preserved FVC, FEV1 and DLCO, measured directly post-chemotherapy and 1-year post-intervention (DLCO, KCO). This coincided with less increase in vWF and factor VIII measured directly post-chemotherapy. These data support a beneficial role of a physical exercise intervention during BEP-chemotherapy on pulmonary and vascular damage in patients with testicular cancer.

TRIAL REGISTRY

Optimal Timing of Physical Activity in Cancer Treatment (ACT) Registry URL: https://clinicaltrials.gov/ct2/show/NCT01642680 .

TRIAL REGISTRATION NUMBER

NCT01642680.

Flow-mediated dilation as a marker of endothelial dysfunction in pulmonary diseases: A narrative review

The endothelium is an active and crucial component of vessels and produces several key regulatory factors for the homeostasis of the entire organism. Endothelial function can be investigated invasively or non-invasively, both in the coronary and peripheral circulation. A widely accepted method for the assessment of endothelial function is measurement of flow-mediated dilation (FMD), which evaluates the vascular response to changes in blood flow. In this current review, we describe FMD applications in the clinical setting of different respiratory diseases: acute SARS-COV2 infection, pulmonary embolism; post-acute SARS-COV2 infection, Chronic Obstructive Pulmonary Disease, Obstructive Sleep Apneas Syndrome, Pulmonary Hypertension, Interstitial Lung Diseases. Emerging evidence shows that FMD might be an effective tool to assess the cardiovascular risk in patients suffering from the undermentioned respiratory diseases as well as an independent predictive factor of disease severity and/or recovery.

Non-apoptotic programmed cell deaths in diabetic pulmonary dysfunction: the new side of advanced glycation end products

Diabetes mellitus (DM) is a chronic metabolic disorder that affects multiple organs and systems, including the pulmonary system. Pulmonary dysfunction in DM patients has been observed and studied for years, but the underlying mechanisms have not been fully understood. In addition to traditional mechanisms such as the production and accumulation of advanced glycation end products (AGEs), angiopathy, tissue glycation, oxidative stress, and systemic inflammation, recent studies have focused on programmed cell deaths (PCDs), especially the non-apoptotic ones, in diabetic pulmonary dysfunction. Non-apoptotic PCDs (NAPCDs) including autophagic cell death, necroptosis, pyroptosis, ferroptosis, and copper-induced cell death have been found to have certain correlations with diabetes and relevant complications. The AGE-AGE receptor (RAGE) axis not only plays an important role in the traditional pathogenesis of diabetes lung disease but also plays an important role in non-apoptotic cell death. In this review, we summarize novel studies about the roles of non-apoptotic PCDs in diabetic pulmonary dysfunction and focus on their interactions with the AGE-RAGE axis.

The epidemiological characteristics and infection risk factors for extrapulmonary tuberculosis in patients hospitalized with pulmonary tuberculosis infection in China from 2017 to 2021

BACKGROUND

Pulmonary tuberculosis (PTB) complicated with extrapulmonary tuberculosis (EPTB) infection can aggravate the disease, but there have been few reports.

METHODS

Retrospective analysis was used to collect the clinical data of PTB patients with pathogen positive in a teaching hospital from 2017 to 2021. We describe the incidence, the invasive site of EPTB patients, and analyze the infection risk factors for PTB with EPTB by univariate and multivariate logistic regression models. We also compared the complications, disease burden with chi-square test and rank-sum test.

RESULTS

A total of 1806 PTB were included, of which 263 (14.6%) were complicated with EPTB. The common invasive sites for EPTB were neck lymph nodes (16.49%), intestines (16.13%), and meninges (10.75%). Age ≤ 40 (OR = 1.735; 95%CI [1.267-2.376]; P = 0.001), malnutrition (OR = 2.029; 95%CI [1.097-3.753]; P = 0.022), anemia (OR = 1.739; 95%CI[1.127-2.683]; P = 0.012), and osteoporosis (OR = 4.147; 95%CI [1.577-10.905]; P = 0.004) were all independent risk factors for PTB infection with EPTB. The incidence of extrathoracic hydrothorax, intestinal bacterial infection, urinary tract bacterial infection, and abdominal bacterial infection were higher in patients with PTB with EPTB. PTB with EPTB patients also had longer median hospitalization durations (19 vs. 14 days), during which time they incurred higher total costs, laboratory test costs, imaging examination costs, and drug use costs.

CONCLUSION

This study found important risk factors for PTB complicated with EPTB, such as age ≤ 40, malnutrition, anemia, and osteoporosis. PTB with EPTB patients have more extrapulmonary complications and higher hospitalization disease burden.

Diabetes-related perturbations in the integrity of physiologic barriers

One of the hallmarks of health is the integrity of barriers at the cellular and tissue levels. The two cardinal functions of barriers include preventing access of deleterious elements of the environment (barrier function) while facilitating the transport of essential ions, signaling molecules and nutrients needed to maintain the internal milieu (transport function). There are several cellular and subcellular barriers and some of these barriers can be interrelated. The principal physiologic barriers include blood-retinal barrier, blood-brain barrier, blood-testis barrier, renal glomerular/tubular barrier, intestinal barrier, pulmonary blood-alveolar barrier, blood-placental barrier and skin barrier. Tissue specific barriers are the result of the vasculature, cellular composition of the tissue and extracellular matrix within the tissue. Uncontrolled diabetes and acute hyperglycemia may disrupt the integrity of physiologic barriers, primarily through altering the vascular integrity of the tissues and may well contribute to the clinically recognized complications of diabetes. Although diabetes is a systemic disease, some of the organs display clinically significant deterioration in function while others undergo subclinical changes. The pathophysiology of the disruption of these barriers is not entirely clear but it may be related to diabetes-related cellular stress. Understanding the mechanisms of diabetes related dysfunction of various physiologic barriers might help identifying novel therapeutic targets for reducing clinically significant complications of diabetes.

Association between haemoglobin A1c and whole-body heat loss during exercise-heat stress in physically active men with type 2 diabetes

NEW FINDINGS

What is the central question of this study? Is the impairment in heat dissipation during exercise observed in men with type 2 diabetes related to glycaemic control (indexed by glycated haemoglobin; haemoglobin A1c )? What is the main finding and its importance? No association was found between haemoglobin A1c (range: 5.1-9.1%) and whole-body heat loss in men with type 2 diabetes during exercise in the heat. However, individuals with elevated haemoglobin A1c exhibited higher body core temperature and heart rate responses. Thus, while haemoglobin A1c is not associated with heat loss per se, it may still have important implications for physiological strain during exercise.

ABSTRACT

Type 2 diabetes is associated with a reduced capacity to dissipate heat. It is unknown whether this impairment is related to glycaemic control (indexed by glycated haemoglobin; haemoglobin A1c ) is unknown. We evaluated the association between haemoglobin A1c and whole-body heat loss (via direct calorimetry), body core temperature, and heart rate in 26 physically active men with type 2 diabetes (43-73 years; HbA1c 5.1-9.1%) during exercise at increasing rates of metabolic heat production (∼150, 200, 250 W m-2 ) in the heat (40°C, ∼17% relative humidity). Haemoglobin A1c was not associated with whole-body heat loss (P = 0.617), nor the increase in core temperature from pre-exercise (P = 0.347). However, absolute core temperature and heart rate were elevated ∼0.2°C (P = 0.014) and ∼6 beats min-1 (P = 0.049), respectively, with every percentage point increase in haemoglobin A1c . Thus, while haemoglobin A1c does not appear to modify diabetes-related reductions in capacity for heat dissipation, it may still have important implications for physiological strain during exercise-heat stress.

Serum apolipoprotein A-IV levels are associated with flow-mediated dilation in patients with type 2 diabetes mellitus

Background

Endothelial dysfunction is common in diabetes. Apolipoprotein (apo) A-IV functions to antagonize inflammation and oxidative stress. The present study aimed to investigate the relationship between flow-mediated dilation (FMD) and serum apoA-IV level in type 2 diabetes mellitus (T2DM) patients. 

Methods

A total of 84 T2DM patients with chest discomfort were enrolled in this study. Their baseline characteristics and clinical parameters were documented. Endothelial function of the participants was evaluated by examining FMD of brachial artery. The severity of coronary atherosclerosis was determined by quantitative coronary angiography. Serum apoA-IV levels were measured by ELISA.

Results

These diabetic patients were dichotomized into low FMD (n = 42) and high FMD (n = 42) groups. Serum apoA-IV levels were significantly higher in high FMD group than in low FMD group (29.96 ± 13.17 vs 17.69 ± 9.16 mg/dL, P < 0.001). Moreover, the patients were also categorized into three apoA-IV tertile groups. FMD was significantly different across three apoA-IV tertiles (P < 0.001). Serum apoA-IV levels were positively correlated to FMD (r = 0.469, P < 0.001). Logistic regression analysis was performed to determine risk factors for low FMD. apoA-IV levels together with the risk factor hsCRP remained significantly to be independent determinants of low FMD (P < 0.01). Linear regression analysis was performed, and apoA-IV levels together with total-to-HDL cholesterol ratio were independently correlated with FMD (P < 0.01).

Conclusions

Serum apoA-IV levels are associated with FMD, suggesting that apoA-IV protects endothelial function in patients with T2DM.

SARS-CoV-2 infection and diabetes: Pathophysiological mechanism of multi-system organ failure

Since the discovery of the coronavirus disease 2019 outbreak, a vast majority of studies have been carried out that confirmed the worst outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in people with preexisting health conditions, including diabetes, obesity, hypertension, cancer, and cardiovascular diseases. Likewise, diabetes itself is one of the leading causes of global public health concerns that impose a heavy global burden on public health as well as socio-economic development. Both diabetes and SARS-CoV-2 infection have their independent ability to induce the pathogenesis and severity of multi-system organ failure, while the co-existence of these two culprits can accelerate the rate of disease progression and magnify the severity of the disease. However, the exact pathophysiology of multi-system organ failure in diabetic patients after SARS-CoV-2 infection is still obscure. This review summarized the organ-specific possible molecular mechanisms of SARS-CoV-2 and diabetes-induced pathophysiology of several diseases of multiple organs, including the lungs, heart, kidneys, brain, eyes, gastrointestinal system, and bones, and sub-sequent manifestation of multi-system organ failure.

Mechanisms of COVID-19 Pathogenesis in Diabetes

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is a global pandemic impacting 254 million people in 190 countries. Comorbidities, particularly cardiovascular disease, diabetes, and hypertension, increase the risk of infection and poor outcomes. SARS-CoV-2 enters host cells through the angiotensin-converting enzyme-2 receptor, generating inflammation and cytokine storm, often resulting in multiorgan failure. The mechanisms and effects of COVID-19 on patients with high-risk diabetes are not yet completely understood. In this review, we discuss the variety of coronaviruses, structure of SARS-CoV-2, mutations in SARS-CoV-2 spike proteins, receptors associated with viral host entry, and disease progression. Furthermore, we focus on possible mechanisms of SARS-CoV-2 in diabetes, leading to inflammation and heart failure. Finally, we discuss existing therapeutic approaches, unanswered questions, and future directions.

Effects of adding L-arginine orally to standard therapy in patients with COVID-19: A randomized, double-blind, placebo-controlled, parallel-group trial. Results of the first interim analysis

BACKGROUND

We and others have previously demonstrated that the endothelium is a primary target of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and L-arginine has been shown to improve endothelial dysfunction. However, the effects of L-arginine have never been evaluated in coronavirus disease 2019 (COVID-19).

METHODS

This is a parallel-group, double-blind, randomized, placebo-controlled trial conducted on patients hospitalized for severe COVID-19. Patients received 1.66 g L-arginine twice a day or placebo, administered orally. The primary efficacy endpoint was a reduction in respiratory support assessed 10 and 20 days after randomization. Secondary outcomes were the length of in-hospital stay, the time to normalization of lymphocyte number, and the time to obtain a negative real-time reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 on nasopharyngeal swab. This clinical trial had been registered at ClinicalTrials.gov, identifier: NCT04637906.

FINDINGS

We present here the results of the initial interim analysis on the first 101 patients. No treatment-emergent serious adverse events were attributable to L-arginine. At 10-day evaluation, 71.1% of patients in the L-arginine arm and 44.4% in the placebo arm (p < 0.01) had the respiratory support reduced; however, a significant difference was not detected 20 days after randomization. Strikingly, patients treated with L-arginine exhibited a significantly reduced in-hospital stay vs placebo, with a median (interquartile range 25^th,75^th percentile) of 46 days (45,46) in the placebo group vs 25 days (21,26) in the L-arginine group (p < 0.0001); these findings were also confirmed after adjusting for potential confounders including age, duration of symptoms, comorbidities, D-dimer, as well as antiviral and anticoagulant treatments. The other secondary outcomes were not significantly different between groups.

INTERPRETATION

In this interim analysis, adding oral L-arginine to standard therapy in patients with severe COVID-19 significantly decreases the length of hospitalization and reduces the respiratory support at 10 but not at 20 days after starting the treatment.

FUNDING

Both placebo and L-arginine were kindly provided by Farmaceutici Damor S.p.A., Naples.

Effect of Glycated Hemoglobin (HbA1c) and Duration of Disease on Lung Functions in Type 2 Diabetic Patients

Diabetes mellitus is a highly challenging global health care problem. This study aimed to assess the effect of glycated hemoglobin (HbA1c) and duration of diabetes on lung function in type 2 diabetic patients and assess whether duration or high HbA1c is more noxious to damage the lung functions. A total of 202 participants, 101 patients with type 2 diabetes mellitus (T2DM), and 101 age-, gender-, height-, and weight-matched controlled subjects were recruited. The HbA1c was measured through a clover analyzer, and lung function test parameters were recorded by spirometry. The results revealed a significant inverse correlation between HbA1c and Vital Capacity (VC) (r = -0.221, p = 0.026), Forced Vital Capacity (FVC) (r = -0.261, p = 0.008), Forced Expiratory Volume in First Second (FEV1) (r = -0.272, p = 0.006), Forced Expiratory Flow 25% (FEF-25%) (r = -0.196, p = 0.050), Forced Expiratory Flow 50% (FEF-50%) (r = -0.223, p = 0.025), and Forced Expiratory Flow 75% (FEF-75%) (r = -0.169, p = 0.016). Moreover, FEV1 (p = 0.029), FEV1/FVC% (p = 0.006), FEF-50% (p = 0.001), and FEF-75% (p = 0.003) were significantly lower in the diabetic group with duration of disease 5-10 and >10 years compared to the control group. The overall results concluded that high HbA1c or uncontrolled diabetes mellitus has a more damaging effect on lung function impairment compared to the duration of diabetes mellitus. Physicians must regularly monitor the HbA1c level while treating diabetic patients, as good glycemic control is essential to minimize the complications of DM, including lung function impairment in patients with T2DM.