Resistin and omentin in breast cancer: A systematic review and meta-analysis.

Breast cancer (BC) is the most frequently diagnosed cancer and a leading cause of cancer-related mortality among women globally. Resistin, omentin and ghrelin, adipokines involved in inflammation and metabolic regulation, have been implicated in cancer development, yet their associations with BC remain unclear. This systematic review and meta-analysis aimed to elucidate the relationships between resistin, omentin, and ghrelin concentrations and BC, while exploring potential moderators such as body mass index (BMI) and menopausal status. A comprehensive search of electronic databases up to 13 May 2024 identified studies comparing resistin and omentin, but not ghrelin, concentrations in BC patients and healthy controls. Standardized mean differences (SMDs) were calculated using random-effects models, and meta-regression and subgroup analyses were performed to investigate sources of heterogeneity. Analysis of 11 studies showed that BC patients exhibited significantly higher resistin concentrations compared to controls, with a pooled SMD of 2.05 (95 % CI 1.24 to 2.86, p < 0.001). Meta-regression indicated that BMI significantly moderated the resistin-BC association (p = 0.003). In contrast, omentin concentrations presented a complex picture, with a pooled SMD of -0.27 (95 % CI -1.39 to 0.84, I^2 = 96.2 %, p < 0.001), indicating substantial heterogeneity and inconclusive results, whereas only one study investigated ghrelin. Our findings support a significant association between elevated resistin concentrations and BC, suggesting a potential role of resistin in BC pathophysiology. The data on omentin and ghrelin remain inconclusive, warranting further investigation. Future research should focus on large, longitudinal studies with standardized methodologies to validate these findings and clarify the role of adipokines in BC.

The role of bilirubin as a biomarker of rheumatic diseases: a systematic review and meta-analysis.

The identification of novel, yet easily measurable biomarkers of inflammation and oxidative stress might assist in the diagnosis and management of patients with rheumatic diseases (RDs). We conducted a systematic review and meta-analysis of studies investigating the circulating concentrations of bilirubin, the end product of heme metabolism and a potent endogenous antioxidant with anti-inflammatory properties, in patients with RDs and healthy controls. The electronic databases PubMed, Scopus, and Web of Science were searched from inception to 31 December 2023 for relevant articles. We evaluated the risk of bias and the certainty of evidence using the Joanna Briggs Checklist and the Grades of Recommendation, Assessment, Development, and Evaluation Working Group system, respectively. In 17 eligible studies, all with low risk of bias, compared to controls, patients with RDs had significantly lower concentrations of total bilirubin (standard mean difference, SMD=-0.68, 95% CI -0.91 to -0.44, p<0.001; I2 = 92.5%, p<0.001; low certainty of evidence), direct (conjugated) bilirubin (SMD=-0.67, 95% CI -0.92 to -0.41, p<0.001; I2 = 81.7%, p<0.001; very low certainty of evidence), and the active antioxidant and anti-inflammatory indirect (unconjugated) form of bilirubin (SMD=-0.71, 95% CI -1.18 to -0.24, p=0.003; I2 = 95.1%, p<0.001; very low certainty of evidence). The results of the meta-analysis were stable in sensitivity analysis. In meta-regression, there were no significant associations between the SMD of total bilirubin and several clinical and demographic characteristics, including age, male to female ratio, number of participants, liver enzymes and erythrocyte sedimentation rate. In subgroup analysis, the SMD of total bilirubin was significant across a range of RDs, including rheumatoid arthritis, systemic lupus erythematosus, primary Sjögren syndrome, and myositis. Therefore, the results of our systematic review and meta-analysis suggests that the reductions in bilirubin concentrations observed in patients with RDs reflect a state of impaired antioxidant and anti-inflammatory defence due to bilirubin consumption and highlight the promising role of this endogenous product as a biomarker of RDs. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023500649.

The association between bilirubin concentrations and inflammatory bowel disease: Insights from a systematic review and meta-analysis.

BACKGROUND: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), poses a significant challenge to health care systems because of its chronic nature and increasing global prevalence. Effective management of IBD requires accurate diagnostic tools and biomarkers. This systematic review and meta-analysis aimed to evaluate the relationship between bilirubin concentrations and IBD activity and outcomes. METHODS: A comprehensive search of electronic databases identified 11 studies that included 2606 subjects with IBD and 3607 healthy controls. RESULTS: Bilirubin concentrations were significantly lower in subjects with IBD when compared to controls (SMD = -0.96, 95% CI -1.21 to -0.70; p < .001). Although substantial heterogeneity was observed, sensitivity analysis confirmed the robustness of the results. Publication bias was detected, but subgroup analyses did not significantly alter the results. Meta-regression showed that age was a significant factor influencing the association between bilirubin concentrations and IBD. Subgroup analyses showed a more pronounced reduction in bilirubin concentrations in subjects with CD than those with UC. CONCLUSION: This study supports the potential utility of bilirubin as a biomarker in IBD, emphasizing the need for further research to validate its clinical significance.

The potential role of serum amyloid A as biomarker of rheumatic diseases: a systematic review and meta-analysis.

The identification of novel, robust biomarkers for the diagnosis of rheumatic diseases (RDs) and the presence of active disease might facilitate early treatment and the achievement of favourable long-term outcomes. We conducted a systematic review and meta-analysis of studies investigating the acute phase reactant, serum amyloid A (SAA), in RD patients and healthy controls to appraise its potential as diagnostic biomarker. We searched PubMed, Scopus, and Web of Science from inception to 10 April 2024 for relevant studies. We evaluated the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively (PROSPERO registration number: CRD42024537418). In 32 studies selected for analysis, SAA concentrations were significantly higher in RD patients compared to controls (SMD = 1.61, 95% CI 1.24-1.98, p < 0.001) and in RD patients with active disease compared to those in remission (SMD = 2.17, 95% CI 1.21-3.13, p < 0.001). Summary receiving characteristics curve analysis showed a good diagnostic accuracy of SAA for the presence of RDs (area under the curve = 0.81, 95% CI 0.78-0.84). The effect size of the differences in SAA concentrations between RD patients and controls was significantly associated with sex, body mass index, type of RD, and study country. Pending the conduct of prospective studies in different types of RDs, the results of this systematic review and meta-analysis suggest that SAA is a promising biomarker for the diagnosis of RDs and active disease.

Recent temporal trends, characteristics and outcomes of patients with non-COVID-19 community-acquired pneumonia at two tertiary hospitals in Australia: an observational study.

BACKGROUND: Community-acquired pneumonia (CAP) leads to considerable morbidity and mortality globally. However, data on CAP burden in Australia, especially during the coronavirus disease 2019 (COVID-19) pandemic, are limited. AIMS: We characterised and assessed clinical outcomes of non-COVID-19 CAP hospitalisations over a 6-year period at two major hospitals in South Australia. METHODS: All non-COVID-19 CAP hospitalisations were identified using the International Statistical Classification of Diseases and Related Health Problems, Tenth revision, Australian modification (ICD-10-AM) codes, between 1 January 2018 and 31 December 2023, at two tertiary hospitals in Adelaide. Clinical outcomes included in-hospital and 30-day mortality, length of stay (LOS) in, intensive care unit (ICU) admission and 30-day readmissions. Multilevel regression models were utilised to identify predictors of clinical outcomes. RESULTS: Over the 6-year period, there were 7853 non-COVID-19 CAP hospitalisations, with a temporal increase from 100 per 100 000 population in 2018 to 208 per 100 000 population in 2023 (P < 0.001). The mean (SD) age was 75.1 (17.6) years, and 54.6% were males. The mean age declined over time (P < 0.05), while other characteristics remained stable. Streptococcus pneumoniae was the most commonly identified bacterium (21.8% of cases). In-hospital mortality occurred in 7.8% of patients, with 30-day mortality and readmission rates of 14.3% and 16.9% respectively. LOS declined significantly during the pandemic years; however, mortality remained stable over time. Frailty status, malnutrition and number of comorbidities significantly predicted 30-day mortality and LOS, in addition to pneumonia severity and ICU admission. CONCLUSIONS: There has been an increasing trend of hospitalisations for non-COVID-19 CAP during the COVID-19 pandemic, with a concomitant trend towards shorter LOS and no significant shift in other clinical outcomes.

The relationship between haemoglobin concentrations and obstructive sleep apnea syndrome: A systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis investigates the relationship between haemoglobin (Hb) concentrations and obstructive sleep apnea syndrome (OSAS). METHODS: Following PRISMA guidelines, we searched PubMed, EMBASE, and Cochrane Library from inception to March 8, 2024. Eligible studies included cross-sectional, cohort, and case-control designs comparing Hb concentrations in OSAS patients and healthy controls. Two reviewers independently screened records and extracted data. The risk of bias was assessed using the Joanna Briggs Institute checklist. RESULTS: A total of 27 studies involving 6499 OSAS subjects and 5199 controls were included. Hb concentrations were significantly higher in OSAS patients compared to controls (SMD: 0.28; 95 % CI: 0.18 to 0.39; I2 = 84.4 %). Subgroup analysis by OSAS severity showed that severe OSAS patients had higher Hb concentrations than those with mild/moderate OSAS. Sensitivity analyses confirmed the robustness of the findings. However, 7 studies reported opposite results, indicating possible regional or methodological differences. CONCLUSION: Hb concentrations are elevated in OSAS patients, with higher levels observed in severe cases. The significant heterogeneity and the predominance of studies from Turkey highlight the need for further research in diverse populations. Limitations include potential publication bias and variability in study designs.

Association of Drug-Disease Interactions with Mortality or Readmission in Hospitalised Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVE: Multimorbidity is common in hospitalised adults who are at increased risk of inappropriate prescribing including drug-disease interactions. These interactions occur when a medicine being used to treat one condition exacerbates a concurrent medical condition and may lead to adverse health outcomes. The aim of this review was to examine the association between drug-disease interactions and the risk of mortality and readmission in hospitalised middle-aged and older adults. METHODS: A systematic review was conducted on drug-disease interactions in hospitalised middle-aged (45-64 years) and older adults (≥65 years). The study protocol was prospectively registered with PROSPERO (Registration Number: CRD42022341998). Drug-disease interactions were defined as a medicine being used to treat one condition with the potential to exacerbate a concurrent medical condition or that were inappropriate based on a comorbid medical condition. Both observational and interventional studies were included. The outcomes of interest were mortality and readmissions. The databases searched included MEDLINE, CINAHL, EMBASE, Web of Science, SCOPUS and the Cochrane Library from inception to 12 July, 2022. A meta-analysis was performed to pool risk estimates using the random-effects model. RESULTS: A total of 563 studies were identified and four met the inclusion criteria. All were observational studies in older adults, with no studies identified in middle-aged adults. Most of the studies were at risk of bias because of an inadequate adjustment for covariates and a lack of clarity around individuals lost to follow-up. There were various definitions of drug-disease interactions within these four studies. Two studies assessed drugs that were contraindicated based on renal function, one assessed an individual drug-disease combination, and one was based on the clinical judgement of a pharmacist. There were two studies that showed an association between drug-disease interactions and the outcomes of interest. One reported that the use of diltiazem in patients with heart failure was associated with an increased risk of readmissions. The second reported that the use of medicines contraindicated according to renal function were associated with increased risk of all-cause mortality and a composite of mortality and readmission. Three of the studies (total study population = 5705) were amenable to a meta-analysis, which showed no significant association between drug-disease interactions and readmissions (odds ratio = 1.0, 95% confidence interval 0.80-1.38). CONCLUSIONS: Few studies were identified examining the risk of drug-disease interactions and mortality and readmission in hospitalised adults. Most of the identified studies were at risk of bias. There is no universal accepted definition of drug-disease interactions in the literature. Further studies are needed to develop a standardised and accepted definition of these interactions to guide further research in this area.

The Clinical Impact of Hospital-Acquired Adverse Drug Reactions in Older Adults: An Australian Cohort Study.

INTRODUCTION: Hospital-acquired adverse drug reactions (HA-ADRs) are common in older adults. However, there is limited knowledge regarding the association between HA-ADRs and adverse clinical outcomes. OBJECTIVE: To investigate the incidence and characteristics of HA-ADRs in older adults, and any association with mortality, length of stay, and readmissions. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: Flinders Medical Centre, a large tertiary referral hospital in Adelaide, South Australia. Older adults admitted under the General Medicine and Acute Care of the Elderly units with no previous diagnosis of dementia. METHODS: All patients had a Multidimensional Prognostic Index (MPI) assessment performed within 3 days of the admission. Data collected included age, gender, estimated glomerular filtration rate (eGFR), length of stay, readmissions, and mortality. HA-ADRs were identified by review of individual discharge summaries. Univariate and multivariate analyses were performed to investigate associations with clinical outcomes including mortality, length of stay, and readmissions. Exploratory analyses were performed for HA-ADR groups based on Medical Dictionary for Regulatory Activities System Organ Class and World Health Organization Anatomical Therapeutic Chemical classifications that accounted for ≥10% of all HA-ADRs. RESULTS: There were 737 patients in the cohort with 72 having experienced a HA-ADRs (incidence = 9.8%). Patients with an HA-ADR had increased length of stay and 30-day readmissions compared with those without an HA-ADR. In multivariate analysis, the number of HA-ADRs was associated with in-hospital mortality and length of stay but not post-discharge mortality or readmissions within 30 days. In exploratory analyses, patients with an HA-ADR to antibacterial drugs had significantly higher rates of in-hospital mortality compared with those without these reactions. CONCLUSIONS AND IMPLICATIONS: The number of HA-ADRs are associated with in-hospital mortality and length of stay in older Australian inpatients. The occurrence of HA-ADRs may be a trigger to offer advice to prescribers to prevent future ADRs to similar agents and proactively manage disease to improve health outcomes.

Ischemia-modified albumin in rheumatic diseases: A systematic review and meta-analysis.

INTRODUCTION: The identification of novel, easily measurable disease biomarkers might enhance the diagnosis and management of patients with rheumatic diseases (RDs). We conducted a systematic review and meta-analysis of ischemia-modified albumin (IMA), a marker of oxidative stress, acidosis, and ischemia, in RD patients and healthy controls. METHODS: We searched PubMed, Web of Science, and Scopus from inception to January 15, 2024. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and GRADE, respectively. RESULTS: In 20 studies investigating a total of 1188 RD patients (mean age 45 years, 64% females) and 981 healthy controls (mean age 44 years, 66% females), RD patients had significantly higher IMA concentrations when compared to controls (standard mean difference, SMD = 0.50, 95% CI: 0.18-0.83, p = .003; I2 = 92.4%, p < .001; low certainty of evidence). In subgroup analysis, the pooled SMD was significantly different in studies investigating ankylosing spondylitis (p < .001), Behçet's disease (p < .001), and rheumatoid arthritis (p = .033), but not familial Mediterranean fever (p = .48). Further associations were observed between the pooled SMD and the broad classification of autoimmune and/or autoinflammatory diseases, the study country, and the method used to measure IMA. CONCLUSION: Our study suggests that IMA is a promising biomarker of oxidative stress, acidosis, and ischemia, as it can effectively discriminate between patients with different types of RDs and healthy controls. Our results warrant confirmation in longitudinal studies of patients with different types of RDs and different ethnicities (PROSPERO registration number: CRD42024509126).

Meeting medical emergency response criteria for hypertension is not associated with an increased likelihood of in-hospital mortality in a tertiary referral center.

Backgrounds: Rapid response team or medical emergency team (MET) calls are typically activated by significant alterations of vital signs in inpatients. However, the clinical significance of a specific criterion, blood pressure elevations, is uncertain. Objectives: The aim of this study was to evaluate the likelihood ratios associated with MET-activating vital signs, particularly in-patient hypertension, for predicting in-hospital mortality among general medicine inpatients who met MET criteria at any point during admission in a South Australian metropolitan teaching hospital. Results: Among the 15,734 admissions over a two-year period, 4282 (27.2%) met any MET criteria, with a positive likelihood ratio of 3.05 (95% CI 2.93 to 3.18) for in-hospital mortality. Individual MET criteria were significantly associated with in-hospital mortality, with the highest positive likelihood ratio for respiratory rate ≤ 7 breaths per minute (9.83, 95% CI 6.90 to 13.62), barring systolic pressure ≥ 200 mmHg (LR + 1.26, 95% CI 0.86 to 1.69). Conclusions: Our results show that meeting the MET criteria for hypertension, unlike other criteria, was not significant associated with in-hospital mortality. This observation warrants further research in other patient cohorts to determine whether blood pressure elevations should be routinely included in MET criteria.

Comparing Outcomes of Community-Acquired Pneumonia Patients Discharged from General Medicine and Respiratory Units in Australia: A Propensity Score-Matched Analysis.

Background/Objectives: Community-acquired pneumonia (CAP) is a common emergency presentation in Australia, with the choice of admitting specialty unit often influenced by pneumonia severity and comorbidities. However, it remains unclear whether there are between-specialty differences in patient characteristics and outcomes. We sought to address this issue by investigating the characteristics and outcomes of CAP patients admitted to General Medicine (GM) versus Respiratory units. Methods: This retrospective observational study utilised data from the two largest metropolitan hospitals in South Australia, encompassing all non-COVID-19-related CAP admissions throughout 2021 to 2023. The hospital length of stay (LOS), in-patient and 30-day mortality, and 30-day readmission rates were assessed by propensity score matching (PSM) using 17 variables. Results: Of the 3004 cases of non-COVID-19 CAP admitted across the two hospitals during the study period, 2673 (71.8%) were admitted under GM units and 331 (9.1%) under Respiratory units. GM patients were, on average, a decade older, presented with a significantly higher burden of comorbidities, exhibited a greater prevalence of frailty, and had higher pneumonia severity compared to those admitted under a Respiratory unit (p < 0.05). Unadjusted analysis revealed a shorter median LOS among GM-admitted patients (5.9 vs. 4.1 days, p < 0.001). After PSM adjustment, patients admitted under the Respiratory units had an 8-fold higher odds of a longer LOS compared to GM (adjusted odds ratio [aOR] 8.53, 95% CI 1.96-37.25, p = 0.004). Other clinical outcomes were comparable between the two groups. Conclusions: Our findings indicate that GM units compared to Respiratory units provide efficient and safe care for patients requiring hospitalisation for CAP.

Association between blood Pentraxin-3 concentrations and rheumatic diseases: A systematic review and meta-analysis.

BACKGROUND: Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics. METHODS: We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records. RESULTS: Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations. CONCLUSIONS: Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600).

The association between the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio and systemic sclerosis and its complications: a systematic review and meta-analysis.

Introduction: The identification of new, easily measurable biomarkers might assist clinicians in diagnosing and managing systemic sclerosis (SSc). Although the full blood count is routinely assessed in the evaluation of SSc, the diagnostic utility of specific cell-derived inflammatory indices, i.e., neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR), has not been critically appraised in this patient group. Methods: We conducted a systematic review and meta-analysis of studies investigating the NLR, PLR, and MLR, in SSc patients and healthy controls and in SSc patients with and without relevant complications. PubMed, Scopus, and Web of Science were searched from inception to 23 February 2024. Risk of bias and certainty of evidence were assessed using validated tools. Results: In 10 eligible studies, compared to controls, patients with SSc had significantly higher NLR (standard mean difference, SMD=0.68, 95% CI 0.46 to 0.91, p<0.001; I2 = 74.5%, p<0.001), and PLR values (SMD=0.52, 95% CI 0.21 to 0.83, p=0.001; I2 = 77.0%, p=0.005), and a trend towards higher MLR values (SMD=0.60, 95% CI -0.04 to 1.23, p=0.066; I2 = 94.1%, p<0.001). When compared to SSc patients without complications, the NLR was significantly higher in SSc with interstitial lung disease (ILD, SMD=0.31, 95% CI 0.15 to 0.46, p<0.001; I2 = 43.9%, p=0.11), pulmonary arterial hypertension (PAH, SMD=1.59, 95% CI 0.04 to 3.1, p=0.045; I2 = 87.6%, p<0.001), and digital ulcers (DU, SMD=0.43, 95% CI 0.13 to 0.74, p=0.006; I2 = 0.0%, p=0.49). The PLR was significantly higher in SSc patients with ILD (SMD=0.42, 95% CI 0.25 to 0.59, p<0.001; I2 = 24.8%, p=0.26). The MLR was significantly higher in SSc patients with PAH (SMD=0.63, 95% CI 0.17 to 1.08, p=0.007; I2 = 66.0%, p=0.086), and there was a trend towards a higher MLR in SSc patients with ILD (SMD=0.60, 95% CI -0.04 to 1.23, p=0.066; I2 = 94.1%, p<0.001). Discussion: Pending the results of appropriately designed prospective studies, the results of this systematic review and meta-analysis suggest that blood cell-derived indices of inflammation, particularly the NLR and PLR, may be useful in the diagnosis of SSc and specific complications. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024520040.

Efficacy and safety of vitamin C supplementation in the treatment of community-acquired pneumonia: a systematic review and meta-analysis with trial sequential analysis.

Community-acquired pneumonia (CAP) poses a significant global health challenge, prompting exploration of innovative treatments. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of vitamin C supplementation in adults undergoing treatment for CAP. A comprehensive search of the MEDLINE, Embase, CINAHL, the Cochrane Central Register of Controlled Trials, and Clinical Trials.gov databases from inception to 17 November 2023 identified six randomized-controlled-trials (RCTs) meeting inclusion criteria. The primary outcome analysis revealed a non-significant trend towards reduced overall mortality in the vitamin C group compared to controls (RR 0.51; 95% CI 0.24 to 1.09; p = 0.052; I2 = 0; p = 0.65). Sensitivity analysis, excluding corona-virus-disease 2019 (COVID-19) studies and considering the route of vitamin C administration, confirmed this trend. Secondary outcomes, including hospital length-of-stay (LOS), intensive-care-unit (ICU) LOS, and mechanical ventilation, exhibited mixed results. Notably, heterogeneity and publication bias were observed in hospital LOS analysis, necessitating cautious interpretation. Adverse effects were minimal, with isolated incidents of nausea, vomiting, hypotension, and tachycardia reported. This meta-analysis suggests potential benefits of vitamin C supplementation in CAP treatment. However, inconclusive findings and methodological limitations warrants cautious interpretation, emphasising the urgency for high-quality trials to elucidate the true impact of vitamin C supplementation in CAP management.

Recent advances in DDAH1 inhibitor design and discovery: insights from structure-activity relationships and X-ray crystal structures.

Nitric oxide (NO) is an important signalling molecule which modulates several biological and pathological processes. Dimethylarginine dimethylaminohydrolase 1 (DDAH1) plays a key role indirectly regulating NO concentrations in the body. It has been shown that DDAH1 inhibition may be an effective therapeutic strategy in certain pathological states in which excessive NO is produced. In recent years, specific DDAH1 inhibitors have shown promise in suppressing abnormal neovascularization in cancer. However, the available DDAH1 inhibitors lack potency and selectivity and are mostly arginine-based. Further, these inhibitors display unfavourable pharmacokinetics and have not been tested in humans. Thus, the development of potent, selective, and chemically diverse DDAH1 inhibitors is essential. In this review, we examine the structure activity relationships (SARs) and X-ray crystal structures of known DDAH1 inhibitors. Then, we discuss current challenges in the design and development of novel DDAH1 inhibitors and provide future directions for developing potent and chemically diverse compounds.

Arginine metabolomics in mood disorders.

Alterations of nitric oxide (NO) homeostasis have been described in mood disorders. However, the analytical challenges associated with the direct measurement of NO have prompted the search for alternative biomarkers of NO synthesis. We investigated the published evidence of the association between these alternative biomarkers and mood disorders (depressive disorder or bipolar disorder). Electronic databases were searched from inception to the June 30, 2023. In 20 studies, there was a trend towards significantly higher asymmetric dimethylarginine (ADMA) in mood disorders vs. controls (p = 0.072), and non-significant differences in arginine (p = 0.29), citrulline (p = 0.35), symmetric dimethylarginine (SDMA; p = 0.23), and ornithine (p = 0.42). In subgroup analyses, the SMD for ADMA was significant in bipolar disorder (p < 0.001) and European studies (p = 0.02), the SMDs for SDMA (p = 0.001) and citrulline (p = 0.038) in European studies, and the SMD for ornithine in bipolar disorder (p = 0.007), Asian (p = 0.001) and American studies (p = 0.005), and patients treated with antidepressants (p = 0.029). The abnormal concentrations of ADMA, SDMA, citrulline, and ornithine in subgroups of mood disorders, particularly bipolar disorder, warrant further research to unravel their pathophysiological role and identify novel treatments in this group (The protocol was registered in PROSPERO: CRD42023445962).

Ischemia-Modified Albumin (IMA) Is Associated with Poor Survival in Patients with Newly Diagnosed Idiopathic Pulmonary Fibrosis (IPF): A Pilot Study.

There are increasing efforts to better predict adverse outcomes for idiopathic pulmonary fibrosis (IPF). Our aim was to assess the prognostic potential of ischemia-modified albumin (IMA), an established circulating marker of ischemia and, more recently, oxidative stress, in a cohort of 56 IPF patients recruited between 2015 and 2023 at the University of Sassari, Italy. Demographic and functional parameters and serum IMA concentrations were measured at baseline. Non-survivors had significantly higher IMA concentrations vs. survivors (508 ± 64 vs. 474 ± 42 mABSU, respectively; p = 0.035). The Kaplan-Meier analysis showed a significant association between higher IMA values and poor survival (HR: 3.32, 95% CI from 1.06 to 10.4, p = 0.039). In the Cox regression analysis, this association remained significant after adjusting for the force expiratory volume at 1 s, the total lung capacity, lymphocyte count, and pharmacological treatment (HR: 1.0154, 95% CI from 1.0035 to 1.0275, p = 0.01). IMA, an oxidative stress biomarker measurable using relatively simple and available methods, is independently associated with mortality in IPF. Therefore, its determination may enhance risk stratification and treatment decisions. Prospective studies involving larger cohorts are needed to confirm this association and to endorse the use of IMA in routine practice.

Redefining the biological and pathophysiological role of dimethylarginine dimethylaminohydrolase 2.

The enzyme dimethylarginine dimethylaminohydrolase (DDAH) 1 metabolizes asymmetric dimethylarginine (ADMA), a critical endogenous cardiovascular risk factor. In the past two decades, there has been significant controversy about whether DDAH2, the other DDAH isoform, is also able to directly metabolize ADMA. There has been evidence that DDAH2 regulates several critical processes involved in cardiovascular and immune homeostasis. However, the molecular mechanisms underpinning these effects are unclear. In this opinion, we discuss the previous and current knowledge of ADMA metabolism by DDAH in light of a recent consortium study, which convincingly demonstrated that DDAH2 is not capable of metabolizing ADMA, unlike DDAH1. Thus, further research in this field is needed to uncover the molecular mechanisms of DDAH2 and its role in various disorders.

A Systematic Review and Meta-Analysis of Mean Platelet Volume and Platelet Distribution Width in Patients with Obstructive Sleep Apnoea Syndrome.

Obstructive sleep apnoea syndrome (OSAS) is a highly prevalent yet underestimated disorder caused by the complete or partial obstruction of the upper airways. Although polysomnography is the gold standard for OSAS diagnosis, there is an active search for easily accessible biomarkers of disease presence and severity, particularly those reflecting morphological changes in specific blood cells. We investigated the associations between the presence and severity of OSAS, continuous positive airway pressure (CPAP) treatment, mean platelet volume (MPV), and platelet distribution width (PDW), routinely assessed as part of the complete blood count. From 262 retrieved records from PubMed, the Web of Science, Scopus, and Google Scholar, 31 manuscripts were selected for a final analysis, 30 investigating MPV and 15 investigating PDW. MPV was not statistically different between OSAS patients and healthy controls; however, it progressively increased with disease severity. By contrast, OSAS patients had significantly higher PDW values than controls (SMD = 0.40, 95% CI: 0.25 to 0.56; p ˂ 0.001), and the difference increased with disease severity. In a univariate meta-regression, there were significant associations between the MPV and publication year, the apnoea-hypopnea index, and diabetes mellitus, while no associations were observed with the PDW. No significant between-group differences were observed in the subgroup analyses. These data suggest that PDW, and to a lesser extent, MPV, are potential biomarkers of OSAS and require further research to ascertain their pathophysiological significance (PROSPERO, CRD42023459413).

Transsulfuration and folate pathways in rheumatoid arthritis: A systematic review and meta-analysis.

BACKGROUND: Metabolomic assessment of the transsulfuration and folic acid biochemical pathways could lead to the identification of promising biomarkers of nitric oxide dysregulation and oxidative stress in rheumatoid arthritis (RA). METHODS: We conducted a systematic review and meta-analysis of transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B6 , and vitamin B12 ) metabolites in RA patients in remission and healthy controls. Electronic databases were searched from inception to 15 July 2023 for relevant articles. We assessed the risk of bias using the JBI checklist and the certainty of evidence using GRADE. RESULTS: In 28 eligible studies, compared to controls, RA patients had significantly higher concentrations of homocysteine (standardized mean difference, SMD = 0.74, 95% CI 0.54-0.93, p < 0.001; low certainty of evidence) and methionine (SMD = 1.00, 95% CI 0.57-1.44, p < 0.001; low certainty) and lower concentrations of vitamin B6 (SMD = -6.62, 95% CI -9.65 to -3.60, p < 0.001; low certainty). By contrast, there were non-significant between-group differences in vitamin B12 and folic acid. In meta-regression and subgroup analysis, there were no associations between the effect size and several study and patient characteristics except for homocysteine (year of publication, C-reactive protein, triglycerides, and analytical method) and folic acid (biological matrix). CONCLUSIONS: The results of our study suggest that homocysteine, methionine, and vitamin B6 are promising biomarkers to assess nitric oxide dysregulation and oxidative stress in RA. (PROSPERO registration number: CRD42023461081).