The Role of NK and T Cells in Endometriosis.

Endometriosis, a debilitating condition, affects one in ten women of reproductive age. Its pathophysiology remains unclear, though deficiencies in immune surveillance are thought to create an environment conducive to the evasion of ectopic endometrial cells from the immune system. Our research explores the immunological impact of endometriosis both locally and systemically, emphasizing natural killer (NK) and T cell subpopulations. We incorporated 62 female patients who underwent laparoscopic surgery; of those, 47 had endometriosis, and 15 were controls. We collected peritoneal fluid (PF) and peripheral blood (PB) samples which were tagged with monoclonal antibodies and subsequently scrutinized using flow cytometry. Our findings revealed significant differences in immunological profiles based on demographic factors and symptomatology. In the endometriosis cohort, there was an increase in PB CD56HiCD16dim and PF CD8+ CD56dimCD16Hi NK cells. CD16+ CD4 T cell levels were significantly lower in the PB of endometriosis patients who smoke. Individuals with more severe disease displayed significantly higher levels of PB CD16+ CD8 T cells, which also increased in those with non-menstrual pelvic pain. Dysmenorrhea severity correlated with a progressive increase in PF CD8+ CD56dimCD16Hi NK cells. These variations in specific lymphocyte subsets, namely, within NK and T cells, suggest potential immunological mechanisms in the evolution and clinical presentation of endometriosis.

Aboveground and belowground biodiversity have complementary effects on ecosystem functions across global grasslands.

Grasslands are integral to maintaining biodiversity and key ecosystem services and are under threat from climate change. Plant and soil microbial diversity, and their interactions, support the provision of multiple ecosystem functions (multifunctionality). However, it remains virtually unknown whether plant and soil microbial diversity explain a unique portion of total variation or shared contributions to supporting multifunctionality across global grasslands. Here, we combine results from a global survey of 101 grasslands with a novel microcosm study, controlling for both plant and soil microbial diversity to identify their individual and interactive contribution to support multifunctionality under aridity and experimental drought. We found that plant and soil microbial diversity independently predict a unique portion of total variation in above- and belowground functioning, suggesting that both types of biodiversity complement each other. Interactions between plant and soil microbial diversity positively impacted multifunctionality including primary production and nutrient storage. Our findings were also climate context dependent, since soil fungal diversity was positively associated with multifunctionality in less arid regions, while plant diversity was strongly and positively linked to multifunctionality in more arid regions. Our results highlight the need to conserve both above- and belowground diversity to sustain grassland multifunctionality in a drier world and indicate climate change may shift the relative contribution of plant and soil biodiversity to multifunctionality across global grasslands.

TIM-3 Expression in Endometriosis.

PROBLEM: Endometriosis is a prevalent chronic gynecological disease linked to immune dysfunction. The protein T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) plays a crucial role in immune system balance. Malfunction of TIM-3 may result in excessive immune activation and inflammatory tissue damage. Given TIM-3's established role in the development of cancer and autoimmune diseases, we decided to study its role in women suffering from endometriosis. STUDY METHOD: We included a total of 62 female patients, all of whom had undergone laparoscopic surgery. Of these, 47 had endometriosis and 15 did not. During surgery, we collected peritoneal fluid (PF) and peripheral blood (PB) samples from every patient for analysis using flow cytometry. To mark the samples, we used a panel of monoclonal antibodies and examined TIM-3 expression in their immune cells. RESULTS: Endometriosis patients in PB demonstrated a significantly lower percentage of CD56+ T cells with TIM-3 expression. As endometriosis progressed through its stages, this expression lessened. This decrease was particularly notable in women with stage III/IV endometriosis. Additionally, both women diagnosed with intestinal endometriosis and those with recent endometriosis diagnoses showed a significantly reduced percentage of CD56+ T cells expressing TIM-3. CONCLUSIONS: Patients with endometriosis exhibit diminished TIM-3 expression within circulating T cells. This warrants further investigation to discern whether it contributes to the progression of endometriosis, potentially through the amplification of autoreactive T cells and inflammation.

Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer.

Reef-building corals live in highly hydrodynamic environments, where water flow largely controls the complex chemical microenvironments surrounding them-the concentration boundary layer (CBL). The CBL may be key to alleviate ocean acidification (OA) effects on coral colonies by partially isolating them. However, OA effects on coral CBL remain poorly understood, particularly under different flow velocities. Here, we investigated these effects on the reef-building corals Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. We preconditioned corals to a control (pH 8.0) and OA (pH 7.8) treatment for four months and tested how low flow (2 cm s-1) and moderate flow (6 cm s-1) affected O2 and H+ CBL traits (thickness, surface concentrations, and flux) inside a unidirectional-flow chamber. We found that CBL traits differed between species and flow velocities. Under OA, traits remained generally stable across flows, except surface pH. In all species, the H+ CBL was thin and led to lower surface pH. Still, low flow thickened H+ CBLs and increased light elevation of surface pH. In general, our findings reveal a weak to null OA modulation of the CBL. Moreover, the OA-buffering capacity by the H+ CBL may be limited in coral species, though low flow could enhance CBL sheltering.

Identifying subgroups in heart failure patients with multimorbidity by clustering and network analysis.

This study presents a workflow for identifying and characterizing patients with Heart Failure (HF) and multimorbidity utilizing data from Electronic Health Records. Multimorbidity, the co-occurrence of two or more chronic conditions, poses a significant challenge on healthcare systems. Nonetheless, understanding of patients with multimorbidity, including the most common disease interactions, risk factors, and treatment responses, remains limited, particularly for complex and heterogeneous conditions like HF. We conducted a clustering analysis of 3745 HF patients using demographics, comorbidities, laboratory values, and drug prescriptions. Our analysis revealed four distinct clusters with significant differences in multimorbidity profiles showing differential prognostic implications regarding unplanned hospital admissions. These findings underscore the considerable disease heterogeneity within HF patients and emphasize the potential for improved characterization of patient subgroups for clinical risk stratification through the use of EHR data.

Cytokine Dynamics in Acute Pancreatitis: The Quest for Biomarkers from Acute Disease to Disease Resolution.

Background: Acute pancreatitis (AP) is an inflammatory disease of the pancreas with incompletely known pathogenic mechanisms. This study aimed to explore the temporal changes in serum cytokines in patients with AP and to assess the association of these changes with disease severity. Methods: Fifty patients hospitalized with AP were enrolled, and their serum cytokine levels were analyzed at four different time points. A healthy control (HC) group of 30 outpatients was included. Results: AP patients showed increased levels of interleukin (IL)-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-alpha, and monocyte chemoattractant protein (MCP)-1 at admission when compared with HC. IL-6, VEGF, and EGF remained elevated 1 month after hospitalization and 6 months after discharge. Conclusions the Bedside Index of Severity in Acute Pancreatitis (BISAP) and severity classification of the revised Atlanta classification system, IL-6 and VEGF, determined 48 h after hospitalization, were the two cytokines consistently elevated in the most severe patients. Increased levels of IL-4, IL-6, IL-10, and TNF-alpha at admission and MCP-1 48 h after admission are also related to the length of hospital stay. Conclusions: Our study highlights the role cytokines play in the pathogenesis of AP and can be useful in the development of future drug trials for AP.

Portuguese Advance Directives-a twist against futility? A cross sectional study.

BACKGROUND: Advance Directive documents allow citizens to choose the treatments they want for end-of-life care without considering therapeutic futility. OBJECTIVES: To analyze patients' and caregivers' answers to Advance Directives and understand their expectations regarding their decisions. DESIGN AND SETTING: This study analyzed participants' answers to a previously published trial, conceived to test the document's efficacy as a communication tool. METHODS: Sixty palliative patients and 60 caregivers (n = 120) registered their preferences in the Advance Directive document and expressed their expectations regarding whether to receive the chosen treatments. RESULTS: In the patient and caregiver groups, 30% and 23.3% wanted to receive cardiorespiratory resuscitation; 23.3% and 25% wanted to receive artificial organ support; and 40% and 35% chose to receive artificial feeding and hydration, respectively. The participants ignored the concept of therapeutic futility and expected to receive invasive treatments. The concept of therapeutic futility should be addressed and discussed with both the patients and caregivers. Legal Advanced Directive documents should be made clear to reduce misinterpretations and potential legal conflicts. CONCLUSION: The authors suggest that all citizens should be clarified regarding the futility concept before filling out the Advance Directives and propose a grammatical change in the document, replacing the phrase "Health Care to Receive / Not to Receive" with the sentence "Health Care to Accept / Refuse" so that patients cannot demand treatments, but instead accept or refuse the proposed therapeutic plans. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05090072. URL: https://clinicaltrials.gov/ct2/show/NCT05090072.

Walk or be walked by the dog? The attachment role.

BACKGROUND: The human-animal bond has been recognized as having positive effects on the health and well-being of both humans and pets. The present study aims to explore the influence of attachment on physical activity (PA), lifestyle, and health outcomes of dog owners (DO), highlighting the mutual benefits resulting from the relationship between DO and dogs. METHODS: Thirty-eight DO and their dogs participated in this study. Socio-demographic data, the Self-Rated Health (SRH), FANTASTICO Lifestyle Scale, and the Lexington Attachment Pet Scale (LAPS) were assessed. PA was measured in both the DO and the dogs, using an ActiGraph GT3X accelerometer in the context of daily routine. Descriptive statistics and Spearman rank correlation analyses were performed to examine the associations between LAPS, PA levels, socio-demographic variables, lifestyle behaviors, and SRH. RESULTS: Significant correlations were found between the dog owners' light-level PA and the pets' vigorous level of PA (rho = 0.445, p = 0.01). Furthermore, the importance of the pets' health (rho = -0.785, p = 0.02) and the LAPS subscales, namely proximity (rho = 0.358, p = 0.03), and attachment (rho = 0.392, p = 0.01), were related to taking the pet for a walk. Regarding lifestyle, DO with a healthier lifestyle had a better self-assessment of their health using the SRH (rho = 0.39, p = 0.02). Moreover, DO with better lifestyles also exhibited greater concern for their pet's health (rho = 0.398, p = 0.01). CONCLUSIONS: This study emphasizes that individuals who adopt healthier habits tend to perceive themselves as healthier and exhibit greater concern for their pets' health. The attachment between DO and dogs is important in promoting healthy lifestyle behaviors and engagement in PA. Our results highlight that the presence of a dog is associated with a higher level of PA in DO, depending on the strength of the human-animal bond.

Nanocomposite hydrogel microneedles: a theranostic toolbox for personalized medicine.

Due to the severity and high prevalence of cancer, as well as its complex pathological condition, new strategies for cancer treatment and diagnostics are required. As such, it is important to design a toolbox that integrates multiple functions on a single smart platform. Theranostic hydrogels offer an innovative and personalized method to tackle cancer while also considering patient comfort, thereby facilitating future implementation and translation to the clinic. In terms of theranostic systems used in cancer therapy, nanoparticles are widely used as diagnostic and therapeutic tools. Nanoparticles can achieve systemic circulation, evade host defenses, and deliver drugs and signaling agents at the targeted site, to diagnose and treat the disease at a cellular and molecular level. In this context, hydrogel microneedles have a high potential for multifunctional operation in medical devices, while avoiding the complications associated with the systemic delivery of therapeutics. Compared with oral administration and subcutaneous injection, microneedles offer advantages such as better patient compliance, faster onset of action, and improved permeability and efficacy. In addition, they comprise highly biocompatible polymers with excellent degradability and tunable properties. Nanoparticles and microneedles thus offer the possibility to expand the theranostic potential through combined synergistic use of their respective features. We review herein recent advances concerning processing methods and material requirements within the realm of hydrogel microneedles as theranostic platforms, various approaches toward cancer therapy, and the incorporation of nanoparticles for added functionality.

Clinical Relevance of Lepidoglyphus destructor Sensitisation in Allergic Rhinitis: Nasal Provocation Test as in vivo Assessment.

BACKGROUND: Dust mites are the leading cause of respiratory allergic diseases worldwide. Allergy to storage mites (SMs) has mostly been related to occupational exposures. However, recent studies have shown that sensitisation to SM, such as Lepidoglyphus destructor (Lep d), is of considerable importance also in urban populations, with high prevalence in dust samples of domestic environments. Co-sensitisation between house dust mites (HDMs) and SM is now regarded as very frequent in some regions, and cross-reactivity between them seems to be narrow. Therefore, SM allergenic capacity is increasingly a subject of study. The nasal provocation test (NPT), as an in vivo technique, could be considered the gold standard for the clinical relevance assessment of an allergen, in polysensitised rhinitis patients. OBJECTIVE: The objective of this study was to analyse the clinical relevance of the SM Lep d, by assessing the relationship between in vivo sensitisation and expression of allergic respiratory disease in an urban setting. PATIENTS AND METHODS: In our study, we enrolled a total of 32 allergic patients with rhinitis (with or without asthma) with proven sensitisation by skin prick test (SPT) and specific IgE (sIgE) to HDMs and/or SM. Patients underwent NPT with Lep d using subjective (Lebel Symptom Score Scale) and objective measurements (peak nasal inspiratory flow [PNIF]) for assessment of nasal response. RESULTS: Most of the patients with positive SPT and sIgE to Lep d had a positive NPT (24/27; 89%). True Lep d allergy, assessed by a positive NPT, could be predicted by a SPT wheal size >9.7 mm and a sIgE >0.42 kUA/L, with 100%/95.7% sensitivity and 75.0%/83.3% specificity, respectively. Co-sensitisation between Lep d and Der p was high, 75.0%. Asthma was more frequent in the positive Lep d NPT group (54 vs. 12%, p < 0.05). Significantly more patients from this group reported physical exercise, nonspecific irritants, and respiratory infections as relevant triggers of respiratory symptoms (p < 0.01-p < 0.05). CONCLUSIONS: To our knowledge, this is the first study to show that sensitisation to Lep d may have clinical relevance in a non-occupational setting. In this group, there seems to be a relationship between allergy to Lep d and severity of respiratory disease, with more bronchial inflammation, when comparing with mite-allergic patients sensitised only to HDM. Therefore, the authors consider that sensitisation to Lep d should be considered when assessing and treating allergic respiratory disease in urban environments.

B Cells and Double-Negative B Cells (CD27-IgD-) Are Related to Acute Pancreatitis Severity.

Acute pancreatitis (AP) is an increasingly frequent disease in which inflammation plays a crucial role. Fifty patients hospitalized with AP were included and peripheral blood samples were analyzed for B and T cell subpopulations at the time of hospitalization and 48 h after diagnosis. The Bedside Index of Severity in Acute Pancreatitis (BISAP) and length of hospital stay were also recorded. A healthy control (HC) group of 15 outpatients was included. AP patients showed higher neutrophil/lymphocyte (N/L) ratios and higher percentages of B cells than the HC group. The total B cell percentages were higher in patients with moderate/severe AP than in patients with mild AP. The percentages of B cells as well as the percentages of the CD27-IgD- B cell subset decreased from admission to 48 h after admission. The patients with higher BISAP scores showed lower percentages of peripheral lymphocytes but higher percentages of CD27-IgD- B cells. Higher BISAP scores, N/L ratios, and peripheral blood B cell levels emerged as predictors of hospital stay length in AP patients. Our findings underscore the importance of early markers for disease severity. Additionally, the N/L ratio along with the BISAP score and circulating B cell levels form a robust predictive model for hospital stay duration of AP patients.

Programmed death-ligand 1 (PD-L1) expression in cervical intraepithelial neoplasia and cervical squamous cell carcinoma of HIV-infected and non-infected patients.

Programmed death-ligand 1 (PD-L1) is overexpressed in cervical carcinoma, hindering tumor destruction. The aim of this study was to assess PD-L1 expression by immunohistochemistry in cervical squamous cell carcinoma (SCC) and squamous intraepithelial lesions (SILs) from human immunodeficiency virus-positive (HIV+) and human immunodeficiency virus-negative (HIV-) patients. A total of 166 SCC and SIL samples of HIV+ and HIV- patients were included and analyzed for PD-L1 expression through tumor proportion score (TPS), and results were stratified in five TPS groups using SP263 antibody and, combined positive score (CPS) using 22C3 antibody. In cohort 1 (SP263 clone), all HIV+ patients were negative for intraepithelial lesion or malignancy (NILM), and low-grade squamous intraepithelial lesions (LSILs) scored < 1; and 87.5% of high-grade squamous intraepithelial lesions (HSILs) adjacent to SCC, 19% of HSILs non-adjacent to SCC, and 69% of SCCs scored ≥ 1 (15.4% scored 5). In HIV- patients, all NILM, LSILs, HSILs adjacent to SCC, and two HSILs non-adjacent to SCC scored < 1. SCC: 88.2% scored ≥ 1 and 5.9% scored 5. In cohort 2 (SP263 and 22C3 clones), 16.7% of HIV+ patients with SCC were positive with both clones, CPS ≥ 1 (22C3) or score 5 (≥ 50%) (SP263), showing no significant differences in positivity between both clones. These results indicate that a relatively low percentage of SCCs (16.7%; both in HIV+ and in HIV- patients) express PD-L1 (TPS ≥ 50% and CPS > 1), which may be due to some samples being archival material, sample characteristics, or use of different methodologies, highlighting the need for standardization of PD-L1 assessment in SCC of the cervix. The fact that PD-L1 is overexpressed in SILs of HIV+ patients suggests potential additional applications for immunotherapy in this disease.

Portuguese Advance Directives-a twist against futility? A cross sectional study

ABSTRACT BACKGROUND: Advance Directive documents allow citizens to choose the treatments they want for end-of-life care without considering therapeutic futility. OBJECTIVES: To analyze patients' and caregivers' answers to Advance Directives and understand their expectations regarding their decisions. DESIGN AND SETTING: This study analyzed participants' answers to a previously published trial, conceived to test the document's efficacy as a communication tool. METHODS: Sixty palliative patients and 60 caregivers (n = 120) registered their preferences in the Advance Directive document and expressed their expectations regarding whether to receive the chosen treatments. RESULTS: In the patient and caregiver groups, 30% and 23.3% wanted to receive cardiorespiratory resuscitation; 23.3% and 25% wanted to receive artificial organ support; and 40% and 35% chose to receive artificial feeding and hydration, respectively. The participants ignored the concept of therapeutic futility and expected to receive invasive treatments. The concept of therapeutic futility should be addressed and discussed with both the patients and caregivers. Legal Advanced Directive documents should be made clear to reduce misinterpretations and potential legal conflicts. CONCLUSION: The authors suggest that all citizens should be clarified regarding the futility concept before filling out the Advance Directives and propose a grammatical change in the document, replacing the phrase "Health Care to Receive / Not to Receive" with the sentence "Health Care to Accept / Refuse" so that patients cannot demand treatments, but instead accept or refuse the proposed therapeutic plans. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05090072 URL: https://clinicaltrials.gov/ct2/show/NCT05090072.

Litter and soil biodiversity jointly drive ecosystem functions.

The decomposition of litter and the supply of nutrients into and from the soil are two fundamental processes through which the above- and belowground world interact. Microbial biodiversity, and especially that of decomposers, plays a key role in these processes by helping litter decomposition. Yet the relative contribution of litter diversity and soil biodiversity in supporting multiple ecosystem services remains virtually unknown. Here we conducted a mesocosm experiment where leaf litter and soil biodiversity were manipulated to investigate their influence on plant productivity, litter decomposition, soil respiration, and enzymatic activity in the littersphere. We showed that both leaf litter diversity and soil microbial diversity (richness and community composition) independently contributed to explain multiple ecosystem functions. Fungal saprobes community composition was especially important for supporting ecosystem multifunctionality (EMF), plant production, litter decomposition, and activity of soil phosphatase when compared with bacteria or other fungal functional groups and litter species richness. Moreover, leaf litter diversity and soil microbial diversity exerted previously undescribed and significantly interactive effects on EMF and multiple individual ecosystem functions, such as litter decomposition and plant production. Together, our work provides experimental evidence supporting the independent and interactive roles of litter and belowground soil biodiversity to maintain ecosystem functions and multiple services.

Advanced directives' knowledge among Portuguese palliative patients and caregivers: do the sociodemographic factors influence it? A cross-sectional survey.

BACKGROUND: The influence of demographic factors on the completion and knowledge of the Portuguese Advance Directives (PAD) and the Health Care Proxy's (HCP) role is still not clear. OBJECTIVES: To identify sociodemographic features associated with knowledge and adherence to PAD and HCP in palliative care. DESIGN: Cross-Sectional analysis of the sociodemographic data, PAD and HCP role knowledge, and PAD Register from a group of Portuguese palliative patients and their caregivers enrolled on the DAVPAL trial to test the PAD efficacy in promoting better concordance between patients and caregivers. PARTICIPANTS: One hundred twenty participants (60 palliative patients and 60 caregivers). METHODS: After enrollment, the participants' sociodemographic data was acquired, their knowledge of PAD and the role of an HCP was questioned, and their prior register of the PAD was asked. RESULTS: 60 patients and 60 caregivers were included (n=120), with differences among them regarding age (p<.001), gender (p=.003), education (p<.001), job (p<.001), marital status (p=.043), and access to the internet (p=.003), but not regarding religion (p=.21). Only 13.3% of the participants were aware of PAD, 15.0% were aware of the HCP role, and 5.0% had previously filled a PAD. Religious beliefs (Non-Catholic) were the only sociodemographic factor significantly related to these three topics. CONCLUSIONS: There is low awareness of PAD and the HCP's role in palliative care, and there is higher knowledge on these topics among non-Catholic individuals. End-of-life decisions seem to be influenced by similarities in religious beliefs between patients and HCP. Improving education is necessary, namely in palliative care. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05090072 . Retrospectively registered on 22/10/2021.

Kinetics of Torque Teno Virus Viral Load Is Associated with Infection and De Novo Donor Specific Antibodies in the First Year after Kidney Transplantation: A Prospective Cohort Study.

Torque teno virus (TTV) was recently identified as a potential biomarker for the degree of immunosuppression, and potentially as a predictor of rejection and infection in solid organ transplant patients. We evaluated TTV viral load in kidney transplant (KT) patients during the first year post-transplant to examine overall kinetics and their relationships with deleterious events, including episodes of infection and the formation of de novo donor-specific antibodies (DSAs). In a single-center, prospective observational cohort study, 81 KT patients were monitored at baseline, week 1, and month 1, 3, 6, 9 and 12, post-KT, and whenever required by clinical events. Kidney function, plasma TTV load, immunoglobulins and lymphocyte subpopulations were assessed at each time point. Twenty-six patients (32.1%) presented a total of 38 infection episodes post-KT. Induction immunosuppression with thymoglobulin, compared to basiliximab, was not associated with more infections (p = 0.8093). Patients with infectious events had lower T-cells (p = 0.0500), CD8+ T-cells (p = 0.0313) and B-cells (p = 0.0009) 1 month post-KT, compared to infection-free patients. Patients with infection also showed higher increases in TTV viral loads between week 1- month 1, post-KT, with TTV viral load variations >2.65 log10 cp/mL predicting the development of infectious events during the 12-month study period (p < 0.0001; sensitivity 99.73%; specificity 83.67%). Patients who developed de novo DSAs had lower TTV DNA viral loads at month 12 after KT, compared to patients who did not develop DSA (3.7 vs. 5.3 log10 cp/mL, p = 0.0023). Briefly, evaluating early TTV viremia is a promising strategy for defining infectious risk in the 1st year post-KT. The availability of standardized commercial real-time PCR assays is crucial to further validate this as an effective tool guiding immunosuppression prescription.

Advance directives in palliative care-a new tool to improve the communication between patients and caregivers?

BACKGROUND: In palliative care, caregivers frequently act as surrogate decision-makers, but their knowledge of patients' preferences for end-of-life care is sometimes scarce and incorrect. Advance Directives might be a powerful communication tool to promote the dialogue between patients and caregivers. AIMS: This work aims to find evidence supporting the use of the Advance Directives documents by health practitioners as a communication tool to improve caregivers' capacity as health surrogates in palliative care. METHODS: A literature review was conducted in four databases-Medline, Web of Science, Scopus, and Cochrane to identify studies published until February 27th, 2021, analysing advance directive's use as a communication tool between palliative patients and their caregivers. FINDINGS: Of the 1251 papers screened, only one article met the defined criteria, presenting results statistically favourable to advance directive's use, although with the risk of significant bias. CONCLUSIONS: Although the results seem promising, more studies are needed to validate this strategy scientifically.

Pet's influence on humans' daily physical activity and mental health: a meta-analysis.

Abstract: The benefits of the human-animal bond on owners' health and quality of life have been the focus of research in recent decades. However, the results are still inconsistent. Thus, this study aims to investigate whether the presence of a pet, compared to a control group, influences daily physical activity levels and mental health using a meta-analytic method. Methods: The PubMed, Web of Science, and Scopus databases were searched for all research articles that included pets as an object of study and related mental health and quality of life variables between pet owners and non-owners until April 2022. The PRISMA 2020 checklist was used, and the Downs and Back checklist was used to assess the methodological quality of the studies. Standardized mean differences and 95% confidence intervals were used to assess the difference between a group of pet owners and non-pet owners. Results: An initial search located 11,389 studies, but only 49 studies fulfilled all requirements. Our results indicate that pets have a moderately significant positive effect on the physical activity of owners compared to non-pet owners. Among the moderating variables, the frequency of physical activity showed a highly significant effect, indicating that owners had a higher frequency of physical activity than non-owners. Moreover, our results indicate a significant impact but with a low effect size of pets on owners' mental health when compared to non-pet owners. Conclusion: Pet ownership does not seem to influence owners' mental health, but it does influence their physical activity. Specifically, owners show a higher frequency of physical activity than non-owners.