Persistence and Sexual Dimorphism of Gut Dysbiosis and Pathobiome after Sepsis and Trauma.

OBJECTIVE: To evaluate the persistence of intestinal microbiome dysbiosis and gut-plasma metabolomic perturbations following severe trauma or sepsis weeks after admission in patients experiencing chronic critical illness (CCI). SUMMARY: Trauma and sepsis can lead to gut dysbiosis and alterations in the plasma and fecal metabolome. However, the impact of these perturbations and correlations between gut dysbiosis and the plasma metabolome in chronic critical illness have not been studied. METHODS: A prospective observational cohort study was performed with healthy subjects, severe trauma patients, and patients with sepsis residing in an intensive care unit for 2 to 3 weeks. A high-throughput multi-omics approach was utilized to evaluate the gut microbial and gut-plasma metabolite responses in critically ill trauma and sepsis patients 14 to 21 days after intensive care unit admission. RESULTS: Patients in the sepsis and trauma cohorts demonstrated strikingly depleted gut microbiome diversity, with significant alterations and specific pathobiome patterns in the microbiota composition compared to healthy subjects. Further subgroup analyses based on sex revealed resistance to changes in microbiome diversity among female trauma patients compared to healthy counterparts. Sex--specific changes in fecal metabolites were also observed after trauma and sepsis, while plasma metabolite changes were similar in both males and females. CONCLUSIONS: Dysbiosis induced by trauma and sepsis persists up to 14 to 21 days after onset and is sex-specific, underscoring the implication of pathobiome and entero-septic microbial-metabolite perturbations in post-sepsis and posttrauma chronic critical illness. This indicates resilience to infection or injury in females' microbiome and should inform and facilitate future precision/personalized medicine strategies in the intensive care unit.

Gut mycobiome dysbiosis after sepsis and trauma.

BACKGROUND: Sepsis and trauma are known to disrupt gut bacterial microbiome communities, but the impacts and perturbations in the fungal (mycobiome) community after severe infection or injury, particularly in patients experiencing chronic critical illness (CCI), remain unstudied. METHODS: We assess persistence of the gut mycobiome perturbation (dysbiosis) in patients experiencing CCI following sepsis or trauma for up to two-to-three weeks after intensive care unit hospitalization. RESULTS: We show that the dysbiotic mycobiome arrays shift toward a pathobiome state, which is more susceptible to infection, in CCI patients compared to age-matched healthy subjects. The fungal community in CCI patients is largely dominated by Candida spp; while, the commensal fungal species are depleted. Additionally, these myco-pathobiome arrays correlate with alterations in micro-ecological niche involving specific gut bacteria and gut-blood metabolites. CONCLUSIONS: The findings reveal the persistence of mycobiome dysbiosis in both sepsis and trauma settings, even up to two weeks post-sepsis and trauma, highlighting the need to assess and address the increased risk of fungal infections in CCI patients.

Novel insights on the role of spexin as a biomarker of obesity and related cardiometabolic disease.

Spexin (SPX) is a 14-amino acid neuropeptide, discovered recently using bioinformatic techniques. It is encoded by the Ch12:orf39 gene that is widely expressed in different body tissues/organs across species, and secreted into systemic circulation. Recent reports have highlighted a potentially important regulatory role of SPX in obesity and related comorbidities. SPX is also ubiquitously expressed in human tissues, including white adipose tissue. The circulating concentration of SPX is significantly lower in individuals with obesity compared to normal weight counterparts. SPX's role in obesity appears to be related to various factors, such as the regulation of energy expenditure, appetite, and eating behaviors, increasing locomotion, and inhibiting long-chain fatty acid uptake into adipocytes. Recent reports have also suggested SPX's relationship with novel biomarkers of cardiovascular disease (CVD) and glucose metabolism and evoked the potential role of SPX as a key biomarker/player in the early loss of cardiometabolic health and development of CVD and diabetes later in life. Data on age-related changes in SPX and SPX's response to various interventions are also emerging. The current review focuses on the role of SPX in obesity and related comorbidities across the life span, and its response to interventions in these conditions. It is expected that this article will provide new ideas for future research on SPX and its metabolic regulation, particularly related to cardiometabolic diseases.

The Development of Chronic Critical Illness Determines Physical Function, Quality of Life, and Long-Term Survival Among Early Survivors of Sepsis in Surgical ICUs.

OBJECTIVES: This study sought to examine mortality, health-related quality of life, and physical function among sepsis survivors who developed chronic critical illness. DESIGN: Single-institution, prospective, longitudinal, observational cohort study assessing 12-month outcomes. SETTING: Two surgical/trauma ICUs at an academic tertiary medical and level 1 trauma center. PATIENTS: Adult critically ill patients that survived 14 days or longer after sepsis onset. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline patient characteristics and function, sepsis severity, and clinical outcomes of the index hospitalization were collected. Follow-up physical function (short physical performance battery; Zubrod; hand grip strength) and health-related quality of life (EuroQol-5D-3L, Short Form-36) were measured at 3, 6, and 12 months. Hospital-free days and mortality were determined at 12 months. We compared differences in long-term outcomes between subjects who developed chronic critical illness (≥ 14 ICU days with persistent organ dysfunction) versus those with rapid recovery. The cohort consisted of 173 sepsis patients; 63 (36%) developed chronic critical illness and 110 (64%) exhibited rapid recovery. Baseline physical function and health-related quality of life did not differ between groups. Those who developed chronic critical illness had significantly fewer hospital-free days (196 ± 148 vs 321 ± 65; p < 0.0001) and reduced survival at 12-months compared with rapid recovery subjects (54% vs 92%; p < 0.0001). At 3- and 6-month follow-up, chronic critical illness patients had significantly lower physical function (3 mo: short physical performance battery, Zubrod, and hand grip; 6 mo: short physical performance battery, Zubrod) and health-related quality of life (3- and 6-mo: EuroQol-5D-3L) compared with patients who rapidly recovered. By 12-month follow-up, chronic critical illness patients had significantly lower physical function and health-related quality of life on all measures. CONCLUSIONS: Surgical patients who develop chronic critical illness after sepsis exhibit high healthcare resource utilization and ultimately suffer dismal long-term clinical, functional, and health-related quality of life outcomes. Further understanding of the mechanisms driving the development and persistence of chronic critical illness will be necessary to improve long-term outcomes after sepsis.

Prognostic value of NT-proBNP levels in the acute phase of sepsis on lower long-term physical function and muscle strength in sepsis survivors.

BACKGROUND: Sepsis survivors often develop chronic critical illness (CCI) and demonstrate the persistent inflammation, immunosuppression, and catabolism syndrome predisposing them to long-term functional limitations and higher mortality. There is a need to identify biomarkers that can predict long-term worsening of physical function to be able to act early and prevent mobility loss. N-terminal pro-brain natriuretic peptide (NT-proBNP) is a well-accepted biomarker of cardiac overload, but it has also been shown to be associated with long-term physical function decline. We explored whether NT-proBNP blood levels in the acute phase of sepsis are associated with physical function and muscle strength impairment at 6 and 12 months after sepsis onset. METHODS: This is a retrospective analysis conducted in 196 sepsis patients (aged 18-86 years old) as part of the University of Florida (UF) Sepsis and Critical Illness Research Center (SCIRC) who consented to participate in the 12-month follow-up study. NT-proBNP was measured at 24 h after sepsis onset. Patients were followed to determine physical function by short physical performance battery (SPPB) test score (scale 0 to12-higher score corresponds with better physical function) and upper limb muscle strength by hand grip strength test (kilograms) at 6 and 12 months. We used a multivariate linear regression model to test an association between NT-proBNP levels, SPPB, and hand grip strength scores. Missing follow-up data or absence due to death was accounted for by using inverse probability weighting based on concurrent health performance status scores. Statistical significance was set at p ≤ 0.05. RESULTS: After adjusting for covariates (age, gender, race, Charlson comorbidity index, APACHE II score, and presence of CCI condition), higher levels of NT-proBNP at 24 h after sepsis onset were associated with lower SPPB scores at 12 months (p < 0.05) and lower hand grip strength at 6-month (p < 0.001) and 12-month follow-up (p < 0.05). CONCLUSIONS: NT-proBNP levels during the acute phase of sepsis may be a useful indicator of higher risk of long-term impairments in physical function and muscle strength in sepsis survivors.

Heart-Rate Variability Threshold as an Alternative for Spiro-Ergometry Testing: A Validation Study.

Mankowski, RT, Michael, S, Rozenberg, R, Stokla, S, Stam, HJ, and Praet, SFE. Heart-rate variability threshold as an alternative for spiro-ergometry testing: a validation study. J Strength Cond Res 31(2): 474-479, 2017-Although spiro-ergometry is the established "gold standard" for determination of the second ventilatory threshold (VT2), it is a costly and rather time-consuming method. Previous studies suggest that assessing the second anaerobic threshold (AT2) on the basis of heart rate variability (HRV) during exercise may be a more cost-effective and noninvasive manner. However, appropriate validation studies, are still lacking. Eleven healthy, moderately trained subjects underwent 3 incremental exercise tests. Ventilation, oxygen uptake (V[Combining Dot Above]O2), CO2 production (V[Combining Dot Above]CO2), and HRV were measured continuously. Exercise testing was performed in 3 oxygen (FiO2) conditions of inspired air (14, 21, and 35% of oxygen). Participants and assessors were blinded to the FiO2 conditions. Two research teams assessed VT2s and HRVT2s independently from each other. Mean workloads corresponding to VT2 and HRVT2 in hypoxia were, respectively, 19 ± 17% (p = 0.01) and 15 ± 15% (p = 0.1) lower in comparison with hyperoxic conditions. Bland-Altman analysis showed low estimation bias (2.2%) and acceptably precise 95% limits of agreement for workload -15.7% to 20.1% for all FiO2 conditions. Bias was the lowest under normoxic conditions (1.1%) in comparison with hypoxia (3.7%) and hyperoxia (4.7%). Heart rate variability-based AT2 assessment had a most acceptable agreement with VT2 under normoxic conditions. This simple HRVT2 assessment may have potential applications for exercise monitoring in commercial fitness settings.

Oxygen delivery is not a limiting factor during post-exercise recovery in healthy young adults.

PURPOSE: It is still equivocal whether oxygen uptake recovery kinetics are limited by oxygen delivery and can be improved by supplementary oxygen. The present study aimed to investigate whether measurements of muscle and pulmonary oxygen uptake kinetics can be used to assess oxygen delivery limitations in healthy subjects. METHODS: Sixteen healthy young adults performed three sub-maximal exercise tests (6 min at 40% Wmax) under hypoxic (14%O2), normoxic (21%O2) and hyperoxic (35%O2) conditions on separate days in randomized order. Both Pulmonary VO2 and near infra red spectroscopy (NIRS) based Tissue Saturation Index (TSI) offset kinetics were calculated using mono-exponential curve fitting models. RESULTS: Time constant τ of VO2 offset kinetics under hypoxic (44.9 ± 7.3s) conditions were significantly larger than τ of the offset kinetics under normoxia (37.9 ± 8.2s, p = 0.02) and hyperoxia (37±6s, p = 0.04). TSI mean response time (MRT) of the offset kinetics under hypoxic conditions (25.5 ± 13s) was significantly slower than under normoxic (15 ± 7.7, p = 0.007) and hyperoxic (13 ± 7.3, p = 0.008) conditions. CONCLUSION: The present study shows that there was no improvement in the oxygen uptake and muscle oxygenation recovery kinetics in healthy subjects under hyperoxic conditions.Slower TSI and VO2 recovery kinetics under hypoxic conditions indicate that both NIRS and spiro-ergometry are appropriate non-invasive measurement tools to assess the physiological response of a healthy individual to hypoxic exercise.

Intraoperative hemidiaphragm electrical stimulation reduces oxidative stress and upregulates autophagy in surgery patients undergoing mechanical ventilation: exploratory study.

BACKGROUND: Mechanical ventilation (MV) during a cardio-thoracic surgery contributes to diaphragm muscle dysfunction that impairs weaning and can lead to the ventilator- induced diaphragm dysfunction. Especially, it is critical in older adults who have lower muscle reparative capacity following MV. Reports have shown that the intraoperative intermittent hemidiaphragm electrical stimulation can maintain and/or improve post-surgery diaphragm function. In particular, from a molecular point of view, intermittent ES may reduce oxidative stress and increase regulatory autophagy levels, and therefore improve diaphragm function in animal studies. We have recently shown in humans that intraoperative ES attenuates mitochondrial dysfunction and force decline in single diaphragm muscle fibers. The aim of this study was to investigate an effect of ES on oxidative stress, antioxidant status and autophagy biomarker levels in the human diaphragm during surgery. METHODS: One phrenic nerve was simulated with an external cardiac pacer in operated older subjects (62.4 ± 12.9 years) (n = 8) during the surgery. The patients received 30 pulses per min every 30 min. The muscle biopsy was collected from both hemidiaphragms and frozen for further analyses. 4-hydroxynonenal (4-HNE), an oxidative stress marker, and autophagy marker levels (Beclin-1 and the ratio of microtubule-associated protein light chain 3, I and II-LC3 II/I) protein concentrations were detected by the western blot technique. Antioxidant enzymatic activity copper-zinc (CuZnSOD) and manganese (MnSOD) superoxide dismutase were analyzed. RESULTS: Levels of lipid peroxidation (4-HNE) were significantly lower in the stimulated side (p < 0.05). The antioxidant enzyme activities (CuZnSOD and MnSOD) in the stimulated side of the diaphragm were not different than in the unstimulated side (p > 0.05). Additionally, the protein concentrations of Beclin-1 and the LC3 II/I ratio were higher in the stimulated side (p < 0.05). CONCLUSION: These results suggest that the intraoperative electrical stimulation decreases oxidative stress levels and upregulates autophagy levels in the stimulated hemidiaphragm. These results may contribute future studies and clinical applications on reducing post-operative diaphragm dysfunction.

Iron homeostasis in older adults: balancing nutritional requirements and health risks.

Iron plays a crucial role in many physiological processes, including oxygen transport, bioenergetics, and immune function. Iron is assimilated from food and also recycled from senescent red blood cells. Iron exists in two dietary forms: heme (animal based) and non-heme (mostly plant based). The body uses iron for metabolic purposes, and stores the excess mainly in splenic and hepatic macrophages. Physiologically, iron excretion in humans is inefficient and not highly regulated, so regulation of intestinal absorption maintains iron homeostasis. Iron losses occur at a steady rate via turnover of the intestinal epithelium, blood loss, and exfoliation of dead skin cells, but overall iron homeostasis is tightly controlled at cellular and systemic levels. Aging can have a profound impact on iron homeostasis and induce a dyshomeostasis where iron deficiency or overload (sometimes both simultaneously) can occur, potentially leading to several disorders and pathologies. To maintain physiologically balanced iron levels, reduce risk of disease, and promote healthy aging, it is advisable for older adults to follow recommended daily intake guidelines and periodically assess iron levels. Clinicians can evaluate body iron status using different techniques but selecting an assessment method primarily depends on the condition being examined. This review provides a comprehensive overview of the forms, sources, and metabolism of dietary iron, associated disorders of iron dyshomeostasis, assessment of iron levels in older adults, and nutritional guidelines and strategies to maintain iron balance in older adults.

Sex differences in frailty among older adults.

By definition, aging is a natural, gradual and continuous process. On the other hand, frailty reflects the increase in vulnerability to stressors and shortens the time without disease (health span) while longevity refers to the length of life (lifespan). The average life expectancy has significantly increased during the last few decades. A longer lifespan has been accompanied by an increase in frailty and decreased independence in older adults, with major differences existing between men and women. For example, women tend to live longer than men but also experience higher rates of frailty and disability. Sex differences prevent optimization of lifestyle interventions and therapies to effectively prevent frailty. Sex differences in frailty and aging are rooted in a complex interplay between uncontrollable (genetic, epigenetic, physiological), and controllable factors (psychosocial and lifestyle factors). Thus, understanding the underlying causes of sex differences in frailty and aging is essential for developing personalized interventions to promote healthy aging and improve quality of life in older men and women. In this review, we have discussed the key contributors and knowledge gaps related to sex differences in aging and frailty.

Understanding Post-Sepsis Syndrome: How Can Clinicians Help?

Sepsis is a global health challenge, with over 49 million cases annually. Recent medical advancements have increased in-hospital survival rates to approximately 80%, but the escalating incidence of sepsis, owing to an ageing population, rise in chronic diseases, and antibiotic resistance, have also increased the number of sepsis survivors. Subsequently, there is a growing prevalence of "post-sepsis syndrome" (PSS). This syndrome includes long-term physical, medical, cognitive, and psychological issues after recovering from sepsis. PSS puts survivors at risk for hospital readmission and is associated with a reduction in health- and life span, both at short and long term, after hospital discharge. Comprehensive understanding of PSS symptoms and causative factors is vital for developing optimal care for sepsis survivors, a task of prime importance for clinicians. This review aims to elucidate our current knowledge of PSS and its relevance in enhancing post-sepsis care provided by clinicians.

Relationship between Mitochondrial Quality Control Markers, Lower Extremity Tissue Composition, and Physical Performance in Physically Inactive Older Adults.

Altered mitochondrial quality and function in muscle may be involved in age-related physical function decline. The role played by the autophagy-lysosome system, a major component of mitochondrial quality control (MQC), is incompletely understood. This study was undertaken to obtain initial indications on the relationship between autophagy, mitophagy, and lysosomal markers in muscle and measures of physical performance and lower extremity tissue composition in young and older adults. Twenty-three participants were enrolled, nine young (mean age: 24.3 ± 4.3 years) and 14 older adults (mean age: 77.9 ± 6.3 years). Lower extremity tissue composition was quantified volumetrically by magnetic resonance imaging and a tissue composition index was calculated as the ratio between muscle and intermuscular adipose tissue volume. Physical performance in older participants was assessed via the Short Physical Performance Battery (SPPB). Protein levels of the autophagy marker p62, the mitophagy mediator BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), the lysosomal markers transcription factor EB, vacuolar-type ATPase, and lysosomal-associated membrane protein 1 were measured by Western immunoblotting in vastus lateralis muscle biopsies. Older adults had smaller muscle volume and lower tissue composition index than young participants. The protein content of p62 and BNIP3 was higher in older adults. A negative correlation was detected between p62 and BNIP3 and the tissue composition index. p62 and BNIP3 were also related to the performance on the 5-time sit-to-stand test of the SPPB. Our results suggest that an altered expression of markers of the autophagy/mitophagy-lysosomal system is related to deterioration of lower extremity tissue composition and muscle dysfunction. Additional studies are needed to clarify the role of defective MQC in human muscle aging and identify novel biological targets for drug development.

Intraoperative Hemi-Diaphragm Electrical Stimulation Demonstrates Attenuated Mitochondrial Function without Change in Oxidative Stress in Cardiothoracic Surgery Patients.

Mechanical ventilation during cardiothoracic surgery is life-saving but can lead to ventilator-induced diaphragm dysfunction (VIDD) and prolong ventilator weaning and hospital length of stay. Intraoperative phrenic nerve stimulation may preserve diaphragm force production to offset VIDD; we also investigated changes in mitochondrial function after stimulation. During cardiothoracic surgeries (n = 21), supramaximal, unilateral phrenic nerve stimulation was performed every 30 min for 1 min. Diaphragm biopsies were collected after the last stimulation and analyzed for mitochondrial respiration in permeabilized fibers and protein expression and enzymatic activity of biomarkers of oxidative stress and mitophagy. Patients received, on average, 6.2 ± 1.9 stimulation bouts. Stimulated hemidiaphragms showed lower leak respiration, maximum electron transport system (ETS) capacities, oxidative phosphorylation (OXPHOS), and spare capacity compared with unstimulated sides. There were no significant differences between mitochondrial enzyme activities and oxidative stress and mitophagy protein expression levels. Intraoperative phrenic nerve electrical stimulation led to an acute decrease of mitochondrial respiration in the stimulated hemidiaphragm, without differences in biomarkers of mitophagy or oxidative stress. Future studies warrant investigating optimal stimulation doses and testing post-operative chronic stimulation effects on weaning from the ventilator and rehabilitation outcomes.

Low muscle mass is associated with a higher risk of all-cause and cardiovascular disease-specific mortality in cancer survivors.

OBJECTIVES: Individuals with prior cancer diagnosis are more likely to have low muscle mass (LMM) than their cancer-free counterparts. Understanding the effects of LMM on the prognosis of cancer survivors can be clinically important. The aim of this study was to investigate whether risks for all-cause and cardiovascular disease (CVD)-specific mortality differ by status of LMM in cancer survivors and a matched cohort without cancer history. METHODS: We used cohort data from the 1999-2006 and 2011-2014 National Health and Nutrition Examination Survey. Participants included 946 adults surviving for ≥1 since cancer diagnosis and a matched cohort (by age, sex, and race) without cancer history (N = 1857). LMM was defined by appendicular lean mass and body height (men <7.26 kg/m2, women <5.45 kg/m2). Death was ascertained via the National Death Index and cause of death was assessed via International Classification of Diseases, Tenth Revision. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratio (aHR) and 95% confidence interval (CI) of LMM. RESULTS: The mean age of cancer survivors and matched cohort was 60.6 y (SD 15) and 60.2 y (SD 14.9), respectively. The median follow-up was 10.5 y for survivors and 10.9 y for matched cohort. Overall, 22.2% of cancer survivors and 19.7% of the matched cohort had LMM, respectively. In all, 321 survivors (33.9%) and 495 participants (26.7%) in the matched cohort died during follow-up. CVD-specific deaths were identified in 58 survivors (6.1%) and 122 participants in the matched cohort (6.6%). The multivariable Cox model suggested that LMM was positively associated with all-cause (aHR, 1.73; 95% CI, 1.31-2.29) and CVD-specific (aHR, 2.13; 95% CI, 1.14-4.00) mortality in cancer survivors. The associations between LMM and risk for all-cause (aHR, 1.24; 95% CI, 0.98-1.56) and CVD-specific (aHR, 1.21; 95% CI, 0.75-1.93) mortality were not statistically significant in the matched cohort. CONCLUSION: Cancer survivors with LMM have an increased risk for all-cause and CVD-specific mortality. This increase appears to be larger than that in counterparts without cancer history.

Sepsis-Induced Myopathy and Gut Microbiome Dysbiosis: Mechanistic Links and Therapeutic Targets.

ABSTRACT: Sepsis is currently defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. The skeletal muscle system is among the host organ systems compromised by sepsis. The resulting neuromuscular dysfunction and impaired regenerative capacity defines sepsis-induced myopathy and manifests as atrophy, loss of strength, and hindered regeneration after injury. These outcomes delay recovery from critical illness and confer increased vulnerability to morbidity and mortality. The mechanisms underlying sepsis-induced myopathy, including the potential contribution of peripheral organs, remain largely unexplored. The gut microbiome is an immunological and homeostatic entity that interacts with and controls end-organ function, including the skeletal muscle system. Sepsis induces alterations in the gut microbiota composition, which is globally termed a state of "dysbiosis" for the host compared to baseline microbiota composition. In this review, we critically evaluate existing evidence and potential mechanisms linking sepsis-induced myopathy with gut microbiota dysbiosis.

Older Adults Demonstrate Biomarker Evidence of the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) After Sepsis.

BACKGROUND: Hospital deaths after sepsis have decreased substantially and most young adult survivors rapidly recover (RAP). However, many older survivors develop chronic critical illness (CCI) with poor long-term outcomes. The etiology of CCI is multifactorial and the relative importance remains unclear. Sepsis is caused by a dysregulated immune response and biomarkers reflecting a persistent inflammation, immunosuppression, and catabolism syndrome (PICS) have been observed in CCI after sepsis. Therefore, the purpose of this study was to compare serial PICS biomarkers in (i) older (vs young) adults and (ii) older CCI (vs older RAP) patients to gain insight into underlying pathobiology of CCI in older adults. METHOD: Prospective longitudinal study with young (≤45 years) and older (≥65 years) septic adults, who were characterized by (i) baseline predisposition, (ii) hospital outcomes, (iii) serial Sequential Organ Failure Assessment (SOFA) organ dysfunction scores over 14 days, (iv) Zubrod Performance status at 3-, 6-, and 12-month follow-up, and (v) mortality over 12 months, was conducted. Serial blood samples over 14 days were analyzed for selected biomarkers reflecting PICS. RESULTS: Compared to the young, more older adults developed CCI (20% vs 42%) and had markedly worse serial SOFA scores, performance status, and mortality over 12 months. Additionally, older (vs young) and older CCI (vs older RAP) patients had more persistent aberrations in biomarkers reflecting inflammation, immunosuppression, stress metabolism, lack of anabolism, and antiangiogenesis over 14 days after sepsis. CONCLUSION: Older (vs young) and older CCI (vs older RAP) patient subgroups demonstrate early biomarker evidence of the underlying pathobiology of PICS.

Sex differences associate with late microbiome alterations after murine surgical sepsis.

BACKGROUND: Sepsis-induced gut microbiome alterations contribute to sepsis-related morbidity and mortality. Given evidence for improved postsepsis outcomes in females compared with males, we hypothesized that female mice maintain microbiota resilience versus males. METHODS: Mixed-sex C57BL/6 mice underwent cecal ligation and puncture (CLP) with antibiotics, saline resuscitation, and daily chronic stress and were compared with naive (nonsepsis/no antibiotics) controls. For this work, the results of young (3-5 months) and old (18-22 months) adult mice were analyzed by sex, independent and dependent of age. Mice were sacrificed at days 7 and 14, and 16S rRNA gene sequencing was performed on fecal bacterial DNA. α and ß diversity were determined by Shannon index and Bray-Curtis with principal coordinate analysis, respectively. False discovery rate (FDR) correction was implemented to account for potential housing effect. RESULTS: In control mice, there was no difference in α or ß diversity between male and female mice (FDR, 0.76 and 0.99, respectively). However, male mice that underwent CLP with daily chronic stress had a decrease in microbiota α diversity at 7 days post-CLP (Shannon FDR, 0.005), which was sustained at 14 days post-CLP (Shannon FDR, 0.001), compared with baseline. In addition, male mice maintained differences in ß diversity even at day 14 compared with controls (FDR, <0.0001). In contrast, female mice had a decreased microbiota α diversity (Shannon FDR, 0.03) and ß diversity (FDR, 0.02) 7 days post-CLP but recovered their α and ß diversity by post-CLP day 14 (Shannon FDR, 0.5, and FDR, 0.02, respectively). Further analysis of females revealed that only young female mice were not different (ß diversity) post-CLP day 14 to controls. CONCLUSION: Although sepsis-induced perturbations of the intestinal microbiota occur initially in both male and female C57BL/6 mice, females demonstrate different microbiota by day 14. This may be seen primarily in younger females. This difference in recovery may play a role in outcome differences between sexes after sepsis.

Pathophysiology and Treatment Strategies of Acute Myopathy and Muscle Wasting after Sepsis.

Sepsis survivors experience a persistent myopathy characterized by skeletal muscle weakness, atrophy, and an inability to repair/regenerate damaged or dysfunctional myofibers. The origins and mechanisms of this persistent sepsis-induced myopathy are likely complex and multifactorial. Nevertheless, the pathobiology is thought to be triggered by the interaction between circulating pathogens and impaired muscle metabolic status. In addition, while in the hospital, septic patients often experience prolonged periods of physical inactivity due to bed rest, which may exacerbate the myopathy. Physical rehabilitation emerges as a potential tool to prevent the decline in physical function in septic patients. Currently, there is no consensus regarding effective rehabilitation strategies for sepsis-induced myopathy. The optimal timing to initiate the rehabilitation intervention currently lacks consensus as well. In this review, we summarize the evidence on the fundamental pathobiological mechanisms of sepsis-induced myopathy and discuss the recent evidence on in-hospital and post-discharge rehabilitation as well as other potential interventions that may prevent physical disability and death of sepsis survivors.

Impact of COVID-19 on Future Ischemic Stroke Incidence.

With the ever-expanding population of patients infected with SARS-CoV-2, we are learning more about the immediate and long-term clinical manifestations of coronavirus disease 2019 (COVID-19). Ischemic stroke (IS) is now one of the well-documented additional clinical manifestations of COVID-19. Most COVID-19 related IS cases have been categorized as cryptogenic or embolic stroke of undetermined source (ESUS), which are most often suspected to have an undiagnosed cardioembolic source. COVID-19 is known to also cause cardiac dysfunction, heart failure, and atrial arrhythmias (AA), but the long-term impact of this cardiac dysfunction on stroke incidence is unknown. With millions afflicted with COVID-19 and the ever-rising infection rate, it is important to consider the potential long-term impact of COVID-19 on future IS incidence. Accomplishing these goals will require novel strategies that allow for diagnosis, data capture, and prediction of future IS risk using tools that are adaptable to the evolving clinical challenges in patient care delivery and research.

Erratum to "Impact of COVID-19 on Future Ischemic Stroke Incidence" [eNeurologicalSci, 22C (2021) 100325].

[This corrects the article DOI: 10.1016/j.ensci.2021.100325.].