Intermittent fasting improves hepatic end points in nonalcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND AIMS

Despite NAFLD being the most prevalent liver disease globally, currently there are no FDA-approved treatments, and weight loss through caloric restriction and enhanced physical activity is the recommended treatment strategy. Intermittent fasting (IF) has been proposed as an alternative strategy with additional cardiometabolic benefits. In this systematic review and meta-analysis, we evaluated the anthropometric, biochemical, and hepatic impacts of IF in patients with NAFLD.

METHODS

MEDLINE, EMBASE, Cochrane Central, and conference abstracts were searched for IF interventions in adults with NAFLD until April 2, 2023. Meta-analysis with a random effects model was used to compare pre-intervention and post-intervention changes in anthropometric, biochemical, and hepatic end points in the IF intervention group with the control group. Publication bias was assessed using Egger's test.

RESULTS

Fourteen studies were included in the systematic review and ten in the meta-analysis (n = 840 participants, 44.64% male). Studies varied in modalities for NAFLD diagnosis, duration of IF (4-52 weeks), and type of IF (5:2 diet, modern alternate-day fasting, time-restricted eating, or religious fasting). Body weight, body mass index, and waist to hip ratio all significantly improved following fasting intervention (p< 0.05). Adults with NAFLD showed an improvement in serum alanine transaminase, aspartate aminotransferase, hepatic steatosis (controlled attenuation parameter measured by vibration-controlled transient elastography), and hepatic stiffness (measured by vibration-controlled transient elastography) after fasting intervention (p < 0.05).

CONCLUSIONS

There is limited, but moderate- to high-quality evidence to suggest that IF can improve hepatic end points and promote weight loss in adults with NAFLD. Larger randomized controlled studies with extended duration are needed to further validate our findings.

Methicillin-resistant Staphylococcus aureus bacteremia with elevated vancomycin minimum inhibitory concentrations

This case-control study of 25 cases with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with vancomycin minimum inhibitory concentration (MIC) ≥ 2 µg/mL and 391 controls (MIC < 2 µg/mL) characterized the clinical characteristics, treatments, and outcomes associated with elevated vancomycin MIC. Elevated vancomycin MIC was associated with baseline hemodialysis, prior MRSA colonization, and metastatic infection.

204. Genomic comparison of blood and colonizing nasal isolates in patients hospitalized with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of health-care associated infections, particularly bloodstream infections (BSI). Concomitant colonization of the anterior nares has been shown to have implications on persistence, recurrence, and transmission events. We performed genomic comparisons between paired nasal and blood MRSA isolates obtained from the same patient to elucidate the genetic differences that may contribute to within-host invasion and virulence.

Methods

Patients hospitalized with MRSA bloodstream infection were swabbed in the bilateral nares. Paired blood and nasal isolates underwent DNA extraction and spa typing. Nasal and blood isolates from the same patients with matching spa types were sequenced by Illumina and PacBio respectively. For genomic analysis, PathoSPOT and Snippy were used to compare genomes of nasal and blood isolate pairs to evaluate single nucleotide polymorphisms, insertions and deletions.

Results

Of 121 patients with MRSA BSI, 87 patients (72%) had concomitant colonization of the anterior nares with MRSA. Spa type of t002 predominated in both blood and nasal isolates. From the 76 pairs that underwent genomic analysis, several mutated genes were identified across all pairwise comparisons, 8 of which recurred in more than one patient pair. These included genes involved in conferring antibiotic resistance, increased mutability, immune evasion, and adaptive metabolism.

Conclusion

In patients with MRSA BSI and concomitant MRSA nasal colonization, mutations identified by genomic analysis in blood-nasal pairs are implicated in contributing to invasion and within-host adaptability.

Disclosures

All Authors: No reported disclosures.

COVID-19 is not associated with worse long-term inflammatory bowel disease outcomes: a multicenter case-control study

BACKGROUND

Inflammatory bowel disease (IBD) is not associated with worse coronavirus disease 2019 (COVID-19) outcomes. However, data are lacking regarding the long-term impact of severe acute respiratory syndrome coronavirus 2 infection on the disease course of IBD.

OBJECTIVES

We aimed to investigate the effect of COVID-19 on long-term outcomes of IBD.

DESIGN

We performed a multicenter case-control study of patients with IBD and COVID-19 between February 2020 and December 2020.

METHODS

Cases and controls were individuals with IBD with presence or absence, respectively, of COVID-19-related symptoms and confirmatory testing. The primary composite outcome was IBD-related hospitalization or surgery.

RESULTS

We identified 251 cases [ulcerative colitis (n = 111, 45%), Crohn's disease (n = 139, 55%)] and 251 controls, with a median follow-up of 394 days. The primary composite outcome of IBD-related hospitalization or surgery occurred in 29 (12%) cases versus 38 (15%) controls (p = 0.24) and on multivariate Cox regression, COVID-19 was not associated with increased risk of adverse IBD outcomes [adjusted hazard ratio (aHR): 0.84, 95% confidence interval [CI]: 0.44-1.42]. When stratified by infection severity, severe COVID-19 was associated with a numerically increased risk of adverse IBD outcomes (aHR: 2.43, 95% CI: 1.00-5.86), whereas mild-to-moderate COVID-19 was not (aHR: 0.68, 95% CI: 0.38-1.23).

CONCLUSION

In this case-control study, COVID-19 did not have a long-term impact on the disease course of IBD. However, severe COVID-19 was numerically associated with worse IBD outcomes, underscoring the continued importance of risk mitigation and prevention strategies for patients with IBD during the ongoing COVID-19 pandemic.

261. A Single-Center Case Series of Methicillin-Resistant S. aureus Bacteremia with Elevated Minimal Inhibitory Concentrations to Vancomycin

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious nosocomial pathogen, and is listed as a “High Priority Pathogen” by the WHO due to concerns of antimicrobial resistance and lack of novel therapeutics. Even in vancomycin-susceptible MRSA, increased rates of treatment failure occur in the setting of an increased minimum inhibitory concentration (MIC) to vancomycin, which is considered the gold-standard of therapy. We performed a case series of 25 patients infected with MRSA with an elevated MIC to vancomycin. Additionally, we describe the use of combination therapy with beta-lactams for the management of these highly complex cases.

Methods

We conducted a retrospective case series of 25 patients hospitalized at MSH between 8/2014–5/2019 who were treated for MRSA bacteremia where the isolate had an MIC ≥ 2. Data was centralized into the REDCap program. Clonal typing of bacteria and analysis of clinical features were performed in SAS and R.

Results

In total, 25 patients developed MRSA bacteremia with a vancomycin MIC ≥ 2. The majority of cases involved infection from vascular access, arteriovenous fistula/graft, and septic joint/osteomyelitis. All 25 patients were initially treated with vancomycin, with modification of therapy varying widely depending on clinician. The most common vancomycin-alternative was daptomycin (14/25 patients, alone and in combination). Combination therapy with vancomycin or daptomycin and a beta-lactam was used in 9 cases (36% of cases). Average number of days to clearance was 18.3 (range 1–69 days). Univariate and multivariate analyses revealed significant correlation MRSA bacteremia with vancomycin MIC ≥ 2 and admission from a nursing home or skilled nursing facility (p=0.02), history of MRSA colonization (p=0.006), and persistent bacteremia (bacteremia &gt;7 days)(p&lt; .0.001).

Conclusion

With few novel therapeutics under development, management of MRSA bacteremia with a rising MIC to vancomycin is a clinical challenge for practitioners. In our case series we found that treatment is largely patient and practitioner-dependent, and far from standardized. Further definition of the clinical risk factors for development and novel therapeutic strategies will enable understanding of how to best manage these challenging infections.

Disclosures

All Authors: No reported disclosures

Staphylococcus aureus Bacteremia in Patients Infected With COVID-19: A Case Series

Background

Previous viral pandemics have shown that secondary bacterial infections result in higher morbidity and mortality, with Staphylococcus aureus being the primary causative pathogen. The impact of secondary S. aureus bacteremia on mortality in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unknown.

Methods

This was a retrospective observational case series of patients with coronavirus disease 2019 (COVID-19) who developed secondary S. aureus bacteremia across 2 New York City hospitals. The primary end point was to describe 14-day and 30-day hospital mortality rates of patients with COVID-19 and S. aureus bacteremia. Secondary end points included predictors of 14-day and 30-day hospital mortality in patients with COVID-19 and S. aureus bacteremia.

Results

A total of 42 patients hospitalized for COVID-19 with secondary S. aureus bacteremia were identified. Of these patients, 23 (54.8%) and 28 (66.7%) died at 14 days and 30 days, respectively, from their first positive blood culture. Multivariate analysis identified hospital-onset bacteremia (≥4 days from date of admission) and age as significant predictors of 14-day hospital mortality and Pitt bacteremia score as a significant predictor of 30-day hospital mortality (odds ratio [OR], 11.9; 95% CI, 2.03-114.7; P = .01; OR, 1.10; 95% CI, 1.03-1.20; P = .02; and OR, 1.56; 95% CI, 1.19-2.18; P = .003, respectively).

Conclusions

Bacteremia with S. aureus is associated with high mortality rates in patients hospitalized with COVID-19. Further investigation is warranted to understand the impact of COVID-19 and secondary S. aureus bacteremia.

Predicting resource-dependent maternal health outcomes at a referral hospital in Zanzibar using patient trajectories and mathematical modeling

Poor intra-facility maternity care is a major contributor to maternal mortality in low- and middle-income countries. Close to 830 women die each day due to preventable maternal complications, partly due to the increasing number of women giving birth in health facilities that are not adequately resourced to manage growing patient populations. Barriers to adequate care during the ‘last mile’ of healthcare delivery are attributable to deficiencies at multiple levels: education, staff, medication, facilities, and delays in receiving care. Moreover, the scope and multi-scale interdependence of these factors make individual contributions of each challenging to analyze, particularly in settings where basic data registration is often lacking. To address this need, we have designed and implemented a novel systems-level and dynamic mathematical model that simulates the impact of hospital resource allocations on maternal mortality rates at Mnazi Mmoja Hospital (MMH), a referral hospital in Zanzibar, Tanzania. The purpose of this model is to provide a rigorous and flexible tool that enables hospital administrators and public health officials to quantitatively analyze the impact of resource constraints on patient outcomes within the maternity ward, and prioritize key areas for further human or capital investment. Currently, no such tool exists to assist administrators and policy makers with effective resource allocation and planning. This paper describes the structure and construct of the model, provides validation of the assumptions made with anonymized patient data and discusses the predictive capacity of our model. Application of the model to specific resource allocations, maternal treatment plans, and hospital loads at MMH indicates through quantitative results that medicine stocking schedules and staff allocations are key areas that can be addressed to reduce mortality by up to 5-fold. With data-driven evidence provided by the model, hospital staff, administration, and the local ministries of health can enact policy changes and implement targeted interventions to improve maternal health outcomes at MMH. While our model is able to determine specific gaps in resources and health care delivery specifically at MMH, the model should be viewed as an additional tool that may be used by other facilities seeking to analyze and improve maternal health outcomes in resource constrained environments.

Modeling patient access to therapeutic oxytocin in Zanzibar, Tanzania

BACKGROUND

Our objective is to estimate the effects of therapeutic oxytocin supply chain factors and social determinants of health on patient access to oxytocin in low-income settings using system dynamics modeling. Postpartum hemorrhage (PPH), a major cause of maternal mortality disproportionately affects women in low and middle income countries (LMICs). The World Health Organization recommends therapeutic oxytocin as the frontline uterotonic for PPH management and prevention. However, lack of access to quality therapeutic oxytocin in Tanzania, and throughout Sub-Saharan Africa, continues to result in a high number of preventable maternal deaths.

METHODS

We used publicly available data from Zanzibar and Sub-Saharan Africa, literature review, oxytocin degradation kinetics and previously developed systems dynamics models to understand the barriers in patient access to quality therapeutic oxytocin.

RESULTS

The model makes four basic predictions. First, there is a major gap between therapeutic oxytocin procurement and availability. Second, it predicts that at current population increase rates, oxytocin supply will have to be doubled in the next 30 years. Third, supply and storage temperature until 30 °C has minimal effect on oxytocin quality and finally distance of 5 km or less to birthing facility has a small effect on overall access to oxytocin.

CONCLUSIONS

The model provides a systems level approach to therapeutic oxytocin access, incorporating supply and procurement, socio-economic factors, as well as storage conditions to understand how women's access to oxytocin over time can be sustained for better health outcomes.

Examining the need & potential for biomedical engineering to strengthen health care delivery for displaced populations & victims of conflict

Conflict and the subsequent displacement of populations creates unique challenges in the delivery of quality health care to the affected population. Equitable access to quality care demands a multi-pronged strategy with a growing need, and role, for technological innovation to address these challenges. While there have been significant contributions towards alleviating the burden of conflict via data informatics and analytics, communication technology, and geographic information systems, little has been done within biomedical engineering. This article elaborates on the causes for gaps in biomedical innovation for refugee populations affected by conflict, tackles preconceived notions, takes stock of recent developments in promising technologies to address these challenges, and identifies tangible action items to create a stronger and sustainable pipeline for biomedical technological innovation to improve the health and well-being of an increasing group of vulnerable people around the world.

eIF1A/eIF5B interaction network and its functions in translation initiation complex assembly and remodeling

Eukaryotic translation initiation is a highly regulated process involving multiple steps, from 43S pre-initiation complex (PIC) assembly, to ribosomal subunit joining. Subunit joining is controlled by the G-protein eukaryotic translation initiation factor 5B (eIF5B). Another protein, eIF1A, is involved in virtually all steps, including subunit joining. The intrinsically disordered eIF1A C-terminal tail (eIF1A-CTT) binds to eIF5B Domain-4 (eIF5B-D4). The ribosomal complex undergoes conformational rearrangements at every step of translation initiation; however, the underlying molecular mechanisms are poorly understood. Here we report three novel interactions involving eIF5B and eIF1A: (i) a second binding interface between eIF5B and eIF1A; (ii) a dynamic intramolecular interaction in eIF1A between the folded domain and eIF1A-CTT; and (iii) an intramolecular interaction between eIF5B-D3 and -D4. The intramolecular interactions within eIF1A and eIF5B interfere with one or both eIF5B/eIF1A contact interfaces, but are disrupted on the ribosome at different stages of translation initiation. Therefore, our results indicate that the interactions between eIF1A and eIF5B are being continuously rearranged during translation initiation. We present a model how the dynamic eIF1A/eIF5B interaction network can promote remodeling of the translation initiation complexes, and the roles in the process played by intrinsically disordered protein segments.

Immunochemical evidence supporting 2-pentylpyrrole formation on proteins exposed to 4-hydroxy-2-nonenal

Previous model studies suggested the formation of lysine-based 2-pentylpyrroles as novel late adduction products formed upon exposure of proteins to the lipid peroxidation product 4-hydroxy-2-nonenal (HNE). Two 2-pentylpyrrole immunogens were prepared, one by treating keyhole limpet hemocyanin (KLH) directly with 4-oxononanal and the other by preformation of 6-(2-pentylpyrrol-1-yl)hexanoic acid from 6-aminocaproic acid and 4-oxononanal, followed by carbodiimide coupling to KLH. Pyrrole content and lysine modification in KLH were assayed independently. Following immunization of rabbits, antibody titer increased and plateaued over a 4 month period. The structural specificity of the IgG fractions of the antisera was evaluated through comprehensive competitive ELISA studies. These antibodies were used to verify the time-dependent appearance of the 2-pentylpyrrole epitope in protein exposed to HNE. Potential advantages of antibodies recognizing "advanced lipid peroxidation end products" over those recognizing "early" HNE adduction products are discussed.

Hepatic albumin and urea synthesis: The mathematical modelling of the dynamics of [14C]carbonate-derived guanidine-labelled arginine in the isolated perfused rat liver

A mathematical model was constructed to define the dynamics of incorporation of radioactivity into urea carbon and the guanidine carbon of arginine in plasma albumin after the rapid intraportal-venous administration of Na214CO3 in the isolated perfused rat liver. 2. The model was formulated in terms of compartmental analysis and additional experiments were designed to provide further information on subsystem dynamics and to discriminate between alternative model structures. 3. Evidence for the rapid-time-constant of labelling of intracellular arginine was provided by precursor-product analysis of precursor [14C]carboante and product [14C]urea in the perfusate. 4. Compartmental analysis of the dynamics of newly synthesized urea was based on the fate of exogenous [13C]urea, endogenous [14C]urea and the accumulation of [12C]urea in perfusate water, confirming the early completion of urea carbon labelling, the absence of continuing synthesis of labelled urea, and the presence of a small intrahepatic urea-delay pool. 5. Analysis of the perfusate dynamics of endogenously synthesized and exogenously administered [6-14C]arginine indicated that although the capacity for extrahepatic formation of [14C]-urea exists, little or no arginine formed within the intrahepatic urea cycle was transported out of the liver. However, the presence of a rapidly turning-over intrahepatic arginine pool was confirmed. 6. On the basis of these subsystem analyses it was possible to offer feasible estimations for the parameters of the mathematical model. However, it was not possible to stimulate the form and magnitude of the dynamics of newly synthesized labelled urea and albumin which were simultaneously observed after administration of [14C]carbonate on the basis of a preliminary model which postulated that both products were derived from a single hepatic pool of [16-14C]arginine. On the other hand these observed dynamics could be satisfied to a two-compartment arginine model, which also provided an explanation for discrepancies observed between albumin synthesis measured radioisotopically and immunologically. This was based on a relative overestimation of [14C]urea specific radioactivity resulting from the rapid dynamics of [14C]carbonate and the [14C]urea subsystem relative to the labelled albumin subsystem. The effects of arginine compartmentalization could be minimized in the model by minor slowing of the rate of [14C]carbonate turnover or by constant infusion of [14C]carbonate, both of which permitted valid determination of albumin-synthesis rates.