Red blood cell distribution width (RDW) - A new nutritional biomarker to assess nutritional risk and response to nutritional therapy?

BACKGROUND & AIMS: Red cell distribution width (RDW) has been proposed as a surrogate marker for acute and chronic diseases and may be influenced by nutritional deficits. We assessed the prognostic value of RDW regarding clinical outcomes and nutritional treatment response among medical inpatients at nutritional risk. METHODS: This is a secondary analysis of EFFORT, a randomized, controlled, prospective, multicenter trial investigating the effects of nutritional support in patients at nutritional risk in eight Swiss hospitals. We examined the association between RDW and mortality in regression analysis. RESULTS: Among 1,244 included patients (median age 75 years, 46.6 % female), high RDW (≥15 %) levels were found in 38 % of patients (n = 473) with a significant association of higher malnutrition risk [OR 1.48 (95%CI 1.1 to 1.98); p = 0.009]. Patients with high RDW had a more than doubling in short-term (30 days) mortality risk [adjusted HR 2.12 (95%CI 1.44 to 3.12); p < 0.001] and a signficant increase in long-term (5 years) mortality risk [adjusted HR 1.73 (95%CI 1.49 to 2.01); p < 0.001]. Among patients with high RDW, nutritional support reduced morality within 30 days [adjusted OR 0.56 (95%CI 0.33 to 0.96); p = 0.035], while the effect of the nutritional intervention in patients with low RDW was markedly smaller. CONCLUSIONS: Among medical patients at nutritional risk, RDW correlated with several nutritional parameters and was a strong prognostic marker for adverse clinical outcomes at short- and long-term, respectively. Patients with high baseline RDW levels also showed a strong benefit from the nutritional intervention. Further research is needed to understand whether monitoring of RDW over time severs as a nutritional biomarker to assess effectiveness of nutritional treatment in the long run. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02517476.

Association of admission cortisol levels with outcomes and treatment response in patients at nutritional risk : A secondary analysis of a randomized clinical trial.

INTRODUCTION: Cortisol is a metabolically active stress hormone that may play a role in the pathogenesis of malnutrition. We studied the association between admission cortisol levels and nutritional parameters, disease severity, and response to nutritional support among medical inpatients at nutritional risk. METHODS: Admission cortisol was measured in a subset of 764 patients participating in the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a multicentre, randomized-controlled trial that compared individualized nutritional support with usual nutritional care. RESULTS: Overall, mean cortisol levels were 570 (± 293) nmol/L and significantly higher in patients with high nutritional risk (NRS ≥ 5) and in patients reporting loss of appetite. Cortisol levels in the highest quartile (> 723 nmol/l) were associated with adverse outcomes including mortality at 30 days and 5 years (adjusted HR 2.31, [95%CI 1.47 to 3.62], p = 0.001 and 1.51, [95%CI 1.23 to 1.87], p < 0.001). Nutritional treatment tended to be more effective regarding mortality reduction in patients with high vs. low cortisol levels (adjusted OR of nutritional support 0.54, [95%CI 0.24 to 1.24] vs. OR 1.11, [95%CI 0.6 to 2.04], p for interaction = 0.134). This effect was most pronounced in the subgroup of patients with severe malnutrition (NRS 2002 ≥ 5, p for interaction = 0.047). CONCLUSION: This secondary analysis of a randomized nutritional trial suggests that cortisol levels are linked to nutritional and clinical outcome among multimorbid medical patients at nutritional risk and may help to improve risk assessment, as well as response to nutritional treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02517476.

Is food insecurity contributing to malnutrition in older adults in Switzerland? - A cross-sectional study.

Background: Food insecurity has been defined as "limited access to food, at the level of individuals or households, due to lack of money or other resources" and may increase the nutritional risk, which in turn leads to poor health, development of chronic diseases, poor psychological and cognitive functioning, and substandard academic achievements. There is limited data on the importance of food insecurity in a rich country such as Switzerland. Methods: This is a cross-sectional analysis of data from a structured survey in an elderly population of Switzerland. The data was assessed between June and August 2021 in the course of a 7-year phone call follow-up from the EFFORT trial, which included medical inpatients at nutritional risk from 2014 to 2018. A validated questionnaire (Six-Item Short Form 2012 of the U.S: Household Food Security Survey Module) was used to assess food security status. Results: Of the 433 included patients, 30 (6.9%) were food insecure. A significant association between food insecurity and age, governmental financial support and self-reported loneliness was found. When compared with the food secure group, there was a significant lower quality of life measured by the EQ-5D VAS. Conclusion: In an older Swiss population of patients at nutritional risk, food insecurity was named as a contributing factor for malnutrition in about 7% of patients, particularly younger individuals with financial support, and self-reported loneliness. In the assessment of malnutrition, physician and dieticians should ask for food insecurity and if detect take appropriate actions.

Rate of Cardiovascular Events and Safety Outcomes Seven Years Following Gastric Bypass Versus Sleeve Gastrectomy.

Objective: The study aimed to assess major adverse cardiovascular events (MACEs), complications requiring revision surgery, and bariatric conversion surgery 7 years after gastric bypass (GB) and sleeve gastrectomy (SG) using real-world data. Background: GB and SG both result in weight loss and improved cardiometabolic health. Whether the long-term rate of MACE differs between the 2 bariatric procedures is unclear. Methods: In this population-based retrospective cohort study, we used inhospital National Health Registry data from January 2012 to December 2018. Patients undergoing GB were 1:1 propensity score-matched with patients who had SG. The primary outcome was the incidence of MACE, defined as acute myocardial infarction, ischemic stroke, cardiac arrest, or hospitalization for heart failure. Secondary outcomes encompassed individual MACE components, postoperative complications, and the need for bariatric conversion surgery. Results: Among 5240 propensity score-matched pairs, the incidence rate per 1000 person-years of MACE was 2.8 among patients undergoing GB and 3.2 among those undergoing SG (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.62-1.37). Single components of MACE were not different between both groups. Patients after GB had a higher risk of long-term postoperative complications requiring a revision surgery compared with those after SG (HR, 3.53 [95% CI, 2.78-4.49]). Bariatric conversion surgery was less frequently performed among patients undergoing GB compared with patients undergoing SG (HR, 0.09 [95% CI, 0.06-0.13]). Conclusions: In this study, the performance of GB versus SG was associated with a similar risk of MACE. While postoperative complications were more frequent among patients undergoing GB, patients following SG had a higher probability of bariatric conversion surgery.

Association of Sociodemographic, Socioeconomic and Lifestyle Characteristics with Low Protein and Energy Intake in the Healthy Swiss Population.

A balanced diet has the goal of providing adequate amounts of different nutrients to promote and maintain physical and psychological health. Our aim was to study the association between different sociodemographic, socioeconomic and lifestyle factors and low energy or protein intake among the Swiss population. This is a cross-sectional cohort study based on the national nutritional survey "MenuCH", which is the first representative, detailed assessment of dietary habits in the adult Swiss population conducted in 2014/2015. We compared the mean protein and caloric intake based on two 24 h recall nutritional assessments with current recommendations based on resting metabolic rate calculation and DACH guidelines. A total of 1919 participants with a median age of 46 years and 53% females were included. Overall, 10.9% and 20.2% of participants had an energy and protein intake, respectively, below the dietary reference values. However, a high income (>9000 CHF per month) reduced the risk of low energy intake (OR 0.49 [0.26-0.94], p = 0.032), obesity (OR 6.55 [3.77-11.38], p < 0.01), and living in a household with children (OR 2.1 [1.15-3.85], p = 0.016) was associated with higher risk. Regarding low protein intake, the most important risk factors were an age group of 65-75 years (OR 2.94 [1.57-5.52], p = 0.001) and female gender (OR 1.73 [1.15-2.6], p = 0.008). Regular meat consumption reduced the risk of low protein intake (OR of 0.23 (0.1-0.53), p = 0.001). Within this survey, several socio-economic and lifestyle factors were associated with low energy and protein intake in the healthy Swiss population. A bunderstanding of these factors may help to reduce the risk of malnutrition.

Changes in serum albumin concentrations over 7 days in medical inpatients with and without nutritional support. A secondary post-hoc analysis of a randomized clinical trial.

BACKGROUND: Serum albumin concentrations are frequently used to monitor nutritional therapy in the hospital setting but supporting studies are largely lacking. Within this secondary analysis of a randomized nutritional trial (EFFORT), we assessed whether nutritional support affects short-term changes in serum albumin concentrations and whether an increase in albumin concentration has prognostic implications regarding clinical outcome and response to treatment. METHODS: We analyzed patients with available serum albumin concentrations at baseline and day 7 included in EFFORT, a Swiss-wide multicenter randomized clinical trial that compared individualized nutritional therapy with usual hospital food (control group). RESULTS: Albumin concentrations increased in 320 of 763 (41.9%) included patients (mean age 73.3 years (SD ± 12.9), 53.6% males) with no difference between patients receiving nutritional support and controls. Compared with patients that showed a decrease in albumin concentrations over 7 days, those with an increase had a lower 180-day mortality [74/320 (23.1%) vs. 158/443 (35.7%); adjusted odds ratio 0.63, 95% CI 0.44 to 0.90; p = 0.012] and a shorter length of hospital stay [11.2 ± 7.3 vs. 8.8 ± 5.6 days, adjusted difference -2.2 days (95%CI -3.1 to -1.2)]. Patients with and without a decrease over 7 days had a similar response to nutritional support. CONCLUSION: Results from this secondary analysis indicate that nutritional support did not increase short-term concentrations of albumin over 7 days, and changes in albumin did not correlate with response to nutritional interventions. However, an increase in albumin concentrations possibly mirroring resolution of inflammation was associated with better clinical outcomes. Repeated in-hospital albumin measurements in the short-term is, thus, not indicated for monitoring of patients receiving nutritional support but provides prognostic information. TRAIL REGISTRATION: ClinicalTrials.gov Identifier: NCT02517476.

[Malnutrition in internal medicine : Screening, assessment and importance]. / Mangelernährung in der Inneren Medizin : Screening, Assessment und Bedeutung.

Disease-related malnutrition has a strong influence on the further course of the disease and mortality, especially in chronically ill patients. In recent years it could be shown in large randomized studies that an individual nutrition therapy could significantly and relevantly improve the clinical outcome of patients in internal medicine with a risk of malnutrition, both in hospital and in aftercare. Therefore, due to the increasing proportion of multimorbid patients the significance of malnutrition and its treatment is becoming increasingly more important in the practice and in research. Nutritional medicine should nowadays be considered as an effective and integral component of a holistic treatment in internal medicine; however, further research is necessary in order to investigate new nutritional biomarkers and for a better integration of an evidence-based personalized nutritional medicine into routine clinical practice.

Association of CT-based diagnosis of sarcopenia with prognosis and treatment response in patients at risk of malnutrition - A secondary analysis of the Effect of early nutritional support on Frailty, Functional Outcomes, and Recovery of malnourished medical inpatients Trial (EFFORT) trial.

BACKGROUND & AIM: CT-derived measures of muscle mass may help to identify patients with sarcopenia. We investigated the prognostic significance of CT-derived sarcopenia and muscle attenuation with nutritional markers, clinical outcomes and response to nutritional support in medical in-patients at nutritional risk. METHOD: Within this secondary analysis of the randomized-controlled Effect of early nutritional support on Frailty, Functional Outcomes, and Recovery of malnourished medical inpatients Trial (EFFORT) comparing individualized nutritional support with usual care nutrition in medical inpatients, we investigated associations of CT-based sarcopenia and muscle attenuation at the level L3 with different nutritional and clinical outcomes, and the response to the nutritional intervention. The primary composite endpoint was adverse clinical outcome within 30 days of hospital admission. RESULTS: We included 573 of 2028 EFFORT patients with available CT scans, of which 68.4% met the CT-based definition of sarcopenia and 72.9% had low muscle attenuation. In multivariate analysis, low skeletal muscle index was associated with higher nutritional risk (coefficient per NRS class -0.94 (95%CI -1.87 to -0.01) p = 0.049) and higher risk for adverse clinical outcomes (adjusted odds ratio 1.59 (95% CI 1.06 to 2.38), p = 0.024). Low muscle attenuation was also associated with adverse clinical outcome (adjusted odds ratio 1.67 (95%CI 1.08 to 2.58), p = 0.02). Nutritional support tended to be more effective in reducing mortality in non-sarcopenic patients compared to patients with CT-based sarcopenia (p for interaction 0.058). CONCLUSIONS: Within a population of medical patients at nutritional risk, CT-based sarcopenia and muscle attenuation were associated with several nutritional parameters and predicted adverse clinical outcomes. Information from CT scans, thus may help to better characterize these patients, and may be helpful in guiding therapeutic interventions.

Association between prealbumin, all-cause mortality, and response to nutrition treatment in patients at nutrition risk: Secondary analysis of a randomized controlled trial.

BACKGROUND: Because of the shorter half-life as compared with albumin, serum prealbumin concentrations have been proposed to be useful nutrition biomarkers for the assessment of patients at nutrition risk. In a post hoc analysis of patients at nutrition risk from a randomized controlled nutrition trial, we tested the hypothesis that (1) prealbumin is associated with higher all-cause 180-day mortality rates and that (2) individualized nutrition support compared with usual-care nutrition more effectively improves survival at 30 days in patients with low prealbumin levels compared with patients with normal prealbumin levels. METHODS: We performed a prespecified cohort study in patients included in the pragmatic, Swiss, multicenter randomized controlled EFFORT trial comparing the effects of individualized nutrition support with usual care. We studied low prealbumin concentrations (<0.17 g/L) in a subgroup of 517 patients from one participating center. RESULTS: A total of 306 (59.2%) patients (mean age 71.9 years, 53.6% men) had low admission prealbumin levels (<0.17 g/L). There was a significant association between low prealbumin levels and mortality at 180 days (115/306 [37.6%] vs 47/211 [22.3%], fully adjusted hazard ratio [HR]=1.59, 95% CI 1.11-2.28; P = 0.011). Prealbumin levels significantly improved the prognostic value of the Nutritional Risk Screening total score regarding mortality prediction at short- and long-term. The difference in mortality between patients receiving individualized nutrition support and usual-care nutrition was similar for patients with low prealbumin levels compared with patients with normal prealbumin levels (HR=0.90 [95% CI=0.51-1.59] vs HR=0.88 [95% CI=0.35-2.23]) with no evidence for interaction (P = 0.823). CONCLUSION: Among medical inpatients at nutrition risk, low admission prealbumin levels correlated with different nutrition markers and higher mortality risk, but patients with low or high prealbumin levels had a similar benefit from nutrition support. Further studies should identify nutrition markers that help further personalize nutrition interventions.

Low T3 Syndrome on Admission and Response to Nutritional Support in Malnourished Medical Inpatients.

CONTEXT: During illness, deiodination of thyroxine (T4) to triiodothyronine (T3) is downregulated. This is called "low T3 syndrome", an adaptive metabolic mechanism to reduce energy expenditure and prevent catabolism. OBJECTIVE: We aimed to investigate the prognostic role of low T3 syndrome in patients at nutritional risk regarding mortality, clinical outcomes, and response to nutritional support. METHODS: This is a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a randomized controlled, Swiss, multicenter trial comparing effects of individualized nutritional support with usual care in adult medical inpatients at nutritional risk. The primary endpoint was all-cause mortality over 30, 180 days, and 5 years. RESULTS: We had complete data including fT3 concentration of 801/2028 (39.5%) patients from the initial trial. Of these 492 (61.4%) had low T3 syndrome (fT3 < 3.2 pmol/L). Low T3 syndrome was associated with higher mortality over 30 days (adjusted hazard ratio 1.97, 95% CI 1.17-3.31, P = .011) and other adverse clinical outcomes. Nutritional support only lowered mortality in the group of patients with low T3 syndrome but not in those without low T3 syndrome (adjusted odds ratio of nutritional support of 0.82 [95% CI 0.47-1.41] vs 1.47 [95% CI 0.55-3.94]). This finding, however, was not significant in interaction analysis (P for interaction = .401). CONCLUSION: Our secondary analysis of a randomized trial suggests that medical inpatients at nutritional risk with low T3 syndrome have a substantial increase in mortality and may show a more pronounced beneficial response to nutritional support interventions.

Nutritional support after hospital discharge improves long-term mortality in malnourished adult medical patients: Systematic review and meta-analysis.

BACKGROUND & AIMS: In patients with malnutrition there is an increased long-term risk for mortality beyond the preciding hospital stay. We investigated the effects of postdischarge nutritional support in the outpatient setting on all-cause mortality in the populaton of malnourished medical patients in a systematic review of randomized controlled trials. METHODS: We searched MEDLINE and EMBASE, from inception to December 21, 2022. Randomized-controlled trials investigating nutritional support in medical patients following hospital discharge vs. control group (usual care, placebo and no nutritional support) were included. Data were independently extracted by two authors and were pooled using random effects model. Our primary outcome was all cause-mortality up to 12-months (end of intervention) of hospital discharge. RESULTS: We included 14 randomized-controlled trials with a total of 2438 participants and mostly moderate trial quality. Compared to the control group, patients receiving outpatient nutritional support had lower mortality (13 trials, odds ratio [OR] 0.63, 95% confidence interval [CI] 0.48 to 0.84, p = 0.001, I2 = 1%). Nutritional support was also associated with a significant increase in the mean daily intake of energy (568 kcal, 95% CI 24 to 1,113, p = 0.04), proteins (24 g, 95% CI 7 to 41), p = 0.005) and body weight (1.1 kg, 95% CI 0.6 to 1.7), p < 0.001). No differences were found on hospital readmissions and handgrip strength. CONCLUSIONS: This meta-analysis of randomized-controlled trials with mostly moderate trial quality suggests that nutritional support in the outpatient setting significantly increases nutritional intake as well as body weight, and importantly improves survival. Further large-scale and high-quality intervention trials are needed to confirm these findings.

Handgrip Strength Values Depend on Tumor Entity and Predict 180-Day Mortality in Malnourished Cancer Patients.

BACKGROUND: Cancer-related malnutrition is a prevalent condition associated with a loss of muscle mass and impaired functional status, leading to immunodeficiency, impaired quality of life and adverse clinical outcomes. Handgrip strength (HGS) is a practical measure to assess muscle strength in individual patients during clinical practice. However, HGS reference values refer to populations of healthy people, and population-specific values, such as those in the population of cancer patients, still need to be defined. METHODS: Within a secondary analysis of a previous randomized controlled nutritional trial focusing on hospitalized cancer patients at risk for malnutrition, we investigated sex-specific HGS values stratified by age and tumor entity. Additionally, we examined the association between HGS and 180-day all-cause mortality. RESULTS: We included data from 628 cancer patients, which were collected from eight hospitals in Switzerland. Depending on the age of patients, HGS varied among female patients from 7 kg to 26 kg and among male patients from 20.5 kg to 44 kg. An incremental decrease in handgrip strength by 10 kg resulted in a 50% increase in 180-day all-cause mortality (odds ratio 1.52 (95%CI 1.19 to 1.94), p = 0.001). CONCLUSION: Our data provide evidence of the prognostic implications of HGS measurement in cancer patients and validate the prognostic value of handgrip strength in regard to long-term mortality. In addition, our results provide expected HGS values in the population of hospitalized malnourished cancer patients, which may allow better interpretation of values in individual patients.

Prospective validation of five malnutrition screening and assessment instruments among medical inpatients: Secondary analysis of a randomized clinical trial.

BACKGROUND & AIMS: Screening for malnutrition upon hospital admission is the first crucial step for proper nutritional assessment and treatment. While several nutritional screening and assessment instruments exist, there is a lack of head-to-head validation of these instruments. We studied the ability of five different nutrition screening and assessment instruments to predict 1-year mortality and response to nutritional treatment in participants of the EFFORT randomized trial. METHODS: In this secondary analysis of a Swiss-wide multicenter, randomized clinical trial comparing individualized nutritional support with usual care nutrition in medical inpatients, we prospectively classified patients as low, intermediate, and high nutritional risk based on five nutritional screening and assessment instruments (NRS 2002, SGA, SNAQ, MNA and MUST). RESULTS: Overall mortality at 1-year in the 1866 included patients was 30.4%. There were significant correlations and a significant concordance between all instruments with r-values ranging from 0.23 to 0.55 and kappa values ranging from 0.10 to 0.36. While high nutritional risk was associated with higher mortality in all instruments, SGA and MNA showed the strongest association with adjusted odds ratios of 3.17 (95%CI, 2.18 to 4.61, p < 0.001) and 3.45 (95%CI, 2.28 to 5.22, p < 0.001). When comparing mortality in intervention group patients to control group patients stratified by severity of malnutrition, there was overall no clear trend towards more benefit in patients with more severe malnutrition, with NRS 2002 and SGA showing the most pronounced relationship between the severity of malnutrition and reduction in mortality as a response to nutritional support. CONCLUSION: Among all five screening and assessment instruments, higher nutritional risk was associated with higher risk for mortality and adverse clinical outcome, but not with more or less treatment response from nutritional support with differences among scores. Adding more specific parameters to these instruments is important when using them to decide for or against nutritional support interventions in an individual patient. TRIAL REGISTRATION: ClinicalTrials.gov NCT02517476.

Validation of modified GLIM criteria to predict adverse clinical outcome and response to nutritional treatment: A secondary analysis of a randomized clinical trial.

BACKGROUND & AIMS: The Global Leadership Initiative on Malnutrition (GLIM) recently suggested specific criteria to standardize the diagnosis of malnutrition. There is need for validation of these criteria regarding response to nutrition treatment. Our aim was to validate modified GLIM (mGLIM) criteria among medical inpatients at risk of disease related malnutrition for prediction of outcome and response to nutritional therapy. METHODS: This is a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a multicenter randomized controlled trial conducted between April 2014 and February 2018. Adult medical inpatients at nutritional risk (Nutrition Risk Score 2002 ≥ 3 points) were randomly assigned to receive nutritional therapy according to an algorithm based on individualized nutritional requirements (intervention group) or standard hospital food (control group). We included all participants with available information regarding mGLIM criteria. The primary outcome was adverse clinical outcome, which was a composite of 30-day all-cause mortality, ICU-admission, rehospitalization rate, major complications and decline in functional status. RESULTS: Of 1917 eligible participants at nutritional risk, 1181 (61.6%) met the diagnosis of malnutrition based on mGLIM criteria. The incidence of adverse clinical outcome was significantly higher in mGLIM-positive participants compared with mGLIM-negative participants [330/1181 (27.9%) versus 140/736 (19.0%); multivariable adjusted odds ratio [OR] 1.53; 95% CI 1.22-1.93; p < 0.001]. Regarding the effect of nutritional therapy, the reduction in adverse clinical outcomes was higher in mGLIM-positive participants [180/581 (31.0%) vs. 150/600 (25.0%), OR 0.69; 95% CI 0.53-0.9, p = 0.007], compared with mGLIM-negative participants [75/379 (19.8%) versus 65/357 (18.2%), OR 0.95; 95% CI 0.65-1.40, p = 0.797], a finding that was, however, not significant in interaction analysis (p for interaction = 0.217). CONCLUSION: Data from this secondary analysis of a multicenter randomized trial involving medical inpatients at nutritional risk validate the strong prognostic value of mGLIM criteria regarding adverse clinical outcomes and other long-term outcomes. However, further research is needed to improve the ability of GLIM criteria to predict therapeutic response to nutritional interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02517476.

Structure-guided unlocking of NaX reveals a non-selective tetrodotoxin-sensitive cation channel.

Unlike classical voltage-gated sodium (NaV) channels, NaX has been characterized as a voltage-insensitive, tetrodotoxin-resistant, sodium (Na+)-activated channel involved in regulating Na+ homeostasis. However, NaX remains refractory to functional characterization in traditional heterologous systems. Here, to gain insight into its atypical physiology, we determine structures of the human NaX channel in complex with the auxiliary ß3-subunit. NaX reveals structural alterations within the selectivity filter, voltage sensor-like domains, and pore module. We do not identify an extracellular Na+-sensor or any evidence for a Na+-based activation mechanism in NaX. Instead, the S6-gate remains closed, membrane lipids fill the central cavity, and the domain III-IV linker restricts S6-dilation. We use protein engineering to identify three pore-wetting mutations targeting the hydrophobic S6-gate that unlock a robust voltage-insensitive leak conductance. This constitutively active NaX-QTT channel construct is non-selective among monovalent cations, inhibited by extracellular calcium, and sensitive to classical NaV channel blockers, including tetrodotoxin. Our findings highlight a functional diversity across the NaV channel scaffold, reshape our understanding of NaX physiology, and provide a template to demystify recalcitrant ion channels.

Admission serum albumin concentrations and response to nutritional therapy in hospitalised patients at malnutrition risk: Secondary analysis of a randomised clinical trial.

BACKGROUND: Historically, admission serum albumin concentrations have been considered useful biochemical markers for nutrition assessment. However, there is a lack of randomised trial data investigating whether low albumin concentrations are helpful for identifying patients benefitting from nutritional support. METHODS: This study was a secondary analysis of the EFFORT trial, a Swiss-wide multicentre, randomised controlled trial comparing individualised nutritional support with usual care nutrition in medical inpatients from April 1, 2014, to February 1, 2018. 1389 of 2028 patients at nutritional risk with available albumin concentrations on admission were included. The primary endpoint was all-cause mortality within 30 and 180 days. Patients were stratified into groups of low or normal albumin based on the albumin cut-off of 30 g/L. ClinicalTrials.gov number, NCT02517476. FINDINGS: 1389 patients (mean age, 73.1 (SD 3.5) years; 747 (53.8%) men) were included and 676 (48.7%) had low serum albumin concentrations at admission (<30 g/L). Mortality at 180 days was significantly increased in the low albumin group compared with patients with normal albumin concentrations (219/676 (32.4%) vs. 162/713 (22.7%), fully adjusted HR 1.4, 95%CI 1.11 to 1.77, p = 0.005]. Effects of nutritional support on 30-day mortality were similar for patients with low compared to patients with normal albumin concentrations (HR 0.68, 95%CI 0.44 to 1.05 vs. HR 0.70, 95%CI 0.41 to 1.20), with no evidence for a subgroup effect (p for interaction=0.97). INTERPRETATION: Based on this secondary analysis of a randomised trial, low admission serum albumin concentrations in hospitalised, non-critically ill, medical patients at nutritional risk had prognostic implications and indicated higher mortality risk but were not helpful in selecting patients for nutritional interventions. FUNDING: The Swiss National Science Foundation (SNSF) (PP00P3_150531) and the Research Council of the Kantonsspital Aarau (1410.000.058 and 1410.000.044) provided funding for the EFFORT trial.

Effect of micronutrient supplementation in addition to nutritional therapy on clinical outcomes of medical inpatients: results of an updated systematic review and meta-analysis.

BACKGROUND: There is increasing evidence from randomized controlled trials showing that different types of nutritional support interventions improve clinical outcomes in malnourished medical inpatients. Whether trials using micronutrient supplementation in addition to nutritional therapy are superior to trials without micronutrient supplementation remains unclear. METHODS: This is a secondary analysis of a systematic search and meta-analysis. We searched Cochrane Library, MEDLINE, and EMBASE electronic database from inception to December 15, 2020, for randomized controlled trials comparing the nutritional support interventions vs. usual care on all-cause mortality (primary endpoint) of medical inpatients with nutritional risk. We stratified trials based on whether or not micronutrient supplementation was used as part of the nutritional strategy. RESULTS: We included 23 randomized controlled trials (5 trials with and 18 trials without micronutrient supplementation) with a total of 6745 patients. Overall, mortality was significantly lower in patients receiving nutritional support compared to control group patients with an odds ratio of 0.74 (95% CI 0.59-0.94, p = 0.01). There was no difference between trials with and without micronutrient supplementation on mortality (odds ratio 0.70 (95% CI 0.46-1.08) vs. 0.77 (95% CI 0.57-1.04), I2 = 0%, p for subgroup difference = 0.73). Similarly, no differences in effect were found regarding non-elective readmissions and length of hospital stay. CONCLUSIONS: While nutritional support reduces mortality and improves other clinical outcomes, we did not find evidence that trials using micronutrient supplementation in addition to nutritional therapy were superior to trials with no supplementation. The role of micronutrient supplementation in addition to nutritional support needs further research.

The suitability of high throughput automated patch clamp for physiological applications.

Although automated patch clamp (APC) devices have been around for many years and have become an integral part of many aspects of drug discovery, high throughput instruments with gigaohm seal data quality are relatively new. Experiments where a large number of compounds are screened against ion channels are ideally suited to high throughput APC, particularly when the amount of compound available is low. Here we evaluate different APC approaches using a variety of ion channels and screening settings. We have performed a screen of 1920 compounds on GluN1/GluN2A NMDA receptors for negative allosteric modulation using both the SyncroPatch 384 and FLIPR. Additionally, we tested the effect of 36 arthropod venoms on NaV 1.9 using a single 384-well plate on the SyncroPatch 384. As an example for mutant screening, a range of acid-sensing ion channel variants were tested and the success rate increased through fluorescence-activated cell sorting (FACS) prior to APC experiments. Gigaohm seal data quality makes the 384-format accessible to recording of primary and stem cell-derived cells on the SyncroPatch 384. We show recordings in voltage and current clamp modes of stem cell-derived cardiomyocytes. In addition, the option of intracellular solution exchange enabled investigations into the effects of intracellular Ca2+ and cAMP on TRPC5 and HCN2 currents, respectively. Together, these data highlight the broad applicability and versatility of APC platforms and also outlines some limitations of the approach. KEY POINTS: High throughput automated patch clamp (APC) can be used for a variety of applications involving ion channels. Lower false positive rates were achieved using automated patch clamp versus a fluorometric imaging plate reader (FLIPR) in a high throughput compound screen against NMDA receptors.  Genetic variants and mutations can be screened on a single 384-well plate to reduce variability of experimental parameters. Intracellular solution can be perfused to investigate effects of ions and second messenger systems without the need for excised patches. Primary cells and stem cell-derived cells can be used on high throughput APC with reasonable success rates for cell capture, voltage clamp measurements and action potential recordings in current clamp mode.