Standard Laboratory Measurements Research Articles

Relation of skinfold thickness with the serum lipids, glucose and blood pressure among Indian sedentary office workers

Background:Serum glucose, cholesterol, triglycerides and high-density lipoproteins (HDL) are established cardiovascular disease (CVD) markers, however accessibility to these markers is less in individuals from low-middle income countries. The non-invasive CVD risk marker especially skinfold measured fat percentages are less explored for its relevance with established serum biochemistry markers.Methods:A cross-sectional study was conducted in 70 sedentary office workers (aged 30–40 years) who were healthy. Peripheral fat percentages were estimated from four skinfold thickness measurements and biochemistry markers were measured and analysed using standard laboratory measurements. Blood pressure was also measured. Multivariate linear regression models were drawn to establish the association between the non-invasive and invasive CVD risk markers.Results:The skinfold measured fat percentage was negatively associated with the HDL (coefficient β = -0.15, standard error SE = 0.07, p < 0.05). No significant relation between the other biochemistry parameters with the skinfold thickness. Age and BMI were found to be mediating the above relationship.Conclusions:Skinfold thickness derived fat percentage is associated with the few of the CVD markers (especially HDL). Age and BMI are crucial mediating factors for the fat measurement. Skinfold measurements could be included as part of routine primary care screening for CVD risk, alongside invasive biochemistry parameters.

Evaluation of point-of-care capillary and venous blood glucose concentrations in hospitalized neonatal foals.

To compare glucose measurements from capillary and venous blood samples using a point-of-care (POC) glucometer with a standard laboratory (colorimetric, glucose oxidase) assay (LABGLU) in a population of hospitalized, neonatal foals. Multicenter, prospective, experimental study, conducted between March 2019 and June 2020. Four university teaching hospitals and 1 private referral hospital. Fifty-four hospitalized neonatal (≤30days of age) foals. Simultaneous capillary (muzzle, POCMUZ) and venous (jugular, POCJUG) blood samples were obtained to determine POC glucose concentrations. Venous samples were also analyzed by LABGLU. Each foal was sampled at the time of enrollment or admission to the hospital and at 1 subsequent point during hospitalization. Indirect mean arterial pressure and hematocrit were concurrently recorded. Bland-Altman analysis showed a mean bias (95% limits of agreement) of -28.0(-88.6to32.6)mg/dL for comparison of POCJUG with LABGLU, -8.2(-94.3to78.0)mg/dL for POCMUZ and LABGLU, and 18.8(-44.4to82.0)mg/dL for POCMUZ and POCJUG. A total of 63.5% of the POCJUG and 45.2% of the POCMUZ samples exceeded the reference value by ±15mg/dL (for LABGLU samples <75mg/dL) or ±15% (for LABGLU samples ≥75mg/dL). Concordance correlation coefficient (95% confidence interval [CI]) indicated a fair agreement between POCJUG and LABGLU (0.75, 95% CI: 0.66-0.82) and between POCMUZ and LABGLU (0.71, 95% CI: 0.58-0.80). Fifty percent (14/28) of hypoglycemic foals on the reference method were incorrectly classified as euglycemic by POCJUG, and 5 of 28 were incorrectly classified by POCMUZ. In the sampled population, the chosen POC glucometer lacked agreement with the standard laboratory measurement. Limits of agreement were wide for both POCJUG and POCMUZ. Inaccuracies in POC results could impact decision-making in the clinical management of glycemic control in hospitalized neonatal foals and, importantly, increase the risk of hypoglycemic events being underdiagnosed in critical patients.

Differentiation of Prior SARS-CoV-2 Infection and Postacute Sequelae by Standard Clinical Laboratory Measurements in the RECOVER Cohort.

There are currently no validated clinical biomarkers of postacute sequelae of SARS-CoV-2 infection (PASC). To investigate clinical laboratory markers of SARS-CoV-2 and PASC. Propensity score-weighted linear regression models were fitted to evaluate differences in mean laboratory measures by prior infection and PASC index (≥12 vs. 0). (ClinicalTrials.gov: NCT05172024). 83 enrolling sites. RECOVER-Adult cohort participants with or without SARS-CoV-2 infection with a study visit and laboratory measures 6 months after the index date (or at enrollment if >6 months after the index date). Participants were excluded if the 6-month visit occurred within 30 days of reinfection. Participants completed questionnaires and standard clinical laboratory tests. Among 10 094 participants, 8746 had prior SARS-CoV-2 infection, 1348 were uninfected, 1880 had a PASC index of 12 or higher, and 3351 had a PASC index of zero. After propensity score adjustment, participants with prior infection had a lower mean platelet count (265.9 × 109 cells/L [95% CI, 264.5 to 267.4 × 109 cells/L]) than participants without known prior infection (275.2 × 109 cells/L [CI, 268.5 to 282.0 × 109 cells/L]), as well as higher mean hemoglobin A1c (HbA1c) level (5.58% [CI, 5.56% to 5.60%] vs. 5.46% [CI, 5.40% to 5.51%]) and urinary albumin-creatinine ratio (81.9 mg/g [CI, 67.5 to 96.2 mg/g] vs. 43.0 mg/g [CI, 25.4 to 60.6 mg/g]), although differences were of modest clinical significance. The difference in HbA1c levels was attenuated after participants with preexisting diabetes were excluded. Among participants with prior infection, no meaningful differences in mean laboratory values were found between those with a PASC index of 12 or higher and those with a PASC index of zero. Whether differences in laboratory markers represent consequences of or risk factors for SARS-CoV-2 infection could not be determined. Overall, no evidence was found that any of the 25 routine clinical laboratory values assessed in this study could serve as a clinically useful biomarker of PASC. National Institutes of Health.

What Are We Transfusing? Evaluating the Quality and Clinical Utility of Intraoperatively Salvaged Red Blood Cells in Spinal Deformity Surgery: A Nonrandomized Controlled Trial.

Intraoperative red blood cell (RBC) salvage is frequently used in contemporary spine surgery, despite clinical concern in its efficacy as a surrogate for blood-banked allogeneic packed RBCs (pRBCs). During spine surgery, salvaged RBCs (sRBCs) are exposed to injurious high-heat electrocautery, prolonged stasis, and abrasive pharmaceuticals, potentially making sRBCs a poor blood substitute. We therefore sought to scientifically and objectively define the quality of sRBCs in the context of complex spine surgery. This is a single-center, prospective, nonrandomized controlled trial of patients undergoing posterior-based multilevel thoracolumbar instrumented fusion for spinal deformity with planned use of intraoperative RBC salvage between June 2022 and July 2023. Surgeries were performed by fellowship-trained spinal neurosurgeons and orthopedic surgeons. The participants were split based on transfusion of sRBCs (given sufficient yield) vs no sRBC transfusion. Primary outcomes were RBC electrolyte composition, indices, deformability, and integrity, which were evaluated in comparison blood samples: Baseline, pRBC, and sRBC. Secondary outcomes were related to clinical effects of sRBC transfusion. Morphological assessment used Stimulated Raman Histology and machine learning. Deformability was assessed using ektacytometry. A total of 174 patients were included. The mean age was 50.2years ±25.4, 58.6% was female, the mean level fused was 10.0 ± 3.9, and 58.0% received sRBCs (median 207.0 mL). sRBCs differed significantly on standard laboratory measures, had a high proportion (30.7%) of shrunken and irregularly spiculated morphologies, and demonstrated abnormal deformability and relaxation kinetics. The hemolysis index was significantly elevated in sRBCs (2.9 ± 1.8) compared with Baseline samples and pRBCs (P < .01). Transfusion of sRBCs was associated with suboptimal resuscitation and provided no practical clinical benefit. RBCs salvaged during posterior thoracolumbar spine surgery are irreversibly injured, with hemolysis index exceeding Food and Drug Administration and Council of Europe transfusion standards in all samples, questioning their efficacy and safety as a blood substitute.

Validity of BiliDx as a point-of-care bilirubin measurement device to diagnose and monitor neonatal jaundice at Muhimbili National Hospital, an observational study

BackgroundNeonatal jaundice is a condition caused by elevated levels of bilirubin in the bloodstream. Laboratory determination of serum bilirubin concentration by total serum bilirubin (TSB) test is still considered as gold standard for clinical guidance and practice. In developed countries, diagnosis of neonatal jaundice is shifting towards point-of-care medical devices. BiliDx is a device developed to allow a fast, blood-based determination of bilirubin levels at the point of care. This study aimed to determine the accuracy of the BiliDx device relative to a standard laboratory total serum bilirubin to diagnose and monitor jaundice among neonates admitted at Muhimbili National Hospital (MNH).Material and methodologyThis was a prospective hospital-based observational study conducted at the Neonatal Ward – MNH, Dar-es-Salaam, Tanzania from November 2022 to January 2023. A total of 180 neonates admitted at the neonatal ward with jaundice and whose parents consented were enrolled in the study. Blood samples were collected; 2 ml of venous blood into the vacutainer bottle for standard laboratory measurement of total serum bilirubin (TSB) and 25µL blood collected into a transfer pipette tube and applied to BiliDx. STATA version 15.1 was used for data analysis.ResultsOut of 180 neonates, 39.4% (71/180) had birth weight between 1500 − 2499.9 g, approximately 2/3rd (120/180) were preterm, 92/180 (51.1%) were males and 100/180 (55.6%) were undergoing phototherapy treatment the moment sample taken. The mean bilirubin concentration was 92 mmol/l for BiliDx and 118 mmol/l for standard laboratory TSB. The minimum and maximum values obtained with BiliDx were, 3.4 and 427.5 mmol/l respectively, compared with 10.7 and 382.1 mmol/l using standard laboratory TSB. A linear relationship and correlation coefficient of 0.8408 (p = 0.000) between BiliDx and standard laboratory TSB was found. The regression analysis showed the presence of constant error [coefficient of BiliDx/slope = 0.91, 95% CI (0.82–0.99), p = 0.000] and random error exclusively [coefficient of constant/y-intercept = 48.52, 95%CI (37.70-59.34), p = 0.000]. The Bland–Altman plot showed an acceptable mean difference of 39.1mmol/l, limits of agreement of -48.3mmol/l to 126.4mmol/l, and 179 points (179/180 = 99.4%) lying inside the limits of agreement.ConclusionThe results support the use of BiliDx for rapid and accurate testing of elevated levels of bilirubin in the bloodstream among neonates since 99.4% of the differences between BiliDx and standard laboratory TSB lie between the lines of agreement.

Etiologies of Mild and Moderate Diarrheal Illness among Children in Consuelo, Dominican Republic.

Since the rotavirus vaccine was included in the Dominican Republic's national immunization schedule in 2012, the microbiologic etiologies of acute gastroenteritis have not been described. This study aimed to determine the contribution of rotavirus as an etiology of acute gastroenteritis over a 12-month period in children under 5 years of age in both an inpatient and an outpatient setting in Consuelo, Dominican Republic. All children who were seen at Niños Primeros en Salud clinic or admitted to Hospital Municipal Dr. Angel Ponce Pinedo for acute gastroenteritis during January 2021-April 2022 were enrolled in the study. Stools were evaluated for rotavirus, enteric parasites, and pathogenic bacteria. Pathogen detection was compared between outpatients and inpatients and on the basis of child's vaccination status. From 181 children enrolled, 170 stool samples were collected, 28 (16.5%) from inpatients and 142 (83.5%) from outpatients. Rotavirus was the most commonly detected pathogen and was proportionately more common among hospitalized children, with nine (32.1%) cases among hospitalized children and 16 (11.3%) among outpatient children. (Pearson χ2 = 8.1, P = 0.004). Among patients with a positive rotavirus result, vaccination rate was lower among moderate (hospitalized) (three of six; 50%) compared with mild (outpatient) diarrhea patients (12 of 15; 80%). Giardia lamblia (10%) was the next most prevalent pathogen detected in both inpatients and outpatients using standard laboratory measures. Despite the availability of rotavirus vaccination, rotavirus remains a common cause of gastrointestinal illness among children under 5 years of age in our cohort. Incomplete vaccination status was associated with hospitalization for gastrointestinal illness.

Analysis of transcriptomic features reveals molecular endotypes of SLE with clinical implications

BackgroundSystemic lupus erythematosus (SLE) is known to be clinically heterogeneous. Previous efforts to characterize subsets of SLE patients based on gene expression analysis have not been reproduced because of small sample sizes or technical problems. The aim of this study was to develop a robust patient stratification system using gene expression profiling to characterize individual lupus patients.MethodsWe employed gene set variation analysis (GSVA) of informative gene modules to identify molecular endotypes of SLE patients, machine learning (ML) to classify individual patients into molecular subsets, and logistic regression to develop a composite metric estimating the scope of immunologic perturbations. SHapley Additive ExPlanations (SHAP) revealed the impact of specific features on patient sub-setting.ResultsUsing five datasets comprising 2183 patients, eight SLE endotypes were identified. Expanded analysis of 3166 samples in 17 datasets revealed that each endotype had unique gene enrichment patterns, but not all endotypes were observed in all datasets. ML algorithms trained on 2183 patients and tested on 983 patients not used to develop the model demonstrated effective classification into one of eight endotypes. SHAP indicated a unique array of features influential in sorting individual samples into each of the endotypes. A composite molecular score was calculated for each patient and significantly correlated with standard laboratory measures. Significant differences in clinical characteristics were associated with different endotypes, with those with the least perturbed transcriptional profile manifesting lower disease severity. The more abnormal endotypes were significantly more likely to experience a severe flare over the subsequent 52 weeks while on standard-of-care medication and specific endotypes were more likely to be clinical responders to the investigational product tested in one clinical trial analyzed (tabalumab).ConclusionsTranscriptomic profiling and ML reproducibly separated lupus patients into molecular endotypes with significant differences in clinical features, outcomes, and responsiveness to therapy. Our classification approach using a composite scoring system based on underlying molecular abnormalities has both staging and prognostic relevance.

Airborne sound transmission loss of ship bulkheads: A new methodological approach for in-laboratory assessment by including low frequencies

Current standard laboratory measurements of sound transmission loss properties of ship bulkheads at low frequencies, below 100 Hz, are not accurate enough due to the non-diffuse acoustic field of typical laboratory volumes. However, what has been recently observed in non-diffuse field conditions is the transmission of source modes into the receiving room through the partition. On the basis of this, in this paper, a novel procedure to determine the laboratory airborne sound transmission loss properties of ship bulkheads at low frequencies through the airborne modal sound transmission loss is investigated. It is defined as the difference between the average sound pressure levels of source room modes peaks that occur in both source and receiving rooms. A correction method is proposed to suppress the influence of natural receiving room modes. Normalization terms related to receiving room volume and modal damping are introduced, and an envelope method is applied to extend the results in third octave bands. Measurements on five different ship bulkheads show that the standard transmission loss in the low frequency range provides unlikely results, whereas the proposed descriptor follows the expected theoretical curve. This evidence confirms the validity of the proposed method, at least for comparison purposes in marine applications.

Benchmark VERCORS 2022: blind prediction of time-dependent behavior of concrete containment building with low and high-fidelity models

The VERCORS program aims to acquire an extensive experimental dataset collected to provide a solid basis for numerical modeling of concrete containment buildings (CCBs). In order to cover the entire life-span of a real containment, the measurements are done on 3× smaller mock-up which leads to 9-fold acceleration of all processes related to drying. The goal for the participants of the third VERCORS benchmark was to predict the behaviour of the CCB based on standard laboratory measurements on VERCORS concrete. The previous paper [1] presented the calibration procedure of material models for moisture transport and time-dependent behavior of concrete and summarized the results obtained with a computationally efficient low-fidelity model (LFM). The present paper compares the responses of the LFM and a high-fidelity model (HFM) with a detailed geometry of the entire containment and presents a comparison with the experimental data collected over the last 8 years on the VERCORS mockup.

Sleep duration and testosterone levels in community older men: results from the West China Health and Aging Trend study.

Sleep duration and testosterone levels in community older men: results from the West China Health and Aging Trend study.

Predicting milk protein fractions using infrared spectroscopy and a gradient boosting machine for breeding purposes in Holstein cattle

In recent years, increasing attention has been focused on the genetic evaluation of protein fractions in cow milk with the aim of improving milk quality and technological characteristics. In this context, advances in high-throughput phenotyping by Fourier transform infrared (FTIR) spectroscopy offer the opportunity for large-scale, efficient measurement of novel traits that can be exploited in breeding programs as indicator traits. We took milk samples from 2,558 Holstein cows belonging to 38 herds in northern Italy, operating under different production systems. Fourier transform infrared spectra were collected on the same day as milk sampling and stored for subsequent analysis. Two sets of data (i.e., phenotypes and FTIR spectra) collected in 2 different years (2013 and 2019-2020) were compiled. The following traits were assessed using HPLC: true protein, major casein fractions [αS1-casein (CN), αS2-CN, β-CN, κ-CN, and glycosylated-κ-CN], and major whey proteins (β-lactoglobulin and α-lactalbumin), all of which were measured both in grams per liter (g/L) and proportion of total nitrogen (% N). The FTIR predictions were calculated using the gradient boosting machine technique and tested by 3 different cross-validation (CRV) methods. We used the following CRV scenarios: (1) random 10-fold, which randomly split the whole into 10-folds of equal size (9-folds for training and 1-fold for validation); (2) herd/date-out CRV, which assigned 80% of herd/date as the training set with independence of 20% of herd/date assigned as the validation set; (3) forward/backward CRV, which split the data set in training and validation set according with the year of milk sampling (FTIR and gold standard data assessed in 2013 or 2019-2020) using the "old" and "new" databases for training and validation, and vice-versa with independence among them; (4) the CRV for genetic parameters (CRV-gen), where animals without pedigree as assigned as a fixed training population and animals with pedigree information was split in 5-folds, in which 1-fold was assigned to the fixed training population, and 4-folds were assigned to the validation set (independent from the training set). The results (i.e., measures and predictions) of CRV-gen were used to infer the genetic parameters for gold standard laboratory measurements (i.e., proteins assessed with HPLC) and FTIR-based predictions considering the CRV-gen scenario from a bi-trait animal model using single-step genomic BLUP. We found that the prediction accuracies of the gradient boosting machine equations differed according to the way in which the proteins were expressed, achieving higher accuracy when expressed in g/L than when expressed as % N in all CRV scenarios. Concerning the reproducibility of the equations over the different years, the results showed no relevant differences in predictive ability between using "old" data as the training set and "new" data as the validation set and vice-versa. Comparing the additive genetic variance estimates for milk protein fractions between the FTIR predicted and HPLC measures, we found reductions of -19.7% for milk protein fractions expressed in g/L, and -21.19% expressed as % N. Although we found reductions in the heritability estimates, they were small, with values ranging from -1.9 to -7.25% for g/L, and -1.6 to -7.9% for % N. The posterior distributions of the additive genetic correlations (ra) between the FTIR predictions and the laboratory measurements were generally high (>0.8), even when the milk protein fractions were expressed as % N. Our results show the potential of using FTIR predictions in breeding programs as indicator traits for the selection of animals to enhance milk protein fraction contents. We expect acceptable responses to selection due to the high genetic correlations between HPLC measurements and FTIR predictions.

Point-of-care self-testing for measuring total white blood cells and C-reactive protein – a pilot study for future home-monitoring of patients during antibiotic treatment at home

Background During home treatment with antibiotics, patients’ laboratory results of total white blood cell count (WBC) with neutrophil counts and C-reactive protein (CRP) are drawn and monitored at the hospital. The aim of the study was to examine the feasibility and analytical accuracy of hospitalized patients 18 years or older self-testing using two point-of-care tests (POCT). Methods The pilot study included 41 hospitalized patients. A subjective judgment of the patients’ ability to conduct the self-testing was made along with a comparison of the POCT measurements of WBC, neutrophil counts and CRP with standard laboratory measurements. Correlation between the POCTs and laboratorial values was assessed by coefficient of determination and the level of agreement between the means was assessed by Bland Altman test. Results Of the 38 patients conducting self-testing, 78% were men and the mean age was 61.8 years. 28 patients (73.7%) successfully performed self-testing on the first try while, 10 (26.3%) ‘HemoCue WBC DIFF’ measurements showed an error code. All the patients successfully performed the ‘QuickRead go CRP’ self-test. Comparison of the ‘HemoCue WBC DIFF’ results with the laboratory results of WBC and neutrophil counts showed good agreement. On the other hand, ‘QuickRead go CRP’ results showed a small but significant systematic disagreement compared to the laboratory results. Conclusion Our results showed that the POCTs can be used by some patients and factors influencing the patient participation included psychological and physical limitations. Both POCTs appeared to have an acceptable clinical level of accuracy.

Inflammatory Biomarker Clusters Are Predictive of Response and Toxicity in Large B-Cell Lymphoma Treated with CD19 CAR-T Cell Therapy

Disease recurrence and toxicity are common sequelae of CD19-directed chimeric antigen T-cell (CAR-T) cell therapy in large B-cell lymphoma (LBCL). We have developed a machine learning approach that is informative of adverse CAR-T outcomes and can support personalized treatment approaches. In a single-center cohort of 198 LBCL patients treated with CD19-CAR-T cells (axicabtagene ciloleucel [axi-cel] 50%, tisagenlecleucel [tisa-cel] 32%, lisocabtagene maraleucel [liso-cel] 18%), we applied unsupervised k-means clustering on standard laboratory and cytokine measurements collected within the day prior to CAR-T infusion. Three distinct biomarker clusters emerged (Fig. A) - inflammatory (n=27, 14%), neutral (n=121, 61%), and favorable (n=50, 25%). The inflammatory subgroup was enriched for patients with high levels of inflammatory markers such as IL-6, TNFa, and ferritin, while the favorable cluster tended to have higher complete blood counts and albumin; intermediate values were characteristic of the neutral subgroup. To determine the clinical implications of these subgroups, we studied their association with day 100 best response to CAR-T, significant toxicity by day 30 (defined as life-threatening complications such as immune toxicities requiring intervention, bloodstream infections, or early death), and overall survival (OS) after multivariate adjustment for CAR-T costimulatory domain (CD28 vs 41BB), patient age, primary refractory disease, and pre-lymphodepletion LDH. Compared to those in the favorable biomarker cluster, patients in the inflammatory cluster (Fig. A) had increased odds of not achieving CR by day 100 (odds ratio [OR] 4.23, 95% confidence interval [CI] 1.37-14.4, p < 0.05) and a high toxicity profile (OR 12.5, 95% CI 3.66-49.5, p < 0.001). OS was also reduced with the inflammatory subgroup in univariable analysis (Fig. B) and a multivariable Cox regression model (hazard ratio [HR] 4.03, 95% CI 1.99-8.16, p < 0.001). Patients in the neutral subgroup, compared to those in the favorable group, had reduced overall survival (HR 1.80, 95% CI 1.00-3.24, p < 0.05) and increased odds of high toxicity (OR 3.40, 95% CI 1.56-7.79, p <0.01). Serial assessment of the uncommon biomarkers and cytokines in our day 0 panel may not be readily available to many centers. We developed a random forest prediction model for cluster type based on patient, disease, and widely available pre-lymphodepletion laboratory features. Our random forest model outperformed gradient boosting and logistic regression model alternatives and achieved a high discrimination (AUC 0.81) for cluster prediction. Next, we applied the random forest model to pre-lymphodepletion data from an independent LBCL cohort (n=155) from a different center (Fig. B). Most patients were assigned to the neutral subgroup (n=108, 70%) followed by the inflammatory (21%) and favorable (9%) subgroup. Assignment to the inflammatory cluster was strongly associated with inferior OS compared to the favorable subgroup (HR 2.89, 95% CI 1.12-7.48, p < 0.05) after multivariate adjustment for CAR-T costimulatory domain (CD28 vs 41BB), patient age, primary refractory disease, and pre-lymphodepletion LDH. In conclusion, we identified three pre-infusion (day 0) biomarker clusters, which are tightly associated with CAR-T outcomes. These clusters could guide decision-making regarding hospitalization after CAR-T infusion and to preempt early inflammation and disease relapse in high-risk subgroups. Finally, to improve accessibility to cluster assignment, we developed a prediction model for cluster type based on readily available pre-lymphodepletion data and applied it towards an external center cohort as a proof-of-principle. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Prognostic peripheral blood biomarkers at ICU admission predict COVID-19 clinical outcomes.

The COVID-19 pandemic continues to challenge the capacities of hospital ICUs which currently lack the ability to identify prospectively those patients who may require extended management. In this study of 90 ICU COVID-19 patients, we evaluated serum levels of four cytokines (IL-1β, IL-6, IL-10 and TNFα) as well as standard clinical and laboratory measurements. On 42 of these patients (binned into Initial and Replication Cohorts), we further performed CyTOF-based deep immunophenotyping of peripheral blood mononuclear cells with a panel of 38 antibodies. All measurements and patient samples were taken at time of ICU admission and retrospectively linked to patient clinical outcomes through statistical approaches. These analyses resulted in the definition of a new measure of patient clinical outcome: patients who will recover after short ICU stays (< 6 days) and those who will subsequently die or recover after long ICU stays (≥6 days). Based on these clinical outcome categories, we identified blood prognostic biomarkers that, at time of ICU admission, prospectively distinguish, with 91% sensitivity and 91% specificity (positive likelihood ratio 10.1), patients in the two clinical outcome groups. This is achieved through a tiered evaluation of serum IL-10 and targeted immunophenotyping of monocyte subsets, specifically, CD11clow classical monocytes. Both immune biomarkers were consistently elevated ( ≥15 pg/ml and ≥2.7 x107/L for serum IL-10 and CD11clow classical monocytes, respectively) in those patients who will subsequently die or recover after long ICU stays. This highly sensitive and specific prognostic test could prove useful in guiding clinical resource allocation.

Noise from above: A summary of studies regarding the perceived annoyance due to impact sounds

To support efforts of introducing an impact sound requirement into the National Building Code of Canada (NBCC), the National Research Council of Canada has initiated a long-term research project. In cooperation with the Hochschule Duesseldorf in Germany and Kangwon National University in Korea, several listening tests were performed to investigate the annoyance due to impact sound as it is perceived by building occupants, and how this annoyance relates to the results of standardized laboratory measurements. In this contribution, the different listening test setups will be described and compared. Tests were performed in the laboratory using loudspeakers, headphones, and also with a Virtual Reality headset. In addition, an online listening test was launched to expand the reach of such studies to the general population. The results will be summarized and discussed regarding appropriate rating methods. The goal of these studies is to gain a better understanding of the relevant factors that affect the perceived annoyance, such as the impact source type and the dominant frequency range, but also how the test environment influences the results.

Utility of INSCYD athletic performance software to determine Maximal Lactate Steady State and Maximal Oxygen Uptake in cyclists

&#x0D; Serious amateur and elite athletes regularly take part in structured physiological testing sessions so that their progress gets tracked and training loads in the training plan correctly prescribed. Commonly, athletes are tested for the maximal oxygen uptake (V̇O2max) and maximal lactate steady state intensity (MLSS). While for the former expensive laboratory equipment is required, the latter requires multiple exercise trials for accurate determination. INSCYD athletic performance software is designed to enable continuous monitoring of these two parameters throughout the season after undertaking a single visit exercise testing session involving blood lactate sampling and power output measurement. The purpose of the present study was to assess validity of the software by its estimates of V̇O2max and MLSS and compare them to gold standard laboratory measures. 11 trained participants (V̇O2max 61.0 ± 7.9 mL ∙ kg-1 ∙ min-1) took part in this study consisting of formal graded V̇O2max test, multiple MLSS trials and a recommended test to obtain the data later fed the INSCYD athletic performance software. Both V̇O2max relative (∆=0.13 ml.kg-1.min-1, p=0.885) and MLSS calculated values (∆=2 W, p=0.655) were within expected daily variation and thus the estimations considered valid. It can be concluded that INSCYD athletic performance software offers its users utility to accurately predict V̇O2max and MLSS provided that the practitioner has a good idea of where the MLSS lies. However, caution is required when interpreting other parameter estimates provided by the software due their questionable scientific validity.&#x0D;

61-OR: Machine Learning Framework Predicts Metabolic Subphenotypes Using Glucose Dynamics during Oral Glucose Tolerance Test

Type 2 diabetes (T2D) is classically defined by measures of glycemia which do not take into account its physiologic basis, which differs between individuals. Defining the relative contribution of fundamental physiologic processes to glucose dysregulation would facilitate targeted treatment approaches for diabetes prevention and treatment. We propose that muscle insulin resistance, beta cell dysfunction, incretin defect, and hepatic insulin resistance are present to varying degrees in individuals predisposed to T2D, who can be thus classified according to their metabolic subphenotype. While this transformative approach to T2D is appealing, traditional metabolic tests are invasive and unavailable outside research units. We tested the ability of the shape of the glucose response curve during an oral glucose tolerance test (OGTT) to identify metabolic subphenotypes. 32 participants underwent gold-standard metabolic tests including frequently-sampled 3-hour OGTT, isoglycemic intravenous glucose infusion for quantification of incretin effect, steady-state plasma glucose measurement of insulin resistance, and calculated hepatic insulin resistance. We developed a machine learning framework to predict metabolic subphenotypes of an individual using dynamic features of the glucose time series during the OGTT. Metabolic testing revealed extensive inter-individual heterogeneity and the existence of four major metabolic subphenotypes. The features of the glucose time series identified insulin resistance, beta cell deficiency, and incretin deficiency with auROCs of 94%, 76%, and 75%, respectively. These were superior to standard clinical and laboratory measures of metabolic phenotypes. We suggest that identification of distinct metabolic subphenotypes using features of the glucose time series during OGTT may both enhance early identification of at-risk individuals as well as inform targeted therapeutic approaches to prevent and treat T2D. Disclosure A.A.Metwally: None. D.Perelman: None. H.Park: None. A.L.Gloyn: Other Relationship; Genentech, Inc., Roche Pharmaceuticals. T.Mclaughlin: Board Member; January, Inc., Research Support; Merck &amp; Co., Inc., Novo Nordisk, Stock/Shareholder; Eiger BioPharmaceuticals. M.Snyder: Stock/Shareholder; January, Inc. Funding National Institutes of Health (R01DK110186-01) National Institute of Diabetes and Digestive and Kidney Diseases (U01-DK105535; U01-DK085545, UM1DK126185)

MO892: Depression and Symptom Burden in Patients on Chronic Haemodialysis

Abstract BACKGROUND AND AIMS Expanding complexity of the comorbid disorders is becoming increasingly common in patients treated with chronic haemodialysis (HD) related to technique improvements, better treatment options and resultant prolonged survival. This contributes to development of physical and emotional symptoms, which further affect patients’ health. We aimed to examine the symptom burden, symptom severity and prevalence of depression in patients treated with chronic HD. METHOD Three hundred and four chronic adult HD patients (58.9% males, 67.1% under 65 years of age, 15.7% with diabetes, time on dialysis 3—324 months) from five dialysis centrrs were enrolled in this cross-sectional study. All patients were under stable condition, without any severe acute comorbidities, and able to understand and fill-in the self-administered questionnaires. Standard laboratory parameters and Kt/V were measured in all patients. Presence and severity of physical and emotional symptoms were assessed by the 30-item Dialysis Symptom Index (DSI), while the presence of depression was assessed with Beck Depression Inventory (BDI). Other relevant demographic and clinical data were obtained from patients’ medical records. The results were analyzed with independent sample T-test, χ2 and ANOVA statistic. RESULTS The average BDI was 15.10 ± 11.04, the average symptom burden 15.49 ± 12.85 and the average symptom severity 23.38 ± 18.78. Nearly half of the patients (45.1%) had depressive symptoms (BDI ≥ 14). The demographic (sex, age, marital status, level of education, employment status, smoking habit), clinical (body mass index, comorbidities, dialysis vintage, shift and adequacy, type of membrane and vascular access) were not significantly associated with depression. Patients with depressive symptoms had significantly higher serum urea (24.5 ± 5.5 mmol/L versus 22.7 ± 5.4 mmol/L; P = 0.028) and creatinine (896.7 ± 196.2 umol/L versus 809.5 ± 206.4 umol/L; P = 0.003), but no significant difference in other standard laboratory measurements. Women, patients &amp;gt;65 and diabetic patients had significantly higher symptom burden than men, younger and non-diabetic patients (17.50 ± 12.88 versus 14.08 ± 11.68, P = 0.017; 18.65 ± 15.47 versus 13.94 ± 10.04, P = 0.002; 22.80 ± 18.75 versus 14.32 ± 10.39, P = 0.017, respectively), while diabetic and patients with inadequate dialysis had siginifcantly higher symptom severity (29.65 ± 21.69 versus 22.37 ± 18.26, P &amp;lt; 0.01 and 27.33 ± 20.70 versus 17.37 ± 14.62, P &amp;lt; 0.01, respectively). Depressive patients had significantly higher symptom burden (19.68 ± 13.29 versus 12.04 ± 10.20; P &amp;lt; 0.01) and symptom severity (31.92 ± 19.71 versus 16.37 ± 14.69; P &amp;lt; 0.01). The symptoms significantly more prevalent in depressive patients included constipation, nausea, diarrhoea, muscle cramps, restless legs, numbness/tingling in feet, lack of energy, bone/joint pain, dry mouth (all P &amp;lt; 0.001), shortness of breath (P = 0.036), dizziness (P = 0.048) and chest pain (P = 0.027). CONCLUSION These results highlight the need for routine surveillance of symptoms and emotional status in chronic HD patients.

Temporal pole volume is associated with episodic autobiographical memory in healthy older adults.

Recollection of personal past events differs across the lifespan. Older individuals recall fewer episodic details and convey more semantic information than young. Here we examine how gray matter volumes in temporal lobe regions integral to episodic and semantic memory (hippocampus and temporal poles, respectively) are related to age differences in autobiographical recollection. Gray matter volumes were obtained in healthy young (n = 158) and old (n = 105) adults. The temporal pole was demarcated and hippocampus segmented into anterior and posterior regions to test for volume differences between age groups. The Autobiographical Interview was administered to measure episodic and semantic autobiographical memory. Volume associations with episodic and semantic autobiographical memory were then assessed. Brain volumes were smaller for older adults in the posterior hippocampus. Autobiographical memory was less episodic and more semanticized for older versus younger adults. Older adults also showed positive associations between temporal pole volumes and episodic autobiographical recall; in the young, temporal pole volume was positively associated with performance on standard laboratory measures of semantic memory. Exploratory analyses revealed that age-related episodic autobiographical memory associations with anterior hippocampal volumes depended on sex. These findings suggest that age differences in brain structures implicated in episodic and semantic memory may portend reorganization of neural circuits to support autobiographical memory in later life.

Varying association of laboratory values with reference ranges and outcomes in critically ill patients: an analysis of data from five databases in four countries across Asia, Europe and North America

BackgroundDespite wide usage across all areas of medicine, it is uncertain how useful standard reference ranges of laboratory values are for critically ill patients.ObjectivesThe aim of this study is to...