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Monitoring training and recovery responses with heart rate measures during standardized warm-up in elite badminton players.
Schneider, C, Wiewelhove, T, McLaren, SJ, Röleke, L, Käsbauer, H, Hecksteden, A, Kellmann, M, Pfeiffer, M, Ferrauti, A
PloS one. 2020;(12):e0244412
Abstract
PURPOSE To investigate short-term training and recovery-related effects on heart rate during a standardized submaximal running test. METHODS Ten elite badminton players (7 females and 3 males) were monitored during a 12-week training period in preparation for the World Championships. Exercise heart rate (HRex) and perceived exertion were measured in response to a 5-min submaximal shuttle-run test during the morning session warm-up. This test was repeatedly performed on Mondays after 1-2 days of pronounced recovery ('recovered' state; reference condition) and on Fridays following 4 consecutive days of training ('strained' state). In addition, the serum concentration of creatine kinase and urea, perceived recovery-stress states, and jump performance were assessed before warm-up. RESULTS Creatine kinase increased in the strained compared to the recovered state and the perceived recovery-stress ratings decreased and increased, respectively (range of average effects sizes: |d| = 0.93-2.90). The overall HRex was 173 bpm and the observed within-player variability (i.e., standard deviation as a coefficient of variation [CV]) was 1.3% (90% confidence interval: 1.2% to 1.5%). A linear reduction of -1.4% (-3.0% to 0.3%) was observed in HRex over the 12-week observational period. HRex was -1.5% lower (-2.2% to -0.9%) in the strained compared to the recovered state, and the standard deviation (as a CV) representing interindividual variability in this response was 0.7% (-0.6% to 1.2%). CONCLUSIONS Our findings suggest that HRex measured during a standardized warm-up can be sensitive to short-term accumulation of training load, with HRex decreasing on average in response to consecutive days of training within repeated preparatory weekly microcycles. From a practical perspective, it seems advisable to determine intra-individual recovery-strain responses by repeated testing, as HRex responses may vary substantially between and within players.
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Bioelectrical Impedance Measurements for Assessment of Kidney Function in Critically Ill Patients.
de Jong, LAA, Otten-Helmers, AG, Spronk, PE, van Kan, HJM
Critical care medicine. 2019;(12):e984-e992
Abstract
OBJECTIVES To evaluate the use of multifrequency bioelectrical impedance analysis to predict creatinine/urea clearance based on 24 hours urine collection. A practical formula was developed, and its performance was compared with that of established formulas such as Cockcroft-Gault, Modification of Diet in Renal Disease, and Jelliffe's. DESIGN An open-label prospective observational cohort study. SETTING A 12-bed ICU at a nonuniversity major teaching hospital (Gelre ziekenhuizen Apeldoorn/Zutphen, The Netherlands). PATIENTS Adult critical care patients with an expected ICU length of stay at admission of at least 48 hours. INTERVENTIONS Each patient's body composition was assessed using a validated Quadscan 4000 analyzer (Bodystat, Isle of Man, British Isles). Twenty-four hours urine was collected, and laboratory variables in serum including creatinine, urea, and albumin were obtained at the beginning and end of the collection period. MEASUREMENTS AND MAIN RESULTS A total of 151 patients, stratified to an acute and nonacute ICU-group, were enrolled in the study over a 2-year period. A formula to predict creatinine/urea clearance based on 24 hours urine collection was developed using stepwise linear regression using a training data set of 75 patients. This formula was subsequently tested and compared with other relevant predictive equations using a validation data set of 76 patients. Serum creatinine values ranged from 40 to 446 µmol/L. With the predictive model based on estimated body cell mass and a "prediction marker" more than 71% of the observed variance in creatinine/urea clearance based on 24 hours urine collection could be explained. Predictive performance was superior to the other eight evaluated models (R = 0.39-0.55) and demonstrated to be constant over the whole range of creatinine/urea clearance based on 24 hours urine collection values. CONCLUSIONS Multifrequency bioelectrical impedance analysis measurements can be used to predict creatinine/urea clearance based on 24 hours urine collection with superior performance than currently established prediction models. This rapid, noninvasive method enables correction for influences of a patient's actual body composition and may prove valuable in daily clinical practice.
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Use of the Fractional Excretion of Urea in an Azotemic Nonoliguric State: Type 1 Cardiorenal Syndrome.
Diskin, JB, Walker, CB, Oberle, MD, Diskin, CJ
Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy. 2018;(4):319-324
Abstract
The fractional excretion of urea is a useful tool to evaluate renal function in oliguric states; however, it remains unexplored in nonoliguric states. We evaluated its use to predict responses in patients with type 1 cardiorenal syndrome. This was a prospective observational study of 116 patients with type 1 cardiorenal syndrome referred over a 4-year period. Fractional excretion of urea and sodium, ejection fraction, mean arterial pressure, age, sex, diabetes, brain natriuretic peptide (BNP), serum sodium and blood urea nitrogen were analyzed for effects upon serum creatinine and survival. Improvement of renal function correlated most significantly with FeUrea (P = 0.00001) followed by the FeNa (P = 0.005) but no other variable studied reached significance. Survival was best predicted by improvement of the serum creatinine at 24 h (P = 0.005) and 7 days after all inotropes were stopped (P = 0.001). A limitation of this study is that it cannot be extrapolated to all cardiorenal syndrome patients other than type 1. Also, the study was not randomized and those with potentially worse disease have had worse outcomes due merely to worse underlying disease. The success of the FeUrea may possibly be related to interference of dobutamine on creatinine levels. Despite being a nonoliguric state, the FeUrea appears to provide insight to those patients with type 1 cardiorenal syndrome whose renal function (as measured by serum creatinine) and survival might improve.
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A combination of routine blood analytes predicts fitness decrement in elderly endurance athletes.
Haslacher, H, Ratzinger, F, Perkmann, T, Batmyagmar, D, Nistler, S, Scherzer, TM, Ponocny-Seliger, E, Pilger, A, Gerner, M, Scheichenberger, V, et al
PloS one. 2017;(5):e0177174
Abstract
Endurance sports are enjoying greater popularity, particularly among new target groups such as the elderly. Predictors of future physical capacities providing a basis for training adaptations are in high demand. We therefore aimed to estimate the future physical performance of elderly marathoners (runners/bicyclists) using a set of easily accessible standard laboratory parameters. To this end, 47 elderly marathon athletes underwent physical examinations including bicycle ergometry and a blood draw at baseline and after a three-year follow-up period. In order to compile a statistical model containing baseline laboratory results allowing prediction of follow-up ergometry performance, the cohort was subgrouped into a model training (n = 25) and a test sample (n = 22). The model containing significant predictors in univariate analysis (alanine aminotransferase, urea, folic acid, myeloperoxidase and total cholesterol) presented with high statistical significance and excellent goodness of fit (R2 = 0.789, ROC-AUC = 0.951±0.050) in the model training sample and was validated in the test sample (ROC-AUC = 0.786±0.098). Our results suggest that standard laboratory parameters could be particularly useful for predicting future physical capacity in elderly marathoners. It hence merits further research whether these conclusions can be translated to other disciplines or age groups.
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Blood urea impairs brachial artery flow mediated dilation.
Tripolino, C, Irace, C, Carallo, C, De Franceschi, MS, Della Valle, E, Gnasso, A
International angiology : a journal of the International Union of Angiology. 2015;(4):392-7
Abstract
AIM: Urea, the main product of protein catabolism, is a biochemical marker of renal function. Though it is known that serum urea impairs vascular health, the relationship between its concentration and vascular reactivity in vivo has not been explored. Our study was undertaken to investigate possible association between serum urea and endothelial function in subjects without chronic kidney disease (CKD). METHODS Eighty free-living subjects with serum creatinine ≤1 mg/dL and without CKD were enrolled for the present study. Serum analyses and evaluation of endothelial function were performed in all subjects. Endothelial function was measured using the flow-mediated dilation (FMD) technique. Simple and multiple regression analyses were used to test the association between FMD and considered variables. RESULTS In correlation analyses FMD was found directly associated with HDL cholesterol (r=0.21; P=0.05) and eGFR (r=0.25; P=0.02) and inversely associated with age (r=-0.26; P=0.02), serum urea (r=-0.37; P<0.01), serum creatinine (r=-0.31; P<0.01) and brachial artery baseline diameter (r=-0.41; P<0.01). In multiple regression analysis only baseline artery diameter and serum urea predicted FMD; age, gender and cardiovascular risk factors did not relate with FMD. CONCLUSION Our study demonstrates the association between serum urea and FMD, suggesting that the accumulation of waste products of protein metabolism may impair vascular health in subjects without CKD.
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6.
Creatinine index as a surrogate of lean body mass derived from urea Kt/V, pre-dialysis serum levels and anthropometric characteristics of haemodialysis patients.
Canaud, B, Granger Vallée, A, Molinari, N, Chenine, L, Leray-Moragues, H, Rodriguez, A, Chalabi, L, Morena, M, Cristol, JP
PloS one. 2014;(3):e93286
Abstract
BACKGROUND AND OBJECTIVES Protein-energy wasting is common in long-term haemodialysis (HD) patients with chronic kidney disease and is associated with increased morbidity and mortality. The creatinine index (CI) is a simple and useful nutritional parameter reflecting the dietary skeletal muscle protein intake and skeletal muscle mass of the patient. Because of the complexity of creatinine kinetic modeling (CKM) to derive CI, we developed a more simplified formula to estimate CI in HD patients. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS A large database of 549 HD patients followed over more than 20 years including monthly CKM-derived CI values was used to develop a simple equation based on patient demographics, predialysis serum creatinine values and dialysis dose (spKt/V) using mixed regression models. RESULTS The equation to estimate CI was developed based on age, gender, pre-dialysis serum creatinine concentrations and spKt/V urea. The equation-derived CI correlated strongly with the measured CI using CKM (correlation coefficient = 0.79, p-value <0.001). The mean error of CI prediction using the equation was 13.47%. Preliminary examples of few typical HD patients have been used to illustrate the clinical relevance and potential usefulness of CI. CONCLUSIONS The elementary equation used to derive CI using demographic parameters, pre-dialysis serum creatinine concentrations and dialysis dose is a simple and accurate surrogate measure for muscle mass estimation. However, the predictive value of the simplified CI assessment method on mortality deserves further evaluation in large cohorts of HD patients.