Maja Bučar Pajek

Integrative Examination of Motor Abilities in Dialysis Patients and Selection of Tests for a Standardized Physical Function Assessment

To reduce the need for a large number of executed physical function tests we examined inter‐relations and determined predictive power for daily physical activity of the following tests: 6‐min walk, 10 repetition sit‐to‐stand, time up‐and‐go, Storke balance, handgrip strength, upper limb tapping and sitting forward bend tests. In 90 dialysis and 140 healthy control subjects we found high correlations between all tests, especially those engaging lower extremities. Sit‐to‐stand, forward bend and handgrip strength were selected for the test battery and composite motor performance score. Sit‐to‐stand test was superior in terms of sensitivity to uremia effects and association with daily physical function in adjusted analyses. There was no incremental value in calculating the composite performance score. We propose to standardize the physical function assessment of dialysis patients for cross‐sectional and longitudinal observations with three simple, cheap, well‐accessible and easily performed test tools: sit‐to‐stand test, handgrip strength and Human Activity Profile questionnaire.

Six-Minute Walk Test in Renal Failure Patients: Representative Results, Performance Analysis and Perceived Dyspnea Predictors.

Objectives Six-minute walk test in dialysis population hasn’t been consistently evaluated for the isolated impact of renal failure and other predictive factors. We measured six-minute walk distance in patients representative for low level of comorbidity and searched for potentially modifiable predictive factors of performance and dyspnea. Methods This was a cross-sectional study with hemodialysis patients (N = 90) and control subjects (N = 140). Main outcome measures: six-minute walk test distance and dyspnea severity using the 10-item Borg scale. Results Median distance decreased from 600m below the 6th decade to 420m in the 8th decade of age. Dialysis dependence predicted 101.5m shorter distance in the adjusted model that explained 70% of variability in results. Adjusted for significant covariates of age, height and spontaneous gait speed, fat mass (but not lean body mass) and serum total iron binding capacity were significantly associated with distance (95% CI for B coefficients -4.6 to –1.4 m/kg and 0.1 to 5 m/μmol/l, respectively). Serum total iron binding capacity as an explanatory variable was superior to C-reactive protein and albumin. Dialysis dependence, odds ratio (OR) 2.97 (1.11–7.94), spontaneous gait speed, OR 0.08 (0.02–0.41), rate-pressure product, OR 1.15 (1.08–1.23) and hemoglobin, OR 0.95 (0.92–0.98) predicted dyspnea in the adjusted model. Conclusions Renal failure without the confounding effect of comorbidity is a significant negative predictor of performance at six-minute walk test and perceived level of dyspnea. Body fat mass and serum total iron binding capacity are the main potentially modifiable predictors of performance, total iron binding capacity being superior to C-reactive protein and albumin. Although hemoglobin is not associated with test performance, it negatively predicts perceived shortness of breath.

Is the Quality of Judging in Women Artistic Gymnastics Equivalent at Major Competitions of Different Levels

In the present study, the reliability and validity of judging at the European championship in Berlin 2011 were analysed and the results were compared to a different level gymnastic competition - Universiade 2009 in Belgrade. For reliability and consistency assessment, mean absolute judge deviation from final execution score, Cronbach’s alpha coefficient, intra-class correlations (ICC) and Armor’s theta coefficient were calculated. For validity assessment mean deviations of judges’ scores, Kendall’s coefficient of concordance W and ANOVA eta-squared values were used. For Berlin 2011 in general Cronbach’s alpha was above 0.95, minima of item-total correlations were above 0.8, and the ICC of average scores and Armor’s theta were above 0.94. Comparison with Universiade 2009 identified vault and floor scores at both competitions to have inferior reliability indices. At both competitions average deviations of judges from the final E score were close to zero (p=0.84) but Berlin 2011 competition showed a higher number of apparatuses with significant Kendall’s W (5 vs. 2 for Universiade 2009) and higher eta-squared values indicating higher judge panel bias in all-round and apparatus finals. In conclusion, the quality of judging was comparable at examined gymnastics competitions of different levels. Further work must be done to analyse the inferior results at vault and floor apparatuses.

Effects of an Ad Libitum Consumed Low-Fat Plant-Based Diet Supplemented with Plant-Based Meal Replacements on Body Composition Indices

Objective. To document the effect of a diet free from animal-sourced nutrients on body composition indices. Methods. This was a nonrandomized interventional (n = 241)-control (n = 84) trial with a 10-week, low-fat, plant-based diet supplemented with two daily meal replacements. The meals were allowed to be eaten to full satiety without prespecified calorie restrictions. Control subjects received weekly lectures on the rationale and expected benefits of plant-based nutrition. Body composition indices were measured with bioimpedance analysis. Results. Relative to controls, in cases, postintervention body fat percentage was reduced by 4.3 (95% CI 4.1–4.6)% points (a relative decrement of −13.4%), visceral fat by 1.6 (95% CI 1.5–1.7) fat cross-sectional surface units, and weight by 5.6 kg (95% CI 5.2–6), while muscle mass was reduced by 0.3 kg (95% CI 0.06–0.5) with a relative increase of muscle mass percentage of 4.2 (3.9–4.4)% points. Analysis of covariance showed significantly larger adjusted fat reductions in cases compared to controls. Late follow-up revealed further weight loss in 60% of cases and no significant change in controls. Conclusions. Low-fat, plant-based diet in free-living nonresidential conditions eaten ad libitum enables significant and meaningful body fat reductions with relative preservation of muscle mass. This trial is registered with NCT02906072, ClinicalTrials.gov.

Low back pain in physically active young adults

Background: Research of low back pain (LBP) has been recently directed towards the younger age groups due to high predictive value for later life. The aim of the study was to assess the prevalence and risk factors for LBP in the Slovene population of young adults, which are yet unknown. Methods: In this cross sectional study firstgrade students at the Faculty of Sport (FS) and the Faculty of Chemistry (FC), University of Ljubljana, in 2009 were included. The Slovene translation of Chronic Pain Grade questionnaire was implemented. In the FS subgroup the associations between questionnaire results and results of the entrance examination were analyzed and a follow-up questionnaire survey was done after the 1st semester Results: The questionnaire was returned by 283 students. Average age was 19.9 (2.3) years. Lifelong and 6-month LBP prevalences were 87.3 % (83.1–90.9 %) and 63 % (57.4–68.6 %), respectively. Average LBP intensity was 36.6 (16.9) (range 0–90) out of 100 points, average disability was 18 (18.7) (range 0–83) out of 100 points. Females had higher intensity and disability scores. Competitors had higher pain disability scores than students engaging in sports at recreational level. Gender and level of physical activity were significant independent predictors of intensity and disability scores at multivariate linear regression. LBP was not associated with entrance test results and there were no important changes in the follow- up after the 1st semester in the FS students. Conclusions: We found high LBP prevalence, which was of moderate intensity and caused minor disability. LBP was more severe in females and associated with the level of physical activity. Information about LBP and preventive workout programs should be incorporated into study programs.

Association of Uremic Toxins and Inflammatory Markers with Physical Performance in Dialysis Patients

Association of higher serum levels of uremic toxins and inflammatory markers with poorer physical performance is understudied. We measured the six-minute walk test (6MWT), 10 repetition sit-to-stand test (STS-10), handgrip strength (HGS), and Human Activity Profile (HAP) questionnaire score in 90 prevalent hemodialysis patents, with low comorbidity to reduce the potential confounding of concomitant disease. Midweek pre-dialysis serum levels of asymmetric dimethyl-arginine (ADMA), β2-microglobulin (B2M), high-sensitivity C-reactive protein (hs-CRP), indoxyl sulfate (IS), insulin-like growth factor 1 (IGF-1), interleukin 6 (IL-6), myostatin, and urea were analyzed as predictor parameters of physical performance measures in adjusted models. Serum levels of most measured toxins were not significantly related to performance, except for ADMA, which was significantly related to poorer performance in the STS-10 test (B = 0.11 ± 0.03 s, p < 0.01). Higher hs-CRP was associated with poorer results in the 6MWT (B = −2.6 ± 0.97 m, p < 0.01) and a lower HAP score (B = −0.36 ± 0.14, p = 0.01). There were no other significant associations found. We conclude that inflammation may be a more important pathway to physical impediment than uremic toxemia. This suggests that there is a large physical rehabilitation potential in non-inflamed uremic patients.

Relation of Lean Body Mass and Muscle Performance to Serum Creatinine Concentration in Hemodialysis Patients

Introduction Serum creatinine concentration is an important uremic marker and predictor of survival in dialysis patients. This cross-sectional case-control study was made to quantitatively describe the relation between lean body mass (LBM), physical performance measures, and serum creatinine values. Methods Ninety hemodialysis patients and 106 controls were measured by bioimpedance spectroscopy, handgrip strength, sit-to-stand test, and biochemical serum tests. Univariate and multivariate general linear models were used to analyze quantitative relations. Results At univariate regression LBM accounted for 13.6% variability of serum creatinine concentration. In adjusted analyses with age, height, and body mass, LBM persisted as the only significant predictor of midweek predialysis serum creatinine concentration. Physical performance measures handgrip strength and sit-to-stand performance did not improve prediction of serum creatinine. With addition of serum urea concentration and residual diuresis the predictive value of the regression model improved to account for 45% of serum creatinine variability. Each kg of LBM was associated with 7.7 μmol/l increase in creatinine concentration (95% CI 3.4-12.1, p=0.001). Conclusion Bioimpedance derived LBM has a significant linear relation with predialysis serum creatinine concentrations. Hereby described quantitative relation should help clinicians to better evaluate observed creatinine concentrations of hemodialysis patients when bioimpedance derived LBM is available.

Vascular Access Effects on Motor Performance and Anthropometric Indices of Upper Extremities.

A decrement of upper extremity motor performance is a concern with vascular access creation. We analyzed differences in handgrip strength, tapping test and anthropometric indices of arms with and without vascular access (N = 87) and compared them to bilateral differences in control subjects (N = 140). Fistula harboring arms had weaker grip strength than contralateral arms of 2.7 kg and this difference was statistically marginally larger than the difference between non‐dominant and dominant arms in controls of 1.6 kg (mean difference 1.1 kg, P = 0.06). No difference in the magnitude of inferiority of fistula arms compared to control non‐dominant arms was present in the tapping test. Absolute results of both motor tests on any side were significantly worse in dialysis patients. Although weaker and slower, fistula arms showed larger mean upper‐arm and forearm circumferences of 0.4–0.6 cm. Our results show no significant negative effect of arteriovenous access on motor performance of upper extremities.