Influence of dietary protein intake on body composition in chronic kidney disease patients in stages 3-5: A cross-sectional study.

INTRODUCTION: A controlled protein intake has shown beneficial effects to preserve renal function and nutritional status in chronic kidney disease (CKD) patients. This study aimed to analyze usual dietary protein intake and its potential contribution to body composition in CKD patients in stages 3-5. METHOD: Cross-sectional study in 134 CKD patients in stages 3-5 (mean e-GFR: 19.4±8.7ml/min/1.73m2; males 68.7% and primary CKD etiology was diabetes mellitus, 35.8%). Demographic, clinical and nutritional parameters were evaluated. Normalized protein nitrogen appearance (nPNA), was used as a surrogate marker of dietary protein intake. The sample was classified into three nPNA groups (Gn): G1: <0.8g/kg/day; G2: 0.8-1g/kg/day and, G3: ≥1g/kg/day. Assessment of nutritional status using the malnutrition-inflammation score (MIS), anthropometric measures and laboratory parameters. Analysis of body composition and hydration status by bioelectrical impedance analysis (BIVA-101-RJL system). Statistical analysis by SPSS v.20. RESULTS: Overall mean nPNA values were 0.91±0.23g of protein/kg BW/day and only 32.1% had a dietary protein intake <0.8g of protein/kg BW/day. Most of the CKD patients (65.5%) were in stages 4 or 5. Prevalence of protein-energy-wasting (PEW) syndrome measured by MIS was 15%. By analyzing differences between nPNA groups, body weight (BW), BMI and triceps-skinfold (TSF) thickness were significantly higher in the group with nPNA ≥1g/kg BW/day (G3), whereas a significant inverse relationship was found with the percentages of body cell mass (BCM%), fat-free mass (FFM%), muscle mass (MM%) and phase angle (PA) in the group with the lowest nPNA (G1). Analysis of gender among subjects showed significant differences with BW, FFM%, TSF and mid-arm muscle circumference (MAMC%). Linear regression analysis showed that resistance, BCM%, MM%, and serum albumin were significant predictors of nPNA as a surrogate marker of daily protein intake (R=0.51; R2=0.29; R2 adjusted=0.23; p<0.001). CONCLUSION: Controlled protein intake is one of the cornerstones of treatment in CKD patients. A low protein intake in patients with CKD stages 3 and 4-5 was associated with loss of muscle mass in the advanced-CKD unit. The loss of muscle mass appears as an early indicator of nutritional comprised. Factors such, elderly age and loss of eGFR, showed lower protein intake and were associated with muscle loss, especially in women. Further longitudinal studies are required to evaluate the contribution of different protein intakes to uremic symptoms, nutritional status, body composition and CKD progression.

Re-Paying Attention to Visitor Behavior: A Re-Analysis using Meta-Analytic Techniques.

The present study describes a meta-analytic review of museum visitors' behavior. Although there is a large number of visitor studies available, their cumulative importance has not been determined due to the lack of rigorous methods to determine common causes of visitors' behaviors. We analyzed Serrell's (1998) database of 110 studies, defining a number of variables that measure visitors' behaviors in exhibition spaces which exceeded the most typical and obvious ones. We defined four indexes of effect size and obtained their combined estimates: average time per feature [ATF● = 0.43 (0.49; 0.37)], percentage of diligent visitors [dv● = 30% (0.39; 0.23)], inverse of velocity [Iv● = 4.07 min/100m2 (4.55; 3.59)], and stops per feature [SF● = 0.35 (0.38; 0.33)], and we analyzed the role of relevant moderating variables. Key findings indicate, for example, that the visiting time for each display element relates to the size of the exhibition and its newness, and visitor walking speed is higher in large exhibit areas. The indexes obtained in this study can be understood as references to be used for comparison with new evaluations. They may help to predict people's behavior and appreciation of new exhibitions, identifying important problems in museum designs, and providing new research tools for this field.