Flavia Baria

Physical activity and energy expenditure in haemodialysis patients: an international survey

BACKGROUND The assessment of physical activity and energy expenditure is relevant to the care of maintenance haemodialysis (MHD) patients. In the current study, we aimed to evaluate measurements of physical activity and energy expenditure in MHD patients from different centres and countries and explored the predictors of physical activity in these patients. METHODS In this cross-sectional multicentre study, 134 MHD patients from four countries (France, Switzerland, Sweden and Brazil) were included. The physical activity was evaluated for 5.0 ± 1.4 days (mean ± SD) by a multisensory device (SenseWear Armband) and comprised the assessment of number of steps per day, activity-related energy expenditure (activity-related EE) and physical activity level (PAL). RESULTS The number of steps per day, activity-related EE and PAL from the MHD patients were compatible with a sedentary lifestyle. In addition, all parameters were significantly lower in dialysis days when compared to non-dialysis days (P < 0.001). The multivariate regression analysis revealed that diabetes and higher body mass index (BMI) predicted a lower PAL and older age and diabetes predicted a reduced number of steps. CONCLUSIONS The physical activity parameters of MHD patients were compatible with a sedentary lifestyle. This inactivity was worsened by aging, diabetes and higher BMI. Our results indicate that MHD patients should be encouraged by the health care team to increase their physical activity.

Randomized controlled trial to evaluate the impact of aerobic exercise on visceral fat in overweight chronic kidney disease patients

BACKGROUND The prevalence of obesity has markedly increased in patients with chronic kidney disease (CKD). Studies on the impact of exercise focusing on obese CKD patients are scarce. Therefore, we aimed to investigate the effect of aerobic exercise performed either in an exercise centre or at home on visceral fat in overweight non-dialysed CKD patients. METHODS Twenty-seven sedentary men (52.1 ± 9.5 years, body mass index 30.4 ± 3.8 kg/m(2), estimated glomerular filtration rate (eGFR) 27.5 ± 11.6 mL/min) were randomly assigned to a centre-based exercise group (n = 10), home-based exercise group (n = 8) or control group (n = 9). The aerobic training was prescribed according to ventilatory threshold and performed three times per week during 12 weeks. Body composition was assessed by dual energy X-ray absorptiometry (DEXA) and the distribution of abdominal fat by computed tomography. RESULTS In the centre-based group, visceral fat and waist circumference decreased 6.4 ± 6.4 mm (P < 0.01) and 2.0 ± 2.3 cm (P = 0.03) and leg lean mass increased 0.5 ± 0.4 kg (P < 0.01). No significant changes were observed in the home-based group. Visceral fat increased 5.0 ± 4.4 mm in the control group (P = 0.01). In relation to the control, a group-by-time interaction was significant for visceral fat and waist circumference for both exercise groups and for leg lean mass for the centre-based group. Mean blood pressure decreased in both exercise groups (centre-based 13%, P < 0.01 and home-based 10%, P = 0.03) and eGFR increased 3.6 ± 4.6 mL/min (P = 0.03) in the centre-based group. These parameters remained unchanged in the control group. CONCLUSIONS Centre-based aerobic exercise is an effective approach to reduce visceral fat besides promoting relevant clinical benefits in male overweight CKD patients.

Are prediction equations reliable for estimating resting energy expenditure in chronic kidney disease patients

BACKGROUND The determination of resting energy expenditure (REE) is the primary step for estimating the energy requirement of an individual. Although numerous equations have been formulated for predicting metabolic rates, there is a lack of studies addressing the reliability of those equations in chronic kidney disease (CKD). Thus, the aim of this study was to evaluate whether the main equations developed for estimating REE can be reliably applied for CKD patients. METHODS A total of 281 CKD patients (124 non-dialysis, 99 haemodialysis and 58 peritoneal dialysis) and 81 healthy control individuals were recruited. Indirect calorimetry and blood sample collection were performed after a 12-h fasting. Two most traditionally used equations for estimating REE were chosen for comparison with the REE measured by indirect calorimetry: (i) the equation proposed by Harris and Benedict, and (ii) the equation proposed by Schofield that is currently recommended by the FAO/WHO/UNU. RESULTS Schofields equation exhibited higher REE [1492±220 kcal/day (mean±SD)] in relation to Harris and Benedicts equation (1431±214 kcal/day; P<0.001), and both prediction equations showed higher REE in comparison with the reference indirect calorimetry (1352±252 kcal/day; P<0.001). In patients with diabetes, inflammation or severe hyperparathyroidism, the REE estimated by the Harris and Benedict equation was equivalent to that measured by indirect calorimetry. The intraclass correlation of the REE measured by indirect calorimetry with the Schofields equation was r=0.48 (P<0.001) and with the Harris and Benedicts equation was r=0.58 (P<0.001). According to the Bland and Altman analysis, there was a large limit of agreement between both prediction equations and the reference method. Acceptable prediction of REE (90-110% adequacy) was found in 47% of the patients by using the Harris and Benedicts equation and in only 37% by using the Schofields equation. CONCLUSIONS The most traditionally used prediction equations overestimated the REE of CKD patients, and the errors were minimized in the presence of comorbidities. There is a need to develop population-specific equations in order to adequately estimate the energy requirement of these patients.

Activity-related Energy Expenditure of Patients Undergoing Hemodialysis

OBJECTIVES The aim of this study was to evaluate the activity-related energy expenditure (AEE) of patients undergoing hemodialysis (HD) and to compare it with that of healthy controls. DESIGN This was a cross-sectional study. SETTING This was an in-center study conducted at the Dialysis Unit, Nephrology Division, Federal University of São Paulo-Oswaldo Ramos Foundation, Brazil. PATIENTS AND METHODS AEE was evaluated in 32 patients undergoing HD (20 men, aged: 46.3 ± 12.2 years). A subgroup consisting of 22 patients was pair-matched by gender and age with 22 sedentary, healthy individuals. AEE was measured over a period of 5 days using a portable physical activity monitor. Body fat and lean body mass were assessed by dual energy X-ray absorptiometry and body cell mass by bioelectrical impedance analysis. RESULTS AEE correlated positively with lean body mass and body cell mass, and negatively with age, body fat, and body mass index. From the multiple regression analysis, it was found that age and lean body mass (r(2) = 0.32) or body cell mass (r(2) = 0.30) were the best among the variables that explained variations in AEE. AEE of HD patients in comparison with healthy controls was found to be lower on dialysis days (234 [9.5 to 1,145] kcal/day vs. 565 [214 to 1,319] kcal/day, median [range]; P < .01) as well as on nondialysis days (369 [89.5 to 1,242] kcal/day vs. 565 [214 to 1,319] kcal/day; P = .02). Total energy expenditure of the HD patients on dialysis days (2,051 ± 289 kcal/day) as well as nondialysis days (2,202 ± 283 kcal/day) was also found to be lower in comparison with controls (2,514 ± 307 kcal/day; P < .01). The average contribution of the AEE toward total energy expenditure in HD patients was 15%, whereas in controls it was 24% (P = .03). CONCLUSION As compared with sedentary, healthy individuals, AEE was reported to be considerably lower in HD patients.

Impact of training at ventilatory threshold on cardiopulmonary and functional capacity in overweight patients with chronic kidney disease

INTRODUCTION Chronic kidney disease (CKD) and obesity are both associated with reduced physical capacity. The potential benefit of aerobic training on physical capacity has been recognized. The exercise intensity can be established using different methods mostly subjective or indirect. Ventilatory threshold (VT) is a direct and objective method that allows prescribing exercise intensity according to individual capacity. OBJECTIVES To evaluate the impact of aerobic training at VT intensity on cardiopulmonary and functional capacities in CKD patients with excess of body weight. METHODS Ten CKD patients (eight men, 49.7 ± 10.1 years; BMI 30.4 ± 3.5 kg/m², creatinine clearance 39.4 ± 9.8 mL/min/1.73 m²) underwent training on a treadmill three times per week during 12 weeks. Cardiopulmonary capacity (ergoespirometry), functional capacity and clinical parameters were evaluated. RESULTS At the end of 12 weeks, VO2PEAK increased by 20%, and the speed at VO2PEAK increased by 16%. The training resulted in improvement in functional capacity tests, such as six-minute walk test (9.2%), two-minute step test (20.3%), arm curl test (16.3%), sit and stand test (35.7%), and time up and go test (15.3%). In addition, a decrease in systolic and diastolic blood pressures was observed despite no change in body weight, sodium intake and antihypertensive medication. CONCLUSION Aerobic exercise performed at VT intensity improved cardipulmonary and functional capacities of overweight CKD patients. Additional benefit on blood pressure was observed. These results suggest that VT can be effectively applied for prescribing exercise intensity in this particular group of patients.