Home-based versus center-based aerobic exercise on cardiopulmonary performance, physical function, quality of life and quality of sleep of overweight patients with chronic kidney disease.

BACKGROUND: The association between chronic kidney disease (CKD) and obesity can decrease the patients' cardiopulmonary capacity, physical functioning and quality of life. The search for effective and practical alternative methods of exercise to engage patients in training programs is of great importance. Therefore, we aimed to compare the effects of home-based versus center-based aerobic exercise on the cardiopulmonary and functional capacities, quality of life and quality of sleep of overweight non-dialysis-dependent patients with CKD (NDD-CKD). METHODS: Forty sedentary overweight patients CKD stages 3 and 4 were randomly assigned to an exercise group [home-based group (n = 12) or center-based exercise group (n = 13)] or to a control group (n = 15) that did not perform any exercise. Cardiopulmonary exercise test, functional capacity tests, quality of life, quality of sleep and clinical parameters were assessed at baseline, 12 and 24 weeks. RESULTS: The VO2peak and all cardiopulmonary parameters evaluated were similarly improved (p < 0.05) after 12 and 24 weeks in both exercise groups. The functional capacity tests improved during the follow-up in the home-based group (p < 0.05) and reached values similar to those obtained in the center-based group. The benefits achieved in both exercise groups were also reflected in improvement of quality of life and sleep (p < 0.05). No differences were observed between the exercise groups, and no changes in any of the parameters investigated were found in the control group. CONCLUSION: Home-based aerobic training was as effective as center-based training in improving the physical and functional capabilities, quality of life and sleep in overweight NDD-CKD patients.

Association of Sarcopenia With Nutritional Parameters, Quality of Life, Hospitalization, and Mortality Rates of Elderly Patients on Hemodialysis.

OBJECTIVE: This study aimed to assess whether diminished muscle mass, diminished muscle strength, or both conditions (sarcopenia) are associated with worse nutritional status, poor quality of life (QoL), and hard outcomes, such as hospitalization and mortality, in elderly patients on maintenance hemodialysis (MHD). DESIGN AND SUBJECTS: This is a multicenter observational longitudinal study that included 170 patients on MHD (age 70 ± 7 years, 65% male) from 6 dialysis centers. MAIN OUTCOME MEASURE: The European Working Group on Sarcopenia in Older People defines sarcopenia as the presence of both low muscle mass by appendicular skeletal + low muscle function by handgrip strength. This study evaluated the clinical and nutritional status (laboratory, anthropometry, dual-energy X-ray absorptiometry, 7-point subjective global assessment) and QoL (Kidney Disease Quality of Life) at baseline. Hospitalization and mortality were recorded during 36 months. RESULTS: Reduced muscle mass was observed in 64% of the patients, reduced muscle strength in 52%, and sarcopenia in 37%. The group with sarcopenia was older, had a higher proportion of men and showed worse clinical and nutritional conditions when compared with patients without sarcopenia. Although reduced muscle mass was strongly associated with poor nutritional status, low muscle strength was associated with worse QoL domains. In the multivariate Cox analyses adjusted by age, gender, dialysis vintage, and diabetes mellitus, low muscle strength alone and sarcopenia were associated with higher hospitalization, and sarcopenia was a predictor of mortality. CONCLUSION: In conclusion, in this sample, comprised of elderly patients on MHD, sarcopenia was associated with worse nutritional and clinical conditions and was a predictor of hospitalization and mortality.

A practical approach to dietary interventions for nondialysis-dependent CKD patients: the experience of a reference nephrology center in Brazil.

This paper describes the 30-year experience on nutritional management of non-dialysis dependent chronic kidney disease (CKD) patients in a public outpatient clinic located in the city of São Paulo, Brazil. A team of specialized dietitians in renal nutrition is responsible to provide individual dietary counseling for patients on stages 3 to 5 of CKD. Two different types of nutrition care protocols are employed depending on the level of renal function. For patients with CKD stage 3 a simplified nutritional assessment is performed and the main dietary focus is on the control of protein intake particularly from animal sources. A more complete nutritional assessment as well as a detailed dietary plan focusing not only on the control of protein but also on energy supply and on specific micronutrients is provided for patients on stages 4 or 5 of CKD. Practical approaches and tools used by the dietitians in our clinic for improving patient´s adherence to protein, sodium and potassium restriction while maintaining a healthy diet are described in detail in the sections of the article.

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.

Subjective global assessment for the diagnosis of protein-energy wasting in nondialysis-dependent chronic kidney disease patients.

OBJECTIVES: Subjective global assessment (SGA) has been demonstrated to be a reliable method for protein-energy wasting (PEW) evaluation in chronic kidney disease (CKD) patients on dialysis. Few data are available on PEW evaluation in nondialysis stages of CKD, and the validity of SGA has been scarcely investigated in this population. Herein, we aimed to evaluate in nondialysis-dependent CKD patients (NDD-CKD): (1) the prevalence of PEW by SGA; (2) the most common abnormalities of the SGA components; and (3) the agreement of SGA with the traditional anthropometric parameters. DESIGN AND SUBJECTS: This is a retrospective cross-sectional study including 922 NDD-CKD patients referred to the renal dietitians in the period of 2001 to 2012. Nutritional status was assessed by 7-point SGA. Body mass index (BMI), midarm circumference, midarm muscle circumference, and triceps skinfold thickness were available from 494 patients. RESULTS: From the 922 patients, 58.6% were men, mean age was 63.8 ± 13.6 years, BMI was 27.7 ± 5.3 kg/m(2). The majority of the patients were in CKD Stages 3 (48.9%) or 4 (40.3%). PEW (SGA ≤5) was present in 11% of the patients and 32% had signs of PEW (SGA 6). In the logistic regression analysis, the presence of comorbidities and worse renal function were independently associated with PEW. Among the SGA components, the most frequent abnormality in patients with PEW was muscle and fat wasting (88.6%). BMI, midarm circumference, midarm muscle circumference, and triceps skinfold thickness were lower across the worse SGA scores, and a moderate to good level of agreement was found between the anthropometric parameters and presence of PEW evaluated by SGA. CONCLUSIONS: The prevalence of PEW was 11% in our unselected cohort of NDD-CKD patients. The physical examination component (muscle/fat wasting) was the most frequent alteration found in those patients. When compared with anthropometric parameters, 7-point SGA has shown to be a valid tool to assess PEW in NDD-CKD population.

Usefulness of waist circumference as a marker of abdominal adiposity in peritoneal dialysis: a cross-sectional and prospective analysis.

BACKGROUND: Waist circumference (WC) has been well recognized as a surrogate marker of abdominal adiposity. In peritoneal dialysis (PD) patients, however, aspects related to this dialysis modality, such as abdominal distension, presence of catheter and frequent hernia, raise questions regarding the reliability of WC measurements. Herein, we investigated for the first time whether WC is a reliable marker of abdominal adiposity in PD population. METHODS: This study included 107 prevalent PD patients [56% male, age 52 ± 17 years, 35% diabetics, body mass index (BMI) 24.8 ± 3.9 kg/m(2)]. WC measured at umbilicus level was evaluated against the trunk fat assessed by dual-energy x-ray absorptiometry at baseline and after 6 months. All measurements were taken with the empty abdominal cavity. RESULTS: At baseline, a strong correlation of WC with trunk fat (r = 0.81; P < 0.001) was observed. Adjusting for gender, age, dialysis vintage and BMI, WC was independently associated with trunk fat (ß = 0.30; P < 0.001; R(2) = 0.77). The agreement between WC and trunk fat was 0.59 (kappa statistic) and the area under the curve was 0.90. In the prospective evaluation, we observed that changes in WC correlated with changes in trunk fat as well (r = 0.49; P < 0.001). The kappa statistic of 0.48 remained indicative of a moderate agreement between the methods. The receiver operating characteristic curve analysis showed that WC was sensitive to detect changes in trunk fat (area under the curve 0.76). In the logistic regression analysis adjusting for gender, age and BMI, changes in WC were independently associated with changes in trunk fat. CONCLUSION: The simple anthropometric method of WC is a reliable marker of abdominal adiposity in PD patients.

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.

Cholecalciferol supplementation in chronic kidney disease: restoration of vitamin D status and impact on parathyroid hormone.

BACKGROUND/AIMS: Hypovitaminosis D is highly prevalent among patients with chronic kidney disease (CKD) and has been associated with poor outcome. We aimed to test the effect of a protocol of cholecalciferol supplementation on the restoration of vitamin D status and on parathyroid hormone (PTH) levels in patients with CKD. METHODS: This was a prospective interventional study of 6 months. Forty-five CKD patients (stages 3 and 4) with 25-hydroxyvitamin D deficiency [25(OH)D <15 ng/ml] were included. Patients received a weekly dose of 50,000 IU of cholecalciferol during 3 months, and 50,000 IU/month thereafter for those who had achieved 25(OH)D ≥30 ng/ml. RESULTS: At 3 months, 78% of the patients restored their vitamin D status. At 6 months, only 43% of those patients maintained adequate vitamin D status. PTH decreased at 3 months (p = 0.02) but returned to baseline levels after 6 months. Fibroblast growth factor 23 increased at 3 months (p = 0.001) and returned to initial levels at 6 months. No changes were found in serum 1,25(OH)(2)D, ionized calcium and phosphorus. CONCLUSIONS: A weekly dose of 50,000 IU of cholecalciferol for 3 months restored the vitamin D status of most patients and led to a reduction in PTH. The monthly dose of 50,000 IU appears not to be sufficient to maintain the levels of 25(OH)D.

Risk factors for hypovitaminosis D in nondialyzed chronic kidney disease patients.

BACKGROUND: Hypovitaminosis D is highly prevalent among patients with chronic kidney disease and has been associated with worse outcome even in the earlier stages of the disease. OBJECTIVE: This study aimed to investigate the risk factors for hypovitaminosis D in nondialyzed patients with chronic kidney disease. DESIGN: This cross-sectional study included 120 patients with chronic kidney disease at stages 2 to 5 (62% male, age: 55.4 ± 11.3 year, estimated glomerular filtration rate: 35.1 ± 15 mL/minute, body mass index [BMI]: 27.1 ± 5.2 kg/m(2), 31% diabetics). Serum 25-hydroxivitamin D [25(OH)D] was measured by chemiluminescence. Subjective global assessment, total body fat (dual-energy X-ray absorptiometry), visceral and subcutaneous abdominal fat (computed tomography), and several laboratory parameters were assessed. RESULTS: Insufficiency of 25(OH)D (15 to 30 ng/mL) was observed in 55% and deficiency (<15 ng/mL) in 20% of the patients. Patients with diabetes, BMI ≥30 kg/m(2), and who had the blood collection during the winter or spring had lower levels of 25(OH)D. Serum 25(OH)D correlated inversely with parathyroid hormone, proteinuria, insulin resistance, leptin, and subcutaneous abdominal fat. The risk factors for hypovitaminosis D were diabetes (odds ratio: 3.8; 95% CI: 1.2 to 11.7; P = .022) and BMI ≥30 kg/m(2) (odds ratio: 4.3; 95% CI: 1.2 to 15.3; P = .018). In the logistic regression analysis adjusting for gender, skin color, and season of the year, diabetes and BMI ≥30 kg/m(2) were independently associated with hypovitaminosis D. CONCLUSIONS: Diabetes and obesity were the risk factors for hypovitaminosis D in nondialyzed patients with chronic kidney disease. Effective interventional protocols of vitamin D supplementation taking into account these risk factors are warranted for this population.

Energy expenditure in chronic kidney disease patients.

OBJECTIVE: The assessment of energy expenditure in patients with chronic kidney disease (CKD) is a subject that has started to be investigated in the past 3 decades. This review will focus on studies that have assessed the energy expenditure of CKD predialysis and dialysis patients. Till date, most studies on this subject have focused on the assessment of resting energy expenditure (REE). In this regard, the current published data have demonstrated that clinically stable nondialysed CKD patients have REE similar or slightly lower than that of age- and gender-matched healthy individuals. For dialyzed patients, in both hemodialysis and peritoneal dialysis, the results are indicative that the REE of these patients is similar to that of age- and gender-matched healthy controls. The investigation of REE in specific catabolic conditions, such as poorly controlled diabetes, hyperparathyroidism, and inflammation, has shown that the REE in these catabolic conditions is increased. Additionally, it has also been reported that the hemodialysis procedure per se is also capable of enhancing the energy expenditure. The energy expenditure for physical activity is also an important component of energy expenditure and has been scarcely investigated in patients with CKD. The few studies that have investigated energy expenditure for physical activity have shown values lower than that of healthy sedentary individuals. CONCLUSION: These results are highly suggestive that patients with CKD have a sedentary lifestyle. The effect of the present knowledge of energy expenditure on the energy requirements of the patients with CKD remains to be investigated in studies using gold standard methods for this purpose.

Vitamin D biology: from the discovery to its significance in chronic kidney disease.

Vitamin D was discovered and had its chemical structure described in the early years of the last century. Although classified as a nutrient because it was found in small quantities in butter, it soon became clear that exposure of skin to sunlight, supplies most of the vitamin D necessary for good health in human beings. Vitamin D (D3 or cholecalciferol) synthesis in the skin is extremely rapid and remarkably robust despite the complexity of the mechanisms involved. However, a number of factors related to latitude location, season, and skin characteristics can interfere with the photoproduction of vitamin D. The 2 forms of vitamin D (D3 or D2-ergocalciferol) are biologically inactive and require activation in the liver and kidney. The product of the first hydroxylation of vitamin D in the liver, 25-hydroxyvitamin D (25(OH)D), is the marker of vitamin D status. Hypovitaminosis D (serum 25(OH)D, <30 ng/mL) is highly prevalent in the general population, and patients with chronic kidney disease seem to be at higher risk for the development of hypovitaminosis D. It is believed that, besides the traditional factors, protein losses, gastrointestinal malabsorption, and defective skin synthesis of vitamin D might contribute to the elevated number of patients with suboptimal level of vitamin D status.

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.

Underreporting of energy intake in peritoneal dialysis patients.

OBJECTIVES: This study aimed to assess the prevalence of underreporting among patients treated by peritoneal dialysis (PD), and to investigate whether the reported energy intake is influenced by overweight status in this population. DESIGN: This was a prospective, observational study. SETTING: This study took place at the Dialysis Unit of the Nephrology Division, Federal University of São Paulo-Oswaldo Ramos Foundation, São Paulo, Brazil. PATIENTS: Forty adult patients were recruited: 24 men and 16 women; age, 53.4+/-16.5 years; body mass index (BMI), 25.1+/-3.8 kg/m(2) (x+/-SD); median duration of dialysis, 19 months (range, 3 to 101 months). Only patients on PD >3 months, free of peritonitis for at least 3 months, without catabolic conditions and with normal thyroid function, were included. METHODS: Energy intake was evaluated using a 3-day food record. Resting energy expenditure (REE) was measured by indirect calorimetry. Body composition was assessed using dual-energy x-ray absorptiometry. The total energy (TE) offered was considered the sum of energy intake plus energy provided by glucose absorption. All measurements were collected at baseline and after 6 months. Underreporting of energy intake was considered to have occurred when the TE/REE ratio was <1.40. RESULTS: The TE/REE ratio was 1.35+/-0.31. Twenty-one patients (52.5%) had a TE/REE ratio <1.40. The TE/REE ratio correlated negatively with BMI (r=-0.52, P < .01), and positively with duration of dialysis (r=0.44, P < .01). No correlation was found between TE/REE ratio and any other variables. Patients were divided into two groups according to BMI <25 kg/m(2) and BMI > or =25 kg/m(2). The majority of patients (83.3%) in the higher BMI group had a TE/REE ratio <1.40. In a logistic regression analysis, using TE/REE ratio <1.40 or > or =1.40 as the dependent variable, BMI> or =25 kg/m2 was the only determinant of energy underreporting. After 6 months of follow-up, no change in either body weight or BMI was evident. CONCLUSIONS: This study showed that a significant number of PD patients underreported the energy intake evaluated by 3-day food diaries. This finding was evidenced particularly in overweight patients.

Muscle mass assessment by computed tomography in chronic kidney disease patients: agreement with surrogate methods.

BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) are subjected to muscle wasting. Therefore, it is important to investigate surrogate methods that enable the assessment of muscle mass loss in the clinical setting. We aimed to analyze the agreement between computed tomography (CT) and surrogate methods for the assessment of muscle mass in non-dialysis CKD patients. SUBJECTS/METHODS: Cross-sectional study including 233 non-dialysis patients on CKD stages 3 to 5 (61 ± 11 years; 64% men; glomerular filtration rate 22 (14-33) mL/min/1.73 m2). The muscle mass was evaluated by CT and bioelectrical impedance, skinfold thicknesses, midarm muscle circumference (MAMC), the predictive equations of Janssen and Baumgartner and the physical examination of muscle atrophy from the subjective global assessment. RESULTS: In males, the MAMC showed the best agreement with CT as indicated by the kappa test (k = 0.57, P < 0.01), sensitivity (S = 68%), specificity (S = 89%) and accuracy (area under the curve-AUC = 0.78), followed by the Baumgartner equation (kappa = 0.46, P < 0.01; sensitivity = 60%; specificity = 87% and AUC = 0.73). In female, the Baumgartner equation showed the best agreement with CT (kappa = 0.43, P < 0.01; sensitivity = 57%; specificity = 86% and AUC = 0.71). CONCLUSIONS: The MAMC and Baumgartner equation showed the best agreement with CT for the assessment of muscle mass in non-dialysis CKD patients.

Estimating resting energy expenditure of patients on dialysis: Development and validation of a predictive equation.

OBJECTIVES: The aims of this study were to develop and validate a resting energy expenditure (REE) predictive equation in a cohort of patients on dialysis and to test the accuracy of two previously developed specific equations to estimate REE of these patients. METHODS: A database with REE measured by indirect calorimetry (IC) of 189 patients on hemodialysis and peritoneal dialysis was used to develop and validate the new equation. The sample including only patients on hemodialysis (n = 131) was used to test the accuracy of the specific REE dialysis equations by Vilar and Byham-Gray. RESULTS: Multiple regression analysis generated two equations: REE (kcal/d) = 957.02 - 8.08 × age + 11.07 × body weight + 136.4 (if men) (R2 = 0.515) (1) REE (kcal/d) = 624.6-4.8 × age + 20.6 × fat-free, ass-fat-free mass-8.65 (if men) (R2 = 0.512) (2) In the validation group, REE by both equations did not differ from the REE measured by IC. No bias was found in the Bland-Altman analysis and the intraclass correlation coefficient and P20 test showed good reliability with measured REE. Vilar's equation overestimated REE; whereas REE generated by Byham-Gray's equation did not differ from measured REE. Proportional and systematic biases were significant for both equations. CONCLUSIONS: The new equations developed showed good accuracy and can be valuable to estimate energy needs of patients on dialysis. Byham-Gray's and Vilar's equations presented low to moderate performance to estimate REE of the patients on dialysis.

Is UCP2 gene polymorphism associated with decreased resting energy expenditure in nondialyzed chronic kidney disease patients?

OBJECTIVE: The deletion/deletion (del/del) polymorphism of uncoupling protein 2 (UCP2) was associated with decreased energy expenditure in diabetic and obese patients. There is evidence of decreased resting energy expenditure (REE) in chronic kidney disease (CKD) patients not yet on dialysis. However, whether REE is associated with the UCP2 polymorphism was not previously investigated in this population. This study evaluated whether the del/del polymorphism of the UCP2 gene is associated with lower REE in nondialyzed CKD patients. DESIGN: This was a cross-sectional study. PATIENTS AND METHODS: Forty-four nondialyzed CKD patients (29 male; aged 52 +/- 12 years; creatinine clearance, 37 +/- 13 mL/min/1.73 m(2) [values are mean +/- SD unless otherwise noted]) were included. Their REE was assessed by indirect calorimetry, and body composition by bioelectrical impedance. High-sensitivity C-reactive protein (hs-CRP) was also evaluated. The insertion/deletion (ins/del) polymorphism of the UCP2 gene was determined in all participants. To test whether the deletion/deletion (del/del) polymorphism of the UCP2 gene was associated with lower REE, the REE of carriers of the del/del genotype (n = 24; group Del) was compared with that of carriers of the insertion and ins/del genotype (n = 20; group Ins). MAIN OUTCOME MEASURE: The main outcome measure was REE. RESULTS: The REE of group Del was similar to that of the group Ins (1379 +/- 239 kcal/day vs. 1360 +/- 289 kcal/day, respectively, P = NS). This result was maintained even after the REE was adjusted for lean body mass by analysis of covariance. In addition, in a multiple-regression analysis using REE as the dependent variable, only lean body mass and hs-CRP were significant predictors of REE. CONCLUSION: The results suggest that the del/del polymorphism of the UCP2 gene is not associated with lower REE in nondialyzed CKD patients.

Factors associated with body-fat changes in prevalent peritoneal dialysis patients.

BACKGROUND: Changes in body fat (BF) were shown to occur over time in peritoneal dialysis (PD) patients. However, the factors associated with BF changes have not been fully investigated in this population. METHODS: We studied 45 patients (25 were male; age, 53, SD +/- 15 years; 21 continuous ambulatory peritoneal dialysis/24 automated peritoneal dialysis; PD vintage, 14 ([range, 3 to 104] months; 40% were diabetic; 31% were previously treated by hemodialysis). Body composition was assessed by dual-energy X-ray absorptiometry and bioelectric impedance analysis, nutritional status was assessed by subjective global assessment, energy intake was assessed by 3-day food records, and resting energy expenditure (REE) was assessed by indirect calorimetry. Glucose absorption, serum bicarbonate, and C-reactive protein were also evaluated. All measurements were performed at baseline and after 12 months. RESULTS: Large variability in BF changes was observed among patients: 53% gained BF (+3.0 +/- 2.8), whereas 47% lost BF (-2.3, SD +/- 1.4). At baseline, groups were similar regarding sex, age, percent diabetics, DP modality, characteristics of peritoneal transport, residual renal function, energy intake, glucose absorption, and REE. However, patients who gained BF had lower BF (16.3, SD +/- 6.9 kg, versus 20.9, SD +/- 6.5 kg; P = .03), had a higher ratio of total energy offered (intake plus absorbed glucose) to REE (1.45, SD +/- 0.39, versus 1.26, SD +/- 0.24; P = .04), and were on PD for a shorter time (10 [range, 3 to 104] versus 20 [range, 4 to 76] months; P = .03). This group also had a higher proportion of malnourished patients (50% versus 19%; P = .03) and of patients previously treated by hemodialysis (46% versus 14%; P = .03). After 12 months, a reduction in the frequency of malnutrition (50% to 25%; P = .02) was observed in the group of patients with increased BF. Patients who lost BF reduced their body cell mass (from 21.7 [SD +/- 5.1 kg] to 20.7 [SD +/- 5.0 kg]; P < .01) and level of serum bicarbonate (from 22.7 [SD +/- 3.7 mmol/L] to 20.9 [SD +/- 3.1 mmol/L]; P < .01). Moreover, this group had an increase in frequency of malnutrition (from 19% to 38%; P = .02), a reduction in the proportion of patients with residual renal function (from 62% to 43%; P = .03), and a higher number of hospitalizations (from 25% to 4%; P = .02) during follow-up. Glucose absorption and C-reactive protein were not associated with BF changes. A regression analysis showed that baseline body mass index was independently associated with a gain of BF (-0.19, SE = 0.09, P = .04), and that hospitalization during follow-up was associated with a loss of BF (2.35, SE = 1.19, P = .04). CONCLUSIONS: Prevalent PD patients exhibited a large variability in BF changes. Baseline body mass index and hospitalizations during follow-up were the most important factors associated with these changes.

Nutritional parameters and mortality in incident hemodialysis patients.

OBJECTIVE: To evaluate the impact of nutritional parameters at the time of initiation of hemodialysis (HD) on mortality. DESIGN: Retrospective study. SETTING: Dialysis Unit of the Federal University of Sao Paulo, Oswaldo Ramos Foundation. PATIENTS: Three hundred forty-four incident HD patients (60.5% male, 26% diabetic) with the first nutritional evaluation performed before completing 3 months of onset of HD were included. METHODS: The study consisted of baseline measurements of several nutritional parameters (triceps skinfold thickness [TSF], midarm muscle circumference [MAMC], body mass index [BMI], serum albumin, serum creatinine, and protein and energy intake assessed by 3-day food diary) and records of outcome (death) over a period of 10 years. RESULTS: Muscle and/or fat depletion was observed in 51% of the studied patients, according to the percent standard of MAMC and TSF, respectively. Presence of diabetes, age over 60 years, serum albumin < 3.5 g/dL, MAMC adequacy < 90%, protein intake < 1.0 g/kg/d, and energy intake < 25 kcal/kg/d were associated with worse survival. When patients were analyzed according to tertiles of dialysis vintage, BMI > or = 25 (calculated as kg/m2) had a negative impact on survival only in the highest tertile (> 2.45 years). Patients with BMI < 25 and MAMC adequacy > or = 90% showed the best survival over the study period, and those with BMI > or = 25 but MAMC adequacy < 90% had the worst survival (P = .004). In the multivariate survival analysis adjusting for diabetes, advanced age, and hypoalbuminemia, the reduced MAMC (P = .008) and the low energy intake (P = .03) were independent predictors of death in incident HD patients. CONCLUSIONS: Reduced MAMC and low energy intake at the beginning of chronic dialysis are risk factors for mortality. A negative effect of high BMI on survival was associated with reduced MAMC and longer dialysis vintage.

Effect of cholecalciferol on vitamin D-regulatory proteins in monocytes and on inflammatory markers in dialysis patients: A randomized controlled trial.

BACKGROUND & AIMS: Hypovitaminosis D and inflammation are highly prevalent among patients undergoing dialysis, and the association of both conditions with worse survival has been well recognized. Although a potential role for vitamin D in the immune system has been suggested, the effect of the treatment of hypovitaminosis D on the modulation of the inflammatory response remains unclear. The aim of this study was to investigate the effect of the restoration of the vitamin D status on the expression of vitamin D-regulatory proteins in monocytes and on circulating inflammatory markers in dialysis patients. METHODS: In this randomized double-blind placebo-controlled 12-week trial, 38 patients on dialysis with serum 25-hydroxyvitamin D [25(OH)D] <20 ng/mL were randomized either to the cholecalciferol group (n = 20; 50,000 IU of cholecalciferol twice weekly) or to the control group (n = 18; 50 drops of a placebo solution twice weekly). The expression of vitamin D receptor (VDR), CYP27B1, CYP24A1 and interleukin-6 (IL-6) in monocytes was determined by flow cytometry. Serum concentrations of 25(OH)D, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were measured. The trial is registered at ClinicalTrials.gov #NCT01974245. RESULTS: After 12 weeks, the serum 25(OH)D increased from 14.3 ± 4.7 ng/mL to 43.1 ± 11.0 ng/mL (p < 0.05) in the cholecalciferol group and did not change in the control group (13.9 ± 4.2 ng/mL to 13.5 ± 4.3 ng/mL; p = 0.56). In monocytes, while CYP27B1 expression and VDR expression increased in the cholecalciferol group (p < 0.05), CYP27B1 expression did not change, and VDR expression decreased in the control group (p < 0.05). There were no changes in IL-6 and CYP24A1 expression in both groups. Serum concentration of IL-6 and CRP decreased from 8.1 ± 6.6 pg/mL to 4.6 ± 4.1 pg/mL (p < 0.05) and from 0.50 (0.10-1.27) mg/dL to 0.28 (0.09-0.62) mg/dL (p < 0.05), respectively only in the cholecalciferol group. Assessed overtime, the treatment group differences in 25(OH) D, PTH, CRP and IL-6, CYP27B1 and VDR remained significant. CONCLUSIONS: Restoration of vitamin D status of patients undergoing dialysis promoted upregulation of CYP27B1 and VDR expression in monocytes and a decrease in circulating inflammatory markers.

Is energy intake underestimated in nondialyzed chronic kidney disease patients?

OBJECTIVE: To evaluate whether energy intake of nondialyzed chronic kidney disease (CKD) patients is underestimated. DESIGN: Cross-sectional study. SETTING: Outpatient clinic of the Federal University of Sao Paulo, Oswaldo Ramos Foundation. PATIENTS: One hundred and thirty-one nondialyzed CKD patients (86 male, 66%; body mass index [BMI] 26 +/- 4.21, mean +/- standard deviation) were included. Body weight change was evaluated after 6 to 12 months in 59 patients of the entire group. METHODS: Energy intake was evaluated using 4-day food diaries (3 weekdays and 1 weekend day), and resting energy expenditure (REE) was measured by indirect calorimetry. The ratio of energy intake to REE (EI/REE) was used to evaluate the accuracy of the recorded energy intake. An EI/REE ratio below 1.27 was used to identify patients who were underreporting their current energy intake. RESULTS: The majority of the patients reported an energy intake substantially below the recommendation (22.4 +/- 7.15 kcal/kg/d) and had an EI/REE ratio lower than 1.27. In patients with a BMI >or= 25, the mean EI/REE ratio was significantly lower than that of patients with a BMI < 25 (1.01 +/- 0.28 versus 1.27 +/- 0.42, P < .01, respectively). In addition, only in the group with higher BMI was the mean ratio indicative of underreporting. When the body weight of a subgroup of patients (n = 59) was evaluated after 7.9 +/- 2.4 months, it was observed that the subgroup of patients who maintained or gained body weight had a mean EI/REE not compatible with this condition (1.13 +/- 0.38). The low ratio, despite increasing or maintaining body weight, is highly suggestive of underreported energy intake. CONCLUSION: Energy intake of nondialyzed CKD patients seemed to be underestimated and was more pronounced in overweight and obese patients.