Rachel Bregman

Doença renal crônica: frequente e grave, mas também prevenível e tratável

Chronic kidney disease (CKD) is a public health problem worldwide. In Brazil incidence and prevalence of end stage renal failure are increasing; prognosis is still poor and costs of disease treatment are very high. Regardless of the etiology, main outcomes in patients with CKD are its complications (anemia, metabolic acidosis, malnutrition and alteration in mineral metabolism), death (mainly due to cardiovascular causes) and loss of renal function. Recent studies indicate that these outcomes may be postponed with specific treatment if the CKD is diagnosed early and renoprotective and cardioprotective measures are implemented early in the course of the disease. The current definition and staging of CKD, as well as the discussion of the main preventive measures are addressed in this review.

Can Renal Nutrition Education Improve Adherence to a Low-Protein Diet in Patients With Stages 3 to 5 Chronic Kidney Disease?

OBJECTIVE Low adherence is frequently observed in patients with chronic kidney disease (CKD) who are following a low-protein diet. We have evaluated whether a specific nutrition education program motivates patients with CKD who do not yet receive dialysis to reduce their protein intake and whether such a program improves adherence to a low-protein diet over and above standard dietary counseling. DESIGN AND METHODS This was a randomized controlled clinical trial conducted at the CKD outpatient clinic at Pedro Ernesto University Hospital, Rio de Janeiro, Brazil. SUBJECTS This study included adult patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) who were receiving conservative treatment. Participants had received their first referrals to a renal dietitian. INTERVENTION Patients were randomized to a normal counseling group (individualized dietary program: 0.6 to 0.75 g protein/kg/day or 0.6 to 0.8 g/kg/day for patients with diabetes and 25 to 35 kcal/kg/day with sodium restriction) or an intense counseling group (same dietary program plus nutrition education materials). The nutrition education material included 4 different actions to improve patient knowledge and understanding of the low-protein and low-sodium diet. Both groups were followed by means of individual monthly visits to the outpatient clinic for 4 months. MAIN OUTCOME MEASURE We looked for a change in protein intake from baseline values as well as the adherence rate, assessed as a 20% decrease of the initial protein intake (by 24-hour food recall). RESULTS Eighty-nine patients completed the study (normal counseling n = 46; intense counseling n = 43). The number of patients who adhered to a low-protein diet was high but did not differ between groups (in the last visit 69% vs. 48%; P = .48; intense vs. normal counseling, respectively). The reduction in protein intake from baseline values was greater for the intense counseling group compared with the normal counseling group (at the last visit, -20.7 g/day [-30.9%] vs. -10.5 g/day [-15.1%], intense vs. normal counseling, respectively; P = .04). CONCLUSION An intense nutrition education program contributed to reducing protein intake in patients with stage 3 to 5 CKD over and above our standard dietary counseling. Nutritional education programs are effective in increasing patient adherence to protein intake recommendations.

Body adiposity index assess body fat with high accuracy in nondialyzed chronic kidney disease patients

High body fat (BF) is an alarming condition that also affects nondialyzed chronic kidney disease (CKD) patients. Distinct methods are used to evaluate BF; however, in CKD population it remains unclear which one is more reliable showing high accuracy. Dual‐energy X‐ray absorptiometry (DXA), used as reference method to estimate adiposity, is expensive and time consuming to be applied in clinical settings. Recently, a new body adiposity index (BAI), that estimates BF from easily accessible measures, was validated in the general population. The aim of this study was to evaluate which simple and practical method, routinely used to estimate BF, shows the highest accuracy compared with DXA, in nondialyzed CKD patients.

Annual variation in body fat is associated with systemic inflammation in chronic kidney disease patients Stages 3 and 4: a longitudinal study

BACKGROUND In dialysis patients, cross-sectional studies show that total and abdominal body fat associate with inflammatory markers. Whether this is true in earlier disease stages is unknown. We evaluated the cross-sectional and longitudinal (12-month interval) association between body fat markers and C-reactive protein (CRP) in pre-dialysis chronic kidney disease (CKD) patients. METHODS We studied, over a period of 1 year, clinically stable CKD patients at Stages 3-4 who were under treatment in a single outpatient clinic. Fifty-seven patients were included and 44 concluded the observational period [males: 66%; age: 62.9±13.9 years; body mass index (BMI): 25.5±5.1 kg/m2; estimated glomerular filtration rate (eGFR): 34±12.3 mL/min/1.73 m2]. Total body fat (skinfold thicknesses), waist circumference (WC), laboratory measurements (serum creatinine, total cholesterol, albumin, high-sensitivity CRP and leptin) and food intake (24-h food recall) were assessed at baseline and after 12±2 months. RESULTS Most patients had anthropometric parameters in the range of overweight/obesity and none had signs of protein-energy wasting. In univariate analysis, changes (delta: end-baseline) in CRP were associated (P<0.05) with changes in BMI (r=0.39) and WC (r=0.33). In multiple regression analysis, these associations remained significant (P<0.05) even after adjusted by potential confounders (sex, diabetes, baseline age and eGFR). CONCLUSIONS During a follow-up of 12 months, changes in BMI and WC were directly associated with changes in CRP. Our results support the concept that interventions aimed at reducing weight and/or abdominal adiposity in pre-dialysis CKD patients may also translate into reduced systemic inflammation.

Waist-to-height ratio: An accurate anthropometric index of abdominal adiposity and a predictor of high HOMA-IR values in nondialyzed chronic kidney disease patients

OBJECTIVE Chronic kidney disease (CKD) is associated with metabolic disorders, including insulin resistance (IR), mainly when associated with obesity and characterized by high abdominal adiposity (AbAd). Anthropometric measures are recommended for assessing AbAd in clinical settings, but their accuracies need to be evaluated. The aim of this study was to evaluate the precision of different anthropometric measures of AbAd in patients with CKD. We also sought to determine the AbAd association with high homeostasis model assessment index of insulin resistance (HOMA-IR) values and the cutoff point for AbAd index to predict high HOMA-IR values. METHODS A subset of clinically stable nondialyzed patients with CKD followed at a multidisciplinary outpatient clinic was enrolled in this cross-sectional study. The accuracy of the following anthropometric indices: waist circumference, waist-to-hip ratio, conicity index and waist-to-height ratio (WheiR) to assess AbAd, was evaluated using trunk fat, by dual x-ray absorptiometry (DXA), as a reference method. HOMA-IR was estimated to stratify patients in high and low HOMA-IR groups. The total area under the receiver-operating characteristic curves (AUC-ROC; sensitivity/specificity) was calculated: AbAd with high HOMA-IR values (95% confidence interval [CI]). RESULTS We studied 134 patients (55% males; 54% overweight/obese, body mass index ≥ 25 kg/m(2), age 64.9 ± 12.5 y, estimated glomerular filtration rate 29.0 ± 12.7 mL/min). Among studied AbAd indices, WheiR was the only one to show correlation with DXA trunk fat after adjusting for confounders (P < 0.0001). Thus, WheiR was used to evaluate the association between AbAd with HOMA-IR values (r = 0.47; P < 0.0001). The cutoff point for WheiR as a predictor for high HOMA-IR values was 0.55 (AUC-ROC = 0.69 ± 0.05; 95% CI, 0.60-0.77; sensitivity/specificity, 68.9/61.9). CONCLUSIONS WheiR is recommended as an effective and precise anthropometric index to assess AbAd and to predict high HOMA-IR values in nondialyzed patients with CKD.

Agreement between anthropometry and bioelectrical impedance for measuring body fat in nonobese and obese nondialyzed chronic kidney disease patients.

OBJECTIVES We investigated reproducibility and agreement between anthropometry (ANT) and bioelectrical impedance (BIA) in nonobese and obese nondialyzed chronic kidney disease (CKD) patients, and examined the factors influencing the agreement between these two methods. PATIENTS AND METHODS One hundred and five clinically stable CKD patients, comprising stages 3 and 4 of CKD, had their body fat (BF) assessed by ANT and BIA. Patients were stratified into nonobese (body mass index [BMI] <25 kg/m(2), n = 48, 26 males, aged 64.5 +/- 13.6 years) and overweight/obese (BMI > or =25 kg/m(2), n = 57, 35 males, aged 63.1 +/- 12.1 years; +/-SD in all values) groups. RESULTS In the nonobese group, BF as assessed by ANT was similar to body fat as assessed by BIA (11.4 +/- 3.8 kg vs 11.7 +/- 4.1 kg, respectively, no significance). The concordance correlation coefficient (CCC) was indicative of good reproducibility for males (0.67; 95% confidence interval [CI], 0.41 to 0.83) and females (0.88; 95% CI, 0.71 to 0.95), and the mean inter-method difference between ANT and BIA and limits of agreement were -0.9 (-6.8 to 4.9) kg for males, and 0.4 (-3.4 to 4.3) kg for females. In the overweight/obese group, a weak CCC was observed for males (0.46; 95% CI, 0.26 to 0.62) and females (0.53; 95% CI, 0.29 to 0.70), and the mean inter-method difference between both methods was 5.7 (-3.2 to 14.7) kg for males, and 6.4 (-1.8 to 14.7) kg for females. In the multiple regression analysis (adjusted r(2) = 0.42, n = 105), BMI, sex, body water, and age were independent determinants of the agreement between ANT and BIA. CONCLUSIONS For nonobese patients, ANT and BIA can be applied equally well for assessing BF. For overweight/obese patients a weak agreement was observed. Body mass index, sex, body water, and age were the factors influencing the agreement between ANT and BIA.

Bone disease in patients with chronic kidney disease under conservative management

CONTEXT AND OBJECTIVE Few studies have focused on bone disease in patients with chronic kidney disease under conservative treatment. The objective was to evaluate bone disease in patients with chronic kidney disease. DESIGN AND SETTING Case series, at the Nephrology Division, Hospital Universitário Pedro Ernesto. METHODS 131 patients with creatinine clearance from 10 to 60 ml/min/1.73 m(2) were followed up for at least one year. Serum creatinine, albumin, calcium, phosphorus, alkaline phosphatase, total CO2 (tCO2), intact parathyroid hormone (iPTH), and alkaline phosphatase were measured. Creatinine clearance was calculated from 24-hour urine creatinine measurements and protein ingestion estimates from urea assays. RESULTS Patients presenting creatinine clearance < 30 ml/min/1.73 m(2) had higher iPTH values, but normal serum levels for calcium, phosphorus, alkaline phosphatase and tCO2. Patients presenting iPTH values of twice the normal upper limit (144 pg/ml) showed lower tCO2 values. Bone alkaline phosphatase was evaluated in 37 patients with creatinine clearance < 30 ml/min/1.73 m(2), showing correlation with alkaline phosphatase but not with parathyroid hormone. Bone biopsy on nine patients with creatinine clearance < 30 ml/min/1.73 m(2) and iPTH > 144 pg/ml showed osteitis fibrosa (4), mild lesion (4) and high turnover (1). CONCLUSION The present data suggest the importance of early control for iPTH and metabolic acidosis, among patients under conservative management for chronic kidney disease, in order to prevent complications related to bone disease.

Adiposity and cardiovascular disease risk factors in renal transplant recipients: Are there differences between sexes?

OBJECTIVE The aim of this study was to evaluate high body adiposity and cardiovascular disease (CVD) risk factors prevalence, in renal transplant recipients (RTR), comparing men with women. METHODS In this retrospective cross-sectional study, 102 patients (55 men) who were 49 ± 1.2 y and 114.3 ± 9 mo post-transplant (post-tx) were evaluated. Pretransplant (pre-tx) period data and weight gain during the first year post-tx were obtained from patient charts and post-tx data were collected during a routine visit at nephrology clinic. Body mass index (BMI) ≥ 25 kg/m(2) defined overweight and BMI ≥ 30 kg/m(2) defined obesity. RESULTS Pre-tx overweight prevalence was low and similar between men and women (26%), whereas only women showed obesity (11%). Post-tx body weight increased significantly in the entire group, leading to an increase in overweight (to 38% in men and 51% in women) and obesity (to 11% in men and 23% in women) prevalence. Post-tx comparisons between men and women showed that women had higher (women versus men; P < 0.05) BMI values (26.7 ± 0.8 versus 24.7 ± 0.5 kg/m(2)), weight gain during first year post-tx (9.2 ± 1.1 versus 5.5 ± 1 kg), abdominal obesity (57% versus 23%) and diabetes (34% versus 16%) prevalence. The associations between adiposity and CVD risk factors showed that pre-tx overweight increased the risk for diabetes in post-tx; pos-tx high BMI and abdominal obesity increased the risk for metabolic syndrome; abdominal obesity increased the risk for dyslipidemia in women. CONCLUSIONS High body adiposity prevalence was high after transplantation and increased the risk for metabolic syndrome, an important CVD risk factor. Women showed higher total body adiposity values, abdominal obesity, and diabetes prevalence than men. Abdominal obesity increased the risk for dyslipidemia in women.

Exercise counters diet-induced obesity, proteinuria, and structural kidney alterations in rat.

We studied the effects of exercise training in treating renal impairment due to hypertension and obesity in rats. Diet-induced obese and non-obese Wistar rats were assigned to four groups: Sed-Ob, Ex-Ob, Sed-C, and Ex-C (motor treadmill for 13 weeks; Ex=exercise-trained, C=control, Ob=obese, Sed=sedentary). Creatinine, proteinuria, and kidney structure were evaluated. Sed-C rats had normal and stable blood pressure (BP), while Sed-Ob rats developed hypertension. After 4 weeks of exercise, BP decreased in exercise-trained groups (less than 25% at the end of the experiment in obese rats, and less than 10% in non-obese rats). Both the body mass and retroperitoneal fat mass were lower in the exercise-trained groups than in the sedentary ones. Serum creatinine was not different among the groups, but the urinary protein excretion was significantly higher in the Sed-Ob group than in the matched non-obese group. Compared to the non-obese animals the mean glomerular volume increased by 45% in Sed-Ob rats and by 30% in Ex-Ob rats. Obese animals also showed increased mesangial volume density compared to non-obese animals. The present findings allow us to conclude that the exercise training could be an auxiliary practice to attenuate renal alterations seen in diet-induced obesity.

Periodontal treatment in patients with chronic kidney disease: a pilot study

BACKGROUND AND OBJECTIVE This pilot cohort study evaluated the effect of periodontal treatment on renal function, metabolic markers and asymmetric dimethylarginine (ADMA) in patients with pre-dialysis chronic kidney disease (CKD) presenting chronic periodontitis. MATERIAL AND METHODS Twenty-six patients with CKD and severe chronic periodontitis were selected. Periodontal parameters included plaque index, bleeding on probing, probing pocket depth and clinical attachment level. Estimated glomerular filtration rate (eGFR), triglycerides, total cholesterol, albumin and ADMA levels were evaluated at baseline, 90 and 180 d after periodontal therapy. eGFR was evaluated by the Modification of Diet in Renal Disease equation. RESULTS All periodontal clinical parameters significantly improved (p < 0.05) 180 d after periodontal therapy. There was a significant improvement on the median values (25%; 75% percentiles) of eGFR from 34.6 (27; 44.7) mL/min/1.73 m2 on baseline to 37.6 (29.7; 57) mL/min/1.73 m2 on day 90, and to 37.6 (28.6; 56) mL/min/1.73 m2 (p < 0.05) on day 180. ADMA levels significantly reduced 180 d after periodontal treatment. No significant differences were observed at the median values of metabolic markers comparing baseline and 180 d after periodontal treatment. CONCLUSIONS The results point to a link of kidney disease with endothelium dysfunction and periodontitis, suggesting that periodontal treatment may be beneficial to the course of CKD.