Maria Ayako Kamimura

Waist Circumference and Visceral Fat in CKD: A Cross-sectional Study

BACKGROUND In the general population, waist circumference was noted to be a reliable predictor of visceral fat. In addition, increased waist circumference was strongly associated with risk factors for cardiovascular disease. In patients with chronic kidney disease (CKD), the association of waist circumference with visceral fat was never tested. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 122 patients with CKD not yet on dialysis therapy (75 men; diabetes mellitus, 30%; age, 55.3 +/- 11.3 years; body mass index, 27.1 +/- 5.2 kg/m(2); estimated glomerular filtration rate, 35.4 +/- 15.2 mL/min/1.73 m(2)) were studied. PREDICTOR Waist circumference. OUTCOMES & MEASUREMENTS Anthropometry, abdominal visceral fat measured by means of computed tomography, and cardiovascular disease risk factors. RESULTS Waist circumference strongly correlated with visceral fat (r = 0.75 for men, r = 0.81 for women; P < 0.01). kappa Statistic was 0.56, indicating relatively good agreement between methods. Body mass index showed a lower correlation coefficient (r = 0.68 for men, r = 0.76 for women; P < 0.01) and poor agreement (0.36) with visceral fat in comparison to waist circumference. In men, waist circumference and visceral fat similarly correlated with high-density lipoprotein cholesterol level, triacylglycerol level, and Homeostasis Model Assessment Index (P < 0.05). In women, waist circumference correlated with age, C-reactive protein level, and Homeostasis Model Assessment Index, whereas visceral fat also correlated with low-density lipoprotein cholesterol and triacylglycerol levels (P < 0.05). LIMITATIONS Findings are restricted to patients with CKD not yet on dialysis therapy from a single center. CONCLUSIONS Waist circumference was strongly associated with visceral fat in patients with CKD. Associations between waist circumference and cardiovascular disease risk factors were similar to those observed for visceral fat, particularly in men. These findings suggest that waist circumference may be a simple and inexpensive tool to be used in epidemiological studies.

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.

Increased Resting Energy Expenditure in Hemodialysis Patients with Severe Hyperparathyroidism

Several metabolic derangements, including enhanced protein catabolism, have been suggested to be associated with increased circulating parathyroid hormone (PTH) in patients with secondary hyperparathyroidism (HPT). Such conditions, therefore, might lead to an increase in energy expenditure. The present study examined by indirect calorimetry the resting energy expenditure (REE) of 15 hemodialysis patients who have severe HPT (PTH = 1457 +/- 676 pg/ml) and were pair-matched for age and gender to 15 hemodialysis patients with mild to moderate HPT (PTH = 247 +/- 196 pg/ml). Both groups were also pair-matched for age and gender to a group of 15 healthy adult subjects (control). In six patients from the severe HPT group submitted to total parathyroidectomy, REE was determined 6 mo after the surgery. The groups were not different regarding lean body mass (LBM) measured by bioelectric impedance, serum C-reactive protein, and bicarbonate. Thyroid-stimulating hormone was within the normal range in all groups. Nonadjusted REE was significantly higher in the severe HPT group (1674 +/- 337 kcal/d) compared with patients with mild to moderate HPT (1388 +/- 229 kcal/d; P < 0.05). Both groups did not differ from the control group (1468 +/- 323 kcal/d). When adjustment of REE for LBM was performed using the multiple regression analysis, patients with mild to moderate HPT and control subjects had significantly lower REE (-231 and -262 kcal, respectively) than that of the severe HPT group. Considering all patients together, nonadjusted REE correlated directly with LBM (r = 0.61; P < 0.01). PTH correlated strongly with LBM in the severe HPT group (r = -0.82; P < 0.01). In the multiple linear regression analysis, only LBM and PTH were independent determinants of REE (n = 30; R(2) = 0.47). REE decreased significantly in the six patients who were evaluated 6 mo after parathyroidectomy (from 1617 +/- 339 to 1226 +/- 253; P = 0.02). These results demonstrate that hemodialysis patients with severe HPT have increased REE that might be reduced after parathyroidectomy.

Sarcopenia in chronic kidney disease on conservative therapy: prevalence and association with mortality

BACKGROUND In chronic kidney disease (CKD), multiple metabolic and nutritional abnormalities contribute to the impairment of skeletal muscle mass and function thus predisposing patients to the condition of sarcopenia. Herein, we investigated the prevalence and mortality predictive power of sarcopenia, defined by three different methods, in non-dialysis-dependent (NDD) CKD patients. METHODS We evaluated 287 NDD-CKD patients in stages 3-5 [59.9 ± 10.5 years; 62% men; 49% diabetics; glomerular filtration rate (GFR) 25.0 ± 15.8 mL/min/1.73 m(2)]. Sarcopenia was defined as reduced muscle function assessed by handgrip strength (HGS <30th percentile of a population-based reference adjusted for sex and age) plus diminished muscle mass assessed by three different methods: (i) midarm muscle circumference (MAMC) <90% of reference value (A), (ii) muscle wasting by subjective global assessment (B) and (iii) reduced skeletal muscle mass index (<10.76 kg/m² men; <6.76 kg/m² women) estimated by bioelectrical impedance analysis (BIA) (C). Patients were followed for up to 40 months for all-cause mortality, and there was no loss of follow-up. RESULTS The prevalence of sarcopenia was 9.8% (A), 9.4% (B) and 5.9% (C). The kappa agreement between the methods were 0.69 (A versus B), 0.49 (A versus C) and 0.46 (B versus C). During follow-up, 51 patients (18%) died, and the frequency of sarcopenia was significantly higher among non-survivors. In crude Cox analysis, sarcopenia diagnosed by the three methods was associated with a higher hazard for mortality; however, only sarcopenia diagnosed by method C remained as a predictor of mortality after multivariate adjustment. CONCLUSIONS The prevalence of sarcopenia in CKD patients on conservative therapy varies according to the method applied. Sarcopenia defined as reduced handgrip strength and low skeletal muscle mass index estimated by BIA was an independent predictor of mortality in these patients.

Albumina sérica como marcador nutricional de pacientes em hemodiálise

A prevalencia de desnutricao proteico-energetico em pacientes com insuficiencia renal cronica submetidos a terapia de hemodialise e elevada. Dentre os diversos parâmetros disponiveis para a avaliacao do estado nutricional, a albumina tem sido o mais comumente utilizado para este fim visto a sua estreita associacao com a morbidade e mortalidade nesta populacao. No entanto, varios fatores como idade, comorbidades, hipervolemia e perdas corporeas podem influenciar as concentracoes sericas de albumina. Alem disso, na vigencia de inflamacao, condicao comumente presente neste grupo de pacientes, o metabolismo da albumina pode encontrar-se alterado, influenciando os seus niveis plasmaticos. Sendo assim, esta comunicacao tem como objetivo abordar os aspectos gerais da albumina e discutir a sua utilizacao na avaliacao do estado nutricional de pacientes com insuficiencia renal cronica submetidos a hemodialise.

Resting energy expenditure and its determinants in hemodialysis patients

Objective:Chronic kidney disease is associated with several metabolic disturbances that can affect energy metabolism. As resting energy expenditure (REE) is scarcely investigated in patients on hemodialysis (HD) therapy, we aimed to evaluate the REE and its determinants in HD patients.Design:Cross-sectional study.Setting:Dialysis Unit of the Nephrology Division, Federal University of São Paulo, Brazil.Subjects:The study included 55 patients (28 male, 41.4±12.6 years old) undergoing HD therapy thrice weekly for at least 2 months, and 55 healthy individuals pair matched for age and gender. Subjects underwent fasting blood tests, as well as nutritional assessment, and the REE was assessed by indirect calorimetry.Results:REE of HD patients was similar to that of pair-matched controls (1379±272 and 1440±259 kcal/day, respectively), even when adjusted for fat-free mass (P=0.24). REE of HD patients correlated positively with fat-free mass (r=0.74; P<0.001) and body mass index (r=0.37; P<0.01), and negatively with dialysis adequacy (r=−0.46; P<0.001). No significant univariate correlation was found between REE and age, dialysis vintage, serum creatinine, urea, albumin, bicarbonate, parathyroid hormone (PTH) or high-sensitivity C-reactive protein (CRP). In the multiple linear regression analysis, using REE as dependent variable, the final model showed that besides the well-recognized determinants of REE such as fat-free mass and age, PTH and CRP were the independent determinants of REE in HD patients (R 2=0.64).Conclusions:In this study, the REE of HD patients was similar to that of healthy individuals, even with the positive effect of secondary hyperparathyroidism and inflammation on REE of these patients.Sponsorship:The study was supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Oswaldo Ramos Foundation.

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.

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.

Visceral obesity assessed by computed tomography predicts cardiovascular events in chronic kidney disease patients

BACKGROUND AND AIM Cardiovascular disease is the leading cause of death among patients with chronic kidney disease (CKD). Although there is emerging evidence that excess visceral fat is associated with a cluster of cardiometabolic abnormalities in these patients, the impact of visceral obesity evaluated by a gold-standard method on future outcomes has not been studied. We aimed to investigate whether visceral obesity assessed by computed tomography was able to predict cardiovascular events in CKD patients. METHODS AND RESULTS We studied 113 nondialyzed CKD patients [60% men; 31% diabetics; age 55.3 ± 11.3 years; body mass index (BMI) 27.2 ± 5.3 kg/m(2); estimated glomerular filtration rate (GFR) 33.7 ± 13.6 ml/min/1.73 m(2)]. Visceral and subcutaneous abdominal fat were assessed by computed tomography at L4-L5. Visceral to subcutaneous fat ratio >0.55 (highest tertile cut-off) was defined as visceral obesity. Cardiovascular events including acute myocardial infarction, angina, arrhythmia, uncontrolled blood pressure, stroke and cardiac failure were recorded during 24 months. Cardiovascular events were 3-fold higher in patients with visceral obesity than in those without visceral obesity. The Kaplan-Meier analysis indicated that patients with visceral obesity had shorter cardiovascular event-free time than those without visceral obesity (P = 0.021). In the univariate Cox analysis, visceral obesity was associated with higher risk of cardiovascular events (hazard ratio = 3.4; 95% confidence interval = 1.1-10.5; P = 0.03). The prognostic power of visceral obesity for cardiovascular events remained significant after adjustments for sex, age, diabetes, previous cardiovascular disease, smoking, sedentary lifestyle, BMI, GFR, hypertension, dyslipidemia and inflammation. CONCLUSION Visceral obesity assessed by computed tomography was a predictor of cardiovascular events in CKD patients.

Prospective Evaluation of Waist Circumference and Visceral Adipose Tissue in Patients with Chronic Kidney Disease

Background: Waist circumference (WC), a simple anthropometric measure, is associated with visceral adipose tissue (VAT) in cross-sectional studies, and thus has been used as a surrogate marker for VAT. However, associations between changes over time in WC and VAT have not been studied in chronic kidney disease (CKD) patients. Methods: This prospective study included 87 nondialysis-dependent CKD patients (54 males, 56.2 ± 10.4 years, BMI 27.3 ± 5.1, GFR 35.9 ± 14.6 ml/min/1.73 m2). VAT area was measured by computed tomography (CT) and WC was measured at the umbilicus level at baseline and after 12 months. Results: Changes in WC correlated significantly but weakly with changes in VAT (r = 0.26, p = 0.016), likely due to a substantially smaller change in WC compared to changes in VAT. This was also reflected by a kappa coefficient of 0.26, i.e. indicative of poor agreement between WC and CT measurements in regards to quantification of changes in VAT. Likewise, the receiver operating characteristic curve analysis identified WC as poor predictor of changes in VAT (area under the curve = 0.62). Conclusion: Anthropometric measurement of WC is poorly correlated with changes in VAT measured by CT in nondialysis-dependent CKD patients. Therefore, caution should be taken when using WC as a surrogate marker of VAT changes in this population.