Association between exercise training in haemodialysis patients and burden of their family caregivers: A cross-sectional study.

AIM: Considering that exercise programmes are related with a range of benefits for end-stage renal disease patients, we evaluated the association between haemodialysis (HD) patients' involvement in intradialytic exercise training with the burden of their family caregivers. METHODS: In this cross-sectional study, 60 caregivers of HD patients were recruited, 30 of them who cared for patients that regularly participated in an exercise programme during dialysis sessions and 30 caregivers who looked after patients undergoing usual HD treatment without intradialytic exercise. The caregivers were submitted to the Caregiver Burden Scale (CBS) and their quality of life (short-form-36 (SF-36)), anxiety and depression levels were assessed. Data were expressed as mean ± SD or median (interquartile range). RESULTS: Multiple linear regression showed that the global CBS score was significantly associated with the exercise training after adjusting for age, educational level and anxiety level of caregivers, and dependency level of patients measured by the Lawton scale (coefficient of determination = 0.53; adjusted coefficient of determination = 0.48). Additionally, the caregivers of HD patients submitted to intradialytic exercise (42.0 ± 12.9 years, 33.3% male) compared to caregivers of patients undergoing usual treatment (50.7 ± 17.5 years, 26.7% male) exhibited less caregiver burden (global CBS score = 1.2 (0.2) vs 1.9 (0.7), P < 0.001), better quality of life (physical component score = 53.7 (9.6) vs 49.7 (16.2) and mental component score = 50.6 (17.5) vs 28.2 (32.5), P < 0.05) and lower anxiety (7.2 ± 4.2 vs 10.8 ± 4.1, P = 0.001) and depression levels (3.0 (3.3) vs 6.0 (5.3), P = 0.034), respectively. CONCLUSIONS: Intradialytic exercise training in HD patients was associated with lower burden of their family caregivers.

Uremic Cardiomyopathy: A New Piece in the Chronic Kidney Disease-Mineral and Bone Disorder Puzzle.

Cardiovascular diseases are the main cause of death in chronic kidney disease (CKD) patients. In dialysis patients, sudden cardiac death accounts for 40% of all deaths. In these patients, sudden cardiac death is usually secondary to an underlying cardiomyopathy, which is clinically identified by the high prevalence of left ventricular hypertrophy and the resultant mechanical and electrical dysfunction. CKD-related cardiomyopathy has a multifactorial pathophysiology. Recent evidence has highlighted the central pathophysiological role of chronic kidney disease-mineral and bone disorder (CKD-MBD) with hyperphosphatemia and high fibroblast growth factor 23 (FGF23) levels in these patients. Further, since CKD is known to be an αKlotho deficiency state, experimental studies have demonstrated that the deleterious effects of FGF23 can be minimized by reestablishing adequate soluble Klotho levels. Herein, we present a review that addresses not only the development of the understanding of CKD-related cardiomyopathy pathophysiology, but also explores the recent data that identify the triad of hyperphosphatemia, high FGF23 levels and αKlotho deficiency as playing a central role on it. Taken together, the data suggest that the uremic cardiomyopathy can be considered a new piece in the CKD-DMO puzzle.

Intra-dialytic training accelerates oxygen uptake kinetics in hemodialysis patients.

BACKGROUND: End-stage renal disease is associated with several hemodynamic and peripheral muscle abnormalities that could slow the rate of change in oxygen uptake ([Formula: see text]O2) at the onset and at the end of exercise. This study was performed to determine whether an intra-dialytic aerobic training program would speed [Formula: see text]O2 kinetics at the transition to and from moderate and high-intensity exercise. DESIGN: This study was a randomized controlled trial. METHODS: Twenty-four patients with end-stage renal disease (14 females; 47.0 ± 11.9 years) were randomly assigned to either 12-week cycle ergometer-based training at moderate exertion or a similar control period. At initial and final evaluations, patients underwent 6 min moderate and high-intensity tests to exercise intolerance (Tlim). RESULTS: Training improved Tlim by ∼90% (median (inter-quartile range) = 232 (59) s to 445 (451) s, p < 0.05); in contrast, Tlim decreased by ∼30% in controls (291 (134) s to 202 (131) s). [Formula: see text]O2 kinetics at the onset of moderate-intensity exercise were significantly accelerated with training leading to lower oxygen (O2) deficit (mean ± standard deviation (SD) = 3.2 ± 1.3 l vs 2.3 ± 1.2 l). Similar positive effects were found at the high-intensity test either at the onset of, or recovery from, exercise (p < 0.05). "Excess" [Formula: see text]O2 at the high-intensity test was also lessened with training. Changes in Tlim correlated with faster [Formula: see text]O2 kinetics and lower "excess" [Formula: see text]O2 (Spearman's ρ = -0.56 and -0.75, respectively; p < 0.01). CONCLUSIONS: A symptom-targeted intra-dialytic training program improved sub-maximal aerobic metabolism and endurance exercise capacity. [Formula: see text]O2 kinetics are valuable in providing relatively effort-independent information on the efficacy of exercise interventions in this patient population.

Constant work-rate test to assess the effects of intradialytic aerobic training in mildly impaired patients with end-stage renal disease: a randomized controlled trial.

OBJECTIVE: To investigate if high-intensity constant work rate (CWR) would constitute a more appropriate testing strategy compared with incremental work rate (IWR) to assess the effectiveness of intradialytic aerobic training in patients with end-stage renal disease (ESRD). DESIGN: Randomized controlled trial. SETTING: Nephrology unit at the university hospital. PARTICIPANTS: Patients (N=28; 47.0±11.9y) under hemodialysis (4.4±4.3y) were randomly assigned to exercise and control groups. INTERVENTION: Patients included in the exercise group underwent a moderate-intensity intradialytic aerobic training program 3 times per week for 12 weeks. MAIN OUTCOME MEASURES: Cardiopulmonary and perceptual responses were obtained during an IWR and a high-intensity CWR test to the limit of tolerance on a cycle ergometer. RESULTS: Training-induced increases in peak oxygen uptake (Vo(2)peak) and time to exercise intolerance (Tlim). Mean improvement in Tlim (97.4%±75.6%) was significantly higher than increases in Vo(2)peak (12%±11.3%) (P<.01); in fact, while Tlim improved 50% to 200% in 9 of 12 patients, Vo(2)peak increases were typically in the 15% to 20% range. CWR test revealed lower metabolic, ventilatory, cardiovascular, and subjective stresses at isotime; in contrast, submaximal responses during the incremental work rate (at the gas exchange threshold) remained unaltered after training. CONCLUSIONS: A laboratory-based measure of endurance exercise capacity (high-intensity CWR test to Tlim) was substantially more sensitive than oxygen uptake at the peak IWR test to unravel the physiologic benefits of an intradialytic aerobic training program in mildly impaired patients with ESRD.

Aldosterone antagonism attenuates obesity-induced hypertension and glomerular hyperfiltration.

This study examined the importance of aldosterone (ALDO) in mediating changes in renal function and increased mean arterial pressure (MAP) during the development of dietary-induced obesity in chronically instrumented dogs. Mean arterial pressure, heart rate (HR), and cardiac output (CO) were recorded 24 hours per day in lean dogs (n=7) before and after administration of an ALDO antagonist, eplerenone (EP) (10 mg/kg twice daily), for 10 days. After 10 days of EP treatment, the dogs (n=7) were given a supplement of cooked beef fat for 5 weeks while EP was continued. An untreated group (n=6) was fed a high fat diet for 5 weeks and used as control (C). In lean dogs, EP decreased MAP from 89+/-4 to 84+/-4 mm Hg and glomerular filtration rate from 67.4+/-6.8 to 53.2+/-4.9 mL/min while inducing a small negative Na+ balance (-42+/-12 mEq). Plasma renin activity increased from 0.4+/-0.1 to 2.7+/-0.7 ng AI/mL per hour and plasma K+ increased from 4.8+/-0.1 to 6.1+/-0.3 mEq/L. After 5 weeks of a high fat diet, body weight increased 45% to 53% in EP and C obese dogs. In C dogs, MAP increased by 16+/-3 mm Hg, compared with only 7+/-1 mm Hg in EPLE dogs. Compared with untreated dogs, the EP dogs had smaller increases in CO (18+/-4.6% versus 43+/-1.5%), HR (33+/-5% versus 60+/-3%), glomerular filtration rate (19+/-5% versus 38+/-6%), and cumulative Na+ balance (138+/-35 mEq versus 472+/-110 mEq) after 5 weeks of a high fat diet. Thus, EP markedly attenuated glomerular hyperfiltration, sodium retention, and hypertension associated with chronic dietary-induced obesity. These observations indicate that ALDO plays an important role in the pathogenesis of obesity hypertension.

Obesity-associated hypertension and kidney disease.

PURPOSE OF REVIEW: The worldwide prevalence of obesity and its associated metabolic and cardiovascular disorders has risen dramatically during the past two decades. Our objective is to review the mechanisms that link obesity with hypertension and altered kidney function. RECENT FINDINGS: Current evidence suggests that excess weight gain may be responsible for 65-75% of the risk for essential hypertension. Abnormal renal pressure natriuresis, due initially to increased renal tubular sodium reabsorption, is a key factor linking obesity with hypertension. Obesity increases renal sodium reabsorption by activating the renin-angiotensin and sympathetic nervous systems, and by altering intrarenal physical forces. Adipose tissue functions as an endocrine organ, secreting hormones/cytokines (e.g. leptin) that may activate the sympathetic nervous system and alter kidney function. Excess visceral adipose tissue may physically compress the kidneys, increasing intrarenal pressures and tubular reabsorption. Sustained obesity eventually causes structural changes in the kidneys and loss of nephron function, further increasing arterial pressure and leading to severe renal disease in some cases. SUMMARY: Despite considerable progress in understanding the pathophysiology of obesity, there are still no specific guidelines for the treatment of obesity hypertension other than weight reduction. Special considerations for obese hypertensive patients, in addition to controlling blood pressure, are correcting the metabolic abnormalities and protecting the kidneys from injury. This remains an important area for further research, especially in view of the current 'epidemic' of obesity in most industrialized countries.

Avaliaçäo da eficácia, segurança e tolerabilidade do maleato de enalapril versus nifedipina no tratamento da hipertensäo arterial essencial leve e moderada / Assesment of efficacy, safety, and tolerability of enalapril maleate versus nifedipine in the therapy of mild and moderate essential hypertension

Foram estudados 30 pacientes com hipertensäo arterial essencial leve ou moderada (pressäo diastólica supina > ou = 90 mmHg e < ou = 114 mmHg), com idades médias de 55 anos, sendo três do sexo masculino. O estudo foi aberto, cruzado, comparativo e randomizado, com duraçäo de 16 semanas. O período inicial de palcebo constou de duas semanas e, durante as primeiras seis semanas, o grupo I recebeu enalapril em dose única diária de 20 a 40 mg e o grupo II nifedipina retard 40 a 80 mg diários, com titulaçöes sempre que näo houvesse controle pressórico. Ao final deste período, todos os pacientes voltaram a receber placebo por mais duas semanas e, independentemente da resposta pressórica obtida na primeira fase, passavam a receber por mais seis semanas o outro tratamento. Houve controle da pressäo arterial, freqüência do pulso radial e do peso corporal a cada duas semanas. A queda tensional observada na PAM foi significativa e de magnitude similar, tanto na posiçäo supina quanto na ortostática, com as duas drogas (grupo enalapril de 120 ñ 6,9 mmHg para 112 ñ 13,3 mmHg - p < 0,05 e o grupo nifedipina retard de 122 ñ 8,7 mmHg para 110 ñ 7,8 mmHg - p < 0,05. Dos 30 pacientes estudados, todos concluíram a fase de enalapril e 24 a fase de nifedipina retard (seis foram excluídos por manifestarem efeitos colaterais importantes - cefaléia (26,6%), palpitaçäo(23,3%) e rubor facial (20%). Os parâmetros laboratoriais estudados näo mostraam variaçöes significativas. O presente estudo confirma que tanto o enalapril quanto a nifedipina constituem boas opçöes terapêuticas, como monoterapia das formas leves e moderada da hipertensäo arterial