Exercise prescription based on a population-specific physiological response can help ensure safe and effective physical interventions. However, as a facile approach for exercise prescription in hemodialysis population that is based on their exercise capacity has not yet been established, the aim of our study was to develop a unique prediction formula for peak heart rate (HR) that can be used in this population.

This cross-sectional study measured physical function and HR at peak exercise and anaerobic threshold (AT) during cardiopulmonary exercise tests in 126 individuals. Participants were randomly assigned to the development group (n = 78), whose data were used to calculate the prediction equation, or the validation group (n = 48).

The HR reserve in this population was significantly lower (0.44 ± 0.20%) and there was a large discrepancy between conventional age-predicted maximal HR and measured peak-HR values (R = 0.36). The average of the ratio between HR at AT point and peak HR was 85% (95% CI, 83.5%-86.4%). The peak-HR prediction equation was based on resting HR, presence of diabetes, physical dysfunction (gait speed < 1.0 m/s), and hypoalbuminemia (< 3.5 g/dL). It showed high prediction accuracy (R² [95%CI] = 0.71 [0.70-0.71]) with similar correlation coefficients between the development and validation groups (R = 0.82).

Aerobic exercise based on estimated peak HR < 85% obtained from the equation in this study may enable safe and effective physical intervention in this population.

Small intestinal pathology in hemodialysis (HD) patients has been studied in only a small number of retrospective case series. One method for noninvasively surveying small intestinal disorders is video capsule endoscopy (VCE). The primary aim of this study was to investigate the prevalence of small intestinal abnormalities among asymptomatic maintenance HD outpatients using VCE. The secondary aim was to assess the clinical impact of these abnormalities.

This study consisted of two phases. In phase I, a cross-sectional study, a cohort of patients who received maintenance HD three times weekly at an outpatient hemodialysis clinic were studied using VCE. Phase II was a prospective cohort study with follow up for 1 year after VCE.

Fifty-six patients were enrolled in this study, and two were excluded from analysis due to capsule retention in the stomach. The prevalence of small bowel abnormalities in HD patients was 64.8 % (35/54) (95 % confidential interval 52.1 % - 77.6 %). Of 54 patients, 21 (38.9 %) had mucosal lesions, 10 (18.5 %) had vascular lesions, and 4 (7.4 %) had both lesion types. During the 1-year follow-up period, events occurred in four patients. A small bowel-associated event was observed in one patient, who underwent laparoscopy-assisted small intestinal partial resection 3 months after diagnosis by VCE. All patients in whom events were seen had small bowel abnormalities; no events were observed in the VCE-negative group.

Although asymptomatic maintenance HD patients had a high prevalence of small bowel abnormalities (64.8 %), they did not have a high incidence of small bowel-associated events during the 1-year follow-up.

An association between chronic renal failure (CRF) and gastroesophageal reflux (GER) is well known. The aim of this study was to pharmacologically characterize and investigate the possible contribution of smooth muscle reactivity pathways involving GER on the CRF rat model.

Chronic renal failure was created in Sprague-Dawley rats by 5 of 6 nephrectomy. The rats were divided into 2 groups: the CRF-induced group (CRF group) and the sham-operated group (control group). Esophageal smooth muscle strips were studied in vitro for their contractile (KCl, carbachol) and relaxant (isoproterenol, serotonin, and papaverine) response to receptor activation in the organ chambers set up. Subsequently, the in vitro lower esophageal sphincter (LES) smooth muscle study was generated by KCl, carbachol, isoproterenol, nicotine, sodium nitroprusside (SNP), and papaverine.

Compared with controls, esophageal strips taken from CRF-induced rats associated with decreased smooth muscle responses to carbachol, serotonin, and increased response to KCl. Isoproterenol- and papaverine-induced relaxant responses were not affected. Contractility of the isolated LES strips were significantly increased to KCl and carbachol in the CRF group compared with the control group. Similar relaxant responses were obtained in LES strips stimulated by isoproterenol, SNP, and papaverine in the CRF and control group. Nicotine-induced relaxant responses were decreased in the CRF group compared with the control group.

Our study revealed alterations of receptor-dependent esophageal and LES smooth muscle reactivity in the CRF-induced rats. Impaired foregut smooth muscle reactivity may contribute to the development of GER-related functional abnormalities in patients with CRF.

Neurological complications whether due to the uremic state or its treatment, contribute largely to the morbidity and mortality in patients with renal failure. Despite continuous therapeutic advances, many neurological complications of uremia, like uremic encephalopathy, atherosclerosis, neuropathy and myopathy fail to fully respond to dialysis. Moreover, dialytic therapy or kidney transplantation may even induce neurological complications. Dialysis can directly or indirectly be associated with dialysis dementia, dysequilibrium syndrome, aggravation of atherosclerosis, cerebrovascular accidents due to ultrafiltration-related arterial hypotension, hypertensive encephalopathy, Wernicke's encephalopathy, hemorrhagic stroke, subdural hematoma, osmotic myelinolysis, opportunistic infections, intracranial hypertension and mononeuropathy. Renal transplantation itself can give rise to acute femoral neuropathy, rejection encephalopathy and neuropathy in graft versus host disease. The use of immunosuppressive drugs after renal transplantation can cause encephalopathy, movement disorders, opportunistic infections, neoplasms, myopathy and progression of atherosclerosis. We address the clinical, pathophysiological and therapeutical aspects of both central and peripheral nervous system complications in uremia.

ESRD has well-documented effects on the esophagus, stomach, duodenum, and pancreas. Unless the supply of donor kidneys increases dramatically, these complications of ESRD will continue to be an important clinical issue for gastroenterologists given the large percentage of patients with symptoms. Further study of uremic retention products and abnormal gastrointestinal hormone profiles on the gastrointestinal tract should help provide additional insights into this complex group of patients.