Fluctuations of exercise capacity in patients after kidney transplantation.

INTRODUCTION: The aim of this study was to assess changes in the exercise capacity in subjects with end-stage renal failure undergoing kidney transplantation. MATERIALS AND METHODS: The study group consisted of 16 subjects (9 males and 7 females) of mean age 43.3 +/- 11 years. The control group was composed of 7 healthy subjects (4 males and 3 females) of mean age 43.9 +/- 10 years. The first visit took place at 4-8 weeks after transplantation. Consecutive visits were scheduled for months 4, 10, 16, 24, 36, and 48 thereafter. Heart function was assessed using echocardiography and, an exercise test with analysis of peak oxygen consumption (VO(2)max). Results were correlated with VO(2)max (Pearson). The Mann-Whitney U test was used to compare study and control groups. RESULTS: The results of eligible VO(2)max tests were as follows (medians and ranges): 1 month (n = 15), 19.5 (8.8-27.5) mL/kg/min; 4 months (n = 9), 21.7 (16.0-29.3) mL/kg/min; 10 months (n = 8), 23.3 (13.1-30.0) mL/kg/min; 16 months (n = 9), 26.6 (18.3- 36.0) mL/kg/min; 24 months (n = 9), 22.3 (14.1-35.0) mL/kg/min; 36 months (n = 9) 20.9 (16.4-32.1) mL/kg/min; 48 months (n = 5), 19.7 (17.0-30.9) mL/kg/min; versus 26.8 (26.5-42.5) mL/kg/min in the control group. VO(2)max results achieved by the study group were significantly lower than that in the control group, except for months 16, 24, and 48. VO(2)max was significantly negatively correlated with the following ultrasound parameters: interventricular septum diastolic and systolic diameter, and left ventricle systolic volume. CONCLUSION: The exercise capacity of recipients seemed to be negatively affected by poor blood pressure control, resulting in heart muscle hypertrophy.

Serum 1-84 and 7-84 parathyroid hormone concentrations and bone in patients with primary hyperparathyroidism.

BACKGROUND AND AIMS: Parathyroid hormone (PTH) acts on bone as both anabolic and catabolic factor. It includes two fractions: 1-84 (cyclase activating PTH, CAP) which increases bone turnover and serum calcium, and 7-84 (cyclase inactivating PTH, CIP) acting the opposite way. The aim of this study was to establish whether bone mineral density (BMD) and turnover in patients' primary hyperparathyroidism (HPT) are dependent on CAP and CIP concentrations. PATIENTS/METHODS: Thirty-one patients with HPT and 29 appropriately matched controls were examined. Parameters of calcium-phosphate homeostasis and BMD were estimated. RESULTS: BMD of radius shaft was lower in patients with HPT as compared with controls, whereas BMD of spine and ultradistal radius were similar. Serum calcium, bone alkaline phosphatase, total PTH, 1-84 PTH, and 7-84 PTH were higher in HPT patients, whereas serum phosphate was lower and beta cross-laps similar. Both total PTH and CAP correlated significantly with BMD of radius shaft and serum calcium concentration, but not with other examined parameters. CONCLUSION: Total and 1-84 PTH are similarly associated with examined parameters in patients with HPT. Thus, determination of serum CAP concentration does not seem to have advantages over total PTH with regard to bone mineral density and bone turnover assessment in those patients.

Plasma immunoreactive leptin and neuropeptide Y levels in kidney transplant patients.

UNLABELLED: Leptin and neuropeptide Y (NPY) seem to play an important role in food intake and energy expenditure. Leptin is secreted by adipose tissue in proportion fo fat stores and is presumed to be an important anorectic hormone. NPY is produced by the hypothalamus, and in contrast to leptin, is one of the most potent appetite stimulants yet demonstrated. On the other hand, in most patients increased appetite is present after successful kidney transplantation. Finally, a stimulatory effect of glucocorticoids on leptin secretion was reported. The present study aimed to assess the relationship between plasma leptin and NPY levels and body mass index (BMI) in haemodialyzed patients (HDP) with chronic renal failure and in kidney transplant patients (KTP). In both groups, BMI was of the same magnitude as in healthy controls. Despite the presence of a normal BMI, leptin levels in KTP (25.2 +/- 3.6 ng/ml) and in HDP with chronic renal failure (25.3 +/- 4.2 ng/ml) were higher than in controls (11.7 +/- 1.8 ng/ml). The mean plasma NPY level in KTP (168.0 +/- 10.3 pg/ml) was significantly higher (p < 0. 01) than in controls (70.7 +/- 5.9 pg/ml) and in HDP (77.0 +/- 5.7 pg/ml). In all examined groups, a significant positive correlation was found between leptinaemia and BMI. CONCLUSIONS: (1) KTP are characterized by significantly elevated leptinaemia in spite of a normal BMI. In KTP this increased leptinaemia does not seem to be dependent only upon the fat mass and the kind and dosis of immunosuppressive therapy. (2) Similarly to healthy subjects, female KTP and HDP show markedly higher leptinaemia than males. (3) In contrast to healthy subjects and HDP, KTP are characterized by significantly elevated plasma NPY levels.

Pathophysiological role of leptin in patients with chronic renal failure, in kidney transplant patients, in patients with essential hypertension, and in pregnant women with preeclampsia.

This paper is a summary of results obtained in our studies on leptinemia in patients with chronic renal failure treated with recombinant human erythropoietin (rHuEPO), in kidney transplant patients, in patients with essential hypertension, and in pregnant women with preeclampsia. In this study, we found that rHuEPO treatment has a suppressive effect on leptinemia in patients with endstage renal failure. These results suggest that the appetite stimulating effect of rHuEPO may be mediated by a reduction of leptin synthesis and release. At the early stage of successful kidney transplantation, a significant decline of leptinemia was noticed, which was not related either to the excretory function of the graft or the kind and dose of immunosuppressants. In kidney transplant patients with grafts functioning well for 2.5 years, significantly elevated leptinemia was found. From these results, we may conclude that factors other than the excretory function of the graft and the kind and dosage of immunosuppressants may be involved in the pathogenesis of abnormal leptinemia in these patients. Both in normotensive subjects and patients with essential hypertension, a positive correlation was found between leptinemia and mean blood pressure, suggesting that leptin may be involved in the regulation of blood pressure. Both healthy and preeclamptic pregnant women show higher leptinemia than nonpregnant women. In preeclamptic women, leptin levels in maternal vein blood, umbilical cord blood, and amniotic fluid were significantly higher than respective values found in healthy pregnant women. In contrast to healthy pregnant and nonpregnant women, in women with preeclampsia, no correlation was found between the body mass index (BMI) and leptinemia. In preeclamptic women the abnormally elevated leptinemia was not related to blood pressure. Finally, no correlation was found between leptinemia in maternal and umbilical cord blood. From these studies, it follows that the elucidation of abnormal leptin secretion in the pathogenesis of preeclampsia needs further study.

Influence of long-term recombinant human erythropoietin (rHuEpo) therapy on plasma leptin and neuropeptide Y concentration in haemodialysed uraemic patients.

BACKGROUND: In patients with chronic renal failure, rHuEpo therapy ameliorates anaemia and improves wellbeing, exercise tolerance, and appetite. Both leptin and neuropeptide Y play an important role in regulation of appetite and energy balance in humans. METHODS: The present study aimed to assess the influence of 12 months rHuEpo therapy on plasma leptin and neuropeptide Y concentrations in 15 haemodialysed patients (HDP) (6F, 9M; mean age 40.8+/-2.9 years; mean BMI 23.6+/-1.1 kg/m2; mean duration of HD 3.3+/-0.6 months) (Epo group). A second group (No-Epo group) consisted of 17 HDP (9F, 8M; mean age 44+/-3.2 years; mean BMI 24.3+/-1.0 kg/m2; mean duration of HD 2.5+/-0.4 months) not treated with rHuEpo for 12 months. Basal plasma leptin and neuropeptide Y concentrations were estimated by RIA at the beginning and after 3, 6, 9 and 12 months of rHuEpo therapy (Epo group) or clinical observation (No-Epo group). The control group consisted of 30 healthy subjects (15 females, 15 males, mean age=38.2+/-1.7 years, mean BMI 24.5+/-0.7 kg/m2). RESULTS: Baseline plasma leptin concentrations in HDP were higher, although statistically not significant than leptinaemia in healthy subjects. After 3, 6, and 12 months of rHuEpo therapy plasma leptin concentrations were significantly lower than at the beginning of the study. Baseline plasma neuropeptide Y concentrations in HDP did not differ significantly from controls. After 3 and 6 months of the study period plasma neuropeptide Y concentrations increased significantly in patients of both the Epo and No-Epo group. This increase was, however, significantly higher in rHuEpo-treated than in untreated patients. CONCLUSIONS: (1) rHuEpo treatment in haemodialysed patients with chronic renal failure is followed by a significant decline of leptinaemia and disappearance of the physiological positive BMI/leptinaemia relationship. (2) Suppression of leptinaemia induced by rHuEpo may be of clinical relevance in haemodialysed patients with chronic renal failure.

[Renin plasma profile and sodium sensitivity of blood pressure in hypertensive patients with or without a family history of hypertension]. / Profil reninowy osocza i sodowrazliwosc cisnienia tetniczego u chorych na nadcisnienie tetnicze z lub bez obciazajacego wywiadu rodzinnego w kierunku nadcisnienia tetniczego.

The relationship between sodium-sensitive hypertension, renin profile and genetic predisposition to hypertension have not been fully clarified. The present study aimed to establish the influence of family history of hypertension (at least one of the parents suffering from hypertension) on the renin profile, incidence of sodium-sensitivity of blood pressure and plasma concentration of selected biochemical parameters (creatinine, uric acid, glucose, sodium, potassium, calcium and cholesterol). 85 patients with essential hypertension (38 females, 47 males) were enrolled in the study. Secondary forms of hypertension were excluded in all patients by careful clinical and biochemical examination performed in the Department of Nephrology, Silesian University School of Medicine in Katowice. Plasma renin activity (PRA) was estimated twice: first after administration of a normal sodium diet (100-120 mmol of sodium per day) and 8 hours of supine position (PRA I) and a second time after 3 days of sodium restriction (10-20 mmol of sodium per day) and 3 hours of upright position (PRA II). All other biochemical parameters were measured once. Only patients with urinary sodium excretion lower than 60 mmol per day (after 3 days of low salt diet), were enrolled in the study. Sodium-sensitive hypertension was diagnosed in patients with a decrease of mean arterial blood pressure (MAP) of more or equal to 10 mm Hg after three days of sodium restriction. Reduction of MAP of less than 10 mm Hg was classified as sodium-nonsensitive hypertension. Among 85 patients with essential hypertension 49 (57.6%) had a positive (group I) while 36 (42.4%) a negative family history of hypertension (group II). Using the criteria presented in this study low, normal, high and rigid plasma renin activity were found, in 14.3%, 57.1%, 18.4% and 10.2% respectively of patients of group I. In patients of group II the incidence of the above mentioned renin profiles was similar: 13.9%, 58.3%, 19.4% and 8.4% respectively. In patients of group I 16 (32.7%) had sodium-sensitive and 33 (67.3%) sodium-nonsensitive hypertension, while in patients of group II 16 (44.4%) had sodium-sensitive and 20 (55.6%) sodium-nonsensitive hypertension (difference between group I and group II is statistically not significant). Patients of group I did not differ significantly from patients of group II with respect to : sex, age, blood pressure, sodium urinary excretion and plasma concentration of above mentioned parameters. From results obtained in this study we may conclude, that patients with and without history of essential hypertension do not differ with respect to renin plasma profile, incidence of sodium-sensitivity of blood pressure and other biochemical parameters.

[Requirement for blood in hemodialyzed patients with chronic renal failure in the period before and after introduction to erythropoietin (r-HuEPO) treatment]. / Zapotrzebowanie na krew u hemodializowanych chorych na przewlekla niewydolnosc nerek w okresie przed po wprowadzeniu do leczenia erytropoetyny (r-HuEPO).

The present paper aimed to assess the influence of EPO-therapy on the requirement of blood transfusion in haemodialysed patients with end-stage renal failure. As shown in this paper, introduction of r-HuEPO into the therapy of uraemic anaemia almost completely eliminated the request for blood transfusion in these patients. EPO therapy did not influence significantly to the serum creatinine concentration and mean arterial blood pressure in these patients.