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Background. Successful kidney transplantation is believed to reverse secondary hyperparathyroidism, but persistent disease has emerged in a significant number of allograft recipients. Parathyroid hormone (PTH) is not only involved in the aetiology of calcium/phosphate abnormalities and osteitis fibrosa, but it is also a permissive factor in the occurrence of hypertension, cardiovascular damage and dyslipidaemia. In experimental renal failure, abrogation of hyperparathyroidism by administration of a calcimimetic or parathyroidectomy (PTX) attenuates progression of renal failure. To evaluate the impact of PTX on blood pressure (BP), renal graft function and serum lipids, we performed a retrospective case-controlled study in renal graft recipients.Methods. Charts of 1647 kidney allograft recipients, transplanted between 1989 and 2004, were reviewed. Thirty-two patients with a functioning graft and a history of a successful PTX performed at least 9 months after transplantation were identified. Biochemical and clinical data available 6 months pre- and post-PTX were registered. Changes in BP, renal function and serum lipids were assessed. The data were compared with those obtained in a similar time frame in a control group closely matched for date of transplantation.Results. Systolic BP (149.9 vs 141.7?mmHg), diastolic BP (85.6 vs 81.9?mmHg), pulse pressure (64.3 vs 58.8?mmHg), total cholesterol concentration (221.4 vs 211.1?mg/dl) and low-density lipoprotein cholesterol concentration (123.9 vs 106.7?mg/dl) improved significantly after successful PTX. Serum creatinine, conversely, significantly increased after PTX (1.75 vs 2.13?mg/dl, P<0.0001). No significant changes were observed in the control group in the same time period.Conclusion. In patients with a functioning renal graft, BP and dyslipidaemia improve, whereas serum creatinine worsens following successful PTX. Our data are in agreement with a stimulatory effect of PTH on plasma renin activity and an inhibitory effect on lipase activity, as previously demonstrated by others. To what extent the increased serum creatinine following PTX reflects a true deterioration of the glomerular filtration rate and/or is the consequence of vitamin D-induced reduction of the renal tubular secretion of creatinine needs to be elucidated by further research. [ABSTRACT FROM AUTHOR]

Background: Several alterations in growth hormone (GH) secretion have been reported in patients with chronic renal insufficiency. However, cholinergic modulation of somatotopic cell function has not been fully clarified in uraemic patients. To gain further insight into the disrupted mechanism of GH regulation in chronic renal failure, we investigated whether the blockade of cholinergic muscarinic receptor with pirenzepine could modify the response of GH to its physiological releasing hormone. [ABSTRACT FROM PUBLISHER]

Background.An abnormally high mortality from atherosclerotic cardiovascular (CV) accidents has long been reported in patients on maintenance haemodialysis (HD). However, incidence of atherosclerotic CV accidents had not been so far assessed in predialysis patients. In order to evaluate the respective influence of uraemia and the dialysis procedure, we compared incidence of atherosclerotic accidents before and after initiation of HD in a large population of patients. [ABSTRACT FROM PUBLISHER]

Background: Diabetic nephropathy (DN) is a common cause of chronic renal failure (CRF). Patients with DN have abnormal lipoprotein metabolism that can be influenced by both the impairment of renal function and the metabolic control of diabetes. The aim of the study was to explore the specific composition lipoprotein abnormalities in patients with insulin-dependent DN in comparison with diabetic patients without nephropathy and non-diabetic CRF patients. [ABSTRACT FROM PUBLISHER]

Background and methods To characterize the abnormalities of lipoprotein composition in patients with chronic renal failure (CRF), the lipid and apolipoprotein (apo) concentrations and composition of major lipoprotein density classes were determined in 20 subjects with moderate to advanced renal failure (GFR 5–59 ml/min) and nine controls. Patients were divided into 14 normotriglyceridaemic (NTG) subjects with triglyceride (TG) levels ≤1.7 mmol/1 (150 mg/dl) and six hypertriglyceridaemic (HTG) subjects with TG ≥1.7 mmol/1. Lipoproteins were isolated by preparative ultracentrifugation: very low density (VLDL), intermediate density (IDL), low density (LDL) and high density (HDL) lipoproteins. Results Although all density classes were characterized by abnormal concentration and composition of some lipid and apo constituents, the most profound changes occurred in IDL and HDL. Cholesterol levels were elevated in VLDL and IDL with little change in LDL and reduced in HDL. TG levels were increased in all density classes. ApoB levels were increased in VLDL, IDL and LDL of all CRF patients reaching the significance levels in VLDL and IDL of HTG (P<0.01) In IDL, the levels of apoC-peptides and apoE were increased (P<0.01). ApoC-peptides and apo E were also elevated in VLDL of NTG and HTG, but their increase was only significant in HTG (P<0.01). In LDL, the concentration of apoC-II and apoC-III was significantly increased (P<0.05). However, in HDL there was significant (P<0.01) reduction of apoA-I, apoA-II and apoC-peptides in both patient groups. The major compositional change was a significant increase in the relative contents of apoC-II and apoC-III in VLDL, IDL and LDL (P<0.01). Conclusions Results indicate that the characteristic feature of dyslipoproteinemia in CRF is the accumulation of partially delipidized TG-rich apoB-containing lipoproteins enriched in apoC-peptides and distributed characteristically in the IDL density-range irrespective of fasting TG concentrations. Increased levels of these ‘remnant lipoproteins’ and reduced levels of HDL may represent risk factors for atherogenesis and progressive renal disease. [ABSTRACT FROM PUBLISHER]

In the present study intermediate-density lipoproteins (IDL) and very-low-density lipoproteins (VLDL) composition, structure, and mass were analysed in fasting uraemic patients on continuous ambulatory peritoneal dialysis (CAPD) ( = 12) and on haemodialysis (HD) ( = 15), and in 15 healthy volunteers. All the groups were matched for sex, age, and time on dialysis. Both groups of patients had elevated very-low-density lipoprotein levels, CAPD patients four and HD group three times that of control. We found a fourfold and a twofold increase in the concentration of IDL cholesterol in the CAPD and HD group respectively when they were compared with the control group. Both groups of patients present an increased VLDL mass. The CAPD group showed a four-fold increase in IDL mass compared with the control group, which indicated a preponderance of large size and suggested that defective IDL clearance was involved. The IDL composition of the CAPD patients was significantly different from that of the HD patients: a twofold increase in IDL mass was observed in the CAPD patients if compared with HD patients. We report new data concerning the metabolism of triglyceride-rich lipoproteins in CAPD treated patients, which confirm the adverse effect of CAPD on serum lipids. [ABSTRACT FROM PUBLISHER]

To characterize lipoprotein metabolism during early renal insufficiency, plasma lipid and apolipoprotein profiles were determined in normotriglycer-idaemic (NTG, =31) and hypertriglyceridaemic (HTG, = 30) middle-aged patients with primary renal disease and with moderately impaired renal function (GFR 20–55 ml/min, mean: 37.2). Mean GFR was similar in the two patient groups. They were compared with 102 normolipidaemic control subjects. In comparison with controls the NTG patients (plasma triglycer-ides TG≤1.7 mmol/l, mean TG: 1.16 mmol/l) had significantly increased plasma concentrations of apo C-III and apoB. The apoA-I levels tended to be lower and as a consequence the apoA-I/apoC-III ratio, considered to represent the hallmark of the altered apoli-poprotein profile in renal dyslipoproteinaemia, was markedly lower in NTG patients (8.7 versus 16.8, < 0.001). There was also a reduction of the antiatherogenic ratio apoA-I/apoB and an increase of the apoC-III/apoE ratio. The HTG patients (mean TG: 3.22 mmol/1) showed the same, but even more accentuated, qualitative changes as the NTG patients. There was a fourfold increase of apoC-III in VLDL-LDL lipoprotein fractions with little change in HDL in the HTG patients. In NTG patients the increase of apoC-III was found in VLDL-LDL and in HDL. Plasma insulin and PTH levels both correlated with the apoA-I/apoC-III ratio independently of GFR and BMI. This suggests a pathogenetic relationship between PTH-mediated alterations of insulin metabolism and the lipoprotein abnormalities. The findings of this study indicate that dyslipoproteinaemia in early renal insufficiency shares the same qualitative characteristics of that in advanced renal failure with accumulation of apoB-containing lipoproteins at various stages of delipidization. [ABSTRACT FROM PUBLISHER]

Measurement of lipids, apolipoproteins A-I, A-II, B, C-III, Lp(a) and cholesterol, phospholipids, apo C-III in lipoprotein with and without apolipoprotein B was made in 49 patients (18 women and 31 men; mean age 50±15 years) undergoing maintenance haemodialysis for chronic renal failure. A group of 49 healthy people, matched for sex and age, acted as controls. In the haemodialysis group, special attention was placed upon the comparison of patients who had evident cardiovascular alterations (=17) with the residual group (=32). The concentration of apo C-III in apolipoprotein B containing lipoproteins was statistically higher in the patients with arterial disease than in the remaining sub jects, whereas the ratio apo C-III from Lp no B/apo C-III from Lp B was decreased. Compared to controls, haemodialysis patients had significantly higher values of triglycerides, apolipoproteins C-III, Lp(a), and apolipoprotein C-III from apolipoprotein B-containing lipoproteins (LpB); in contrast, concentrations of phospholipids and cholesterol from lipoproteins without apolipoprotein B (Lp no B) and apolipoprotein A-II were significantly reduced in patients. Discriminant analysis indicated that the levels of apolipoprotein C-III and apolipoprotein C-III from LpB were the best indicators of deranged lipid transport in patients with chronic renal failure. Our data suggest that chronic haemodialysis patients tend to exhibit qualitative abnormalities of serum apolipoprotein-B triglyceride rich particles containing apolipoprotein C-III or (a). [ABSTRACT FROM PUBLISHER]

Secondary hyperparathyroidism (SHPT) is a common occurrence in patients with chronic renal failure and is characterized by excessive serum parathyroid hormone (PTH) levels, parathyroid hyperplasia and imbalances in calcium and phosphorus metabolism. PTH acts as a uraemic toxin and it may be responsible for the following long-term consequences: renal osteodystrophy; non-skeletal abnormalities, including severe vascular and heart valve calcification; alterations in cardiovascular structure and function; immune dysfunction; and renal anaemia. The risk of developing SHPT is not the same for all uraemic patients. Black patients appear to have a higher risk of developing SHPT than Caucasian patients, and patients with diabetes have a lower risk than non-diabetic patients. Current treatments include dietary phosphate restriction, oral phosphate binders, vitamin D and its analogues, and, in severe cases, parathyroidectomy. These treatments do not provide optimal treatment for many patients, and compounds that directly inhibit PTH secretion may prove a major step forward in the treatment of SHPT. [ABSTRACT FROM PUBLISHER]