Determining the Levels of Vitamin D and Parathyroid Hormone in Patients on Hemodialysis

Vitamin D deficiency is fequently observed in chronic kidney disease. We conducted this study to determine the concentration of the above-mentioned parameters and the correlation between them in order to optimize therapy with vitamin D in patients with end-stage renal disease (ESRD) on hemodialysis. In 53 patients on hemodialysis due to ESRD, vitamin D [Calcidiol (25(OH)D], parathyroid hormone (PTH), calcium, phosphorus, albuminuria, albumin:creatinine ratio (ACR) and other parameters have been followed up. Analysis of the levels of vitamin D has been carried out by High Performance Liquid Chromatography (HPLC), the PTH is determined by the system Centaur XP, Siemens Diagnostic, Electro-chemiluminescence immunoassay (ECLIA), and for albumin in urine we used immunological method [Miltigent microalbumin assay (Abbott Laboratories Diagnostics). We found out deficiency and insufficiency of vitamin D in 56.6% and 37.7%, as well as average 4.5 times increase in the PTH, hyperphosphatemia, hypocalcemia, albuminuria (A2 or A3), over 10 times increase in the ACR, secondary hyperparathyroidism. We registered a negative correlation between vitamin D and PTH. We confirmed the increase in creatinine and cystatin C in the patients on hemodialysis. There are few literature data for patients on hemodialysis, however, regarding the extent of the vitamin deficiency and its relationship with PTH, albuminuria, calcium, phosphorus, etc. Our data have indicated that patients on hemodialysis due to ESRD are associated with high incidence of vitamin D insufficiency or deficiency.

The effect of smoking on peripheral insulin sensitivity and plasma endothelin level

OBJECTIVES

The aim of the present study was to investigate the effect of smoking on peripheral insulin effectiveness.

METHODS

Seven healthy volunteers, nonsmokers, of mean age 39.6 +/- 7.1 Years and mean BMI 22.65 +/- 11.98 kg/m2, without family history of diabetes mellitus, with normal blood pressure participated in the study. All the parameters were studied twice - at baseline as well as after smoking (4 cigarettes per one hour). The study was performed in three days: at the first day we studied peripheral insulin effectiveness (M) in vivo by the artificial endocrine pancreas (Biostator), using the euglycaemic hyperinsulinaemic clamp technique, and insulin-receptor binding on circulating mononuclear blood cells; at the second day - the same parameters after one-hour smoking during the third hour of clamping; at the third day - plasma endothelin level, blood pressure and heart rate at baseline and after one-hour smoking.

RESULTS

There was a significant decrease in glucose utilization during the second clamp test, when the volunteers smoked during the third hour as compared to the test at baseline (p=0.04). This was accompanied by a significant decrease in insulin receptor affinity (p=0.04). Systolic blood pressure and heart rate increased significantly after one-hour smoking (p=0.03 and p=0.001, respectively). Plasma endothelin level increased significantly after smoking (from 0.62 +/- 0.15 pg/ml to 2.05 +/- 1.67 pg/ml, p=0.03).

CONCLUSION

Our results demonstrate that smoking decreases peripheral insulin sensitivity reducing insulin receptor affinity. We have confirmed that smoking increases plasma endothelin level, which probably by causing vasoconstriction and consequent tIssue hypoxaemia could decrease peripheral glucose utilization. We consider that smoking could also have a direct effect on insulin receptor affinity, thus leading to decreased peripheral insulin effectiveness.

L-carnitine consecutively administered to patients on hemodialysis improves beta-cell response

Eight patients with end stage renal disease (ESRD) on chronic hemodialysis (CHD) treatment were supplemented with 1 g L-carnitine intravenously (i.v.) after each dialysis session for one month. A Tolbutamide test was done and blood sugar (BS), serum C-peptide (CP) were measured at 0, 20 and 60 minutes, as well as the plasma L-carnitine level before and after treatment. Delta CP and the area under CP curve were ascertained. After L-carnitine application delta CP was significantly increased (1.33 +/- 0.63 vs. 2.24 +/- 1.0 nmol/L; p<0.05) and also the area of the stimulated secretion under the CP curve (14.93 +/- 11.11 vs. 36.88 +/- 25.36 nmol/L x 60 min.; p<0.05). The fasting BS-level was significantly lower after the treatment--3.85 +/- 0.43 vs. 4.76 +/- 1.02 mmol/L; p<0.05 and plasma L-carnitine level significantly increased (72.8 +/- 43.2 vs. 35.2 +/- 18.3 mcmol/L; p<0.05) Improving the oxidative processes in peripheral tissues, L-carnitine increases the peripheral effectiveness of insulin and relieves the overstretched beta-cell apparatus.

Plasma levels of branched chain amino acids in patients on regular hemodialysis before and after including a high-protein supplement in their diet

Chronic renal failure (CRF) patients on hemodialysis have low plasma level of the branched chain amino acids (BCAA) leucine, isoleucine, and valine. The abnormalities in the plasma amino acid pool can be corrected with appropriate high-protein supplements. The present study was designed to evaluate the effect of a balanced protein nutritional supplement on the plasma level of BCAA. Twenty eight CRF patients who received hemodialysis treatment three times in a week were enrolled in the trial. The initial plasma levels of BCAA were as follows--leucine 15.46 +/- 3.88 mcg/ml, isoleucine 9.08 +/- 1.97 mcg/ml, and valine 24.05 +/- 5.06 mcg/ml. For a period of 6 months the patients received a balanced nutritional supplement (58-59% total protein content, leucine--8.6, isoleucine--4.8, and valine--5.7 g/100 g protein) on the day of hemodialysis at a dose 1.0 g/kg body weight. Three months after beginning of supplementation the plasma level of BCAA was found to be elevated--leucine by 36% (P < 0.001), valine by 30% (P < 0.001), and isoleucine by 27% (P < 0.001). The body mass index of the patients was also above the initial values. The plasma BCAA levels were maintained high until the sixth month from the beginning of trial and even a month after withdrawal of the supplement. The results obtained allow us to recommend inclusion of protein supplements with balanced amino acid content in the diet of these patients.

Evolution of renal replacement therapy in Central and Eastern Europe 7 years after political and economical liberation. Central and Eastern Europe Advisory Board in Chronic Renal Failure

PURPOSE OF THE STUDY

The conditions of renal replacement therapy (RRT) were very poor in the countries located in Central and Eastern Europe (CEE) when they were members of the so-called 'socialist bloc'. The aim of the present analysis was to document the impact of the socioeconomic changes on dialysis therapy in the CEE countries.

DESIGN

This was a special survey with the participation of 12 CEE countries, with data obtained through national registries (with the exception of Russia).

RESULTS

During the period 1990-1996 the number of haemodialysis units increased by 56% and the number of centres performing peritoneal dialysis by 296%. The number of patients increased respectively by 78% (haemodialysis) and 306% (peritoneal dialysis). The percentage of patients with diabetic nephropathy and elderly patients rose dramatically during this period. One of the main reasons of such expansion was the rapid development of peritoneal dialysis programmes in the majority of the CEE countries. The introduction of modern haemodialysis machines and a wider choice of different dialysers and concentrates permitted individualization of dialysis procedures. These points and the wider use of erythropoietin had a positive influence on quality of life and treatment outcome. There was also a notable increase in the number of transplant centres, but less so of the number of transplanted patients.

CONCLUSION

Renal replacement therapy experienced a major expansion in the CEE countries. Despite the progress achieved, the level of RRT is not yet completely satisfactory in most CEE countries.