Increased serum pancreatic enzymes in uremia: relation with treatment modality and pancreatic involvement.

Increased levels of pancreatic enzymes have been reported in patients with renal insufficiency and ascribed either to impaired urinary excretion or, in a few studies, to the presence of pancreatic damage. In the present study serum total amylase, pancreatic amylase, and lipase were evaluated in 63 patients with chronic renal insufficiency (CRF), in 98 patients on hemodialysis (HD), in 28 patients on continuous ambulatory peritoneal dialysis (CAPD), in 23 patients with renal transplantation (RT), and in 34 normal volunteers (C). Serum parathyroid hormone and triglyceride levels were also measured in the majority of patients. Ultrasound examination of the pancreas was performed in a select number of cases. Mean values of pancreatic enzymes were significantly higher in all the study groups in comparison with controls, but values exceeding three times the upper normal limit were detected only in HD patients, who also showed amylase and lipase levels significantly highly than those of CAPD and CRF subjects. Negligible amounts of pancreatic enzymes were detected in peritoneal fluid of CAPD patients. Significant correlations were found with serum creatinine in CRF, with parathyroid hormone in HD and CAPD, and with duration of treatment in HD. No pancreatic abnormalities were detected by ultrasound. In conclusion, very high levels of pancreatic enzymes are seen mainly in HD patients and might be related more to the metabolic derangement of long-term dialysis treatment than to the occurrence of acute pancreatic damage.

Morphometric evidence of the trophic effect of L-carnitine on human skeletal muscle.

We investigated the effect of long-term i.v. administration of L-carnitine on human muscle fibers using morphometric parameters. We administered 2g/day L-carnitine to patients undergoing hemodialysis for at least 12 months. At the end of this period a marked increase in serum and muscle carnitine levels was observed in all patients, together with hypertrophy and predominance of type 1 fibers. L-carnitine was withheld for 4 months, during which time serum and muscle levels gradually decreased and no changes were observed in muscle fibers. Subsequent addition of L-carnitine to dialysis fluid for another 4 months stabilized lower levels. At the end of this period reduction of diameter of type 1 fibers was observed. Type 2 fibers remained unchanged. Moreover, type 1 fibers remained predominant in all cases. Hence, we suggest that carnitine has a specific trophic effect on type 1 fibers which are characterized by an oxidative metabolism.

L-carnitine addition to dialysis fluid. A therapeutic alternative for hemodialysis patients.

L-Carnitine has been reported to have beneficial effects in the reduction of serum triglycerides and increases high-density lipoprotein cholesterol in hemodialysis patients. The published reports are, however, equivocal. Paradoxical increases in serum triglycerides following intravenous administration of L-carnitine have been observed. It has been suggested that the paradoxical rise in triglycerides may result from the high doses used and intravenous administration, both of which may cause abnormally high tissue concentrations. In the present study 22 hemodialysis patients were selected. All patients had been treated intravenously with 2 g of L-carnitine administered at the end of dialysis for a minimum of 12 months. Treatment with L-carnitine was then discontinued during a 4-month washout period. The patients were then divided into two equal subgroups and placed on L-carnitine therapy (1 g i.v.) at the end of dialysis for 1 month. Thereafter, L-carnitine was added to the dialysate (2 g in group 1, 4 g in group 2) for 3 months. Serum and muscle carnitine levels were determined throughout the study as were lipid parameters, serum chemistry, and hematology. Muscle biopsies obtained at baseline revealed supranormal levels of carnitine which decreased to normal levels following the 4-month washout period. When therapy with L-carnitine was resumed, intravenous administration or in dialysate, the muscle carnitine levels remained within the normal range. Similarly, serum carnitine was markedly elevated at baseline and decreased to normal during the washout period. When L-carnitine was added to the dialysate, total carnitine was observed to significantly increase in the group receiving 4 g.(ABSTRACT TRUNCATED AT 250 WORDS)

Favorable effects of L-carnitine treatment on hypertriglyceridemia in hemodialysis patients: decisive role of low levels of high-density lipoprotein-cholesterol.

Twenty-nine hemodialyzed patients with hypertriglyceridemia were given L-carnitine (20 mg/kg iv at the end of each dialysis) for 120 days and then placebo for the same duration in order to evaluate the lipid-lowering effects of the metabolite. A dramatic reduction in triglyceride levels was observed only in the group of patients (n = 12) with high basal triglyceride values, low levels of high-density lipoprotein-cholesterol, and with apoprotein A at the lower limit of normal range. During L-carnitine treatment these patients exhibited significantly increased high-density lipoprotein-cholesterol and apoprotein A. No rebound effects were observed. L-Carnitine did not provoke changes in the lipid parameters in the group (n = 17) with high basal triglyceride values, and normal high-density lipoprotein-cholesterol and apoprotein A. Hematocrit values increased in all the 29 patients during L-carnitine treatment. At the end of the experimental protocol, L-carnitine dosage was increased to 60 mg/kg iv (at the end of each dialysis) in four patients of the group of nonresponders and prolonged for 60 days. This produced a considerable reduction in triglyceride levels. The above results suggest that L-carnitine can be effective in the management of hypertriglyceridemia in the hemodialyzed patient especially when low high-density lipoprotein-cholesterol levels are present.