Partial correction of lipid disturbances by insulin in experimental renal failure

Effects of 1,25 (OH)2 D3 Treatment on Lipid Levels in Uremic Hemodialysis Patients

The aim of this study was to evaluate the effect of 1,25 (OH)2D3 treatment on lipid levels in uremic hemodialysis (HD) patients. Thirty-one HD patients who had never been treated with vitamin D nor related drugs and 12 healthy subjects with normal renal functions were studied. Uremic HD patients were randomly divided into two groups. Sixteen uremic HD patients were treated with oral calcitriol (0.5 μg/day) for 8 weeks. 13 uremic HD patients and 12 healthy subjects were given placebo. In all these cases before and after 8 weeks of treatments; serum total lipid, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerid levels were determined. After calcitriol treatment, triglycerid levels were significantly decreased. But total lipid, cholesterol, HDL-cholesterol and LDL-cholesterol levels did not significantly change. In the other two groups there were no significant changes. These results show that calcitriol treatment has a positive effect on triglycerid levels in uremic HD patients. This effect of mechanism of calcitriol treatment has not been known yet. But it could be due to regulation carbohydrates metabolism and normalization of parathormone (PTH) levels.

Verapamil prevents chronic renal failure-induced abnormalities in lipid metabolism

Hypertriglyceridemia is common in chronic renal failure (CRF); this derangement is due to decreased peripheral removal of triglycerides. Certain data indicate that the state of secondary hyperparathyroidism of CRF is, at least in part, responsible for derangements in lipid metabolism. It has been proposed that chronic excess of parathyroid hormone exerts its deleterious effects on many organs through its ability to raise basal levels of cytosolic calcium. Prevention of the latter by a calcium channel blocker is followed by the correction of organ dysfunctions. The present study examined the effect of treatment of CRF rats with verapamil on several parameters of lipid metabolism. Chronic renal failure rats displayed hypertriglyceridemia, fat intolerance, reduced postheparin plasma lipoprotein and hepatic lipase activities, decreased hepatic lipase in liver homogenate, and elevated calcium content in liver and epididymal fat. Treatment of the CRF rats with verapamil prevented all these derangements in lipid metabolism. These effects of verapamil were similar to those produced by parathyroidectomy of CRF rats. The data are consistent with the formulation that chronic excess of parathyroid hormone increases the calcium burden of liver and adipose tissue and consequently impairs the synthesis and/or release of lipoprotein and hepatic lipases. Reduced availability of these enzymes in plasma results in impared peripheral removal of triglycerides, leading to hypertriglyceridemia.

Excess parathyroid hormone adversely affects lipid metabolism in chronic renal failure

Hyperlipidemia is common in chronic renal failure (CRF), but the underlying mechanisms are not clearly defined. Certain data points toward a potential role for the state of secondary hyperparathyroidism of CRF in its pathogenesis. We examined the effects of parathyroid hormone (PTH) on lipid metabolism utilizing intravenous fat tolerance test (IVFTT) and post-heparin lipolytic activity in five normal dogs, in six animals with CRF and secondary hyperparathyroidism (NPX) and in six normocalcemic-thyroparathyroidectomized dogs (NPX-PTX) with comparable degree and duration of CRF. NPX dogs had fasting hypertriglyceridemia (82 + 6.0 mg/dl vs. 49 +/- 2.7 mg/dl in normal dogs, P less than 0.01), abnormal IVFTT, and reduced post-heparin plasma LPL activity (151 +/- 10 vs. 275 +/- 15 mumol fatty acids/ml/min in normal dogs, P less than 0.01). The NPX-PTX dogs had normal fasting levels of serum triglycerides (42 +/- 0.6 mg/dl), normal IVFTT, and normal post-heparin plasma LPL (317 +/- 19 mumol fatty acids/ml/min) despite CRF. Post-heparin HL activity in plasma was not different between NPX and NPX-TPX dogs. The results show that excess blood levels of PTH and not other consequences of CRF are mainly responsible for the abnormalities in lipid metabolism. The data are consistent with the notion that excess PTH reduces post-heparin LPL activity in plasma, which in turn results in impaired lipid removal from the circulation and consequently hyperlipidemia.