Roullet Jb

Serum Lipoprotein Disturbances in Primary and Secondary Hyperparathyroidism and Effects of Parathyroidectomy

Serum lipoprotein disturbances were studied in 86 patients with primary (I), and 34 hemodialysis patients with severe secondary (II), hyperparathyroidism (HPTH) before and seven to 14 days after parathyroidectomy (PTx). In addition, a subset of patients had repeat studies more than 12 months after PTx. In patients with I as well as with II HPTH, mean +/- SEM fasting serum concentrations of total triglycerides (TG) (1.51 +/- 0.09 and 2.17 +/- 0.19 mmol/L, respectively) were significantly increased when compared with that of 22 age- and sex-matched healthy control subjects (1.01 +/- 0.09 mmol/L, P less than .001). No consistent anomalies of serum total cholesterol and lipoprotein cholesterol content were observed in Io HPTH patients. In uremic II HPTH patients, the cholesterol content of high-density lipoprotein (HDL) was significantly (P less than .01) depressed, compared with normal subjects. In the short term, PTx normalized serum total TGs (P less than .001) in Io HPTH patients from 1.50 +/- 0.11 to 1.19 +/- 0.07 mmol/L seven days after PTx. The surgical correction of II HPTH in dialysis patients was also followed by an improvement of hypertriglyceridemia from 2.22 +/- 0.21 to 1.46 +/- 0.08 mmol/L and 1.46 +/- 0.09 mmol/L seven and 14 days, respectively, after PTx (P less than .01). Long-term follow-up after PTx shows clearly a persistent decrease in serum TG concentration in I HPTH patients (1.17 +/- 0.11 mmol/L), as well as in II HPTH patients (1.61 +/- 0.18 mmol/L), 12 months after PTx by comparison with values determined before PTx.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Several Atherogenicity Indices by the Analysis of Serum Lipoprotein Composition in Patients with Chronic Renal Failure with or without Haemodialysis, and in Renal Transplant Patients

We investigated serum lipoproteins in uraemic and kidney transplant patients, and compared the results with those from normal persons. In uraemic patients, with or without haemodialysis, and in kidney transplant patients, the ratio of HDL-cholesterol to total cholesterol minus HDL-cholesterol, the ratio of HDL-phospholipids to total phospholipids minus HDL-phospholipids, and the ratio of apolipoprotein A to apolipoprotein B are all decreased, though to different extents, when compared with healthy control subjects. Furthermore, important differences exist in the relative HDL composition between the 3 patient groups and healthy control subjects. Thus, the ratio of apolipoprotein A/HDL-cholesterol and that of HDL-cholesterol/HDL-phospholipids are significantly altered in uraemic haemodialyzed patients, while the ratio of apolipoprotein A/HDL-phospholipids is normal. By contrast, the 3 ratios are normal in uraemic undialyzed patients, and the 2 ratios, apolipoprotein A/HDL-cholesterol and apolipoprotein A/HDL-phospholipids are normal in renal transplant patients. The last ratio, HDL-cholesterol/HDL-phospholipids, is increased in this group of patients. Thus, it appears that HDL-cholesterol, HDL-phospholipids, and total apolipoprotein A represent different aspects of the same lipoprotein. The determination of all three parameters could lead to a different approach in the evaluation of the so-called cardiovascular risk, at least for uraemic patients and renal transplant patients.

Plasma and Pituitary Content of Growth Hormone Luteinizing Hormone, and Prolactin in Uremic Rats

The influence of chronic renal failure on pituitary content and on serum concentrations of growth hormone (GH), prolactin (PRL), and luteinizing hormone (LH) was studied in chronically uremic rats by comparison with control rats fed ad libitum and diet-restricted rats pair-fed with uremic rats. A decrease of pituitary GH content was found in uremic and diet-restricted rats, in association with a normal circulating GH level. A decrease of pituitary PRL and LH content with respectively high and normal serum values was observed in uremic but not in diet-restricted rats. These data strongly suggest that GH disturbances are related to malnutrition, whereas PRL and LH abnormalities are related to the uremic state per se. As hypoinsulinemia was observed in uremic rats, and as insulin is largely implicated in growth, we have investigated the effects of chronic infusion of insulin, using miniosmotic pumps, on pituitary hormone content. In spite of normalization of circulating insulin levels in uremic rats treated with insulin, pituitary GH, LH, and PRL contents were unaffected. Thus, insulin deficiency did not appear to be responsible for the diminished pituitary reserve of these hormones.

Chronic Triiodothyronine Supplementation Does Not Improve the Lipoprotein Disorders of Mildly Uremic Rats

The present study was performed to appreciate the potential role that thyroid deficiency could play in the energy homeostasis and lipid metabolism of experimental chronic renal failure. For this purpose, 12 uremic rats that were supplemented with T3 (0.4 microgram/100 g body weight/day) during 5 weeks by means of osmotically driven minipumps were compared to 12 unsupplemented uremic rats and 12 control rats. The chronic supplementation of uremic rats with T3 induced no significant change in body weight gain or in the serum concentration of insulin, glucose, glycerol, nonesterified fatty acids, total triglycerides (TG), total cholesterol, and total choline phospholipids. Similarly, the metabolism of TG-rich lipoproteins was not affected by the supplementation with T3 in these uremic rats as appreciated by TG production or TG degradation (adipose tissue lipoprotein lipase activity). T3 administration induced a significant decrease in serum beta-hydroxybutyrate concentration and an increase in serum lactate concentration. Furthermore, heparin-releasable hepatic TG lipase activity as expressed per total liver mass was decreased in uremic rats treated with T3. The latter changes were observed in the absence of modifications of serum glucose or TG concentration. We conclude from these observations that rats with a moderate degree of chronic uremia do not seem to have a cellular thyroid deficiency sufficient to disturb their energy or lipid metabolism.

Vergleich mehrerer Atherogenitätsanzeichen durch Analyse der Zusammensetzung der Lipoproteine im Serum von Patienten mit chronischem Nierenversagen mit oder ohne Hämodialyse und nach Nierentransplantation

We investigated serum lipoproteins in uraemic and kidney transplant patients, and compared the results with those from normal persons. In uraemic patients, with or without haemodialysis, and in kidney transplant patients, the ratio of HDL-cholesterol to total cholesterol minus HDL-cholesterol, the ratio of HDL-phospholipids to total phospholipids minus HDL-phospholipids, and the ratio of apolipoprotein A to apolipoprotein B are all decreased, though to different extents, when compared with healthy control subjects. Furthermore, important differences exist in the relative HDL composition between the 3 patient groups and healthy control subjects. Thus, the ratio of apolipoprotein A/HDL-cholesterol and that of HDL-cholesterol/HDL-phospholipids are significantly altered in uraemic haemodialyzed patients, while the ratio of apolipoprotein A/HDL-phospholipids is normal. By contrast, the 3 ratios are normal in uraemic undialyzed patients, and the 2 ratios, apolipoprotein A/HDL-cholesterol and apolipoprotein A/HDL-phospholipids are normal in renal transplant patients. The last ratio, HDL-cholesterol/HDL-phospholipids, is increased in this group of patients. Thus, it appears that HDL-cholesterol, HDL-phospholipids, and total apolipoprotein A represent different aspects of the same lipoprotein. The determination of all three parameters could lead to a different approach in the evaluation of the so-called cardiovascular risk, at least for uraemic patients and renal transplant patients.