[Disorders of lipid and glucose metabolism. Long-term adverse effects of antiretroviral therapy]

In addition to readily controllable short-term side effects, highly active antiretroviral therapy (HAART) also has long-term side effects: lipodystrophy syndrome, hyperlipoproteinemia, insulin resistance, elevated glucose tolerance sometimes leading to diabetes mellitus and lactic acidosis. The pathogenesis remains uncertain although various hypotheses have been advanced. A number of approaches for the treatment of lipodystrophy are available, the effects of which, however, have not been confirmed by study results. Hyperlipoproteinemia probably means an increased cardiovascular risk, but a final pronouncement on this is not yet possible. Fibrates and statins are currently applied for treatment, but interactions with HAART medicaments have to be considered. HAART-induced diabetes mellitus presents clinically as type 2 diabetes, and is treated accordingly.

The Arg123-Tyr166 central domain of human ApoAI is critical for lecithin:cholesterol acyltransferase-induced hyperalphalipoproteinemia and HDL remodeling in transgenic mice

High density lipoprotein (HDL) metabolism and lecithin:cholesterol acyltransferase (LCAT)-induced HDL remodeling were investigated in transgenic mice expressing human apolipoprotein (apo) AI or an apoAI/apoAII chimera in which the Arg123-Tyr166 domain of apoAI was substituted with the Ser12-Ala75 domain of apoAII. Expression of apoAI and of the apoAI/apoAII chimera resulted in a respective 3. 5-fold and 2.9-fold increase of HDL cholesterol. Human LCAT gene transfer into apoAI-transgenic mice resulted in a 5.1-fold increase of endogenous LCAT activity. This increase was associated with a 2. 4-fold increase of the cholesterol ester-to-free cholesterol ratio of HDL, a shift from HDL(3) to HDL(2), and a 2.4-fold increase of HDL cholesterol levels. Agarose gel electrophoresis revealed that human LCAT gene transfer into human apoAI-transgenic mice resulted in an increase of pre-beta-HDL and of pre-alpha-HDL. In contrast, human LCAT gene transfer did not affect cholesterol levels and HDL distribution profile in mice expressing the apoAI/apoAII chimera. Mouse LCAT did not "see" a difference between wild-type and mutant human apoAI, whereas human LCAT did, thus localizing the species-specific interaction in the central domain of apoAI. In conclusion, the Arg123-Tyr166 central domain of apoAI is not critical for in vivo lipoprotein association. It is, however, critical for LCAT-induced hyperalphalipoproteinemia and HDL remodeling independent of the lipid-binding properties of apoAI.

Cyclosporin-induced dyslipoproteinemia is associated with selective activation of SREBP-2

The use of cyclosporin A has contributed greatly to the success of organ transplantation. However, cyclosporin-associated side effects of hypertension, nephrotoxicity, and dyslipoproteinemia have tempered these benefits. Cyclosporin-induced dyslipoproteinemia may be an important risk factor for the accelerated atherosclerosis observed posttransplantation. Using a mouse model, we treated Swiss-Webster mice for 6 days with a daily dose of 20 microg/g body wt of cyclosporin and observed significant elevations of plasma cholesterol, triglyceride, and apolipoprotein B (apoB) levels relative to vehicle-alone treated control animals. Measurement of the rate of secretion of very low-density lipoprotein (VLDL) by the liver in vivo showed that cyclosporin treatment led to a significant increase in the rate of hepatic VLDL triglyceride secretion. Total apoB secretion was unaffected. Northern analysis showed that cyclosporin A treatment increased the abundance of hepatic mRNA levels for a number of key genes involved in cholesterol biosynthesis relative to vehicle-alone treated animals. Two key transcriptional factors, sterol regulatory element-binding protein (SREBP)-1 and SREBP-2, also showed differential expression; SREBP-2 expression was increased at the mRNA level, and there was an increase in the active nuclear form, whereas the mRNA and the nuclear form of SREBP-1 were reduced. These results show that the molecular mechanisms by which cyclosporin causes dyslipoproteinemia may, in part, be mediated by selective activation of SREBP-2, leading to enhanced expression of lipid metabolism genes and hepatic secretion of VLDL triglyceride.

Drugs causing dyslipoproteinemia

Diuretics and beta-blockers have a strong tendency to affect serum lipids adversely, whereas the peripherally acting alpha-blocking agents consistently result in beneficial effects. Most of the other antihypertensive agents (calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists, and drugs that act centrally) are lipid neutral. The effect of steroid hormones varies with the drug, dose, and route of administration. In general, androgens lower HDL-C and have a variable effect on LDL-C. The effects of progestins vary greatly depending on their androgenicity, and estrogens are beneficial except when hypertriglyceridemia occurs with oral estrogens. Glucocorticoids raise HDL-C and may also increase triglycerides and LDL-C. Retinoids increase triglycerides and LDL-C and also reduce HDL-C. Interferons can cause hypertriglyceridemia. Following organ transplantation, a dyslipidemia often ensues. This is caused in part by the medications used to prevent rejection (glucocorticoids, cyclosporine, and FK-506) and requires close attention and, in some patients, drug therapy to prevent coronary artery disease.

[Prevalence of dyslipoproteinemia in workers engaged in the production of higher fatty alcohols]

To reveal serum serum lipoprotein disorders, the authors studied serum lipids and lipoproteins compositions in 116 male workers engaged into production of higher fatty alcohols at oil-processing plant. All the cases of serum lipoprotein disorders were divided into 8 types. Secondary are the disorders of those examines (63.8%) who have chronic diseases. Six types of the disorders were identified in apparently healthy examines (36.2%).

Overexpression of human apolipoprotein A-I in transgenic rats and the hyperlipoproteinemia associated with experimental nephrosis

Hyperlipoproteinemia contributes both to kidney disease progression and the development of atherosclerosis. Elevated high density lipoprotein cholesterol and apolipoprotein A-I (apoA-I) serum levels are independent factors protective against the atherosclerotic process. We examined the effects in a transgenic rat model of human apoA-I expression on the hyperlipoproteinemia and edema after puromycin aminonucleoside-induced nephrosis in three groups of animals: low line (TgR[hAI]low, human plasma apoA-I = 16.0 mg/dl); high line (TgR[hAI]high, 284 mg/dl); and non-transgenic litter mates (TgR[hAI]non). Nephrosis increased total plasma apoA-I levels 2-fold in TgR[hAI]non rats (75 vs. 162 mg/dl) and 4-fold in the TgR[hAI]low (97 vs. 458 mg/dl) and TgR[hAI]high rats (356 vs. 1,346 mg/dl). In both transgenic lines, this increase was due mainly to elevations of serum human apoA-I. The hepatic steady-state levels of rat apoA-I mRNA increased 5- to 7-fold in all three groups, while human apoA-I mRNA levels increased 21- and 65-fold in the low and high expressing groups, respectively, indicating a different degree of responsiveness of the rat and human genes. While nephrotic TgR[hAI]non and TgR[hAI]low rats showed severe hyperlipoproteinemia and edema, much lower levels of edema and of serum triglycerides, phospholipids, and cholesterol were seen in the TgR[hAI]high group. Urinary excretion of apoA-I, phospholipids, and cholesterol was significantly increased in the TgR[hAI]high group, indicating this as one possible mechanism for the relatively lower serum levels of these lipids. We conclude that the human apoA-I gene is responsive to nephrosis and that human apoA-I-transgenic rats with this syndrome provide an animal model for the study of human high density lipoprotein and apoA-I metabolism.

Mitochondrial abnormalities of muscle tissue in mice with juvenile visceral steatosis associated with systemic carnitine deficiency

A mouse with juvenile visceral steatosis (the JVS mouse) has been recognized as a novel animal model for systemic carnitine deficiency. We examined cardiac, skeletal and smooth muscle cells in JVS and control mice by light and electron microscopy. Cardiac and skeletal muscle cells of these mice at 4 weeks of age exhibited a ragged-red appearance after trichrome staining. Electron microscopy, demonstrated increased numbers of mitochondria and lipid droplets in the cells. Compression or distortion of the myofibril bundles, primarily due to the increased number of mitochondria, suggests the possible existence of a functional disturbance of the cardiac and skeletal muscle. In the urinary bladder, only one or two large lipid droplets and slightly increased number of mitochondria were recognized in the perinuclear region of the smooth muscle cells. At 8 weeks of age, the mouse enzyme histochemistry specific for mitochondria, such as cytochrome c oxidase and succinic dehydrogenase, and oil red O staining, confirmed further increases in the number of mitochondria and lipid droplets in the heart. However, the accumulation of these organelles in the skeletal and smooth muscle cells was no greater than that noted in JVS mice at 4 weeks of age. In the cardiac muscle cells, autolysosomes or autophagic vacuoles containing electron-dense membranous, lamellar or whorled structures closely associated with mitochondria and pseudoinclusion bodies in the nucleus were recognized, and bundles of myofibrils were buried under numerous mitochondria, suggesting the existence of disturbed contractile function in the heart of JVS mice. These results indicate that this murine strain associated with systemic carnitine deficiency exhibits a generalized mitochondrial abnormality in the muscle system especially in the heart.

Topical timolol maleate might adversely affect serum lipoproteins

Conflicting observations have been reported about the effects of topically administered timolol maleate on serum lipoproteins. We therefore considered this issue in a series of eight glaucoma patients receiving timolol maleate. Cholesterol and triglycerides were measured in plasma and in low-density lipoproteins (LDL), and high-density lipoproteins (HDL), both before and following three months of treatment. Following the treatment, the mean atherogenic index was increased from 2.72 to 3.38 (p = 0.012). This suggests that the atherogenic index should be determined before and during timolol maleate treatment in high-risk cardiovascular patients.

[Influence of alcohol on plasma lipids and atherogenesis. Epidemiological and biochemical aspects]

The results of epidemiological and clinical studies published since 1980 concerning the effects of alcohol intake on coronary artery disease are rather contradictory. Although some protective action of alcohol, notably of wine against atherosclerosis, has been described by some authors, the methodological limitations of these studies make it impossible to establish a cause-effect relationship in this matter. Biochemical studies have provided a more precise approach of the effect of alcohol on the mechanism of atherosclerosis. An increase of HDL has been shown in patients who regularly consume alcoholic drinks. However, a detailed analysis of HDL subfractions (and notably HDL2 regarded as an antiatherogenic lipoprotein) has given equally contradictory results. When the antiatherogenic lipoprotein particles present in HDL are accurately identified, the physiopathological consequences of regular alcohol consumption will be more clearly determined. Biochemical and epidemiological information is still insufficient for us to attribute an antiatherogenic effect to alcohol.

Copper deficiency and hyperlipoproteinemia induced by a tetramine cupruretic agent in rabbits

The effectiveness of a cupruretic agent, N,N'-bis-(2 amino ethyl)-1,3-propanediamine HCl or 2,3,2-tetramine HCl (TETA), in the induction of copper (Cu) deficiency and the ability of a Cu-deficient diet in the maintenance of the depressed Cu status 10 wk after TETA treatment were examined in this study. In the first experiment, 42 male New Zealand White rabbits, 35 d of age, were randomly divided into three dietary treatments: a copper (Cu)-deficient (2.3 mg Cu/kg diet), a Cu-adequate (13.5 mg Cu/kg diet), and a commercial ration (21.6 mg Cu/kg diet) group. A single oral dose of 100 mg of 2,3,2-tetramine HCl TETA/kg body wt/d were administered to half of the rabbits from each treatment group for 10 d while the remaining rabbits were untreated. In the second experiment, 10 similar rabbits were assigned to three treatments: Cu-deficient plus TETA (n = 4); Cu-adequate plus TETA (n = 3); and Cu-adequate alone (n = 3). The rabbits were fed a TETA dose of 100 mg/d for three 4-d periods over 3 wk, and thereafter maintained on the diets for another 10 wk. Rabbits from the first experiment fed Cu-deficient diet and treated with TETA demonstrated cardiac hypertrophy and markedly reduced plasma and liver Cu concentrations that indicated that the animals were Cu-deficient. Significant elevations (twofold) in low density lipoprotein (LDL) protein, cholesterol, triglyceride, and apolipoprotein B (apo B) concentrations were observed in TETA treated rabbits fed Cu-deficient diet. In the second experiment, the plasma LDL protein level remained elevated, the plasma Cu level was reduced 45%, and the Cu level of the heart when expressed as microgram/g dry tissue was reduced, 10 wk post TETA treatment in rabbits maintained on Cu-deficient diet. Thus, Cu deficiency and hyperlipoproteinemia was rapidly induced by TETA and was still evident 10 wk posttreatment in rabbits maintained on a Cu-deficient diet.

Hyperlipoproteinemia in rats fed polychlorinated biphenyls

Hypercholesterolemia due to feeding of polychlorinated biphenyls (PCB) and due to feeding of high cholesterol was compared. Rats in control group were fed a 25% casein diet, and those in PCB group or cholesterol group were fed the 25% casein diet supplemented with 0.03% PCB or 1% cholesterol and 0.25% cholic acid, respectively. Lipoprotein mass (d less than 1.21 g/ml) was higher 1.9- and 1.3-fold in rats fed PCB and cholesterol, respectively, as compared with controls. In rats fed PCB, protein, cholesterol, and phospholipid in the lipoprotein fraction markedly increased. Cholesterol-feeding resulted in the increase in pre-beta-lipoprotein cholesterol, while PCB-feeding increased alpha-lipoprotein cholesterol and slightly slow migrated pre-beta-lipoprotein cholesterol. PCB-treated rats had more apolipoprotein A-I in the lipoprotein fraction than control and cholesterol-fed rats. The data demonstrated that hyperlipoproteinemia induced by PCB is a novel alpha-lipoproteinemia and a useful model for investigating metabolism of high density lipoprotein.

Predicted reductions in the risk of coronary heart disease by antihypertensive therapy: the confounding effect of lipids

The treatment of arterial hypertension confers several important benefits, e.g. reducing hypertension-induced cardiovascular morbidity and mortality. However, the preventive effect for coronary heart disease is considerably smaller than the effect of treatment on the incidence of strokes. Several factors may explain this discrepancy, but it appears likely that drug-induced increases in serum lipoproteins may, to some extent, offset the risk reduction obtained through the lowering of blood pressure. It appears that more emphasis should be put on therapeutic intervention in other risk factors in addition to the treatment of hypertension. An appropriate therapeutic aim of the treatment of hypertension should be to lower blood pressure to 'normotensive' levels, by using drugs which do not themselves increase cardiovascular risks, e.g. do not increase serum lipoproteins, and to actively intervene against other co-existing risk factors, such as hyperlipidaemia. By using this approach, it seems likely that the risk of coronary heart disease can be reduced.

[The HDL cholesterol level in patients treated with antiepileptic drugs]

Total cholesterol, HDL cholesterol, and HDL2 and HDL3 cholesterol were estimated in individuals undergoing anticonvulsant therapy. Significantly higher, than in the corresponding control groups HDL concentration, concerning mainly HDL2 subfraction was found in female epileptic and in male alcoholic epileptic patients. It was observed that higher drug levels were accompanied by higher HDL cholesterol values. In alcohol addicted subjects undergoing anticonvulsant therapy low-nontherapeutic serum drug concentration was often observed. In spite of this, HDL levels were high. This could result from an additional induction of cytochrome P-450 caused by alcohol and an accelerated oxidation of the drugs. This observation indicates that frequent control of drug concentration in these patients is desirable.

[Modification of lipoprotein metabolism by antihypertensive therapy]

Of various antihypertensive drugs, particularly the unselective as well as the selective beta-receptor blockers but also diuretic drugs unfavourable effects on the lipid metabolism are reported, which above all consist of increases of triglycerides and decreases of HDL-cholesterol. The more modern antihypertensive drugs such as calcium antagonists, alpha 1-receptor blockers or angiotensin converting enzyme inhibitors according to the hitherto existing studies have no significant influence on the serum lipids. The final classification of the antihypertensive drugs regarding their influence on the atherogenic risk by negative changes in the lipoprotein metabolism is, however, at present not yet possible on account of insufficient long-term studies. For the reduction of adequate endangerings dietetic measures, reduction of overweight, physical training and when occasion arises change of the medication are recommended.

A novel explanation for the reduced LDL cholesterol in severe hypertriglyceridemia

When [3H]cholesteryl ester-labeled low density (LDL) and intermediate density lipoproteins (IDL) from a normotriglyceridemic, hypercholesterolemic rabbit were injected into severely hypertriglyceridemic, hypercholesterolemic rabbits, 60% of the label appeared in very low density lipoproteins (VLDL) at 3 hr. A similar experiment showed that 40% of injected 131I-protein-labeled LDL appeared in the IDL fraction at 4 hr. Taken together, these data suggest that the exchange of LDL cholesteryl ester for VLDL triglyceride results in a density shift of injected LDL to the IDL density range. Furthermore, the percent of injected 131I-labeled LDL from normotriglyceridemic rabbits that appeared in the IDL fraction increased in rabbits with increasing levels of plasma triglyceride. This LDL density shift was reproduced in vitro by incubating iodinated LDL from normotriglyceridemic, hypercholesterolemic rabbits with concentrations of VLDL from hypertriglyceridemic, hypercholesterolemic rabbits similar to those in plasma. With such a system, it was shown that the percentage of LDL that appeared in the IDL fraction increased with time, was enhanced fourfold by the addition of plasma lipid transfer protein, increased with increasing molar ratio of triglyceride to cholesteryl ester in VLDL, but apparently did not increase with increasing VLDL particle number. These studies suggest that a pronounced decrease in density of lipoproteins that would normally appear in the LDL density range, resulting from loss of cholesteryl ester in exchange for VLDL triglyceride, may explain, at least in part, the reduced LDL levels in severe hypertriglyceridemia.

Fish oil supplementation results in decreased hypertriglyceridemia in patients with psoriasis undergoing etretinate or acitretin therapy

Although retinoid derivatives are an effective treatment for severe psoriasis, they result in systemic toxicity, including hyperlipidemia. In an attempt to reverse this retinoid-related hyperlipidemia in patients with psoriasis, a prospective 4-week pilot study of fish oil supplementation was carried out in 25 patients with psoriasis vulgaris receiving etretinate (Ro-10-9359) or acitretin (Ro 10-1670). Daily fish oil supplements containing 3 gm of omega-3 fatty acids (1.8 gm of eicosapentaenoic acid 20:5 omega 3, and 1.2 gm of docosahexaenoic acid 22:6 omega 3) were found to be effective in reducing hypertriglyceridemia, with a significant mean reduction from 215.6 +/- 92.5 to 156.9 +/- 58.5 mg/dl (-27%) when compared with controls (203.6 +/- 46.9 to 204.1 +/- 54.3 mg/dl). High-density lipoprotein cholesterol levels increased from 41.4 +/- 10.5 to 46.1 +/- 10.8 mg/dl (+11%), and the ratio of total cholesterol to high-density lipoprotein cholesterol decreased from 6.6 +/- 1.9 to 5.9 +/- 1.7 (-11%). It is concluded that fish oil supplementation may prove a valuable adjunct to ameliorate the lipid changes secondary to retinoids.

[Lipoprotein metabolism and beta receptor blockers]

Including own results a survey is given of the side effects of beta-receptor blockers on the plasma lipoprotein metabolism. The formation of a from the coronary-preventive point of view unfavourable lipoprotein risk profile under influence of individual beta-receptor blockers, among others propranolol, seems to be connected with an inhibition of a key enzyme in the lipoprotein metabolism, the lecithin-cholesterol-acyl transferase. Talinolol does not show these side effects. It is recommended to control the triglyceride level and the HDL cholesterol before the induction and after the beginning of a therapy with beta-receptor blockers and to use talinolol instead of propranolol in pre-existing dyslipoproteinaemia or in unfavourable changes during the treatment.

Severe lipemia induced by tamoxifen

A 61-year-old woman was treated with tamoxifen for breast cancer and had marked hyperlipoproteinemia: high plasma triglyceride levels (2790 mg/dl); increased very low density lipoprotein (VLDL) cholesterol levels (241 mg/dl); and high VLDL apoprotein B levels (126 mg/dl). Low density lipoprotein (LDL) cholesterol was decreased (104 mg/dl) and LDL apoprotein B was at 107 mg/dl. A low activity of both postheparin plasma lipoprotein lipase (LPL) and hepatic triglyceride lipase (h-TGL) was also noted. All these observations were reversed following tamoxifen withdrawal. Plasma triglyceride levels fell to 361 mg/dl. VLDL cholesterol and VLDL apoprotein B decreased to 41 mg/dl (83%) and 21 mg/dl (83%), respectively. Meanwhile, LDL cholesterol rose to 194 mg/dl (86%) and LDL apoprotein B increased to 138 mg/dl (29%). LPL and h-TGL activities did increase following tamoxifen withdrawal. Our observations show that, in some patients, the previously described weak hypertriglyceridemic effect of tamoxifen is amplified. That observation supports the concept and helps to explain that, in such severe induced lipemia, reduction of the activities of LPL and h-TGL might impede the conversion of VLDL to LDL, thus causing an amplification of the effect.

Severe lipemia induced by tamoxifen

A 61-year-old woman was treated with tamoxifen for breast cancer and had marked hyperlipoproteinemia: high plasma triglyceride levels (2790 mg/dl); increased very low density lipoprotein (VLDL) cholesterol levels (241 mg/dl); and high VLDL apoprotein B levels (126 mg/dl). Low density lipoprotein (LDL) cholesterol was decreased (104 mg/dl) and LDL apoprotein B was at 107 mg/dl. A low activity of both postheparin plasma lipoprotein lipase (LPL) and hepatic triglyceride lipase (h-TGL) was also noted. All these observations were reversed following tamoxifen withdrawal. Plasma triglyceride levels fell to 361 mg/dl. VLDL cholesterol and VLDL apoprotein B decreased to 41 mg/dl (83%) and 21 mg/dl (83%), respectively. Meanwhile, LDL cholesterol rose to 194 mg/dl (86%) and LDL apoprotein B increased to 138 mg/dl (29%). LPL and h-TGL activities did increase following tamoxifen withdrawal. Our observations show that, in some patients, the previously described weak hypertriglyceridemic effect of tamoxifen is amplified. That observation supports the concept and helps to explain that, in such severe induced lipemia, reduction of the activities of LPL and h-TGL might impede the conversion of VLDL to LDL, thus causing an amplification of the effect.

[Retinoids and lipid metabolism]

Since systemic administration of synthetic retinoids was introduced into dermatology and oncology, side-effects of synthetic vitamin-A derivatives on lipid and lipoprotein metabolism have become apparent. Retinoids of the first and second generation, 13-cis-retinoic acid and etretinate, are capable of inducing secondary hyperlipoproteinemias. For further evaluation of the atherogenic risk of retinoid-induced hyperlipoproteinemias, the most relevant effects of natural and synthetic retinoids on lipid metabolism as well as the interactions between lipid and retinoid metabolism are considered in this review.

A screening survey of dyslipoproteinemias associated with prescription drug use. The Lipid Research Clinics Program Prevalence Study

In 10 North American study populations, we surveyed alterations in blood cholesterol, triglyceride, and high-density lipoprotein cholesterol levels associated with the use of 20 categories of prescription medications. In addition, odds ratios for use of these medication categories were determined for five of the more common dyslipoproteinemias found in these populations. Increased lipid levels were found in association with use of several categories of cardiovascular drugs as well as allopurinol and warfarin. Decreased lipid levels were found in association with anti-infective agents and thyroid hormone. Few significant lipid level alterations were found with the use of antihistamines, barbiturates, analgesics, and the phenothiazines. The associations described here must be interpreted cautiously because of limitations in the study design, particularly the confounding effects of the conditions under drug treatment. However, several drug-lipid effects are suggested that may alter lipid levels and that require experimental confirmation. These findings have implications for both clinical management of individuals with dyslipoproteinemias and in the determinants and modification of population lipid levels.

A sequential comparison of etretinate (Tigason) and isotretinoin (Roaccutane) with special regard to their effects on serum lipoproteins

Etretinate and isotretinoin were compared with respect to their clinical effects and changes in serum lipoprotein concentrations. Sixteen patients with hyperkeratotic and pustular disorders of hands and feet (mainly palmoplantar pustulosis) underwent a double-blind cross-over study. The daily doses of etretinate and isotretinoin were 50 and 40 mg, respectively. Each drug was given for 2 months with a 2-month intermission. The clinical score was reduced both by isotretinoin (P less than 0.05) and etretinate (P less than 0.001). Both drugs affected the lipoprotein concentrations. Isotretinoin increased the cholesterol concentration in low-density lipoprotein (LDL) by 20% and the triglyceride concentration in very low-density lipoprotein (VLDL) by 35%, but decreased the high-density lipoprotein cholesterol by 12%. Etretinate elevated LDL-cholesterol by 10%. These changes had reverted to normal 8 weeks after the end of treatment. The data suggest that in the diseases studied, etretinate is preferable to isotretinoin with regard to both clinical effect and serum lipid side-effects.

Nephrotic syndrome associated with hyper-high-density lipoproteinemia potentiated by prednisolone therapy

We describe a case of nephrotic syndrome (idiopathic membranous glomerulonephropathy) with high serum HDL cholesterol (91 mg/100 ml) which increased to 240 mg/100 ml following steroid therapy. The increase in HDL was mainly a result of increased HDL2 and increased plasma apolipoprotein A-I.

Diabetes mellitus: considerations in the development of guidelines for the occasional use of alcohol

This article covers the absorption, metabolism, and general effects of alcohol. The effect of alcohol on blood glucose, especially the hypoglycemic effects and the effect on blood lipids, is discussed. A table on the composition of alcoholic beverages and guidelines for use of alcohol in individuals with diabetes are included.

[Atherogenic changes in lipid metabolism caused by alcohol]

Plasma lipid composition, and plasma and myocardial high-density lipoprotein (HDLP) content were examined in subjects who died of acute ethanol poisoning and in cases of sudden coronary death. Alcohol-induced disorders of lipid metabolism were in many respects similar to lipid metabolic disturbances associated with coronary disease (hypertriglyceridemia, hyperpre-beta- and hyper-beta-lipoproteinemia, myocardial lipoidosis). These disorders of lipid metabolism had developed in the presence of increased blood HDLP and cholesterol HDLP, which are known to produce an anti-atherogenic effect.

Ethanol-induced hyperlipoproteinemia. Crucial role of preceding ethanol intake in the removal of chylomicrons

Ethanol produces a number of effects in different steps of lipid metabolism which have been suggested to be responsible for the common phenomenon of ethanol-induced hyperlipoproteinemia in man. The occurrence of hyperchylomicronemia has been attributed to an ethanol-specific disturbance of the clearing mechanism of triglyceride-rich lipoproteins. However, the reports on lipolytic activities and the clearance of chylomicrons after ethanol ingestion are contradictory. In this investigation the short-term excess of serum lipoproteins and the lipolytic activities in healthy volunteers were studied after single and prolonged ethanol ingestion followed by an intravenous lipid load. One hour after a single oral dose of ethanol, the intravenous fat tolerance test was unchanged. After an ethanol load over a 5 hr period, the fat tolerance was reduced, although the same ethanol levels at the time of infusion were maintained. In addition, the lipolytic activities of the serum were significantly reduced after 5 hr of ethanol ingestion followed by intravenous fat load. Hence the time relations between ethanol and fat loads determine whether a defect in chylomicron catabolism can be observed or not. A striking difference in the situations when the fat infusions were performed was the development of endogenous hypertriglyceridemia after 5 hr of ethanol ingestion. Since ethanol-dependent differences in the absorption of fat are ruled out by our experimental design, we attribute our findings to a competitive inhibition of chylomicron degradation by VLDL and partial depletion of the lipolytic system by combined endogenous and exogenous hypertriglyceridemia.

[Secondary hyperlipoproteinemia induced by diuretic therapy (author's transl)]

In order to study the degree and pathogenic aspects of the secondary hyperlipoproteinemia in patients under diuretic therapy we measured serum lipids, lipoproteins and the apoproteins A1, A2 and B in 12 adults after a 4 weeks placebo period and 6 weeks of treatment with chlorthalidon. There was a significant increase in atherogenic low density lipoproteins (LDL), (18%, P less than 0.05) whereas the high density lipoprotein-cholesterol Apo A1 and A2 levels were not significantly altered. The same was true for the total serum triglyceride- and the very low density lipoprotein- and LDL-triglyceride levels. The activity of lipoprotein lipase and hepatic triglyceride lipase was slightly but not significantly increased. A delayed LDL-catabolism seems to be the most probable pathogenic mechanism underlying the Chlorthalidon-induced hyperlipoproteinemia.