Serum lipoproteins and apolipoproteins in young male survivors of myocardial infarction

Concentrations of serum lipoprotein lipids and apolipoproteins A-I, A-II and B were determined 3-6 months after myocardial infarction in 116 males below the age of 45 and in 116 age-matched controls. Among single variables the sum of cholesterol concentration in VLDL and LDL divided by the HDL cholesterol level was the best discriminator between patients and controls. The concentrations of serum triglycerides, apolipoprotein B, VLDL triglycerides and cholesterol, serum cholesterol, HDL cholesterol and LDL triglycerides, in that order, were better discriminators than was LDL cholesterol level. Among variables reflecting HDL concentration and composition HDL cholesterol was the best discriminator followed by HDL2 cholesterol, apolipoprotein A-I and the HDL cholesterol/apolipoprotein A-I ratio. Multivariate analysis indicated independent significance of elevated VLDL lipid and LDL cholesterol concentrations, and a decreased HDL cholesterol concentration, in relation to MI. The present data suggest that a disturbed triglyceride metabolism, in addition to elevated LDL and decreased HDL cholesterol levels, has an independent and pathogenetic significance for MI at a young age.     

Changes in very low and low density lipoproteins with dietary fat modification

Since VLDL and LDL are involved in atherogenesis, their response to dietary modification was studied in 15 normal male prisoners. A 3-month reference diet (P/S ratio 0.3, daily cholesterol intake 370 mg) was compared with a modified fat diet (P/S 1.0, 250 mg) given for further 3 months. The decrement in serum cholesterol by 32 mg/dl reflected a decrease in VLDL and LDL. It was associated with a decrease in serum apolipoprotein B by 16 mg/dl and in serum apolipoprotein E by 1.2 mg/dl. The decrement in VLDL cholesterol was paralleled by a lowered VLDL apolipoprotein E content. Serum and VLDL triglycerides, HDL cholesterol and the serum apolipoproteins A-I and A-II did not change significantly. One beneficial result of a conventional dietary regimen is lowered LDL with unaffected HDL. Another effect is the apparent modification of VLDL with a decrement of cholesterol and apolipoprotein E-enriched particles.     

Serum lipoproteins, apolipoproteins and very low density lipoprotein subfractions during 6-month fibrate treatment in primary hypertriglyceridaemia

Serum lipoproteins and apolipoproteins were studied in 14 hypertriglyceridaemic (HTG) patients during a 24-week period of treatment with gemfibrozil, and after a 6-week washout period. A marked decrease in very low density lipoprotein (VLDL) cholesterol and triglyceride was observed. There was an increase in high density lipoprotein (HDL) cholesterol, particularly the HDL3 component. A slight increase in low density lipoprotein (LDL) cholesterol was observed after 12 weeks, but this had almost disappeared after 24 weeks. The treatment resulted in an increase in serum apolipoprotein A-II levels and a reduction in serum apo C-III and apo E. VLDL subfractionation by density gradient centrifugation in four subfractions of decreasing size (A, B, C and D) showed a predominant reduction of the large subfractions A, B and C, while the decrease in VLDL-D was less marked. Percentage changes from the baseline level of VLDL-A and VLDL-D cholesterol were found to be inversely correlated with percentage changes in HDL and LDL cholesterol, respectively. This might reflect a transfer of cholesterol from VLDL-A to HDL, and from VLDL-D to LDL. The above data suggest fibrate-induced stimulation of lipoprotein lipase, and indicate that the enhanced transfer of cholesterol from VLDL to LDL, induced by fibrates in HTG patients, is less pronounced after a prolonged period of treatment.     

Quantitative and qualitative serum lipoprotein analysis. Part 2. Studies in male survivors of myocardial infarction.

The fasting concentration of cholesterol and triglycerides in serum and in very low (VLDL), low (LDL) and high (HDL) density lipoproteins (LP) was determined 3 months after a myocardial infarction (MI) in 54 men, and the values obtained were compared to those in 61 healthy male control subjects. The mean triglyceride concentration in MI patients was significantly increased in serum, VLDL, LDL and HDL by 74%, 110%, 30% and 12% respectively, compared to controls. The mean cholesterol concentration was significantly raised by 16%, 120% and 14% in serum, VLDL and LDL but decreased by 22% in HDL. Hypertriglyceridaemia occurred in 58% of MI patients. Of these patients, two-fifths had hypertriglyceridaemia only and three-fifths had combined hyperlipidaemia. The hypertriglyceridaemia was caused by elevation of only VLDL triglycerides in 26%, only LDL triglycerides in 19%, VLDL and LDL triglycerides in 23% and by various other combinations of raised LP triglyceride levels in 25% of cases. Hypercholesterolaemia was found in 41% of MI subjects. Of these, one-sixth had elevation of cholesterol levels, while five-sixths had combined hyperlipidaemia. The LP abnormalities underlying hypercholesterolaemia were increased of only VLDL cholesterol levels in 36%, only LDL cholesterol in 14% and both VLDL and LDL cholesterol in 50% of cases. The low HDL cholesterol values in comparison to controls were related to higher VLDL triglyceride values in MI patients, since HDL cholesterol fell significantly with increasing VLDL triglyceride levels. When HDL cholesterol was related to similar VLDL triglyceride levels, there were no major differences between controls and MI.     

Relationship of angiographically defined coronary artery disease to serum lipoproteins and apolipoproteins in young survivors of myocardial infarction

The relationship of serum lipoprotein and apolipoprotein concentrations to angiographically determined coronary artery disease was investigated in 105 consecutive male survivors of myocardial infarction under the age of 45. Concentrations and composition of lipoproteins, lipid indexes, and nonlipid risk factors (tobacco consumption, hypertension, reduced glucose tolerance, and obesity) were related to a recently developed scoring system for semiquantitative estimation of diffuse coronary atheromatosis, as well as to the number and severity of significant coronary artery stenoses. The concentrations of cholesterol in very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL), in combination with serum triglyceride or VLDL triglyceride level, comprised the best set of independent discriminatory lipid variables between patients and control subjects. In the patients, LDL cholesterol and apolipoprotein B levels showed strong relationships to the extent and severity of coronary atheromatosis but not to the number and severity of distinct coronary stenoses. HDL2 cholesterol concentration correlated inversely with the coronary atheromatosis score, whereas other variables reflecting HDL concentration and composition or VLDL lipids were not independently related to any of the coronary scores. The LDL triglyceride level, an index of intermediate-density lipoprotein (IDL) accumulation, was significantly correlated to the coronary atheromatosis score in univariate analysis. Nonlipid risk factors were correlated neither to coronary atheromatosis nor to severity of stenoses. Stepwise multiple regression analyses of data adjusted for age, cumulative tobacco consumption, and weight indicated that 18% of the variation in the coronary atheromatosis score could be accounted for by levels of apolipoprotein B. Addition of other lipoprotein variables or the nonlipid variables hypertension and glucose tolerance did not significantly increase the value of R2. When ratios of lipoprotein lipids and apolipoproteins were included in the regression model, the highest multiple correlation coefficient was obtained with the LDL/HDL cholesterol ratio alone (R2 = .22). The present data demonstrate the importance of elevated LDL cholesterol and apolipoprotein B concentrations for the development of coronary atheromatosis in young male survivors of myocardial infarction. The lack of correlations between the levels of lipoprotein lipids and serum apolipoproteins and the severity of coronary stenoses suggests that mechanisms other than disturbances of lipoprotein metabolism may be involved in the progression of more advanced coronary lesions.     

Gemfibrozil therapy in primary type II hyperlipoproteinemia: effects on lipids, lipoproteins and apolipoproteins

Gemfibrozil lowers triglycerides, low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol. It also promotes a significant increase of high density lipoprotein (HDL) cholesterol. It has been established that normalization of apolipoproteins is an important protective factor against atherosclerosis. The present report examines the effectiveness of 12 months of gemfibrozil treatment on plasma lipids and apolipoproteins in types IIa (VLDL 18 +/- 2 mg cholesterol/dL) and IIb (VLDL 58 +/- 7 mg cholesterol/dL) hypercholesterolemic patients. Gemfibrozil lowered plasma triglycerides, VLDL cholesterol and apolipoprotein B (apoB), increased HDL cholesterol and apoAI levels in both groups, and induced a very substantial reduction in LDL cholesterol in type IIa patients only. Even though HDL particles were enriched in cholesterol, indicating improvement in the reverse cholesterol transport and lower risk of atherosclerosis in both groups, it is important to note that production of cholesterol-poor LDL particles and reduction in LDL cholesterol and the LDL/HDL cholesterol ratio were observed only in the normotriglyceride group (type IIa). Due to the initially elevated concentration of plasma triglycerides and VLDL in type IIb patients and the increased catabolism of VLDL to LDL during gemfibrozil therapy, this drug has a more efficient regulating effect on LDL particles in type IIa compared with type IIb hyperlipidemia.     

Effect of soybean crude fiber on the concentrations of serum lipids and apolipoproteins in hyperlipemic subjects

Effect of soybean crude fiber on the concentrations of serum lipids and apolipoproteins in hyperlipemic subjects was examined. The concentrations of serum triglycerides, VLDL triglycerides and VLDL cholesterol were decreased significantly following the administration of soybean crude fiber for 2 months. Neither were significant changes found in total cholesterol, LDL cholesterol, HDL cholesterol, apo A-I, apo A-II, apo C-II and apo B levels, nor in body weight before and after the administration of soybean crude fiber.     

Vitamin C, high density lipoproteins and heart disease in elderly subjects.

Plasma vitamin C, total and high density lipoprotein (HDL) cholesterol and cortisol levels were measured in a random sample of 337 elderly subjects living at home in S. Wales; measurements of relative body weight and information about fruit intake, smoking habits and symptoms of cardiovascular disease were also collected. There was a sex difference, over all age groups, in plasma vitamin C and in total HDL cholesterol levels. Plasma vitamin C was strongly correlated with fruit intake in both sexes. Both HDL cholesterol and low and very density lipoprotein (LDL + VLDL) cholesterol levels tended to increase with increasing plasma vitamin C but this reached significance only for the LDL + VLDL fraction. In addition, HDL cholesterol was negatively correlated with Quetelet's index in the women. Symptoms and medication for heart disease did not correlate significantly with plasma vitamin C or with HDL cholesterol levels, but reported angina showed a weak positive association with total cholesterol in the men, and there was some evidence of increased cortisol levels in subjects with heart disease.     

Racial (black-white) comparisons of the relationship of levels of endogenous sex hormones to serum lipoproteins during male adolescence: the Bogalusa Heart Study

The cross-sectional relationship of endogenous androgens (testosterone, androstenedione, and dehydroepiandrosterone sulfate [DHEA-S]), estrogen (estradiol) and progestin (progesterone) to serum levels of lipoprotein cholesterol (very low-density [VLDL], low-density [LDL], and high-density lipoprotein [HDL]) and apolipoproteins (apo A-I and apo B) were studied in white (n = 251) and black (n = 258) adolescent boys, ages 11 to 17 years, as part of the Bogalusa Heart Study. Black boys had significantly higher levels of estradiol, HDL cholesterol, and apo A-I, and lower levels of androstenedione and VLDL cholesterol than white boys, independent of age and adiposity. Age was correlated strongly with testosterone and androstenedione, and moderately with DHEA-S and estradiol levels in both races. However, only in white boys was age consistently related to VLDL cholesterol (positively), HDL cholesterol (negatively), and apo A-I (negatively). Overall, testosterone was associated inversely with HDL cholesterol and apo A-I in white boys, while progesterone was related positively to apo A-I in both races after adjusting for age and adiposity. However, these relationships were found to differ with age. Partial correlations between levels of sex hormones and lipoproteins adjusted for age and adiposity showed no associations in the 11 to 12 year age group in boys of either race. A significant positive relation of testosterone to VLDL cholesterol, and inverse relations of testosterone to HDL cholesterol and apo A-I and DHEA-S to HDL cholesterol were apparent only in white boys in the 13 to 14 year age group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Apolipoprotein E polymorphism in men and women from a Spanish population: allele frequencies and influence on plasma lipids and apolipoproteins.

The apolipoprotein (apo) E phenotype and its influence on plasma lipid and apolipoprotein levels were determined in men and women from a working population of Madrid, Spain. The relative frequencies of alleles epsilon(2), epsilon(3) and epsilon(4) for the study population (n=614) were 0.080, 0.842 and 0.078, respectively. In men, apo E polymorphism was associated with variations in plasma triglyceride and very low-density lipoprotein (VLDL) lipid levels. It was associated with the proportion of apo C-II in VLDL, and explained 5.5% of the variability in the latter parameter. In women apo E polymorphism was associated with the concentrations of plasma cholesterol and low-density lipoprotein (LDL) and high-density lipoprotein (HDL) related variables. The allelic effects were examined taking allele epsilon(3) homozygosity as reference. In men, allele epsilon(2) significantly increased VLDL triglyceride and VLDL cholesterol concentrations, and this was accompanied by an increase of the apo C-II content in these particles. Allele epsilon(4) did not show any significant influence on men's lipoproteins. In women, allele epsilon(2) lowered LDL cholesterol and apo B levels, while allele epsilon(4) increased LDL cholesterol and decreased the concentrations of HDL cholesterol, HDL phospholipid and apo A-I. These effects were essentially maintained after excluding postmenopausal women and oral contraceptive users from the analysis. In conclusion: (1) the population of Madrid, similar to other Mediterranean populations, exhibits an underexpression of apo E4 compared to the average prevalence in Caucasians, (2) gender interacts with the effects of apo E polymorphism: in women, it influenced LDL and HDL levels, whereas in men it preferentially affected VLDL, and (3) allele epsilon(2) decreased LDL levels in women, while it increased both VLDL lipid levels and apo C-II content in men, but, in contrast to allele epsilon(4), it did not show an impact on HDL in either sex.     

Lipoprotein and apolipoprotein distribution in Zucker rats following an endurance running program

We examined the response to 12 weeks of endurance running of the obese Zucker rat and its lean littermate with regard to changes in serum lipids, lipoproteins and apoproteins. The obese Zucker rat is hyperlipoproteinemic, characterized by elevated serum triglyceride and cholesterol levels primarily associated with the very low density lipoprotein (VLDL) fraction. In lean Zucker rats, training did not affect the concentrations of serum lipids or apolipoproteins. In marked contrast, obese Zucker rats that were trained had significant decreases in serum concentrations of triglycerides, free and esterified cholesterol, and apolipoprotein B compared to their sedentary counterparts. Training obese rats caused an increase in the serum concentration of apolipoprotein E (HDL fraction). In contrast, training did not affect the concentration of Apo E in lean rats. The VLDL fraction was most affected by training obese rats showing marked 50-65% decreases in VLDL triglyceride and VLDL cholesterol. HDL cholesterol was unchanged in lean rats whereas training prompted a 29% increase in obese rats. These data show that exercise training altered the metabolic abnormalities of obese Zucker rats which are responsible for the accumulation in serum of VLDL, lipids and apolipoproteins.     

Association of plasma intermediate density lipoproteins with atherogenic intimal proliferative activity in abdominal aortas of hyperlipidemic swine

In an earlier study of swine fed hyperlipidemic (HL) diets containing either butter or corn oil we found wide differences in atherogenic intimal proliferative responses among the swine, especially in the corn oil group, that could not be entirely accounted for by differences in serum cholesterol levels. We hypothesized that there might be differences in some lipoprotein constituents other than total cholesterol that might better account for the differences in intimal proliferative responses. In the current experiment, 11 swine were fed HL diets containing butter (n = 5) or corn oil (n = 6). At 90 days on HL diet, plasma was obtained for lipoprotein fractionation. At 120 days the swine were killed and the lesion areas and number of nuclear profiles in the intima or lesions in multiple cross-sections of the distal abdominal aorta were determined under light microscopy. Tritiated thymidine labeling indices of the intima or lesion cells were also determined. On comparing the butter and corn oil groups, only IDL-cholesterol and tritiated thymidine labeling indices of the cells in the lesions were significantly different. Based on the number of nuclear profiles per cross-section (Np/Cx) 7 were classified as high intimal proliferative responders (5 butter, 2 corn oil) and 4 as low responders (4 corn oil). The high-proliferative responders had plasma IDL levels 6-fold greater than those of the low responders with no overlaps. LDL, VLDL and HDL were not significantly different between the high- and low-proliferative responders. Among correlation coefficients between Np/Cx and plasma lipoprotein variables for all swine (n = 11), IDL cholesterol level was best correlated with Np/Cx. However, in the high responder group LDL values showed a highly significant correlation with the amount of intimal proliferation.     

Effects of insulin on hypercholesterolemia in the streptozotocin-induced diabetic rats fed a high cholesterol diet

The effect of dietary cholesterol (Ch) on plasma lipoprotein and apolipoproteins (apo) in diabetic rats was investigated. Ch-fed diabetic rats were severely hypercholesterolemic and hypertriglyceridemic. They had higher concentrations of very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and low density lipoprotein (LDL). Concentration of high density lipoprotein (HDL) was decreased. beta-VLDL increased predominantly in Ch-fed diabetic rats, whereas IDL increased in the Ch and propylthiouracil-fed control rats. According to sodium dodecyl sulfate polyacrylamide gel electrophoresis, VLDL and IDL from Ch-fed diabetic rats were unusual in that they contained more apo E, A-I and A-IV. Concentrations of plasma apo A-I and apo E were measured by radioimmunoassay. The diabetic rats fed a labo chow showed a significantly lower concentration of plasma apo E than control rats. Plasma apo E was extremely higher in the diabetic rats fed a cholesterol diet. Plasma apo A-I was significantly increased in the diabetic rats fed a labo chow and those fed a cholesterol. Insulin treatment significantly decreased the concentrations of VLDL, IDL and LDL and plasma concentration and distribution of apolipoproteins in lipoprotein subfractions changed toward normal. However, decreased HDL in the Ch-fed diabetic rats was not recovered by insulin treatment.     

Accelerated turnover of very low density lipoprotein triglycerides in chronic alcohol users. A possible mechanism for the up-regulation of high density lipoprotein by ethanol

The concentration of high density lipoproteins (HDL) is related to the catabolism of triglyceride-rich lipoproteins. In order to elucidate the mechanisms by which alcohol increases plasma HDL levels we measured the turnover kinetics of very low density lipoprotein (VLDL) triglycerides in 10 alcoholic men without liver disease and in nonalcoholic control men matched for age, weight and plasma VLDL triglyceride level. The study was repeated in the alcoholics after a 2-week abstinence period. The alcoholic men had elevated HDL cholesterol but reduced low density lipoprotein (LDL) cholesterol as compared to the controls. The fractional catabolic rate and the total turnover (production) rate of VLDL triglycerides were both significantly increased (P less than 0.05) in the alcoholic men before abstinence. After withdrawal of alcohol both the synthetic rate and the catabolic rate of VLDL triglycerides returned to normal and the HDL (HDL2 and HDL3) cholesterol fell. The per cent decrease in HDL2 cholesterol during abstinence was positively correlated to the respective fall of VLDL triglyceride fractional catabolic rate (r = +0.51). The results suggest that the absence of hypertriglyceridemia and the elevated levels of HDL in regular alcohol users may be partly based on increased metabolic clearance of VLDL particles and on subsequent accelerated transfer of the VLDL surface components to HDL.     

Effect of fenofibrate on serum lipoproteins in subjects with familial hypercholesterolemia and combined hyperlipidemia

The effects on serum lipoproteins were studied in 8 patients with familial heterozygous hypercholesterolemia and 9 patients with familial combined hyperlipidemia during an 8-week treatment with fenofibrate. VLDL, IDL, LDL and HDL were isolated by ultracentrifugation and precipitation. Lipids and apolipoproteins A-I and B were determined by enzymatic and immunonephelometric techniques, respectively. In hypercholesterolemia, administration of fenofibrate resulted in decreases of VLDL, IDL, and LDL (cholesterol -58.3%, -28.6%, and -24.4%), while, in combined hyperlipidemia, treatment with the drug lowered VLDL and IDL (-33.3% and -42.9%). HDL cholesterol and apolipoprotein A-I increased only in hypercholesterolemia (+22.9% and +6.9%).     

Influence of mild to moderately elevated triglycerides on low density lipoprotein subfraction concentration and composition in healthy men with low high density lipoprotein cholesterol levels

Epidemiologic studies have shown that a dyslipoproteinemia with low concentrations of high density lipoprotein (HDL) cholesterol and elevated serum triglycerides (TG) is associated with a particularly high incidence of coronary artery disease. This lipid profile is associated with increased concentrations of small, dense low density lipoprotein (LDL) particles. To evaluate the role of mild to moderately elevated TG on the LDL subfraction profile in patients with low HDL cholesterol, concentration and composition of six LDL subfractions was determined by density gradient ultracentrifugation in 41 healthy men (31+/-9 years, body mass index (BMI) 25.1+/-3.9 kg/m2) with equally low HDL cholesterol levels < 0.91 mmol/l but different TG levels: TG < 1.13 mmol/l, n = 16; TG = 1.13-2.26 mmol/l, n = 13: TG = 2.26-3.39 mmol/l, n = 12. Those men with moderately elevated TG levels between 2.26 and 3.39 mmol/l had significantly higher concentrations of very low density lipoprotein (VLDL), intermediate low density lipoprotein (IDL), and small, dense LDL apoB and cholesterol than men with TG < 1.13 mmol/l. With increasing serum TG, the TG content per particle also increased in VLDL, IDL as well as total LDL particles while the cholesterol and phospholipid (PL) content decreased in VLDL and IDL, but not in LDL particles. LDL subfraction analysis revealed that only large, more buoyant LDL particles (d < 1.044 g/ml) but not the smaller, more dense LDL, were enriched in TG. Small, dense LDL particles were depleted of free cholesterol (FC) and PL. This study has shown that in men with low HDL cholesterol levels mild to moderately elevated serum TG strongly suggest the presence of other metabolic cardiovascular risk factors and in particular of a more atherogenic LDL subfraction profile of increased concentration of small, dense LDL particles that are depleted in surface lipids.     

Serum adiponectin level is correlated with the size of HDL and LDL particles determined by high performance liquid chromatography

ObjectiveAdiponectin (APN) improves insulin resistance and prevents atherosclerosis, and HDL removes cholesterol from atherosclerotic lesions. We have demonstrated that serum HDL-cholesterol (HDL-C) and APN concentrations are positively correlated and that APN accelerates reverse cholesterol transport (RCT) by increasing HDL synthesis in the liver and cholesterol efflux from macrophages. We previously reported that APN reduced apolipoprotein (apo) B secretion from the liver. It is well-known that insulin resistance influences the lipoprotein profile. In this study, we investigated the clinical significance of APN levels and insulin resistance in lipoprotein metabolism.Material/methodWe investigated the correlation between serum APN concentration, HOMA-R, the lipid concentrations and lipoprotein particle size by high-performance liquid chromatography (HPLC) in 245 Japanese men during an annual health checkup.ResultsSerum APN level was positively correlated with the cholesterol content in large LDL and HDL particles, but inversely correlated with the cholesterol content in large VLDL and small LDL particles. HOMA-R was negatively correlated with the cholesterol content in large LDL and HDL particles and positively correlated with the cholesterol content in large VLDL and small LDL particles. By multivariate analysis, APN was correlated with the particle size of LDL-C and HDL-C independently of age, BMI and HOMA-R.ConclusionsAPN may be associated with the formation of both HDL and LDL particles, reflecting the enhancement of RCT and the improvement in TG-rich lipoprotein metabolism and insulin resistance.     

Lipodystrophy defined by a clinical score in HIV-infected men on highly active antiretroviral therapy: correlation between dyslipidaemia and steroid hormone alterations

BACKGROUND: A syndrome of lipodystrophy, associated with hypertriglyceridaemia, hypercholesterolaemia, hyperinsulinaemia and peripheral insulin resistance has been reported in protease inhibitor (PI)-treated HIV-infected patients. Because lipid metabolism, fat mass distribution and insulin resistance are partly regulated by steroid hormones, we questioned whether lipodystrophy is related to hormonal perturbations. OBJECTIVE: To evaluate serum lipid and steroid hormone concentrations in HIV-positive men on highly active antiretroviral therapy (HAART) in order to determine whether dyslipidaemia, peripheral loss of fatty tissue and central fat accumulation are related to steroid hormone modifications. DESIGN: A cross-sectional study. METHODS: Thirty-seven HIV-1-positive men on HAART, 23 of whom had symptoms of lipodystrophy, according to a subjective clinical score of lipodystrophy (SCSL), were tested. Serum concentrations of cholesterol, triglycerides and their subclasses, apolipoproteins and steroid hormones, including cortisol, dehydroepiandrosterone (DHEA), DHEA sulphate, androstenedione, testosterone and dihydrotestosterone were measured. RESULTS: Serum cholesterol, very low density lipoprotein (VLDL) cholesterol, triglycerides, VLDL triglycerides, high density lipoprotein (HDL) and low density lipoprotein (LDL) triglycerides, apolipoprotein B (ApoB) and atherogenic ratios of cholesterol:HDL cholesterol, LDL cholesterol:HDL cholesterol and ApoB:apolipoprotein A1 (ApoA1) were significantly increased in lipodystrophy-positive compared with lipodystrophy-negative men. The serum cortisol level was similar in lipodystrophy-positive versus lipodystrophy-negative men, but was elevated compared with controls. Serum DHEA was significantly lower in lipodystrophy-positive versus lipodystrophy-negative men and, consequently, the cortisol:DHEA ratio was increased in lipodystrophy-positive patients. A positive correlation was found between the cortisol:DHEA ratio and increased levels of atherogenic lipids. In addition, the SCSL was positively correlated with dyslipidaemia and the cortisol:DHEA ratio. CONCLUSION: This study demonstrates an association between the cortisol:DHEA ratio, lipid alterations and lipodystrophy. This syndrome might result from an imbalance between peripheral lipolysis and lipogenesis, both regulated by cortisol and DHEA.     

Lipoprotein abnormalities and extracoronary atherosclerosis in patients with premature ischemic heart disease

A study of serum lipoprotein (VLDL, LDL, HDL) concentration has been performed on 36 males who had undergone an aorto-coronary bypass operation before age 50. They have been compared to 33 healthy men in the same age range. The presence and severity of coronary, carotid and peripheral atherosclerosis in these patients has been evaluated on the basis of coronary angiograms, continuous wave Doppler and Duplex scanning by echo-Doppler. Lipoprotein abnormalities have been related to the occurrence of extracoronary arterial lesions in association with myocardial ischemia. Total serum cholesterol and triglycerides, LDL cholesterol and triglycerides were higher in IHD patients (p less than 0.05), while HDL cholesterol was lower (p less than 0.01). No statistically significant difference was detected in VLDL lipids or apo B and in LDL apo B. Signs of extracoronary atherosclerosis were more frequent among IHD patients than in controls. Ankle/arm pressure ratio was abnormally low in 12 patients as compared to only one control (p less than 0.01). Echo-Doppler examinations of iliac arteries demonstrated a higher prevalence of lesions among IHD patients as compared to controls (20 versus 2; p less than 0.01). All patients (4 out of 36) with audible carotid bruits had stenoses in the internal carotid artery. In order to evaluate the relationships between lipoprotein concentration and occurrence of extracoronary atherosclerosis, analysis of variance and multiple comparisons were performed on values for lipoprotein concentration in three groups: controls, IHD patients without evidence of extracoronary atherosclerosis, IHD patients with detectable extracoronary lesions. Significant differences among the three groups were demonstrated as regard to LDL cholesterol or triglycerides and HDL cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative and qualitative serum lipoprotein analysis. Part 1. Studies in healthy men and women.

Preparative ultracentrifugal and electrophoretic analysis of serum lipoproteins was performed in 30-70-year-old healthy, fasting males (N = 80) and females (N = 77), randomly selected from the Uppsala region, Sweden. The concentrations of cholesterol and triglycerides in total serum and in VLDL,LDL and HDL lipoprotein classes are reported. Total serum, VLDL and LDL triglycerides and cholesterol concentrations increased with age, while HDL cholesterol and triglyceride concentrations did not vary with age. Overweight persons had higher total serum triglyceride, higher VLDL cholesterol and triglyceride and lower HDL cholesterol levels. The upper 90% population limit values for non-overweight males/females were: total triglycerides (mmol/l) 2.5/2.0, total cholesterol (mg/100 ml) 298/300, VLDL triglyceride 1.80/1.05, VLDL-cholesterol 32/33, LDL triglyceride 0.69/0.69, LDL cholesterol 210/218, HDL triglyceride 0.32/0.34 and HDL-cholesterol 69/93. The 2 major differences between males and females were that females had lower VLDL but higher HDL concentrations. For VLDL there was a very strong and for LDL a moderately strong positive correlation between cholesterol and triglyceride contents. In HDL however, the mearsured amounts of cholesterol and triglycerides did not correlate at all. Sinking pre-beta lipoproteins was found in about 25% of cases and a second pre-beta band floating at d 1.006, late pre-beta, was found in 35% of male and 25% of female subjects. Subjects with sinking pre-beta lipoprotein did not differ from other subjects with regard to the concentration of cholesterol and triglycerides in the 3 lipoprotein classes. Males, but not females, with the late pre-beta (LPB), had an increased amount of cholesterol in VLDL and a raised cholesterol-triglyceride ratio in this lipoprotein class. Also the LDL triglyceride level was increased in males with the late pre-beta lipoprotein.