Nonpharmacologic and pharmacologic alteration of high-density lipoprotein cholesterol: therapeutic approaches to prevention of atherosclerosis

Identification of co-expressed central genes and transcription factors in acute myocardial infarction and diabetic nephropathy

BACKGROUND

Acute myocardial infarction (AMI) and diabetic nephropathy (DN) are common clinical co-morbidities, but they are challenging to manage and have poor prognoses. There is no research on the bioinformatics mechanisms of comorbidity, and this study aims to investigate such mechanisms.

METHODS

We downloaded the AMI data (GSE66360) and DN datasets (GSE30528 and GSE30529) from the Gene Expression Omnibus (GEO) platform. The GSE66360 dataset was divided into two parts: the training set and the validation set, and GSE30529 was used as the training set and GSE30528 as the validation set. After identifying the common differentially expressed genes (DEGs) in AMI and DN in the training set, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses and protein-protein interaction (PPI) network construction were performed. A sub-network graph was constructed by MCODE, and 15 hub genes were screened by the Cytohubba plugin. The screened hub genes were validated, and the 15 screened hub genes were subjected to GO, KEGG, Gene MANIA analysis, and transcription factor (TF) prediction. Finally, we performed TF differential analysis, enrichment analysis, and TF and gene regulatory network construction.

RESULTS

A total of 46 genes (43 up-regulated and 3 down-regulated) were identified for subsequent analysis. GO functional analysis emphasized the presence of genes mainly in the vesicle membrane and secretory granule membrane involved in antigen processing and presentation, lipopeptide binding, NAD + nucleosidase activity, and Toll-like receptor binding. The KEGG pathways analyzed were mainly in the phagosome, neutrophil extracellular trap formation, natural killer cell-mediated cytotoxicity, apoptosis, Fc gamma R-mediated phagocytosis, and Toll-like receptor signaling pathways. Eight co-expressed hub genes were identified and validated, namely TLR2, FCER1G, CD163, CTSS, CLEC4A, IGSF6, NCF2, and MS4A6A. Three transcription factors were identified and validated in AMI, namely NFKB1, HIF1A, and SPI1.

CONCLUSIONS

Our study reveals the common pathogenesis of AMI and DN. These common pathways and hub genes may provide new ideas for further mechanistic studies.

Cytochrome P450--physiological key factor against cholesterol accumulation and the atherosclerotic vascular process

In the early 1960s liver cytochrome P450 (P450) was known as an enzyme in drug metabolism. By the late 1970s, P450 induction was associated with elevation of plasma high-density lipoprotein cholesterol and apolipoprotein AI indicating a reduced risk of atherosclerotic disease. Later on, 57 human P450 genes have been identified. One P450 enzyme participates in cholesterol synthesis, and several others catabolize it to oxysterols and other metabolites. Oxysterols are physiological ligands specific for liver X receptors (LXRs) in the activation of ATP-binding cassette (ABC) transporter and other cholesterol-lowering genes. Elevation of cholesterol leads to an endogenous induction of P450 and consequently to enhanced generation of oxysterols and activation of genes coding proteins which efflux cholesterol out of cells, transport it to the liver, catabolize and excrete cholesterol into bile, and prevent absorption of cholesterol in the intestine in the processes that maintain cellular cholesterol homeostasis and protect arteries from atherosclerosis. Peroxisome proliferator-activated receptors (PPARs) co-operate with LXRs and ABC transporters in cholesterol regulation. Secretion of oxysterol is a direct pathway for cellular cholesterol elimination. Several compounds induce P450 and other genes regulating cholesterol balance and prevent or regress atherosclerosis, whereas inhibition of P450 blocks oxidative reactions, promotes cholesterol accumulation, and enhances the atherosclerotic vascular process.

Nonlinear relation between alcohol intake and high-density lipoprotein cholesterol level: results from the Copenhagen City Heart Study

BACKGROUND

It has been suggested that the level of high-density lipoprotein cholesterol (HDL-C) in the blood can be used as a marker of recent alcohol intake. However, before using HDL-C as a predictor of alcoholism, the relation between alcohol intake and HDL-C in the entire range of consumption must be explored. Most studies model the relation between alcohol intake and HDL-C linearly, although a threshold effect is expected. The objective of this study was to evaluate the shape of the relation between intake of alcohol and HDL-C and to determine whether there are differential effects of beer, wine, and spirits on HDL-C and whether they remain after adjusting for total alcohol.

METHOD

The relation between alcohol intake and HDL-C was investigated by means of generalized additive models using data from the Copenhagen City Heart Study.

RESULTS

A nonlinear effect of alcohol improved the model fit significantly, and the nonlinearity of alcohol was highly significant in both men and women. The relation was concave: HDL-C was stable in men and women who drank more than approximately 35 and 20 drinks per week, respectively. We found a significant nonlinear term of wine on HDL-C in men after adjustment for total alcohol intake.

CONCLUSIONS

There was a concave relation between alcohol intake and HDL-C, indicating a threshold effect of alcohol on HDL-C. The association between wine and HDL-C in men after adjusting for total alcohol intake may be due to residual lifestyle confounding.

Association of carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) with serum lipid profile in the Finnish population

BACKGROUND

Moderate consumption of alcohol may reduce mortality from vascular diseases. The beneficial effects of alcohol may partly be mediated by its effects on lipoprotein metabolism. We studied the connection between alcohol consumption and the serum lipid profile from a well-documented national health program study.

METHODS AND RESULTS

Carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) were used as biochemical markers for alcohol consumption. The laboratory analyses were carried out on 5675 subjects (3097 males and 2578 females). The subjects were divided into quartiles on the basis of CDT or GGT value. The highest CDT quartile and the lowest GGT quartile seemed to be associated with a favorable lipid profile and the lowest CDT quartile and the highest GGT quartile were associated with an unfavorable lipid profile. Serum high density lipoprotein (HDL) cholesterol values were significantly higher and triglycerides lower with increasing serum CDT concentrations for both men and women. Increasing serum GGT was associated with higher serum total cholesterol and higher triglycerides in both men and women and lower HDL cholesterol in men.

CONCLUSIONS

CDT and GGT seem to detect different populations of subjects in regard to lipid metabolism. These observations may lead to a better understanding of the effects of alcohol consumption on lipids as well as mechanisms behind favorable and detrimental effects of alcohol on vascular diseases.

CONDENSED ABSTRACT

Carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) were used as biochemical markers for alcohol consumption. A total of 3097 males and 2578 females were divided into quartiles on the basis of their CDT or GGT values. The highest CDT quartiles had higher HDL and lower triglycerides, whereas the highest GGT quartiles appeared to be associated with higher total cholesterol and triglycerides in both genders and lower HDL in men. CDT and GGT seem to detect different populations of subjects in regard to lipid metabolism. These observations may have important clinical and public health implications.

Temporal effects of testosterone propionate injections on serum lipoprotein concentrations in rats

The chronic abuse of androgenic anabolic steroids, a group of synthetic derivatives of testosterone, to improve athletic performance have demonstrated compromised serum lipoprotein concentrations reflecting an elevated risk for cardiovascular disease. While the detrimental alterations in the lipoprotein profile have been reported consistently for orally administered androgenic anabolic steroids, the reports examining the effects of parenteral administration of testosterone upon the lipid profile remain equivocal.

PURPOSE

The purpose of this study was to determine whether compromised serum lipoprotein concentrations would be manifest in rats receiving testosterone injections (twice per week) over the time course of 7 wk.

METHODS

Male rats were randomly assigned to either an experimental group (dose per injection, 3 mg x kg(-1) testosterone propionate solubilized in 1 mL of safflower oil) or a control group (injected with an isovolumic amount of safflower oil alone). The effects of the steroid regimen on the serum lipoprotein profiles were followed after 1, 3, 5, and 7 wk of injections. To assess the relative effects of testosterone propionate, testicular mass was determined at the time of sacrifice.

RESULTS

Testicular mass (mean +/- SE) was significantly lower (P<0.01) in the experimental group, 3.08+/-0.03 g, compared with that in controls, 3.82+/-0.05 g, by week 3 and continued to decline for the remainder of the steroid regimen, reaching a nadir of 2.70+/-0.01 g at week 5. No significant differences were observed between groups for total serum cholesterol, serum triacylglycerols, or serum low density lipoprotein (LDL)-C at any time point. However, at week 7, serum high density lipoprotein (HDL)-C (mean +/- SE) was significantly lower (P<0.02) in the testosterone treated animals, 32+/-2 mg x dL(-1), compared with that in controls, 47+/-2 mg x dL(-1). As a result, the ratio of total cholesterol to HDL-C (mean +/- SE) significantly increased (P<0.02) by the seventh week in the testosterone treated group, 3.5+/-0.2, versus controls, 2.5+/-0.2.

CONCLUSIONS

The results suggest that while testosterone propionate injections elicit a reduction in testicular mass within 3 wk, the lipoprotein profile is not altered until week 7. Further, the only compromised parameter under the conditions of this study is the decrease in serum HDL-C.

Carbohydrate-deficient transferrin and gamma-glutamyltransferase are inversely associated with lipid markers of cardiovascular risk

BACKGROUND

A variety of epidemiological studies have suggested a U-shaped association between alcohol consumption and atherosclerosis progression and incidence events. Moderate intake of alcohol is considered beneficial, whereas heavy drinking increases cardiovascular disease risk.

METHODS

Alcohol and cardiovascular risk-related laboratory tests were carried out in 70 consecutive male employees in connection with an occupational health survey in 1996. Carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GGT) were used as markers for alcohol consumption. The subjects were divided into quartiles on the basis of CDT or GGT value.

RESULTS

The highest CDT quartile had significantly higher serum high-density lipoprotein (HDL)-cholesterol (P < 0.05) than the lowest quartile. The highest GGT quartile had significantly higher serum total cholesterol (P < 0. 01), lower serum HDL-cholesterol (P < 0.05), higher serum low-density lipoprotein (LDL)-cholesterol (P < 0.01) and higher serum triglyceride (P < 0.01) than the lowest quartile.

CONCLUSIONS

An explanation for the findings is that high alcohol consumption without significant liver induction increases the level of HDL-cholesterol, whereas high alcohol consumption with induction of liver may have adverse effects on lipoprotein metabolism. The results were interpreted to indicate that CDT and GGT detect different populations of drinkers in regard to cardiovascular lipid risk factors.

Estrogen replacement therapy and cardiovascular protection: lipid mechanisms are the tip of an iceberg

Cardiovascular disease remains a major cause of mortality among postmenopausal women. After menopause, atherogenesis is promoted by a number of metabolic and vascular changes. A multitude of observational clinical studies have come to the conclusion that estrogen replacement therapy (ERT) reduces cardiovascular risk by approximately 50% and that estrogen's favorable effects on the lipid profile can explain only 25-50% of the overall observed reduction. Estrogens are now known to have potent anti-atherogenic properties through lipid and non-lipid mechanisms; both will be highlighted in view of the recent literature. Estrogens induce favorable changes on lipids and lipoproteins, partly by increasing HDL-cholesterol and decreasing both LDL-cholesterol and lipoprotein (a). Non-lipid mechanisms of estrogen action include decreasing insulin resistance, serum fibrinogen, factor VII and plasminogen activator inhibitor-1 (PAI-1). Moreover, estrogens maintain endothelial cell integrity, decrease expression of adhesion molecules, lower systemic blood pressure, promote vasodilatation, decrease platelet aggregability, inhibit vascular smooth muscle cell proliferation, possess potent antioxidant and calcium antagonist activities, inhibit adrenergic responses and downregulate platelet and monocyte reactivity. Also mentioned are recent reports linking estrogen to the renin-angiotensin system, relaxin, serotonin and homocysteine. What was once thought of as a simple action is now being increasingly appreciated as a complex, multifaceted mechanism, which serves to prove that estrogen is a powerful cardiovascular agent.

Lack of demonstrated effect of nandrolone on serum lipids

Numerous prior studies of serum lipid levels during anabolic steroid (AS) use have uniformly demonstrated dramatic adverse lipid profiles (eg, average high-density lipoprotein [HDL] depression of 50%) during administration of 17 alpha-alkylated AS. In contrast, the existing studies of 17 beta-esterified AS have shown mild or absent lipid effects (eg, HDL depression 0% to 16%) with these agents. Thus, the potential effects on serum lipids of individual AS are an important clinical consideration. The present study was therefore designed to investigate the lipid effects of nandrolone, a 17 beta-esterified AS. Twenty-one men and three women had lipid profiles measured before and after administration of nandrolone decanoate 100 mg intramuscularly (IM) once a week for 6 weeks. No significant change was noted in HDL cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, the total cholesterol to HDL-C ratio, or the LDL-C/HDL-C ratio from nandrolone treatment. Moreover, observed trends toward HDL-C depression (-2.00 +/- 8.83 mg/dL; values reported are for men only unless noted otherwise) and LDL elevation (+5.05 +/- 20.45 mg/dL) were small. In power analysis, HDL-C depressions of 6.3, 7.6, or 8.7 mg/dL during nandrolone were ruled out with powers of 80%, 95%, and 99%, respectively.

Effect on lipid metabolism of a biphasic desogestrel-containing oral contraceptive: divergent changes in apolipoprotein B and E and transitory decrease in Lp(a) levels

The effect of a low dose biphasic oral contraceptive containing 40 micrograms ethinylestradiol + 25 micrograms desogestrel (7 tablets) and 30 micrograms ethinylestradiol + 125 micrograms desogestrel (15 tablets) on lipid metabolism was investigated in 19 women during 6 cycles of treatment and compared to the values of the pre- and post-treatment cycle. During treatment, all components of HDL increased reversibly by 10 to 30%. The levels of total cholesterol (CH), LDL-CH and IDL-CH rose only slightly, while those of total triglycerides (TG), VLDL-TG and LDL-TG rose continuously by more than 100% until the 6th cycle. At the same time, plasma levels of VLDL-CH increased by 60% and of apolipoprotein B by 20%. Contrary to this, apolipoprotein E decreased by 25% during treatment, and Lp(a) was transitorily reduced during the 3rd cycle. After termination of intake, total CH, LDL-CH, IDL-CH and apolipoprotein B remained elevated, while total TG, VLDL-TG, VLDL-CH and LDL-TG decreased significantly, but were still elevated during the post-treatment cycle. The levels of apolipoprotein E returned to pre-treatment values. The results indicate a marked preponderance of the effect of the estrogen component. The rise in TG and VLDL synthesis seems to be outweighed by an enhanced removal of apolipoprotein E-containing remnants which might offer protection from the development of atherosclerosis.

Utility and evaluation of biochemical markers of alcohol consumption

Biochemical markers of alcohol consumption have a variety of clinical and research applications. Currently available markers such as the serum gamma-glutamyl transpeptidase (GGT), serum transaminases, and the mean corpuscular volume (MCV) lack sufficient sensitivity and specificity to be used for screening of alcoholism in ambulatory patients. However, these tests can be helpful in corroborating a clinical suspicion of alcoholism. A number of special laboratory markers of alcoholism recently have been developed which may have increased diagnostic accuracy. Promising potential markers include serum carbohydrate-deficient transferrin (CDT), red blood cell acetaldehyde, and acetaldehyde adducts. The application of reliable and practical markers of alcohol consumption could lead to significant improvements in the treatment of alcoholism and in the assessment of clinical trials.

Usefulness of the total cholesterol to high-density lipoprotein cholesterol ratio in predicting angiographic coronary artery disease in women

To investigate the relation between lipids and angiographic coronary artery disease (CAD) in women, fasting lipid profiles were obtained on 108 women undergoing coronary angiography (group I). CAD, defined as greater than or equal to 25% luminal diameter narrowing in a major coronary artery, was present in 57 (53%). Neither serum total cholesterol nor triglyceride levels correlated with the presence of CAD. Mean total/high-density lipoprotein (HDL) cholesterol ratio was higher among women with than without CAD (5.5 +/- 0.3 vs 4.2 +/- 0.2, p less than 0.0001). Multiple regression analyses identified a higher total/HDL cholesterol ratio as the variable most predictive of the presence (p less than 0.001), extent (number of narrowed arteries) (p less than 0.0001), and severity (% maximum stenosis) (p less than 0.001) of CAD. Age and lack of estrogen use were also independently associated with the presence of CAD, age and low-density lipoprotein cholesterol level were additional indicators of extent, and age was the only other discriminator of severity of CAD. In 56 women with total cholesterol less than 200 mg/dl (group II), mean total/HDL cholesterol ratio was higher in women with (n = 24) than without CAD (4.3 +/- 0.2 vs 3.5 +/- 0.2, p = 0.01). Higher total/HDL cholesterol ratio was the variable most predictive of the presence of CAD (p = 0.01), and the lone variable associated with severity (p less than 0.001) after adjustment for other risk factors. Age was independently associated with presence and extent, and hypertension was also independently related to extent.(ABSTRACT TRUNCATED AT 250 WORDS)

Significant increase of high-density lipoprotein2-cholesterol under prolonged simvastatin treatment

In a contribution to a prolonged multicenter study 15 patients with primary hypercholesterolemia were treated with simvastatin, a competitive inhibitor of HMG-CoA reductase. The first part of the study was done in a double-blind fashion comparing the effect of this new drug with that of gemfibrozil during 12 weeks, and after this period on open-label treatment was started with the administration to all the patients of simvastatin in doses ranging from 2.5 to 40 mg q.p.m. Persistent and significant reductions (P less than 0.001) were achieved for total serum cholesterol (TC), LDL-cholesterol (LDL-C), apo B and triglycerides: by 38, 49, 44 and 33%, respectively, after 40 weeks of the open-label extension. From week 12, LDL-C levels were maintained at a cut point less than or equal to 140 mg/dl in every patient throughout the study. At week 40, cholesterol values of HDL subfractions showed a significant increase in HDL2-C (28%, P less than 0.01) and a concomitant reduction in HDL3-C (12%, P less than 0.01) in spite of a nonsignificant elevation of total HDL-C (by 6%). The HDL2-C/HDL3-C ratio rose by 47% (P less than 0.001) and the TC/HDL-C ratio was significantly reduced by 43%: from 6.1 +/- 1.2 to 3.5 +/- 0.7 (mean +/- SD, P less than 0.001). No adverse effects were detected. Our results suggest a conversion of HDL3 into HDL2, which could imply a beneficial effect of simvastatin upon the so-called reverse cholesterol transport, in addition to the striking reduction in atherogenic lipoproteins.

Effect of physical training on lipids, lipoproteins, apolipoproteins, lipases, and endogenous sex hormones in men with premature myocardial infarction

In 17 men, aged 27 to 54 years, with myocardial infarction 2 to 10 months before the current exercise study, we aimed to determine whether 3 months of exercise training, at a level designed to elevate high-density lipoprotein cholesterol (HDLC), would be associated with changes in endogenous sex steroid hormones and postheparin lipoprotein and hepatic lipases, and whether the changes in sex hormones, lipids, lipoproteins, apolipoproteins, and physical activity were interrelated. Supervised bicycle ergometry, 30 minutes, 3 days per week, eliciting 75% of maximum heart rate, produced a significant training effect, with a 26% increase in the duration of the exercise test at a standardized, submaximal workload (P less than or equal to .001), and a reduction in heart rate measured at a standardized submaximal workload, P = .08. After 3 months' training, mean HDLC increased 23% (30 to 37 mg/dL), P less than or equal to .001, mean apo A2 increased 19% (43 to 51 mg/dL), P less than or equal to .001, and the ratio of total cholesterol (TC) to HDLC decreased 26% (P less than or equal to .01), while estradiol (E2) levels decreased 45% (50.1 to 27.8 pg/mL), P less than or equal to .0001. After 1 and 2 months' exercise, TC (12% [P less than or equal to .001], 11% [P less than or equal to .01]), and low-density lipoprotein cholesterol (LDLC) (13% [P less than or equal to .01], 12% [P less than or equal to .01]) were reduced. Hepatic lipase decreased 16% (P less than or equal to .01) and 16% (P less than or equal to .05) after 1 and 3 months' exercise. There were no significant changes in apo A1, lipoprotein lipase, testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), or weight. By stepwise regression analysis, after 3 months' training, 66% (P = .0025) of the variance for the increase in HDLC from baseline to day 90 was accounted for independently by a decrease in triglyceride (F = 13.2, P = .003), by reduced heart rate on a fixed submaximal load (F = 12.7, P = .0035), and by a decrease in hepatic lipase (F = 5.5, P = .036). A modest, achievable exercise program can have significant cardiovascular benefit for men after myocardial infarction by ameliorating their hyperestrogenemia, reducing TC and LDLC, improving the TC to HDLC ratio, and elevating HDLC and apo A2. The increment in HDLC was related independently to improved capacity to sustain submaximal exercise and to exercise-induced reductions in triglyceride and postheparin hepatic lipase.

Time-dependent alterations in lipid metabolism during treatment with low-dose oral contraceptives

The effect of sex steroids on lipid metabolism depends on the type and dose of the compounds, the route of administration, and the duration of treatment. Therefore the composition of an oral contraceptive determines the resultant effect on lipids and lipoproteins. During 12 months of treatment, the effects of two oral contraceptives containing 30 micrograms of ethinyl estradiol and 150 micrograms of desogestrel (EE/DG) or 75 micrograms of gestodene (EE/GSD) on 19 serum parameters of lipid metabolism were followed in 11 women each. There was no change in total cholesterol and phospholipids. Total triglyceride levels were significantly elevated only by EE/GSD. After 3 and 6 months of intake of both preparations, a transitory increase in the triglyceride content of very low-density lipoprotein and low-density lipoprotein and a decrease in low-density lipoprotein-phospholipids was observed. After 12 months, very low-density lipoprotein cholesterol, very low-density lipoprotein phospholipids, and apolipoprotein B were significantly elevated, whereas very low-density lipoprotein triglycerides and all components of low-density lipoprotein were unchanged. Most of the components of high-density lipoprotein (HDL) were increased as a result of a rise in HDL3 and apolipoprotein A2, whereas HDL2 and apolipoprotein A1 were not altered. There was no significant difference between the effects of the two preparations, although those of EE/GSD were mostly more pronounced. The increase in high-density lipoprotein, very low-density lipoprotein, and total triglycerides reflects a slight preponderance of the effect of the estrogen component. Because low-density lipoprotein cholesterol and total cholesterol were not changed, treatment with both formulations is in all probability not associated with an elevated risk of atherosclerosis.

Atherosclerosis: the importance of HDL cholesterol and prostacyclin: a role for niacin therapy

Niacin reduces the incidence of non-fatal myocardial way infarction, confers a significant long-term survival benefit after recovery from myocardial infarction, and has had many years of study and usage by the medical community. Recent evidence suggests that via mechanisms which elevate HDL cholesterol and also release endogenous prostacyclin, niacin should be a potent agent in the long-term treatment of atherosclerosis.

New insights and new approaches for the treatment of essential hypertension: selection of therapy based on coronary heart disease risk factor analysis, hemodynamic profiles, quality of life, and subsets of hypertension

The pharmacologic therapy of mild primary hypertension (diastolic blood pressure less than 105 mm Hg) has effectively reduced hypertensive arteriolar end organ disease such as cerebrovascular accidents, congestive heart failure, and nephropathy, but there has been no convincing evidence that coronary heart disease (CHD) or its complications, acute myocardial infarction or angina, have been reduced. The risks of therapy with certain antihypertensive drugs may outweigh their treatment benefits as it relates to CHD. The optimal treatment strategy should be to reduce all CHD risk factors, reverse the hemodynamic abnormalities present by lowering the systemic vascular resistance (SVR), preserving cardiac output (CO) and perfusion, and to select the best antihypertensive drug for concomitant medical diseases or problems while maintaining a good quality of life. Antihypertensive drugs that have favorable or neutral effects on CHD risk factors include alpha blockers, calcium channel blockers, central alpha agonists, and angiotensin-converting enzyme inhibitors. On the other hand, diuretics and beta blockers without intrinsic sympathomimetic activity have unfavorable effects on many CHD risk factors. Baseline and serial evaluation of the effects of these drugs on serum lipids, lipid subfractions, glucose, uric acid, electrolytes, exercise tolerance, left ventricular hypertrophy, blood pressure, SVR, CO, perfusion, concomitant diseases, and side effects is necessary to evaluate overall cardiovascular risk.

Effects of estrogen dose and smoking on lipid and lipoprotein levels in postmenopausal women

The joint effects of conjugated estrogen use, age, body mass index, and smoking on plasma lipid and lipoprotein levels were assessed in 585 women who used oral estrogen and 1093 women who did not who participated in the Walnut Creek Contraceptive Drug Study. Whether administered daily or cyclically, conjugated estrogen was associated with reductions in low-density lipoprotein cholesterol levels and increases in high-density lipoprotein cholesterol and triglyceride levels. The adjusted mean low-density lipoprotein cholesterol concentration was 132 mg/dl for women who used conjugated estrogen in a dose greater than or equal to 1.25 mg/day; the adjusted corresponding mean concentration was 147 mg/dl for postmenopausal women who did not use estrogen. A dose-response pattern was demonstrated between conjugated estrogen and low- and high-density lipoprotein cholesterol levels. A maximum low-density lipoprotein cholesterol level reduction was reached at a dose of 1.25 mg, suggesting a saturation phenomenon. Stepwise dose-response increases in high-density lipoprotein cholesterol levels were also found with estrogen therapy, with a maximum increase of 8 to 10 mg/dl observed with the 1.25 mg dose. Estrogen-related rises in low-density lipoprotein cholesterol levels and decreases in high-density lipoprotein cholesterol levels were offset by 2 to 3 mg/dl in women who smoked. It may be concluded, therefore, that among postmenopausal women, low-risk lipoprotein profiles as assessed by low- and high-density lipoprotein cholesterol levels are found in nonsmokers whose postmenopausal hormone therapy includes the equivalent of a conjugated estrogen dose of 1.25 mg.

Lipoprotein analysis in bodybuilders

The use of anabolic steroids to augment athletic performance is widespread. It is known that these drugs can adversely affect lipoproteins in normal volunteers, leading to increased cholesterol and low density lipoprotein and depressed high density lipoprotein. It has been shown that endurance type exercise can lead to beneficial effects on lipoproteins but the effects of power exercise are less clear-cut and made more difficult to interpret by prior anabolic steroid use. This paper details the lipoprotein results in 24 subjects, eight sedentary controls, eight non-steroid and eight steroid using bodybuilders. The results revealed no significant difference between sedentary controls and non-steroid bodybuilders suggesting that this form of training does not cause beneficial effects on lipoproteins. However, the steroid-using groups had higher cholesterol and low density lipoprotein, with lower high density lipoprotein, high density lipoprotein2, high density lipoprotein3 and high density lipoprotein2/high density lipoprotein3 ratios compared to the other two groups. The long-term effects of such results may be an increased risk of atherosclerosis and requires long-term follow-up.