Serum-lipids in women on oral contraceptives

The Extending Spectrum of NPC1-Related Human Disorders: From Niemann-Pick C1 Disease to Obesity

The Niemann-Pick type C1 (NPC1) protein regulates the transport of cholesterol and fatty acids from late endosomes/lysosomes and has a central role in maintaining lipid homeostasis. NPC1 loss-of-function mutations in humans cause NPC1 disease, a rare autosomal-recessive lipid-storage disorder characterized by progressive and lethal neurodegeneration, as well as liver and lung failure, due to cholesterol infiltration. In humans, genome-wide association studies and post-genome-wide association studies highlight the implication of common variants in NPC1 in adult-onset obesity, body fat mass, and type 2 diabetes. Heterozygous human carriers of rare loss-of-function coding variants in NPC1 display an increased risk of morbid adult obesity. These associations have been confirmed in mice models, showing an important interaction with high-fat diet. In this review, we describe the current state of knowledge for NPC1 variants in relationship to pleiotropic effects on metabolism. We provide evidence that NPC1 gene variations may predispose to common metabolic diseases by modulating steroid hormone synthesis and/or lipid homeostasis. We also propose several important directions of research to further define the complex roles of NPC1 in metabolism. This review emphasizes the contribution of NPC1 to obesity and its metabolic complications.

Metabolic Effects of Contraceptive Steroids 1. Observations of Blood Lipids

Semilongitudinal observations on fasting blood sugar, total lipids, cholesterol, phospholipids, triglycerides, nonesterified fatty acids (NEFA), and lipoproteins were carried out on 116 women taking combination type oral contraceptives for 3-42 cycles. The changes observed differed with each constituent. Total lipids showed significant increase throughout the period of observation. Cholesterol and phospholipds showed significant increases after about 12 cycles of administration whereas triglycerides showed an increase after 6 cycles of medication. NEFA showed significant decrease in the 1st-3rd cycles. The alpha and beta lipoprotein ratios showed significant changes after 13-24 cycles of treatment. The general trend of change observed is similar to that reported during pregnancy.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Putative apolipoprotein B-100 in the freshwater turtle Chrysemys picta: effects of estrogen and progesterone

1. The isolation and purification of a putative apolipoprotein B-100 in the plasma of the freshwater turtle Chrysemys picta is described. 2. The protein was purified through differential ultracentrifugation and subsequent Sepharose 6B column chromatography. 3. The molecular weight of the protein determined by electrophoresis was approximately 350 kDa. 4. An antibody to chicken apolipoprotein B-100 specifically recognizes this 350 kDa protein in Western blots, suggesting its identity with apolipoprotein B-100. 5. An antibody to the putative Chrysemys apolipoprotein B-100-like protein was developed and used in an ELISA to quantitate protein levels in plasma. 6. Acute estrogen treatment increased levels of apolipoprotein B-100 (7.64 +/- 0.79 mg/ml plasma) over that of control animals (5.07 +/- 1.74 mg/ml plasma). 7. In contrast, chronic estrogen treatment reduced apolipoprotein B-100 significantly to 2.94 +/- 0.53 mg/ml plasma (P < 0.05).

Prodrugs: advantage or disadvantage?

Our knowledge of the peculiarities of prohormones is rather limited, both pharmacologically and clinically. Generalizations cannot be made except that the lapse of time until peak blood values of the active drug have been reached are always greater after intake of the prodrug than after intake of the drug. This finding is presumably of no clinical importance. If pharmacokinetic differences are limited to the phase of distribution, bioequivalence may be assumed. If, on the other hand, the area under the curve during the elimination phase is smaller for the prodrug than for the drug, the potency of the former should be decreased. A shift in the spectrum of endocrine actions as a result of the biotransformation of the prodrug into the active drug is rather the exception than the rule, and so is a change in side effects. If there are major differences in this respect, metabolic pathways in addition to those leading to the respective active drug must also be taken into consideration.

Effects of estrogen on very-low-density lipoprotein triacylglycerol metabolism in chicks

Estrogen administration (25 mg/kg body weight) in chicks resulted in a marked elevation of plasma very-low-density lipoprotein (VLDL) triacylglycerol (TG). To determine whether the VLDL produced from estrogen (E)-treated birds is catabolized differently from VLDL of control birds, VLDL-TG kinetic studies were conducted. The [14C]TG-labeled VLDL was prepared by intravenous injection of [14C]palmitate into control and E-treated chicks. The [14C]TG-labeled VLDL prepared from the control (C-VLDL-TG) and E-treated chicks (E-VLDL-TG) were then reinjected into fed and fasted chicks with or without E-treatment. The metabolism of VLDL-TG was found to be different, depending upon whether its donor was the control of E-treated chick. The fractional catabolic rate (FCR) of E-VLDL-TG was significantly (P less than 0.05) lower than that of C-VLDL-TG in both fed and fasted chicks. Compared to the fed state, fasting resulted in significantly (P less than 0.05) increased FCRs of both C-VLDL-TG and E-VLDL-TG. The turnover rate of VLDL-TG was significantly higher in E-treated chicks than in their respective controls. In addition, the endogenously produced VLDL-TG differed in their affinity for lipoprotein lipase in which E-VLDL-TG had a higher Km value for the enzyme than C-VLDL-TG. On agarose gel electrophoresis, the VLDL of E-treated chicks showed beta-mobility and it eluted into two peaks on agarose gel filtration, whereas VLDL of control chicks had a pre-beta-mobility on the former and it eluted into a single peak on the latter. SDS-gel electrophoresis also revealed that the apolipoprotein composition of VLDL from control and E-treated chicks was notably different from each other. Present findings suggest that estrogen treatment results not only in an increased secretion of VLDL but also in the production of different VLDL particles, thereby affecting their clearance from the plasma.

Changes in plasma lipids, lipoproteins, triglyceride secretion and removal in chicks with estrogen implants

Estradiol implants in chicks resulted in marked elevation of all major plasma lipids with greatest increase in triglyceride (TG) followed by phospholipid (PL) and cholesterol (C). During the two-wk period, plasma TG level in estrogen (E)-treated chicks increased to about 45 times that of controls (139.6 vs 6,368.3 mg/dl). The level of cholesterol also increased steadily during the same period, attaining nearly a six-fold increase in comparison with the control (150.7 vs 871.8 mg/dl), and the level of PL was markedly elevated from 209 to 2,861 mg/dl. Besides the induction of hyperlipidemia, E treatment also resulted in a notable alteration in the fatty acid composition of plasma lipids; there was an increase in oleic acid concomitant with a decrease in polyunsaturated fatty acids, particularly, linoleic acid. One day after implantation, the percentage of oleic acid in TG fraction increased from 39.2 to 43.7%, reaching 55.4% of the total fatty acids at day 14. In contrast, the levels of linoleic and arachidonic acid decreased significantly from 16.1 to 8.3% and 4.3 to 0.6%, respectively, during the same period. In cholesteryl ester (CE) and PL, the oleic acid level also increased from 25.2 to 47.3% in the former and from 11.9 to 29.6% in the latter, reflecting enhanced hepatic lipogenesis. Analysis of plasma lipoproteins in E-treated chicks revealed dramatic alterations in the concentrations of lipids and protein in individual lipoprotein fractions, especially very low density lipoprotein (VLDL) fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Sex, plasma lipoproteins, and atherosclerosis: prevailing assumptions and outstanding questions

We review the hypothesis that the incidence of coronary heart disease (CHD) is higher in men than in women due to differences in plasma lipoprotein risk factors between the sexes. Men and women appear to be equally susceptible to the effects of lipoprotein risk factors for CHD, and the difference between the sexes in lipoprotein risk factors for CHD appears to be consistent with their being, at least in part, responsible for the sex difference in CHD. This is apparent both when men and women of equal age are compared, and when age-related variations in the sex differences in plasma lipoproteins and CHD are considered. Differences between the sexes in lipoprotein concentrations are still present when sex differences in adiposity, cigarette smoking, physical activity, and diet are taken into account. Evidence relating these sex differences in CHD and lipoproteins to the effects of sex hormones is critically examined. It is commonly accepted that androgens induce changes in lipoprotein concentrations that would predispose towards CHD, whereas estrogens are held to have opposite effects. However, much of the evidence for this comes from studies of changes associated with administration of synthetic gonadal steroids or with changes in gonadal function. Studies of differences in lipoprotein metabolism in normal men and women are extremely limited. In males high-density lipoprotein (HDL) cholesterol levels fall at puberty, correlating with the rise in plasma testosterone concentrations. In females, HDL levels do not change at puberty, despite the rise in estrogen concentrations. Evidence for lipoprotein changes during the menopause, when estrogen levels decline, is equivocal. Similarly, the evidence for an increase in CHD incidence at the menopause is inconclusive. National mortality data indicate that the decreasing sex difference in CHD after 50 years of age is due to a declining rate of increase in men rather than to an acceleration in CHD incidence in women. In men the age-related increase in low-density lipoprotein (LDL) concentrations diminishes beyond 50 years of age, whereas in women the rate of increase remains unchanged. Studies of the effects of gonadectomy are of doubtful relevance in assessing the roles of sex hormones in CHD, and have not been performed with sufficient rigor to provide definitive conclusions.(ABSTRACT TRUNCATED AT 400 WORDS)

In vivo oestrogenicity and binding characteristics of alpha-zearalanol (P-1496) to different classes of oestrogen binding proteins in rat liver

It is now well established that the mycotoxin zearalenone and some of its derivatives possess oestrogenic activity. In the present study, the binding characteristics of [3H]zearalanol (P-1496) to different classes of sites including [1] the oestrogen receptor, [2] the higher capacity lower affinity (HCLA) sites, [3] the antioestrogen sites and [4] a new class of binding sites apparently specific for P-1496 were examined in rat liver. Analysis of the binding by sucrose density gradient centrifugation confirmed that P-1496 binds to the oestrogen receptor but not to the higher capacity lower affinity sites for oestradiol-17 beta. Furthermore, saturation experiments using partially-purified fractions showed that P-1496 binds to the oestrogen receptor with an affinity very similar to that of oestradiol-17 beta (apparent dissociation constants ranged from 0.1-0.3 nM). Competition studies using partially purified cytosolic oestrogen receptor suggested that P-1496 binds to a second high affinity site distinct from the oestrogen receptor. This binding site was further characterized as selective for P-1496 by saturation analysis following the complete occupancy of oestrogen receptor by oestradiol-17 beta. The in vitro binding characteristics of P-1496 were then compared with in vivo effects on concentrations of serum triglycerides. Treatment of ovariectomized female rats daily with 1.5 or 2 mg P-1496/kg body weight resulted in marked increases in the concentrations of serum triglycerides associated with the very low density lipoprotein (VLDL) fraction. Dose-response studies indicated that there was no sex difference with respect to the dose necessary to produce significant increases in serum triglycerides. The present study shows striking similarities between the binding of P-1496 and oestradiol-17 beta to liver oestrogen receptor in vitro. However, differences are observed with respect to their binding to other cytoplasmic components of liver. In addition, although P-1496 is capable of eliciting in vivo oestrogenic effects in liver, it is much less potent than oestradiol-17 beta.

Effect of long-term hormonal contraception on plasma lipids

Serum lipid and apoprotein levels were determined in fasting women after long-term use (5-12 years) of Depo Provera, Orgametril, Ortho Novum SQ, Binordiol, Microgynon-50, and Ministat. Compared with matched controls, pure progestogens (Depo Provera and Orgametril) caused a moderate decrease of TG, HDL chol, and Apo A1, whereas estrogen-dominant oral contraceptives (Ortho Novum SQ) increased the same parameters. The effects of long-term use of hormonal contraception on lipids did not differ from those predicted from short-term (6 months) studies.

Long-term effects of Depo-Provera on carbohydrate and lipid metabolism

Long-term effects of injection Depo-Provera (depo-medroxyprogesterone acetate) on carbohydrate and lipid metabolism were studied in 157 women who were treated continuously for a mean duration of 43.3 months. The patients were matched with 162 controls for race, age, parity and height. Glucose tolerance was impaired with higher intolerance at longer duration. Glucose areas were significantly higher at 48 and 60 months of injection. Insulin levels were also significantly decreased at 30 minutes and increased at 150 minutes but the area was normal. Triglycerides were initially decreased, being significant at 36 months (p less than 0.001) and returned to normal at 60 months while cholesterols were significantly higher at 24 and 36 months (p less than 0.05) and 60 months (p less than 0.001). In view of these findings, Depo-Provera may have an advantage over oral pills on a short term basis as there are less alterations in carbohydrate and lipid metabolism.

Clinical and metabolic effects of Gynodian-depot in vegetoneurotic disorders following removal of uterine myoma in menopausal patients

Clinical and metabolic effects of depot-injections of estradiol valerianate-dehydroepiandrosterone enanthate at a 1:50 ratio (Gynodian-depot) in the treatment of severe clinical manifestations of the vegetoneurotic syndrome were evaluated in menopuasal patients after hysterectomy for uterine myoma. Favourable comprehensive effects of the drug were noted, which in most patients contributed to the elimination or significant alleviation of major vegetoneurotic, psychoemotional and metabolic-endocrine disorders. An effective combination of the estrogenic and androgenic hormonal components and their ratios, coupled with very insignificant side-effects, is an important advantage of the drug, permitting its large-scale use for the control of menopausal complications, particularly after surgery for a uterine tumour.

Plasma high-density-lipoprotein cholesterol levels during long-term use of an oral contraceptive in Nigerian women

Total and high-density lipoprotein (HDL) cholesterol were estimated in 131 blood samples obtained from women who had been taking the oral contraceptive Noriday 1 + 50Fe (one packet contains 21 tablets of 1 mg of norethindrone + 0.05 mg of mestranol, and 7 of 75 mg of ferrous fumarate) for 1-60 months. Thirty five women who had never used oral contraception (OC) formed the control group. There was a significantly higher mean HDL cholesterol level, and HDL cholesterol/total cholesterol ratio but not total cholesterol level in the women who had been using OC for 19-60 months. The values in women who had been using OC for 1-18 months were not significantly different from those in the control group. The increase in the HDL cholesterol level may not depend on the oestrogen content of the oral contraceptive but on the duration of its intake.

Canine vascular tissues are targets for androgens, estrogens, progestins, and glucocorticoids

Sex differences and steroid hormones are known to influence the vascular system as shown by the different incidence of atherosclerosis in men and premenopausal women, or by the increased risk of cardiovascular diseases in women taking birth control pills or men taking estrogens. However, the mechanisms for these effects in vascular tissues are not known. Since steroid actions in target tissues are mediated by receptors, we have looked for cytoplasmic steroid receptor proteins in vascular tissues of dogs. We find specific saturable receptors, sedimenting at 8S on sucrose density gradients for estrogens (measured with [3H]estradiol +/- unlabeled diethylstilbestrol), androgens (measured with [3H]R1881 +/- unlabeled R1881 and triamcinolone acetonide), and glucocorticoids (measured with [3H]dexamethasone +/- unlabeled dexamethasone); they are absent for progesterone (measured with [3H]R5020 +/- unlabeled R5020 and dihydrotestosterone). Progesterone receptors can, however, be induced by 1-wk treatment of dogs with physiological estradiol concentrations (100 pg/ml serum estrogen), indicating a functional estrogen receptor. Receptor levels range from 20 to 2,000 fmol/mg DNA. They are specific for each hormone; unrelated steroids fail to complete for binding. Low dissociation constants, measured by Scatchard analyses, show that binding is of high affinity. Steroid binding sites are in the media and/or adventitia since they persist when the intima is removed. Compared with the arteries, receptor levels are reduced 80% in inferior venae cavae of females, and are absent in the venae cavae of males. We hypothesize that steroid hormones can have direct effects on vascular tissues medicated by specific receptors present in arterial blood vessel walls.

The effect of progestins in combined oral contraceptives on serum lipids with special reference to high-density lipoproteins

Fasting serum lipids were measured in a group of 293 women desirous of using oral contraceptives (OCs) and 536 women who had been taking five varieties of OCS for many months before being tested. Parameters studied were serum cholesterol, triglyceride, high-density lipoprotein (HDL), the two main subfractions of HDL, namely, HDL2 and HDL3, and the ratio of HDL2 cholesterol to low-density lipoprotein (LDL) cholesterol. Studies of these five groups of women enabled us to compare the effect of varying amounts of levonorgestrel with norethindrone and to study the effects of estrogen combined with these progestins. The levonorgestrel-containing pills and the progestin-only OC significantly depressed HDL2 cholesterol levels and the ratio of HDL2 to LDL cholesterol.

Nutritional implications of the free-radical theory of aging

Aging is the progressive accumulation of changes with time associated with and/or responsible for the ever-increasing susceptibility to disease and death. These time-related changes are attributed to the aging process. This process may be due in part to free radical reactions, largely those involving oxygen, going on continuously throughout the cells and tissues. Dietary manipulations expected to lower the rate of production of free-radical reaction damage have been shown to 1) increase the life span of mice, rats, fruit flies, nematodes, and rotifers, as well as the life span of neurospora, 2) inhibit development of some forms of cancer, 3) enhance humoral and cell-mediated immune responses, and 4) slow development of amyloidosis and the autoimmune disorders of NZB mice. Free-radical reactions may also play a significant role in the deterioration of the cardiovascular and central nervous systems with age. It is reasonable to expect, on the basis of present data, that the healthy life span can be increased by five or more years by keeping body weight down, at a level compatible with a sense of well-being, while ingesting diets adequate in essential nutrients but designed to minimize random free-radical reactions in the body.

Selective elevation of plasma free cholesterol concentration by administration of estrogen in the presence of total biliary obstruction

On the basis of clinical observations suggesting interactive effects of biliary obstruction and estrogen therapy on plasma cholesterol levels, a prospective study of the effect of ethinyl estradiol on plasma lipid levels was carried out in a patient with total biliary obstruction. A daily dose of 50 micrograms of ethinyl estradiol raised the plasma free cholesterol concentration from 265 mg/dl to 550 mg/dl over a period o 3 weeks; there was no change in plasma ester cholesterol concentration. Withdrawal of the estrogen was followed by a fall to baseline of the free cholesterol concentration over a 45-day period; once again there was no change in ester cholesterol. Plasma phospholipid concentration rose and fell in direct proportion to the changes in free cholesterol; plasma triglyceride concentration was unaffected by the estrogen. To account for the results of this study, it is suggested that the already elevated plasma levels of lipoprotein-X in biliary obstruction are further elevated by estrogen administration.

The effect of ethanol on lipoprotein metabolism

A major effect of ethanol on lipoprotein metabolism is the development of hypertriglyceridemia. Triglyceride-rich lipoproteins are secreted by the liver and intestine and undergo a two-stage sequential catabolism--first in peripheral tissues, and second in the liver--mediated in part by the associated apolipoproteins. The arguments for increased very low density lipoprotein production as an explanation for the hypertriglyceridemia are reviewed and found to be unconvincing. Experiments investigating the catabolism of chylomicrons are conflicting but appear on balance to suggest a catabolic defect. A potential relationship between plasma triglyceride-rich lipoprotein metabolism and hepatic steatosis is considered. The lack of knowledge of the status of apolipoproteins in the setting of ethanol precludes definite conclusions, but defects in the incorporation or dissociation of the apolipoproteins on the triglyceride-rich lipoproteins could explain some of the ethanol-induced metabolic derangements.

Influence of dietary fats and an oral contraceptive on plasma lipids, high density lipoproteins, gallstones, and atherosclerosis in african green monkeys

Twenty-nine African green monkeys were fed diets for 22 months containing 0.79 mg cholesterol/kcal and 40% of calories as either safflower oil or butter with or without the addition of an estrogen- and progestin-containing oral contraceptive. Plasma cholesterol concentrations ranged from 199 to 250 mg/dl. Animals consuming the safflower oil diet had plasma cholesterol concentrations that averaged 61 mg/dl lower than those consuming butter. At least 72% of this lowering was due to a reduction in low density lipoproteins. Triglyceride concentrations were also slightly lower in animals consuming the safflower oil diet. The oral contraceptive lowered total plasma cholesterol concentrations in both diet groups by an average of 41 mg/dl with 54% of this lowering (22 mg/dl) due to a reduction in high density lipoprotein cholesterol. This effect occurred only during the 3 weeks while the contraceptive was being administered and was not apparent 1 week after stopping the drug. Animals consuming safflower oil had bile that was more lithogenic and had more gallstones than did those consuming butter. Addition of the oral contraceptive caused a slight increase in bile lithogenicity, but this increase was not statistically significant. There was no significant interaction between the oral contraceptive and either of the diets to exacerbate cholelithiasis. At the plasma cholesterol concentrations achieved only minimal amounts of atherosclerosis developed and there were no indications of differences due to diet or oral contraceptive in the extent of atherosclerosis.

Nucleo-cytoplasmic relationships of oestrogen receptors in rat liver during the oestrous cycle and in response to administered natural and synthetic oestrogen

Oestrogen receptors were measured in the cytosolic and purified nuclear fractions of rat liver. Both cytosolic and nuclear receptors bind oestrogen with high affinity (Kd = 1.47 and 2.28 nM respectively) and specificity similar to that of receptors in order oestrogen-target tissues such as the uterus. During the 4-day oestrous cycle the receptor content and distribution between cytosol and nucleus did not vary; in particular, the content of nuclear receptor did not appear to fluctuate in concert with known cyclic changes in the concentration of plasma oestrogen. Injection of 50 micrograms of oestradiol-17 beta or 10 micrograms of ethynyloestradiol resulted in a 4--6-fold increase in the nuclear receptor content, with a concomitant decrease in the unoccupied-receptor content of cytosol 1 h after injection. The nuclear receptors present after injection bind oestrogens with similar affinity (Kd = 2.78 nM) and specificity to receptors present in uninjected animals. The administration of lower doses of either oestrogen was less effective in producing increases in nuclear receptor content. Hence there is apparently substantial translocation of receptor to the nucleus in response to hyperphysiological doses of oestrogen, but not to the physiological changes in plasma oestrogen concentrations during the oestrous cycle. The response to exogenous oestrogens is discussed in relation to the clinical use of synthetic oestrogens and progestogens.

Effect of estrogen on fasting serum cholesterol and triglyceride levels in postmenopausal women

Sixty postmenopausal women with climacteric symptoms were treated with either clonidine hydrochloride or piperazine estrone sulfate in two different dosage strengths. Neither drug had an adverse effect on serum lipid levels and there was no significant change in the serum cholesterol and triglyceride levels during treatment.

Evolution of plasma levels of apolipoprotein B, cholesterol and triglycerides in women during long-term oral contraception

Apolipoprotein B (apo B) was measured by a sensitive and specific double antibody radioimmunoassay in plasma from 15 normal women and 47 women taking oral contraceptives. The plasma apo B concentration in normal women was 0.90 +/- 0.10 g/l (mean +/- S.D.) whereas the overall value for all women taking contraceptives was 0.69 +/- 0.19 g/l. The maximum decrease (p less than 0.001) occurred in women investigated within three months after the beginning of the steroid intake, whose mean apo B value was 0.60 +/- 0.12 g/l (n = 12); decreases found after 3--24 months of contraception were of lesser magnitude. Apo B decreases were associated with significant decreases (p less than 0.01) in total plasma cholesterol, although the latter regained normal values after one year of contraception. Apo B and cholesterol values were in the normal range in women investigated after two years of steroid intake. An inverse trend was observed for plasma triglycerides, which showed a mean increase of 29% (p less than 0.01) after three months of steroid intake, and then stayed elevated without significant change with time.

Oral contraceptives raise the cholesterol saturation of bile by increasing biliary cholesterol secretion

To discover the mechanism by which oral contraceptives increase the level of cholesterol saturation of human bile, we measured biliary lipid secretion rates, gallbladder and hepatic bile lipid composition, bile acid pool size, bile acid composition, and plasma lipoprotein levels in five healthy women during routine oral contraceptive treatment and again during normal menstrual cycles on no medication. The molar percent cholesterol in both gallbladder and hepatic bile was higher in every subject while taking oral contraceptives (p less than .02). Oral contraceptive usage was accompanied by a significant enhancement of biliary cholesterol secretion (65 versus 46 mg/hr, p less than .01), but there was no significant change in bile acid or phospholipid secretion, total bile acid pool size, or bile acid composition. These findings indicate that oral contraceptive usage increases biliary cholesterol secretion, thereby raising the level of cholesterol saturation of bile and predisposing to cholesterol precipitation and gallstone formation.

The effect of oral contraceptives on mononuclear cell cholesteryl ester hydrolase activity

The influence of sex steroids on mononuclear cell cholesteryl ester hydrolase (CEH) activity in premenopausal women and women on combined estrogen-progestin oral contraceptives has been studied. In addition, plasma and mononuclear cell cholesterol and esters were measured along with plasma estrogen and progesterone levels. Mononuclear cell CEH activity in control women is highest on Day 20 of their menstrual cycle. The control women had significantly higher CEH activities than women on oral contraceptives. Plasma esters were higher in the oral contraceptive group. However, in mononuclear cells, free cholesterol but not cholesteryl esters were higher in women on oral contraceptives.

Oral-contraceptive use in relation to myocardial infarction

The effect of oral-contraceptive use on the risk of myocardial infarction and, in particular, the possible accentuation of that effect by cigarette smoking, was investigated in 234 premenopausal women with a first infarction and 1742 hospital controls. The overall rate ratio estimate of acute myocardial infarction for women who had used oral contraceptives in the preceding month was 4.0 (95% confidence interval, 2.5--6.3). Women who smoked heavily and used oral contraceptives had a point estimate of 39 (lower two-sided 95% confidence limit, 22) compared with those who did neither. This value was appreciably larger than could be accounted for by the separate effects of cigarettes and oral contraceptives, and this suggests a considerable accentuation by cigarette smoking of the effect of oral contraceptive use on myocardial infarction.

Comparative studies of the ethynyl estrogens used in oral contraceptives. VII. Effects with and without progestational agents on ultracentrifugally fractionated plasma lipoproteins in humans, baboons, and beagles

Ethynyestradiol and mestranol, in doses ranging from 50 to 100 microgram/day, were given to women in 21-day cycles; baboons and beagle dogs received 1 and 4 microgram/kg/day in a similar regimen. After a number of such cycles, megestrol acetate, norethindrone acetate, or dl-norgestrel was given concomitantly. Protein, cholesterol, triglyceride, and phospholipid levels were determined in total plasma and in ultracentrifugally separated lipoprotein fractions. Over the dosage range studied, the effects of the two kinds of estrogen were indistinguishable. Except for human total plasma triglyceride, no dose-related differences were observed. The lowering of serum protein and the increase in cholesterol induced by estrogen were more pronounced in baboons and beagles than in human subjects. The cholesterol-depressing effect of progestational compounds observed in humans was very pronounced in baboons but absent in beagles. In all three species, estrogen increased the lipoprotein fraction cholesterol, except for human low-density lipoprotein cholesterol, which was decreased. Human plasma triglyceride and phospholipid increased on estrogen administration and were decreased by the progestins; in the two animal species, triglyceride is normally very low and the estrogen-induced changes were negligible; the phospholipid rose with estrogen but was unaffected by progestins. In sum, the two animal species show many similarities to, as well as important differences from, the human response of plasma lipids to various contraceptive steroids.

The effect of oestradiol valerate therapy on coagulation factors and lipid and oestrogen levels in oöphorectomised women

The effect of oestradiol valerate on levels of blood cholesterol, triglycerides, free oestradiol and coagulation factors, as well as on urinary oestrogens and free cortisol was measured in 10 oöphorectomised women. Despite the very high urinary oestrogen levles obtained, there was no significant change found in the other parameters during and after treatment. These findings are discussed, as is the significance of the metabolism of both endogenously produced and orally administered oestrogens in the menopausal woman.

Morphological effects of estrogen on the female rat liver nucleolus

Prolonged administration of nonphysiological amounts of estrogen induced markedly enlarged nucleoli volumes in rat hepatocytes, indicative of increased nucleolar RNA synthesis. Physiological amounts of drug had no apparent morphological effects on the hepatocytes.

Vitamin E status of young women on combined-type oral contraceptives

Differences in vitamin E status between young Caucasian women using oral contraceptives (OCs) for 1 yr or more and control females were obtained with regard to the following parameters: 1) hemolysis, 2) plasma total tocopherols by spectrophotometric analysis, 3) individual tocopherols by a thin-layer gas-liquid chromatographic (TLC-GLC) technique, and 4) dietary intakes of vitamin E, polyunsaturated and saturated lipids, cholesterol and kilocalories. Ten subjects were on Ortho-Novum- or Norinyl-1/50, 8 on Ortho-Novum- or Norinyl-1/80, and 10 had never taken OCs. Analyses of 24-hr recalls and 7-day dietary records revealed no significant differences among groups for intakes of nutrients listed above. No significant differences among groups were observed from hemolytic values. Plasma total tocopherol concentrations measured by spectrophotometric and TLC-GLC techniques revealed that OC-1/80 subjects had significantly lower values than controls. Marginally inadequate vitamin E status as assessed by the various techniques was observed in approximately one subject in the control and OC-1/50 groups and in 2 of the OC-1/80 women. Large individual variations in vitamin E status were observed for subjects in all groups on similar estimated vitamin E intakes. TLC-GLC measurements of total tocopherols in plasma seemed to be perhaps a more sensitive indicator of vitamin E status of subjects than spectrophotometric analysis of tocopherols.

[Metabolic studies under administration of oral contraceptives. A review]

The use of oral contraceptives can produce changes in the metabolism of carbohydrates, lipids, proteins, vitamins, and minerals. Responsible for the alterations seems to be the used oestrogen- and gestagen derivative and not so much the type of the contraceptive. The most frequent findings are raised serum-glucose-, insulin-, and triglyceride levels; disturbances in protein-metabolism increase the risk of developing thrombosis and hypertonia. Little is known about the significance of oral contraceptives on the vitamin- and mineral metabolism--yet extreme deficiencies have not been observed so far. Oral contraceptives can become an extra risk factor when given to women with metabolic disturbances.

Changes in serum high density lipoproteins in women on oral contraceptive drugs

Serum lipids, lipoproteins, and lipoprotein subfractions were measured in a group of 18 women aged 20 through 39 who were users of oral contraceptive drugs, and in 19 age-matched controls. Concentrations of the major lipid and lipoprotein classes were higher in the users, but the elevation was statistically significant only in the case of the high density lipoproteins. This increase was shown to be due to a highly significant increase (275 +/- 9 vs. 223 +/- 9 mg/100 ml, (p less than 0.005) in the denser high density lipoprotein subfraction (HDL3). Levels of the other subfraction (HDL2) were similar in users and controls. Thus, anovulatory steroids have selective effects on individual types of high density lipoproteins. Studies of such specific effects may help to further define the functional properties of the high density lipoproteins such as their apparent protective role in atherosclerosis.

Altered plasma-lipids associated with oral contraceptive or oestrogen consumption. The Lipid Research Clinic Program

Mean plasma cholesterol and triglyceride concentrations were measured in White female users and non-users of oral contraceptives and oestrogens in 10 diverse, demographically defined North American populations. About 50% of the younger women (20-24 years old) were taking oral contraceptives. In these women mean triglyceride concentrations were up to 48% higher and mean cholesterol concentrations were about 5% higher than in non-users. The 95% percentile of the total lipid distribution among non-users was used to define hyperlipidaemia. In young women on oral contraceptives hypercholesterolaemia was up to three times more common and hypertriglyceridaemia was up to five times more common than in non-users. 37% of older women (50-54 years) (presumably intramenopausal and postmenopausal) were hormone users, and in this group there were small, inconsistent alterations in plasma-triglyceride and a modest but consistent reduction in mean cholesterol concentration.

Mechanism of oestrogen and progesterone effects on lipid and carbohydrate metabolism: alteration in the insulin: glucagon molar ratio and hepatic enzyme activity

As in women receiving oestrogens the administration of 17beta-oestradiol to ovariectomized female rats caused a rise in fasting plasma triglycerides and a fall in plasma glucose. Progesterone, on the other hand, had no significant effects. In the oestradiol treated rats, the portal vein basal insulin levels were slightly reduced. Oestradiol, however, had a marked suppressive effect on the alpha cells of the pancreas resulting in a greater reduction in basal glucagon and impaired glucagon response to alanine infusions. The relative insulin to glucagon (I/G) molar concentration ratio in portal vein blood was increased. Oestradiol also produced a dose dependent increase in the activity of the liver lipogenic enzymes, acetyl CoA carboxylase and fatty acid synthetase. On the other hand, the activity of the gluconeogenic rate limiting enzyme phosphoenol-pyruvate carboxykinase (PEPCK) was inhibited. The cross-over pattern of gluconeogenic intermediates confirmed inhibition of gluconeogenesis at this step, an effect which is similar to that induced by relative insulin 'excess'. Progesterone produced an increase in the portal vein insulin concentrations. Both the basal and the alanine-stimulated glucagon levels were also increased. The I/G molar ratio in portal vein blood of progesterone treated rats remained unaltered and the hepatic lipogenic and gluconeogenic enzyme activities were similar to control animals. These data suggest that insulin activity is increased relative to glucagon in the liver of oestradiol-treated rats due to the rise in portal vein I/G ratio. The changes in liver lipogenic and gluconeogenic enzymes and the alterations in fasting plasma triglycerides and glucose in response to oestrogens could be secondary to this effect.

Acute spontaneously recovering ulcerating colitis (ARUC). Report of 6 cases

Six patients each with an extensive ulcerating colitis are reported. Common features were a febrile nonbloody diarrhea; radiological involvement of the whole colon with superficial ulcerations and preservation of haustra, and integrity of the terminal ileum and rectum; the absence of any specific pathological finding; and, most important, the spontaneous recovery of the lesions in the absence of any treatment except sympatomatic measures. The present follow up after recovery range from 18 months to 5 years. Four cases were young women taking oral contraceptives and two patients were older. These patients with colitis could represent a new entity or could be a particular form of Crohn's disease of the colon, with delayed diagnostic pathological features.

Effect of progestins on glucose and lipid metabolism

Gestamimetic amounts of progesterone enhance basal and glucose-stimulated insulin production. Contraceptive doses of synthetic progestins cause a moderate increase or no change in glucose-stimulated insulin production, depending on route of administration and species tested. Estrogens potentiate the insulinotropic effects of progesterone and the synthetic progestins. Basal serum triglyceride concentrations are generally unaffected by progesterone or 17 alpha-acetoxyprogesterone treatment but may decrease during 19-nortestosterone administration. Glucose tolerance does not change during treatment with gestamimetic doses of progesterone alone but may improve in rats and monkeys during concurrent estrogen administration. By contrast, deterioration of glucose tolerance is observed in women treated concurrently with synthetic estrogen plus 19-nortestosterone derivatives and, occasionally, with 19-nortestosterone derivatives alone. No consistent changes in glucose metabolism have been observed after treatment with 17 alpha-acetoxyprogesterone derivatives alone. The cause of the species-related differences in glucose metabolism during 19-nortestosterone treatment is obscure.

An epidemiological study of the haemostatic and other effects of oral contraceptives

Factors V, VII and VIII (each determined by biological assay), fibrinogen, platelet count and adhesiveness, and fibrinolytic activity were measured in 234 white pre-menopausal women, of whom 57 (24%) were on oral contraceptives and 177 (76%) were not. Cholesterol, triglyceride and blood pressure levels were also recorded. In 20 of the women on oral contraceptives, and in an age-matched group of 20 who were not, prothrombin, factor X, antithrombin III and alpha 2-macroglobulin levels were determined, and factors VII and VIII were also measured immunologically. For the majority of the variables studied, the differences between those using and not using oral contraceptives were greater in younger than older women; in the case of factor VII (biological assay) and fibrinogen, the differences between the regression slopes on age were statistically significant, and mean values were substantially higher in those on oral contraceptives. There was also a significant difference between regression slopes on age for cholesterol. Mean levels of prothrombin, factors VII (immunological assay) and X, triglycerides and blood pressure were significantly higher, and mean levels of antithrombin III significantly lower, in those on oral contraceptives compared with those not. Overall, fibrinolytic activity was significantly higher in the women on oral contraceptives; this difference was, however, almost entirely due to the greatly increased fibrinolytic activity of the non-smokers on oral contraceptives, activity in the smokers on oral contraceptives being similar to that of the women not on these preparations. There were no significant differences in mean platelet count or adhesiveness, or in haemoglobin, packed cell volume, uric acid and blood sugar levels. Among the women on oral contraceptives, there was a significant negative correlation between factor VIII and fibrinolytic activity; this was largely due to five women all of blood groups A and B, in whom, besides high factor-VIII levels and poor fibrinolytic activity, other variables (e.g. fibrinogen) were raised in a direction that might be expected to favour thrombogenesis. It is possible that it is those women whose fibrinolytic activity does not increase in order to compensate for the effects of oral contraceptives on clotting factors, lipids and blood pressure, who are at special risk of thromboembolic episodes. The differential effects of oral contraceptives by age must be borne in mind in evaluating the effects of these preparations on the haemostatic and lipid systems.

Myocardial infarction in younger women. Associated clinical features and relationship to use of oral contraceptive drugs

In a study of thromboembolism and oral contraceptive drugs, 136 cases of myocardial infarction in women aged 30 to 44 years were identified, a rare disease in women of this age group. Data from their hospital medical records were compared with those of several other groups, including women without chronic disease admitted for various acute or elective conditions unrelated to thromboembolism, patients with thromboembolic disease other than myocardial infarction, and women queried or examined in the National Health Survey. The following attributes were found to be associated with myocardial infarction in younger women: presence of diabetes; hypertension; history of increased cigarette smoking; and hypercholesterolemia. A history of the use of oral contraceptive drugs was found with greater frequency in cases than in controls. The literature on the possible association of myocardial infarction and the use of oral contraceptives was reviewed.