Metabolic effects of oral contraceptives

Variations in lipid levels according to menstrual cycle phase: clinical implications

Understanding variations in lipoprotein cholesterol levels throughout the menstrual cycle is important because there may be clinical implications regarding the appropriate timing of measurement and implications on the design and interpretation of studies in women of reproductive age. Our objective was to review the evidence comparing lipoprotein cholesterol levels throughout the menstrual cycle among premenopausal women. Overall, lipoprotein cholesterol levels were observed to vary in response to changing estrogen levels. Taken together, the evidence suggests that total cholesterol and LDL-C tend to be highest during the follicular phase and to decline during the luteal phase, with HDL C highest around ovulation. Based on these findings, the menstrual cycle phase should be taken into account when evaluating lipoprotein cholesterol levels among reproductive-aged women. Measuring cholesterol levels during menses is recommended for consistent comparisons as this phase can be more reliably identified than other phases, although women within National Cholesterol Education Program acceptable ranges, but near the boundaries when tested during menses, should undergo additional tests.

Effects of two combined oral contraceptives containing ethinyl estradiol 20 μg combined with either drospirenone or desogestrel on lipids, hemostatic parameters and carbohydrate metabolism

OBJECTIVE

To compare the effect of ethinyl estradiol 20 microg/drospirenone 3 mg (EE 20 microg/DRSP 3 mg) administered according to a 24/4 regimen with ethinyl estradiol 20 microg/desogestrel 150 microg (EE 20 microg/DSG 150 microg) administered according to the conventional 21/7 regimen on lipid, carbohydrate and hemostatic parameters.

STUDY DESIGN

In this open-label study, healthy women were randomized to EE 20 microg/DRSP 3 mg or EE 20 microg/DSG 150 microg for seven cycles. Mean differences in high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol levels at cycle 7 compared to baseline were assessed. Secondary variables included changes in other lipid, hemostatic and carbohydrate parameters.

RESULTS

Both treatments increased HDL-cholesterol, but decreased LDL-cholesterol by a comparable extent. Although slightly elevated in both groups, blood glucose and C-peptide levels measured during oral glucose tolerance tests were within normal reference ranges at cycle 7. Overall, the differences in lipid, hemostatic or carbohydrate parameters were not significant between the two treatments.

CONCLUSION

EE 20 microg/DRSP 3 mg has a good safety profile comparable with EE 20 microg/DSG 150 microg.

A randomized study over 13 cycles to assess the influence of oral contraceptives containing ethinylestradiol combined with drospirenone or desogestrel on carbohydrate metabolism

In this open-label, randomized study we compared the influence of a new oral contraceptive containing 30 microg ethinylestradiol and 3 mg drospirenone (Yasmin) with a reference preparation containing 30 microg ethinylestradiol and 150 microg desogestrel (Marvelon) on variables of carbohydrate metabolism by means of oral glucose tolerance tests at baseline and in the 6th and 13th treatment cycle. The mean levels of fasting glucose and insulin were similar at baseline and after 13 treatment cycles, whereas C-peptide and free fatty acid levels decreased slightly in both groups. All blood glucose and insulin values measured in the oral glucose tolerance tests were within normal ranges, despite a slight increase in the mean areas under the curves of 0-3 h [AUCs (0-3 h)] of both variables from baseline to treatment cycle 13. Differences between both treatments were not statistically significant. The mean AUCs (0-3 h) for C-peptide were not markedly changed in any treatment group. Free fatty acid levels decreased by 42% in the drospirenone group and increased by 48.9% in the desogestrel group, in terms of means of individual changes. Both preparations were well tolerated and equally efficacious regarding contraception and cycle control. The mean body weight was slightly decreased in most cycles during treatment with the drospirenone combination, as compared to baseline, while it was slightly increased versus baseline in all cycles during treatment with the desogestrel combination. The combination with drospirenone had less impact on blood pressure than the combination with desogestrel. In conclusion, Yasmin, a combined low-dose oral contraceptive with 30 microg ethinylestradiol and 3 mg of the novel progestogen drospirenone, as well as the reference Marvelon, containing 30 microg ethinylestradiol and 150 microg desogestrel had little impact on carbohydrate metabolism when used for 1 year. The observed changes were small and not suggestive of a clinically relevant deterioration of carbohydrate metabolism.

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.

Prior oral contraceptive use is associated with higher blood pressure in older women

Studies of young, premenopausal women suggest that changes in coronary risk factors do not persist after discontinuation of oral contraceptive use. However, little is known about longterm effects of past oral contraceptive use in older, postmenopausal women, who typically have a more atherogenic profile. This study examines the relation of past oral contraceptive use (including duration) to heart disease risk factors in postmenopausal women. Subjects were 517 women aged 50-69 from the Rancho Bernardo Study who attended follow-up clinic visits. Past oral contraceptive use was reported by 24.2% and two thirds had used oral contraceptives < or = 5 years. After adjustment for covariates, the only significant difference was that past users had higher diastolic blood pressures than never users (p < 0.01). Among older women, the diastolic blood pressure of past users was 3.9 mm Hg higher than that of never users (p < 0.01). Women who used oral contraceptives for < or = 5 years had diastolic blood pressures 3.6 mm Hg higher than those of never users (p < 0.01). No differences were found among younger women or those who used oral contraceptives > or = 6 years. Past oral contraceptive users may be at increased risk for heart disease because of a small but significant elevation in diastolic blood pressure that persists many years after discontinuing oral contraceptive use.

Safety evaluation of modern oral contraceptives. Effects on lipoprotein and carbohydrate metabolism

An ideal oral contraceptive should either be neutral as regards metabolic risk markers for arterial disease or should only change them in directions that would be expected to reduce risk. Depending on their formulation, modern low dose oral contraceptives affect systems such as hemostasis, lipoprotein metabolism, and glucose and insulin metabolism. Some of these actions would be expected to decrease the risk of arterial disease and some might be expected to increase risk. Despite these associations there is at present no justification for widespread metabolic screening as a strategy to further improve oral contraceptive safety. Recent developments in atherosclerosis research support the introduction of progestogens such as desogestrel that allow the estrogenic increase in high density lipoprotein levels to persist and that may cause less of an elevation in plasma insulin responses to glucose. The predicted benefit of these formulations in terms of arterial disease is difficult to demonstrate in an epidemiological setting because of the rarity of the disease in young women.

The effects of nomegestrol acetate subdermal implant (Uniplant) on carbohydrate metabolism, serum lipoproteins and on hepatic function in women

This study was undertaken to assess possible variations in body weight, blood pressure, fasting glucose, HbA1C, insulin, total cholesterol, HDL-C, LDL-C, triglycerides, SGPT, SGOT, GGT and bilirubin in women bearing a single subdermal Silastic implant containing 55 mg (10%) of nomegestrol acetate during two years. A total of eighteen volunteers of reproductive age who desired to avoid conception were enrolled in this study. Subjects were healthy women with no contraindications to hormonal contraception. All women were investigated before starting treatment and were followed up for one year. At the end of one year the capsules were removed and a new capsule was inserted. Fasting blood samples were drawn at 8:00 to 8:30 am twice prior to implant insertion and then at the first, third, sixth and twelfth months and every six months thereafter. Body weight increased from 54.9 +/- 1.5 kg at admission to 55.3 +/- 2.0 kg at 12 months of use (p < 0.05) and to 56.0 +/- 2.7 kg at 24 months of use. A slight increase in both systolic and diastolic blood pressure was recorded at month 12 (p < 0.01). At month 24, blood pressure was not significantly different from admission values. All levels were within the normal range. Insulin, HbA1C, LDL-C and GGT remained unchanged during twenty-four months of Uniplant use. A significant decrease in total cholesterol (p < 0.05) was observed in the third month while a significant decrease in HDL-C (p < 0.01) was observed only in the sixth month of Uniplant use.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypertriglyceridemia during late pregnancy is associated with the formation of small dense low-density lipoproteins and the presence of large buoyant high-density lipoproteins

Late pregnancy is a unique metabolic state where there are transient increases in the concentrations of plasma triglyceride (TG), cholesterol, and apolipoprotein (apo) B. Despite the hypertriglyceridemic environment, we recently reported that there is an unusual shift in high-density lipoprotein (HDL) subclass distribution from smaller HDL subclasses to the largest, most buoyant HDL2b subclass. In the present investigation, we determined whether the subclasses of low-density lipoprotein (LDL) also change during this transient hyperlipidemic state and whether such changes were associated with plasma TG and apolipoprotein concentrations. Thirty-six Hispanic subjects at 35 to 36 weeks' gestation and at 6 weeks' postpartum were studied. At 35 to 36 weeks of gestation, plasma concentrations of TG, cholesterol, and apo B were increased (218 +/- 62, 234 +/- 48, and 130 +/- 35 mg/dL, respectively) over levels at 6 weeks' postpartum (112 +/- 69, 197 +/- 36, and 97 +/- 25 mg/dL respectively). However, lipoprotein(a) [Lp(a)] concentrations were not changed during pregnancy compared with postpartum. LDL subclass patterns (A, B, or I) were determined by nondenaturing polyacrylamide gradient gel electrophoresis in our group of 36 pregnant women. During late pregnancy, 97% of subjects were categorized as LDL subclass patterns B or I, indicating that small, dense LDL particles predominated. This predominance of small, dense LDL was associated with plasma TG concentration, where there was a significant inverse relationship (r = -.45, P < .01) between the LDL peak particle diameter and plasma TG concentration. In an apparent anomaly, there were significant increases in the concentrations of HDL cholesterol (HDL-C) and HDL2 mass, even though small, dense LDL particles predominated.(ABSTRACT TRUNCATED AT 250 WORDS)

Unusual high-density lipoprotein subclass distribution during late pregnancy

Plasma lipoprotein distribution during late pregnancy is unusual since high-density lipoprotein (HDL) levels are increased in the presence of hypertriglyceridemia; the latter is usually associated with decreases in HDL levels. To determine whether there is a relationship between late-pregnancy lipid levels and specific HDL subclasses, HDL size distribution was determined by nondenaturing gradient gel electrophoresis (GGE) in a group of 36 women at 35 to 36 weeks of gestation and again at 6 weeks' postpartum, and in a group of 10 nonpregnant women. At 35 to 36 weeks of gestation, plasma triglyceride (TG) and cholesterol concentrations were significantly increased over postpartum levels (218 +/- 62 v 112 +/- 69 mg/dL and 234 +/- 48 v 197 +/- 36 mg/dL, respectively). During late pregnancy, apolipoprotein A-I (apo A-I) and HDL cholesterol concentrations were also increased relative to postpartum levels (211 +/- 42 v 168 +/- 20 mg/dL and 63 +/- 13 v 53 +/- 11 mg/dL, respectively). GGE analysis indicated that at 35 to 36 weeks of gestation, 86% of the subjects had a substantial increase of the most buoyant and largest of the HDL species, HDL2b; postpartum and nonpregnant HDL subclass distribution was characterized by the predominance of HDL3a, which are smaller, more dense HDL. The shift in the HDL subclass distribution during late pregnancy was associated with significant positive correlations between HDL2b and apo A-I (r = .50, P < .05) and HDL cholesterol (r = .60, P < .001). There were significant elevations in the concentrations of cholesteryl ester transfer protein (CETP) and estrogen during late pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

A multicenter comparative trial of triphasic and monophasic, low-dose combined oral contraceptives

A comparative multicenter clinical trial of two combined oral contraceptives (OCs) was conducted at clinics located in the Sudan, Sri Lanka, Chile, the Dominican Republic and Ecuador. The trial was designed to determine if there were differences in efficacy, safety and acceptability between a triphasic and a low-dose monophasic OC. This report includes analysis of 1088 women. At each center, subjects were randomly allocated to one of the two OCs. Follow-up visits were scheduled at 1, 4, 8 and 12 months after admission. There were two accidental pregnancies attributed to user failure reported during the study period; one in the triphasic group and one in the monophasic group. Adverse experiences were mainly minor with headaches and dizziness being the most common complaints; frequency of reports was similar in both groups. Cycle control was good in both groups with women in the triphasic group reporting fewer complaints of intermenstrual bleeding. Both OCs were safe and effective.

Diabetes mellitus and fertility control: contraception management issues

The need to prevent complications in the woman and fetus mandates that pregnancies in diabetic women always be planned and that safe and effective contraceptives be used at all times until it is determined that pregnancy is a safe and desired option. Pregnancy may aggravate complications of diabetes such as retinopathy and coronary artery disease. A pregnant diabetic woman is also more likely to experience such complications as hypertension, urinary tract infection, polyhydramnios, and cesarean section. Her fetus is at increased risk for congenital malformations, prematurity, stillbirth, neonatal morbidity, and diabetes later in life. Good diabetic control must be maintained before and throughout the pregnancy to minimize the risk of these and other complications. Until such time as good control is achieved and the woman desires pregnancy, a reliable method of contraception should be used. Most recent research supports the use of barrier methods, low-dose monophasic or triphasic oral contraceptives, or progestin-only methods, at least for the short-term. Under some circumstances the intrauterine device may be an appropriate option. Long-term data regarding the use of these methods is lacking. The decision regarding which method of contraception is used should be made by the woman in consultation with her physician.

Contraceptive steroids increase erythrocyte lipid peroxidation in female rats

In order to investigate the effects of contraceptive steroid combinations on lipid peroxidation in the erythrocyte membranes, adult female rats were divided into 2 groups for short- and long-term investigations; each group was then subdivided into 5 subgroups according to orally given low and high doses of EE/NEA (ethinyl estradiol/norethisterone acetate) and EE/LNG (ethinyl estradiol/levonorgestrel) combinations and control group. Since EE was included in each combination, the groups were named according to the progestin (NEA, LNG) components. At the end of the experiment periods, lipid peroxidation in the erythrocyte membranes from rats was measured. When compared to the controls, except low-dose LNG groups, lipid peroxidation levels were increased in all study groups. It was seen that the effect of NEA and LNG combinations on lipid peroxidation was not time-, but dose-dependent. When these combinations were compared to each other, different effects of NEA and LNG on lipid peroxidation were not detected in the experiment period. As a result, the increased lipid peroxidation following the administration of contraceptive steroid combinations is a very important finding that should be taken into account, in addition to the effects of these steroids on lipid and lipoprotein metabolism.

Effects of a 1-year treatment with a low-dose combined oral contraceptive containing ethinyl estradiol and cyproterone acetate on glucose and insulin metabolism

OBJECTIVE

To study the effects of the slightly estrogen-dominant monophasic low-dose oral contraceptive (OC) Diane-35 (Schering AG, Berlin, Germany) (35 micrograms ethinyl estradiol [EE2] + 2 mg cyproterone acetate, a 17 alpha-hydroxyprogesterone derivative [17-OHP]) on glucose and insulin metabolism.

DESIGN

Seven healthy young women were investigated by using the euglycemic hyperinsulinemic glucose clamp technique (insulin delivery rate = 100 mU/kg per hour for 120 minutes). This test was performed, after an overnight fast, during the last 7 days of a spontaneous cycle and within the last 5 days of pill intake during the sixth and twelfth cycle of a continuous treatment with Diane-35 in each subject.

RESULTS

The three indexes measuring the insulin-induced glucose disposal during the clamp (glucose infusion rate, glucose metabolic clearance rate, and glucose infusion rate divided by plasma insulin plateau levels) were not significantly affected by Diane-35. In contrast, the metabolic clearance rate of the exogenous insulin infused during the clamp tended to be slightly increased with Diane-35 (significant after 6 but not after 12 cycles).

CONCLUSION

These results suggest that a 1-year treatment with the OC Diane-35, which contains EE2 + a 17-OHP rather than a 19-nortestosterone derivative as the progestogen compound, does not significantly alter peripheral (presumably muscular) insulin sensitivity but slightly increases insulin (presumably hepatic) clearance.

A clinical comparison of two triphasic oral contraceptives with levonorgestrel or norethindrone: a prospective, randomized, single-blind study

Menstrual bleeding patterns were investigated in young women taking either a levonorgestrel triphasic, Triquilar, or a norethindrone triphasic, Ortho 7/7/7, two commonly prescribed low-dose oral contraceptives. The levonorgestrel triphasic contains ethinyl estradiol (EE) 30 micrograms + levonorgestrel (LNG) 50 micrograms for the first six days, EE 40 micrograms + LNG 75 micrograms for the following five days, and EE 30 micrograms + LNG 125 micrograms for the last ten days. The norethindrone triphasic contains EE 35 micrograms + norethindrone (NET) 0.5 mg for the first seven days, EE 35 micrograms + NET 0.75 mg for the following seven days and EE 35 micrograms + NET 1.0 mg for the last seven days. Three hundred women from 16 to 25 years of age were randomized to the levonorgestrel triphasic (n = 150) or the norethindrone triphasic (n = 150) groups. Assessments were made from daily diary cards and from bimonthly investigator interviews over 6 pill cycles. The results showed a higher incidence of intermenstrual bleeding (breakthrough bleeding and/or spotting) in the norethindrone triphasic group (NET group) than in the levonorgestrel triphasic group (LNG group): 44.9% of patients (66/147) randomized to the LNG group reported intermenstrual bleeding one or more times during the study compared with 61.9% (91/147) randomized to the NET group (p = 0.0036). Furthermore, in subjects who did not miss any pills, the proportion of patients with intermenstrual bleeding in each cycle was significantly greater (p < 0.02, cycles 1-4, 6; p > 0.05, cycle 5) and was experienced for more days per cycle (p < 0.05, cycle 1) and for more cycles per patient (p < 0.05, 5 cycles) in the NET group compared with the LNG group. Intermenstrual bleeding was also less frequently observed in the LNG group than in the NET group in patients who missed pills (p < 0.05, cycles 3, 5 and 6). In addition, early withdrawal bleeding occurred more often in the NET group than in the LNG group (p < 0.05, cycles 1, 3 and 4). The incidence of amenorrhea was similar in both groups. These results demonstrate a significantly lower incidence of intermenstrual bleeding and therefore better cycle control with the levonorgestrel triphasic Triquilar, compared with the norethindrone triphasic Ortho 7/7/7.

The effect of a biphasic desogestrel-containing oral contraceptive on carbohydrate metabolism and various hormonal parameters

During 6 cycles of treatment of 19 women, 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 various hormonal parameters and glucose metabolism was compared with the values of the pre- and post-treatment cycle. There was a profound reduction in gonadotropin secretion and ovarian steroid synthesis. The serum levels of testosterone were reduced by 35%, free testosterone by 55%, and DHEA-S by 30%. Cortisol increased by 100%, SHBG by 250%, and TBG by 60%, while FT3 and FT4 were only marginally influenced. Fasting levels of glucose and insulin did not change significantly, but the glucose load revealed a slight impairment of glucose tolerance. Three weeks after termination of pill intake, the various parameters returned to pretreatment levels, except for SHBG and TBG which were still elevated by 20 to 30%. The results demonstrate a marked preponderance of the effect of the estrogen component, a reliable inhibition of ovulation and very good cycle control during treatment with the biphasic formulation.

Preclinical evaluation of norgestimate, a progestin with minimal androgenic activity

Norgestimate is a novel progestin with highly selective progestational activity and minimal androgenicity. In rabbits, norgestimate binds to uterine progestin receptors, stimulates the endometrium, and inhibits ovulation. Norgestimate acts directly on target organs, stimulating rabbit endometrium when injected into the uterine cavity and inhibiting luteinizing hormone-releasing hormone-stimulated luteinizing hormone release in dispersed rat pituitary cells in culture. Norgestimate has no estrogenic activity, and like other progestins, it suppresses the action of estrogen. Unlike some other progestins, it is relatively free of androgenic activity. Norgestimate and its 17-deacetylated metabolite demonstrate very poor affinity for androgen receptors compared with levonorgestrel and gestodene and do not exhibit androgenic activity when measured as the stimulation of prostatic growth in immature rats. Norgestimate's lack of affinity for human sex hormone-binding globulin is further evidence of its minimal androgenicity.

Oral contraceptive use and the risk of type 2 (non-insulin-dependent) diabetes mellitus in a large prospective study of women

We examined the association between oral contraceptive use and incidence of Type 2 (non-insulin-dependent) diabetes mellitus among 115117 female nurses free of diabetes, cardiovascular disease and cancer in 1976 and followed-up for 12 years. During 1237440 person years of follow-up, 2276 women who provided information on oral contraceptive use were clinically diagnosed with Type 2 diabetes. Women who used oral contraceptives in the past had only a slight and marginally increased relative risk of 1.10 (95% confidence interval 1.01, 1.21) compared to those women who had never used oral contraceptives after controlling for known risk factors of disease. We found no evidence of increased risk with longer duration of use or with shorter interval since last use. Current users did not have an increased risk of Type 2 diabetes (relative risk = 0.86, 95% confidence interval 0.46, 1.61) when compared to women who had never used the drug. There was no effect modification by obesity, family history of diabetes, or physical activity. These data suggest that past or current oral contraceptive use does not substantially influence subsequent risk of Type 2 diabetes.

Increased capillary permeability for plasma proteins in oral contraceptive users

The transcapillary fluid balance was examined in eleven women before administration of a monophasic oral contraceptive (desogestrel 0.15 mg, ethinylestradiol 0.03 mg), and after three and six months of use. The interstitial colloid osmotic pressure was measured by the "wick" method, and the interstitial hydrostatic pressure by the "wick-in-needle" method in subcutaneous tissue on thorax and leg. During the six-month observation period, the following changes were observed: Plasma colloid osmotic pressure decreased (mean 1.8 mmHg, p = 0.047), as well as serum albumin (mean 5.1 g/l, p = 0.0006), total protein concentration (mean 2.8 g/l, p = 0.0006), hemoglobin (mean 0.5 g/dl, p = 0.014) and hematocrit (mean 1.8%, p = 0.047). Blood pressure and body weight remained unchanged, but foot volume showed a significant increase. The colloid osmotic pressure gradient (plasma-interstitium) was significantly reduced. The results indicate an increase in plasma volume in addition to an increased capillary permeability to plasma proteins during oral contraceptive use. We suggest that the observed changes in transcapillary fluid balance is caused by the estrogen component of the oral contraceptive pill.

Is oral contraceptive use still associated with an increased risk of fatal myocardial infarction? Report of a case-control study

OBJECTIVE

To investigate the association between fatal myocardial infarction and use of modern low-dose oral contraceptives.

DESIGN

A case-control study.

SETTING

General practices throughout England and Wales.

SUBJECTS

161 women aged under 40 dying from myocardial infarction during 1986-1988. Living controls (2 per case), matched for age and marital status, were chosen from general practice lists. Information was collected during structured interviews with general practitioners, and from postal questionnaires sent to surviving partners of the cases and to control women.

MAIN OUTCOME MEASURES

Mortality from myocardial infarction in relation to many risk factors, notably oral contraception, as measured by relative risk.

RESULTS

After allowing for the confounding effects of medical risk factors and for surgical sterilization, the overall relative risk associated with both current and past use of oral contraceptives was estimated to be 1.9 (95% CI 0.7 to 4.9, and 1.0 to 3.5 respectively). The relative risk associated with current use of preparations containing 50 micrograms of oestrogen, however, was estimated to be 4.2 (0.5 to 39.2). At least some of the relative risk associated with oral contraceptive use is likely to be attributable to the confounding effect of cigarette smoking, but it is impossible to estimate how much from the available data.

CONCLUSIONS

If there was an increased risk of fatal myocardial infarction associated with oral contraceptive use in 1986-1988 it is likely to have been less than two-fold; in this study risks were slightly, but not significantly, elevated with both current and previous use. It may be that any increase in risk is associated solely with the older combined preparations containing 50 micrograms of oestrogen.

Progestogens: an occasional review

Progestogens are drugs which share the ability to stimulate the progesterone receptor, but differ in many other aspects. Some of their uses include the regulation of menstrual bleeding, protection of oestrogen-primed endometrium, contraception and as anticancer therapy. However, progesterone physical and psychological side-effects and potentially adverse metabolic effects including lipoprotein changes must be considered. An understanding of these differences will permit appropriate prescribing of these drugs for gynaecological and medical disorders.

Oral contraceptive containing desogestrel in the maintenance of the remission of hirsutism: monthly versus bimonthly treatment

A treatment to keep hirsutism in remission while minimizing lipid disturbances was attempted in 20 formerly hirsute patients with hirsutism scores already greatly reduced after oral contraceptives (OCs) treatment. After OCs discontinuation for one to three months, they were thereafter treated for two years as follows: 9 patients received ethinyl estradiol (30 micrograms/day) plus desogestrel (150 micrograms/day) in three-week cycles every month (monthly); 6 patients received the same formulation during three-week cycles every other month (bimonthly); 5 patients received no treatment. In the untreated patients, abnormal hirsutism scores reappeared within 12-18 months; the levels of testosterone and free testosterone, initially high following discontinuation of OCs, remained elevated. Monthly treatment kept hirsutism in remission, and testosterone and free testosterone levels decreased. Bimonthly treatment was equally effective keeping hirsutism in remission, although testosterone levels did not decrease. Bimonthly treatment was not better than monthly treatment in relation to changes in plasma lipids (cholesterol, HDL-cholesterol, triglycerides).

Serum lipid variations in women on copper intrauterine devices, triphasic oral contraceptives and monthly injectable contraceptives

This is a longitudinal, prospective, comparative controlled study. Patient selection excluded smokers, overweighed, hypertensive, and aged greater than 34 years. 168 women were distributed by random list into four groups: A) fitted with inert IUD (control); B) with Nova T (Cu-IUD); C) received triphasic gestodene (OC); and D) monthly norethisterone enanthate 50 mg + estradiol valerate 5 mg (injectable). Serum lipid patterns were assessed at the beginning of contraceptive use and at 1, 6 and 12 months. The results of the Cu-IUD group did not show any difference with the control group. The OC group showed an increase of HDL and a significant lowering of LDL cholesterol at 6 months but this reverted by 12 months. On the other hand, in the injectable group, a sharp decrease of total lipids, total cholesterol and LDL was observed from the first month, lasting throughout 12 months, yielding significant difference with controls and also with pre-treatment values. In sum, the monthly injectable showed quite favorable patterns that would deserve further study, especially in view of the scarcity of hitherto available information concerning this formulation.

Cyclic fluctuations in human serum lipid and apolipoprotein levels during the normal menstrual cycle: comparison with changes occurring during oral contraceptive therapy

The influence of menstrual cycle phases and hormonal contraception on serum lipid and apolipoprotein (apo) levels was investigated in a group of normally menstruating young women. The study period covered a normal menstrual cycle (pretherapy), the fourth cycle of treatment with a triphasic oral contraceptive (OC) preparation, and the cycle immediately following interruption of therapy (cycle 5, posttherapy). Cycle phases were defined on the basis of serum hormone levels and basal body temperature determinations. Significant differences in cholesterol (free and esterified) levels were observed during the menstrual phase of both the normal menstrual cycle (lower) and the OC cycle (higher), when compared with the other phases. Triglycerides, which were higher under OCs, fluctuated similarly throughout the two cycles, but phase differences did not reach statistical significance. Apo AI and apo B were both higher under OCs, and apo B followed a trend similar to cholesterol during the two cycles. During the first month after discontinuation of OCs, cholesterol levels returned progressively to baseline values, while triglycerides were only partially decreased. We conclude that cyclic fluctuations in lipid levels do occur under the influence of both endogenous and exogenous sex hormones.

Open prospective multicenter trial with a new monophasic contraceptive combination containing gestodene

In a large and open prospective multicenter trial of 12,250 cycles from 2,378 women, contraceptive efficacy, clinical tolerance and acceptability of a new monophasic contraceptive combination containing 75 mcg gestodene (delta-5-levonorgestrel) and 30 mcg ethinyl oestradiol were studied. The objective was to assess efficacy, safety, side effects and cycle control of this oral contraceptive on healthy women using no other additional birth control methods. Two women became pregnant (0.016%) during the trial; both were patient failures. There was no effect on systolic or diastolic pressures. An average weight increase of 0.3 kg was noted. Cycle control was excellent with 95% of the cycles free of spotting and 98% free of breakthrough bleeding after six cycles. No serious complications occurred. There was an overall incidence of 14% reported side effects (after six cycles), indicating that the hormonal combination is well tolerated. It should be noted that 41.4% of the patients had some complaint before starting the treatment. For all complaints, a highly significant improvement was seen during the treatment.

Long-term treatment of hirsutism: desogestrel compared with cyproterone acetate in oral contraceptives

OBJECTIVE

Effectiveness of 2-year treatment of hirsutism with low estrogen oral contraceptives (OCs) containing nonandrogenic or antiandrogenic progestogen. Evaluation of changes in plasma lipids.

DESIGN

Ten patients treated with desogestrel 150 micrograms + 30 micrograms ethinyl estradiol, 6 with desogestrel 150 micrograms + 50 micrograms ethinyl estradiol, 10 with cyproterone acetate 2 mg + 35 micrograms ethinyl estradiol. Random allocation. Paired comparisons.

CONTROL GROUP

19 normal women, not treated.

SETTING

Academic tertiary care.

PATIENTS

Women with hirsutism (idiopathic and/or polycystic ovary), 24 of 26 completed treatment.

INTERVENTION

Two-year treatment.

MAIN OUTCOME MEASURES

Hirsutism score, plasma testosterone, and lipids.

RESULTS

Initial hirsutism scores (11.8 +/- 0.6 SE) declined with treatment (-7.2 +/- 0.4, P less than 0.01) to 4.7 +/- 0.6, almost reaching control (3.6 +/- 0.3). Initial plasma cholesterol (4.33 mmol/L +/- 0.30 SE), similar to control (4.78 +/- 0.24), increased slowly over 2 years (+2.04 +/- 0.34, P less than 0.01). High-density lipoproteins cholesterol (1.05 mmol/L +/- 0.04 SE), similar to control (1.12 +/- 0.07), did not change the 1st year and increased at 2 years (+0.57 +/- 0.11, P less than 0.01). No differences appeared among treatment groups.

CONCLUSIONS

Treatment is very effective, 2 years for best results. The OCs tested are equally efficacious. Changes in plasma lipids are of some concern but of difficult interpretation.

Effect of low-dose oral contraceptives on carbohydrate and lipid metabolism in women with recent gestational diabetes: results of a controlled, randomized, prospective study

Women with recent gestational diabetes mellitus were randomly assigned to one of two low-dose oral contraceptives to evaluate the effect of low-dose oral contraceptives on carbohydrate and lipid metabolism. A cohort of similar women requesting a non-oral-contraceptive method served as controls. The two oral contraceptives studied were ethinyl estradiol (0.035 mg)-norethindrone (0.40 mg) and ethinyl estradiol (0.030 to 0.040 mg)-levonorgestrel (0.050 to 0.125 mg). A 75 gm, 2-hour oral glucose tolerance test and a fasting lipid profile (total cholesterol, triglyceride, high- and low-density lipoprotein cholesterols) were performed at entry, after 3 months, and after 6 to 13 months of treatment. The prevalence of diabetes at 6 to 13 months (27/156 patients) was not significantly different between groups (non-oral-contraceptive group, 17%; ethinyl estradiol-norethindrone, 15%; ethinyl estradiol-levonorgestrel, 20%). When examined by prior gestational diabetes mellitus class, diabetes mellitus was present in 7% of prior class A1 and 29% of women with prior class A2 disease (p less than 0.001). Mean cholesterol and low-density lipoprotein cholesterol levels were significantly improved in all three groups at 3 months and at 6 to 13 months, whereas triglycerides remained unchanged. There were no differences in cholesterol, low-density lipoprotein cholesterol, or triglycerides levels between the groups. After 6 to 13 months, there was a significant increase in high-density lipoprotein cholesterol in the ethinyl estradiol-norethindrone group compared with the ethinyl estradiol-levonorgestrel and non-oral-contraceptive groups.

Comparison of the lipoprotein and hemostatic changes after a triphasic and a monophasic low dose oral contraceptive in premenopausal middle-aged women

Metabolic and hemostatic effects of 2 low dose oral contraceptives (OCs), a triphasic (ethinylestradiol + (-)-norgestrel) and a monophasic (ethinylestradiol + desogestrel) preparation, were compared in a cross-over trial in fertile women over 35 years of age. Both combinations moderately affected plasma lipids, with 17-24% increases of total triglyceridemia. Triglycerides accumulate in low density lipoproteins, thus suggesting the possible formation of an atherogenic lipoprotein particle. Only the monophasic preparation increased high density lipoprotein (HDL)-cholesterol levels significantly, with a rise in HDL3 mass and cholesterol. OC treatment led to slight changes in HDL2 and HDL3 structure, with a rise of the cholesteryl ester and triglyceride contents, indicative of a stimulated cholesterol esterification and reverse transport. Changes in the hemostatic indexes (fibrinogen, antithrombin III and protein C) were negligible. The new low dose OCs, even when prescribed to relatively older women, affect to a relatively small extent lipid/lipoprotein metabolism, with the exception of changes in the low density lipoprotein composition.

Oral contraceptives and cardiovascular risk. Taking a safe course of action

Although a prospective, longitudinal study on the long-term cardiovascular effects of oral contraceptives has yet to be performed, available data are useful in determining a safe course of action while physicians await definitive answers. Exogenous sex steroids produce important effects on lipid metabolism. Early intervention against cholesterol is important in reducing cardiovascular risk. Current users of high-dose formulations, particularly older women who smoke, are at greatest risk for cardiovascular complications, especially myocardial infarction. Low-dose oral contraceptives have more modest effects on lipid metabolism, but important differences in the potency of progestins remain. Fortunately, recent studies among users of lower-dose oral contraceptive formulations fail to show an increase in cardiovascular morbidity and mortality. Nonetheless, prudent physicians will avoid oral contraceptives that may adversely affect lipoprotein metabolism, such as those containing progestins with high androgenic and antiestrogenic potency.

Effects of ethinyl estradiol combined with desogestrel and cyproterone acetate on glucose tolerance and insulin response to an oral glucose load: a one-year randomized, prospective, comparative trial

To investigate the effects of two slightly estrogen-dominant, monophasic, low-dose oral contraceptives on carbohydrate metabolism, 40 healthy young women were randomly allocated to receive either 30 micrograms of ethinyl estradiol + 150 micrograms of desogestrel, a 19-nortestosterone-derived progestin (Marvelon; n = 21) or 35 micrograms of ethinyl estradiol + 2 mg of cyproterone acetate, a 17-acetoxyprogesterone derivative (Diane-35; n = (19) for a prospective observation period of 1 year. At baseline, 6, and 12 months, blood glucose, plasma insulin, and plasma C-peptide levels were measured during an oral glucose tolerance test. Although the changes were absent (Marvelon) or minimal (Diane-35) at 6 months, both groups had a slight increase in blood glucose levels at 12 months; overall glucose tolerance remaining, however, within the normal range. Plasma insulin levels remained unchanged in the Diane-35-group, which suggested increased insulin resistance, but were significantly decreased in the Marvelon group despite significant rises in plasma C-peptide levels. Comparison of plasma C-peptide and insulin changes suggests enhanced pancreatic insulin secretion and increased hepatic insulin metabolism with both Marvelon and Diane-35.

Effects of oral contraceptives on carbohydrate and lipid metabolisms in a healthy population: the Telecom study

In a cross-sectional study that aimed to identify risk factors for diabetes, 1290 consecutive, healthy, nonpregnant women of child-bearing age were examined in a center for preventive medicine. An in-depth interview about menses, use of oral contraceptives, and menopause was performed. Plasma glucose at fasting and 2 hours after a 75 gm glucose load, glycated hemoglobin A1c, fasting plasma insulin, total plasma cholesterol, and triglycerides were measured. Compared with nonusers taking no progestogens, oral contraceptive users (n = 431; 33.4%) were younger (p less than 0.001) and leaner (p less than 0.001). After adjustment for age and body mass index, oral contraceptive users had higher 2-hour plasma glucose (p less than 0.001), higher fasting plasma insulin (p less than 0.01), and higher triglycerides levels (p less than 0.01). Fasting plasma glucose, glycated hemoglobin A1c, and total cholesterol did not significantly differ between the two groups. In relation to dosage and types of steroid components, few differences have been found between high-dose and low-dose oral contraceptives or according to the estrogen-progestogen balance of the preparations. Use of oral contraceptives appears to induce an increase of insulin-resistance markers, which have recently been cited as risk factors for ischemic vascular diseases. These markers should be carefully monitored in oral contraceptive users.

Oral contraceptives, insulin resistance and ischemic vascular disease

From a large prospective study on diabetes risks, 1112 professionally active, non-menopausal, non-pregnant, healthy women were cross-sectionally analysed according to their use of oral contraception. After adjustment for age, weight and diabetes risk factors, those taking the pill, compared to those who did not, had significantly higher fasting serum insulin, triglycerides and 2-h 75 g OGTT blood glucose levels. The insulin-resistance markers which have recently been cited as ischemic vascular disease risk factors should be carefully monitored in pill users.

Influence of a triphasic oral contraceptive preparation on plasma lipids and lipoproteins

The influence of a triphasic oral contraceptive preparation on plasma lipid, lipoprotein, and apolipoprotein levels was studied in 20 women during 12 treatment cycles. Multiple blood samples representing all phases of the therapeutic cycle as well as posttherapy were obtained. Total and low-density lipoprotein (LDL) cholesterol fluctuated transiently in the earlier part of the study but after 9 and 12 cycles of therapy did not differ from baseline. Cyclic elevations in total cholesterol corresponding to changes in LDL cholesterol were noted twice. Total high-density lipoprotein (HDL) cholesterol remained remarkably stable over the entire study while HDL2 cholesterol decreased and HDL3 cholesterol increased. Triglycerides (total and lipoprotein fractions) increased during treatment and fell to baseline levels within one posttreatment cycle. Very low-density lipoprotein (VLDL) cholesterol was also elevated during the study. Apolipoprotein (apo) AI, apo AII, and apo B rose under therapy, the latter increase producing a lowered LDL cholesterol/apo B ratio. Apolipoprotein E showed a temporary decrease early in the study but otherwise remained unchanged.

Epidemiological features of glycated haemoglobin A1c-distribution in a healthy population. The Telecom Study

HbA1c was measured in 3240 healthy non-diabetic adult individuals in a working population. There was no difference in HbA1c between sexes. The distribution of HbA1c was approximately normal with a slight difference between mean and median values at all ages in both sexes. HbA1c increased with deterioration of glucose tolerance and with all the known risk factors for diabetes (age, obesity, family history of diabetes, history of a large newborn delivery); age but not body mass index appeared as a factor influencing HbA1c independently. In women, HbA1c levels rose particularly at the age of menopause but the use of oral contraceptives or oestrogens made no difference. In both sexes, HbA1c was higher in smokers than in non-smokers. No consistent seasonal variation was observed. Haematologic factors had a negligible influence on HbA1c level. HbA1c was more highly correlated with fasting plasma glucose than with 2 h-plasma/glucose (r = 0.20 vs 0.11). In a stepwise multiple regression analysis, age followed by fasting plasma glucose were the only two significant factors associated with the level of HbA1c. These data indicate that HbA1c is influenced only by factors closely linked to diabetes.

Carbohydrate metabolic studies during twelve months of treatment with a low-dose combination oral contraceptive

Carbohydrate metabolism was evaluated in twenty healthy women volunteers using a low-dose combination oral contraceptive (OC) containing 30 micrograms of ethinyl estradiol and 500 micrograms of dl-norgestrel by measurement of serum glucose and insulin levels during 3-hour oral glucose tolerance test (OGTT) before and after 3, 6 and 12 months of medication. There were no significant differences in body weight or blood pressure between pretreatment and posttreatment. Fasting serum glucose levels were slightly reduced, though not significantly, during all periods of treatment. But serum glucose levels were increased at 1, 2 and 3 hours in association with high insulin responses during OGTT in all periods of OC therapy, indicating mild to moderate insulin resistance. These data suggest that the low-dose combination OC used in the study exerts alterations on carbohydrate metabolism in women during one year of OC use.

A study comparing a gestoden triphasic formulation with a fixed combination OC

Metabolic parameters were studied in 30 patients over 12 treatment cycles in a double-blind randomized comparative trial of the new progestogen gestoden in a triphasic formulation against a fixed dose combination pill containing desogrestrel, in Bandung, Indonesia. The results of this laboratory experience affirm findings in similar previous metabolic studies that: (1) the changes induced by modern low-dose pills are clinically and statistically insignificant; (2) throughout the treatment cycles, the values of the various laboratory tests remain well within the normal range; and (3) the favorable balance between coagulation and fibrinolysis is maintained. Results of lipoprotein, coagulation, fibrinolytic and liver function tests in 27 patients are presented. Gestoden's pharmacologic profile and the worldwide clinical experience with the triphasic gestoden formulation in 4285 women are discussed.

Metabolic effects of three new low-dose pills: a six-month experience

We evaluated the effects on glucose and lipid metabolism in 57 healthy volunteers randomly assigned to one of three low-dose oral contraceptives: two monophasic (desogestrel + ethinylestradiol, EE, and cyproterone acetate + EE) and one triphasic (gestodene + EE) contraceptives. Glucose and insulin responses during OGTT were slightly affected by the cyproterone pill. The insulin area/glucose area ratio and HbA1c level were unchanged in all women. No preparation affected total and LDL-cholesterol levels. Triglycerides rose in all groups, while HDL-CH did only in women taking the two monophasic pills. The three low-dose pills assessed in this study have negligible effects on glucose and lipid metabolism.

Evaluation of the clinical performance of three triphasic oral contraceptives: a multicenter, randomized comparative trial

Three hundred thirteen women participated in an open, multicenter comparison of the incidence of intermenstrual bleeding (breakthrough bleeding and or spotting) associated with the use of three triphasic oral contraceptives. Triphasil (n = 107), containing levonorgestrel and ethinyl estradiol, and Ortho-Novum 7/7/7 (n = 97) and Tri-Norinyl (n = 109), both of which contain norethindrone and ethinyl estradiol, were administered over four cycles for a total of 1141 cycles. The total incidence of intermenstrual bleeding was significantly lower with Triphasil (17.2%) than with Ortho-Novum 7/7/7 (39.5%) or Tri-Norinyl (49.0%). The pattern remained the same when findings were analyzed cycle by cycle and for breakthrough bleeding and spotting separately. The incidence of other side effects was comparable for all regimens. Results of this study demonstrate superior cycle control with Triphasil compared with Ortho-Novum 7/7/7 and Tri-Norinyl during the first four cycles of use.

Clinical aspects of three new progestogens: desogestrel, gestodene, and norgestimate

Three new 19-nortestosterone progestogens, which are chemically related to levonorgestrel, are now clinically available in combination oral contraceptives in Europe. Desogestrel and norgestimate must be transformed to metabolites for all or part of their biologic activity; gestodene is active in its original form. Compared with present low-dose monophasic and triphasic levonorgestrel formulations, the new combinations appear to be equivalent in efficacy and type and frequency of side effects. Cycle control may be slightly improved with the gestodene preparation and somewhat poorer with the desogestrel regimen. As with the present triphasics, most changes reported in coagulation indexes for the new combinations remained within normal limits, as did changes in carbohydrate and lipid metabolism. There is no present evidence that either the norgestimate or aesogestrel formulation provides a clinical improvement over the levonorgestrel triphasic. In the gestodene combination, the progestogen's increased biologic activity allows further reduction of total steroid dose.

Comparative metabolic effects of three types of combined oral contraceptive pills in Chinese women

The results of a prospective longitudinal controlled study comparing some metabolic effects of a low-dose levonorgestrel-ethinyl oestradiol combined oral contraceptive (Microgynon 30), a desogestrel-ethinyl oestradiol-containing pill (Marvelon) and a levonorgestrel-ethinyl oestradiol triphasic preparation (Triquilar) after one year of treatment in ethnic Chinese women are presented. Serum cholesterol levels are similar for the three pills at 6 and 12 months of treatment. Marvelon and Triquilar users showed rises in triglyceride levels while Microgynon 30 users had no change after one year of treatment. Lipoprotein fractions showed favourable changes in Triquilar and Marvelon users with significant rise in HDL fractions at 6 and 12 months; Microgynon 30 users had equivocal changes in HDL fractions. Carbohydrate metabolism as reflected by glucose tolerance showed deterioration with all 3 pills, being least with Microgynon 30 and greatest with Marvelon at 12 months.