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

Lipid profile in women over 35 years old using triphasic combined oral contraceptives

Twenty-nine women aged 35 years old or more, using triphasic combined oral contraceptive (COC) were evaluated during six cycles for the following parameters: total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and its subfraction HDL2, triglycerides, apoproteins A and B, Castelli risk index I and II (cholesterol/HDL-C and LDL-C/HDL-C) and apoprotein ratio (apoprotein B/apoprotein A). The same laboratory measurements were done in a control group of 49 non-COC-user women. The results showed that there were no differences on most of the studied parameters between user and nonuser women. There was a significant reduction of HDL-C and HDL2-C, although within the normal range. In addition, it was observed a significant increment of triglycerides and apoprotein B at 6 months of follow-up only in user group (p < 0.05), although within the normal range. It is concluded that the use of levonorgestrel triphasic COC appeared to have no additional adverse impact when used by women aged over 35 years. Further studies are needed to obtain conclusive data.

Triphasic oral contraceptives: review and comparison of various regimens

OBJECTIVE

To review and compare the risk-benefit profile of triphasic oral contraceptives with that of low-dose monophasic oral contraceptives.

DESIGN

Literature on currently marketed triphasics and monophasics.

PATIENT(S)

Healthy women of reproductive age.

MAIN OUTCOME MEASURE(S)

Comparison of the rationale for development, composition, mechanism, efficacy, menstrual cycle control, side effects, health benefits, and risk-benefit profile.

RESULT(S)

All triphasics contain ethinyl estradiol (0.025-0.040 mg/d) and one of several progestins in doses (0.05-1.0 mg/d) related to their relative potencies, which are substantially lower overall (total dose) than those in monophasics. The triphasics are highly efficacious. In general, menstrual cycle control and side effects are similar in both types, but triphasics containing the newer progestins (desogestrel, gestodene, and norgestimate) have better cycle control and a reduced incidence of androgenic side effects compared with those with norethindrone or levonorgestrel. Both triphasics and monophasics have minimal effects on carbohydrate and lipid metabolism and hemostasis parameters, and therefore comparable low risks of coronary heart disease. The health benefits of triphasics and monophasics are similar and include decreased incidence of unwanted and ectopic pregnancies, ovarian cysts, endometrial and ovarian cancers, benign breast disease, and acute pelvic inflammatory disease; less menstrual blood loss and iron deficiency anemia; and lower frequency of irregular bleeding and menorrhagia.

CONCLUSION(S)

The risk-benefit profiles of both triphasics and monophasics are favorable and similar.

Hemostatic effects of third- and second-generation oral contraceptives: absence of a causal mechanism for a difference in risk of venous thromboembolism

Some observational studies have found a difference in the risk of nonfatal venous thromboembolism (VTE) with low-dose, oral contraceptives (OCs) containing desogestrel (DSG) or gestodene (GSD) and those containing levonorgestrel (LNG). However, this does not agree with current pathophysiological concepts. This review compares all 17 comparative studies on the hemostatic effects of DSG/GSD- and LNG- or norgestimate (NGM)-containing OCs, and comments on two recent cross-sectional studies on the effects of third- and second-generation OCs on activated protein C (APC) sensitivity. In the comparative studies, the only difference in hemostatic parameters between DSG/GSD- and LNG- or NGM-containing OC users was a tendency towards higher factor VII (FVII) levels with DSG/GSD OCs. Differential effects on APC sensitivity were observed with the endogenous thrombin generation potential (ETP) assay, but not with the classical APC resistance test. FVII is not a risk marker for VTE, but is affected by dietary fat, estrogens and androgens and may interfere with the ETP assay. As no differences in established VTE risk markers were observed, there is no plausible reason for a differential risk of VTE with DSG/GSD- and LNG-containing OCs. In fact, the lack of differences with regard to established risk markers of VTE gives further support to the findings of the most recent epidemiological studies, which have not found any difference in the risk of VTE between third- and second-generation OCs.

An open label, randomized study to evaluate the effects of seven monophasic oral contraceptive regimens on hemostatic variables. Outline of the protocol. Oral Contraceptive and Hemostasis Study Group

Complementary to the epidemiological knowledge on the association between oral contraceptive use and the occurrence of venous thromboembolism, a study was designed to obtain more conclusive data regarding the effect of estrogen dose and progestogen type of oral contraceptives on risk markers for the occurrence of venous thromboembolism. The protocol for this multicenter, randomized, open label, parallel group, comparative study is outlined in the present article. A total of 730 healthy, nonsmoking, mulliparous women were treated for six cycles with one of the seven monophasic oral contraceptives tested in this study. The effects of progestogen type (desogestrel, gestodene, levonorgestrel, and norgestimate) and the effects of ethinyl estradiol dose (50, 30, and 20 micrograms) on various hemostatic variables was assessed, including the key components of the anticoagulant and fibrinolytic system, as well as the coagulation system. The primary outcome variables in the study were prothrombin fragment 1 + 2 and D-dimer.

Effects on hemostatic variables of desogestrel- and gestodene-containing oral contraceptives in comparison with levonorgestrel-containing oral contraceptives: a review

In some studies third-generation oral contraceptives have been reported to be associated with a higher risk of venous thromboembolism than are second-generation oral contraceptives, whereas recent, more refined studies have not confirmed this. The reasons for the alleged differences are under discussion, and differential effects on hemostasis have been proposed. Eighteen studies comparing second- and third-generation oral contraceptives with respect to their effects on hemostasis were analyzed. Significant changes from baseline were reported for many variables with both second- and third-generation oral contraceptives without significant between-group differences. Also, in a combined analysis of nonsignificant changes, no consistent pattern of change emerged for any marker, with the exception of higher factor VII levels associated with third-generation oral contraceptives. However, factor VII is not related to venous thromboembolism risk. In addition, 1 cross-sectional study with an unvalidated assay reported a higher ratio of activated protein C sensitivity with third-generation oral contraceptives. Only 2 components of the hemostatic system (factor VII and activated protein C sensitivity ratio) emerged as potentially differentially affected by second- and third-generation oral contraceptives; the association with venous thromboembolism risk is questionable in the former case and unknown in the latter.

Cardiovascular risk factors in Norwegian women using oral contraceptives: results from a cardiovascular health screening 1985-88

We analyzed data from 4,905 women aged 20-39 and 14,803 aged 40-49 who attended a health survey in Norway 1985-88, to study cardiovascular risk factors in users of oral contraceptives, all types and specifically by formulation. In age group 20-39, users of low-dose estrogen/ progestin regimens were younger, had lower body mass index (BMI), less often reported coronary heart disease in relatives, and less often used saturated fat on bread than did non-users. In age group 40-49, smoking was more prevalent in users of low-dose estrogen/progestin than in non-users. In both age groups the mean ratio of total/HDL cholesterol, the mean level of non-fasting triglycerides, and the mean systolic and diastolic blood pressures were higher in oral contraceptive users than in non-users. Among the users, a more favorable pattern was found in women using progestin-only oral contraceptives, as blood pressure levels were equal to those of non-users and total cholesterol and triglycerides were both 0.1-0.2 mmol/l below the non-users, in both age groups. However, users of low-dose estrogen formulations containing desogestrel 0.15 mg, norethisterone (norethindrone) 0.5 mg or lynestrenol 2.5 mg had the highest levels of HDL, even higher than the non-users. A pattern of higher triglycerides and higher ratio of total/ HDL cholesterol was found in smokers, compared with non-smokers, among users of any type of contraceptives, and in non-users.

The effects of two phasic oral contraceptives on hemostasis and platelet function

OBJECTIVE

To compare the effects on hemostatic parameters of a combiphasic oral contraceptive containing desogestrel and ethinyl estradiol (DSG/EE) and a triphasic oral contraceptive containing levonorgestrel and ethinyl estradiol (LNG/EE).

METHODS

In an open-label, randomized, group-comparative study in 10 healthy volunteers per treatment group, the effects on parameters of coagulation, anticoagulation, fibrinolysis, antifibrinolysis and platelet function were determined at baseline, after three treatment cycles, and after a post-treatment cycle. Changes from baseline were analyzed using a paired t-test, whereas between-group differences were analyzed by means of an analysis of co-variance.

RESULTS

Both OC preparations induced modest changes of some coagulation, anticoagulation, fibrinolysis and antifibrinolysis parameters, although all mean values remained within the normal range. No significant effects were observed with either OC with respect to platelet function. Statistically significant differences between the two preparations could occasionally e observed: the concentrations of antithrombin II (AT-III) and Factor VII were higher with the DSG/EE preparation than with LNG/EE preparation at the end of treatment and AT-III activity, AT-III concentration, Factor X concentration, and plasminogen activity were higher with DSG/EE than with LNG/EE in the post-treatment cycle.

CONCLUSIONS

Combiphasic DSG/EE and triphasic LNG/EE, both OCs with a comparable amount of EE per cycle, had no clinically significant effect on the overall hemostatic balance.

Sex steroids and lipoprotein metabolism

Lipoprotein metabolism is involved in atherogenesis. Female sex-hormones have substantial effects on both lipoprotein metabolism and the vessel wall. Cholesterol, one of the major lipids in lipoproteins, is both the substrate for, and the target of, the steroidal sex hormones.

New progestogens in oral contraception

The major developments in combined oral contraceptives (COCs) have been a reduction in the total dose of both the oestrogen and progestogen administered per cycle and the introduction of new progestogens which are claimed to be more 'selective' than the older ones. This review examines in detail the clinical efficacy of the new COCs, where possible in comparison with those containing levonorgestrel or norethisterone, and their pharmacological effect on carbohydrate and lipid metabolism, haematological factors, pituitary-ovarian function and serum protein and androgen concentrations. Based mainly on the pharmacological evidence, the newer COCs are an improvement over the older low-dose formulations and are clearly preferable to the high-dose ones. However, the older low-dose COCs, despite many years of use, have not resulted in a high incidence of adverse effects. The increasing use of the new COCs, as evidenced by their increasing market share throughout Europe, does indicate that they have been well accepted in clinical practice.

Drug control of reverse cholesterol transport

Reverse cholesterol transport identifies a series of metabolic events resulting in the transport of excess cholesterol from peripheral tissues to the liver. High-density lipoproteins (HDL) are the vehicle of cholesterol in this reverse transport, a function believed to explain the inverse correlation between plasma HDL levels and atherosclerosis. An attempt to stimulate, by the use of drugs, this transport process may hold promise in the prevention and treatment of arterial disease. Among the agents affecting lipoprotein metabolism, only probucol exerts significant effects on reverse cholesterol transport, by stimulating the activity of the cholesteryl ester transfer protein and, consequently, altering HDL subfraction composition/distribution. Another approach to the stimulation of reverse cholesterol transport consists of raising plasma HDL levels; studies in animals, either by exogenous supplementation or by endogenous overexpression, have shown a consistent benefit in terms of atherosclerosis regression and/or non-progression. Thus, it is time to consider different future treatments of atherosclerosis, combining the classical lipid-lowering treatments with innovative methods to promote cholesterol removal from the arterial wall.

Clinical experience and pharmacological effects of an oral contraceptive containing 20 micrograms oestrogen

The performance of a new low-dose oral contraceptive (Mercilon) containing only 20 micrograms ethinyloestradiol combined with 150 micrograms desogestrel is reviewed. Eight multicentre clinical trials have been completed and provide information on 10,672 women studied over 73,477 cycles. The high efficacy of Mercilon was indicated by the finding that only 10 pregnancies were reported; nine of these occurred in women who omitted to take Mercilon on a number of days and only one in a woman who took all the tablets according to instructions. Cycle control was good; as with all oral contraceptives, the incidence of breakthrough bleeding and spotting was highest in the first treatment cycle and by the sixth treatment cycle the values were usually < 5% and < 7%. More than 80% of women had regular cycles. Side effects were few, the most common being headache, nausea and breast tenderness with incidences in the sixth treatment cycle of less than 2%, 6% and 6%, respectively. There were no significant changes in body weight or blood pressure. Pharmacodynamic investigations showed no adverse effects. Only 1 of 5 studies found an increased response to a glucose tolerance test compared to the pretreatment test. In 8 of 10 studies, serum HDL-C concentrations increased on treatment and this was associated with increases in apoproteins A1 and A2. Serum triglyceride levels also increased but no change occurred in serum cholesterol or LDL-C levels. Haematological factors were assessed in 8 studies and only minor changes were observed. Serum binding protein (SHBG, CBG, caeruloplasmin) concentrations increased and serum androgen levels decreased. Measurements of blood FSH, LH, oestradiol and progesterone indicated adequate inhibition of ovulation. Mercilon is the only oral contraceptive containing 20 micrograms ethinyloestradiol to have high efficacy, to have no adverse pharmacodynamic effects and, importantly, to produce an acceptable bleeding pattern not significantly different from that of oral contraceptives with a higher content of ethinyloestradiol.