Oral contraceptives and the decline in mortality from circulatory disease

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.

Oral contraceptives and myocardial infarction

The risk of myocardial infarction in contraceptive users is limited to women over 35 years of age who smoke. The cause of myocardial infarction in oral contraceptive users is thrombotic and not atherosclerotic. Minor lipid changes have no clinical relevance to myocardial infarction in contraceptive pill users and do not appear to increase coronary plaques.

Comparative studies of 30 micrograms ethinyl estradiol combined with gestodene and desogestrel on blood coagulation, fibrinolysis, and platelets

An association between an increase in the incidence of thromboembolic disease and the use of combined oral contraceptives has been shown by several epidemiologic studies. Evidence of the vascular complications of oral contraceptives suggests that venous thromboembolism correlates with estrogen dosage and arterial complications with both estrogen and progestogen components. In 60 healthy, randomly allocated women, the effects of ethinyl estradiol, 30 micrograms, combined with gestodene, 75 micrograms, and desogestrel, 150 micrograms, on blood coagulation, fibrinolysis, and platelet function were compared. Subjects were studied before oral contraceptive use, at 12, 24, 36, and 48 weeks of treatment, and at 6 and 12 weeks after treatment. Both oral contraceptives affected the hemostatic system, but our results indicate that the ethinyl estradiol/gestodene combination causes changes in the hemostatic system similar to those in the ethinyl estradiol/desogestrel combination. Factors VII and X activity were slightly higher with the ethinyl estradiol/desogestrel combination than with the ethinyl estradiol/gestodene combination, possibly reflecting a greater estrogenic effect.

Mortality among oral contraceptive users: 20 year follow up of women in a cohort study

OBJECTIVE

To see whether the use of oral contraceptives influences mortality.

DESIGN

Non-randomised cohort study of 17,032 women followed up on an annual basis for an average of nearly 16 years.

SETTING

17 Family planning clinics in England and Scotland.

SUBJECTS

Women recruited during 1968-74. At the time of recruitment each woman was aged 25-39, married, a white British subject, willing to participate, and either a current user of oral contraceptives or a current user of a diaphragm or intrauterine device (without previous exposure to the pill).

MAIN OUTCOME MEASURES

Overall mortality and cause specific mortality.

RESULTS

238 Deaths occurred during the follow up period. The main analyses concerned women entering the study while using either oral contraceptives or a diaphragm or intrauterine device. The overall relative risk of death in the oral contraceptive users was 0.9 (95% confidence interval 0.7 to 1.2). Though the numbers of deaths were small in most individual disease categories, the trends observed were generally consistent with findings in other reports. Thus the relative risk of death in the oral contraceptive users was 4.9 (95% confidence interval 0.7 to 230) for cancer of the cervix, 3.3 (95% confidence interval 0.9 to 17.9) for ischaemic heart disease, and 0.4 (95% confidence interval 0.1 to 1.2) for ovarian cancer. There was a linear trend in the death rates from cervical cancer and ovarian cancer (in opposite directions) with total duration of oral contraceptive use. Death rates from breast cancer (relative risk 0.9; 95% confidence interval 0.5 to 1.4) and suicide and probable suicide (relative risk 1.1; 95% confidence interval 0.3 to 3.6) were much the same in the two contraceptive groups. In 1981 the relative risk of death in oral contraceptive users from circulatory diseases as a group was reported to be 4.2 (95% confidence interval 2.3 to 7.7) in the Royal College of General Practitioners oral contraception study. The corresponding relative risk in this study was only 1.5 (95% confidence interval 0.7 to 3.0).

CONCLUSIONS

These findings contain no significant evidence of any overall effect of oral contraceptive use on mortality. None the less, only small numbers of deaths occurred during the study period and a significant adverse (or beneficial) overall effect might emerge in the future. Interestingly, the mortality from circulatory disease associated with oral contraceptive use was substantially less than that found in the Royal College of General Practitioners study.

The influence of oral contraceptives and habitual physical activity on serum lipids in black adolescents and young women

The effects of oral contraceptive use and habitual physical activity on serum cholesterol and lipoproteins were studied in 37 black females ages 16 to 28 years over a 3-month period. By the third month of oral contraceptive use, high-density lipoprotein (HDL) levels were lower and the low-density lipoprotein (LDL) to HDL ratio and total serum cholesterol (T Chol) to HDL ratio were significantly higher in those receiving oral contraceptive with norgestrel. The level of physical activity had no significant effect on HDL levels. The active subjects had lower T Chol and HDL levels and a lower T Chol to HDL ratio at the end of 3 months. Subjects in the active-norethindrone group had lower T Chol to HDL ratios than those taking norgestrel. The nonactive norgestrel group had a continuous increase in their T Chol to HDL ratio over the 3-month period. These effects should be considered when counseling sexually active teenagers and when recommending an oral contraceptive.

Cerebrovascular deaths before and after the appearance of oral contraceptives

The mortality of cerebrovascular diseases in Denmark was analysed for men and women 15-44 years of age, in a 14-year period before and after the appearance of oral contraceptives (OC) in 1966. 1,670 deaths were registered over 28 years, during which the female incidence of cerebrovascular deaths increased by 19% (P less than 0.025), while the male mortality was unchanged. Women showed a percentage increase in deaths from cerebral thromboembolic attacks (CTA) of 33%, men a fall of 14%. The increase of female CTA deaths was most pronounced in the young fertile group, the age group with a high OC use. A relative risk of CTA of 3.3-4.5 for OC users compared with non-users could explain the CTA trend difference between women and men. No other single risk factor responsible for the observed trends could be identified. Both women and men had a significant increase in the mortality of subarachnoidal hemorrhages, and a significant fall in the mortality of intracerebral hemorrhages.

Oral contraceptives and cardiovascular disease: a critique of the epidemiologic studies

Observational study designs used to investigate the relationship of oral contraceptive use to the occurrence of venous thromboembolism, stroke, myocardial infarction, and cardiovascular death include case-control, cohort, and mortality statistics studies. This analysis catalogs the findings of each of these epidemiologic studies, its statistical significance, and its performance with regard to scientific methodologic standards. An association between current oral contraceptive use and incidence of venous thromboembolism without predisposition has been consistently observed in case-control and cohort studies. Associations are less consistent for various types of stroke and for myocardial infarction. Only the Royal College of General Practitioners study found a significantly elevated risk of cardiovascular death with oral contraceptive use. The majority of mortality statistics studies offer little support for a relationship between oral contraceptive use and cardiovascular events. Major systematic problems in the epidemiologic studies include potential for bias in the detection of cardiovascular events and differences in the prognostic susceptibility of compared groups. Bias in the ascertainment of drug exposure is an unresolved issue for most of the case-control studies. Because of possible biases arising from methodologic deficiencies in these epidemiologic studies, questions as to the validity of the observed associations between oral contraceptive use and cardiovascular events should remain.

Oral contraceptives, lipids and cardiovascular disease

Evidence for the involvement of changes in lipid metabolism and oral contraceptive use in the development of cardiovascular disease is briefly reviewed with particular reference to the main object of the article, to assess the effect of different oral contraceptive formulations on serum lipid levels. The preferred formulations should contain a low dose of ethynyloestradiol and should not increase serum levels of cholesterol and LDL-C or reduce those of HDL-C. Such formulations appear to be the triphasic one containing ethynyloestradiol and levonorgestrel and the ethynyloestradiol-desogestrel combination, which appears to be unique in that it may actually increase HDL-C. However other determinants in addition to effects on lipid metabolism will be important in deciding the choice of an oral contraceptive. Any changes which do occur in serum lipid concentrations with OC use appear within the first three months and do not appear to be progressive with continued use after this time.

Stroke before 55 years of age at Karolinska Hospital 1973-77. A study of 399 well-defined cases. Risk indicators and etiological considerations

The etiological characteristics of cerebrovascular disease (CVD) before the age of 55 are reviewed in 399 patients admitted to the Department of Neurology, Karolinska Hospital, Stockholm, from 1973-77. The material was well-defined with regard to subtypes of stroke as well as to the diseased population. The control material consists of 829 males and females of corresponding age randomly selected from the Stockholm population. In the ischemic group, 61% had angiographic evidence of atherosclerosis and, compared to controls, in most patient groups a significant (P less than 0.05-0.001) association with hypertension, diabetes, heart disease and smoking was found as well as for female patients under age 40 the use of oral contraceptives (P less than 0.001). In the hemorrhagic group, angiography demonstrated aneurysms in 76% of the patients with subarachnoidal bleeding but also atherosclerotic lesions in about 12% of the whole group. This would imply that atherosclerosis is an important precursor also for hemorrhagic lesions, further supported by a significant (P less than 0.01-0.001) association of hypertension, diabetes and smoking with this group.

Trends in mortality from carcinoma of the liver and the use of oral contraceptives

There is increasing concern that contraceptive pill usage may increase the risk of hepatocellular carcinoma. As primary malignant liver cancer is very rare in this country, any effect due to oral contraceptives should be apparent in national mortality statistics. An analysis of mortality rates over the last 24 years shows a small but consistent increase for young women starting to occur during the end of the last decade. However no such trend is apparent in data from other countries where pill usage is comparable to that in the U.K. Overall liver cancer remains an extremely uncommon cause of death in developed countries, but it will be particularly important to monitor trends in this disease in the future.

Oral contraceptives and mortality from circulatory system diseases: an epidemiologic study in Taiwan

An epidemiological study on the association between oral contraceptive (OC) use and circulatory system disease (CSD) mortality undertaken in Taiwan by proxy interview of closest family members of 306 deceased cases, 305 deceased controls, and 611 healthy neighborhood controls indicated that the relative risk between the cases and health controls was 0.98 (0.62-1.54) and that between cases and health controls was 0.82 (0.56-1.21). Use of OC by Taiwanese women has not produced any overwhelming adverse effects on CSD mortality.