Oestrogens and endometrial cancer: effect of other risk factors on the association

We analyzed data from a case-control study of endometrial cancer to determine whether, in a woman's menstrual and medical history, factors could be identified that modify the increased risk resulting from menopausal oestrogen use. Overweight, hypertension, low parity, non-smoking, late age at menopause, and a history of cholecystectomy were all associated with endometrial cancer, but oestrogen use produced large increases in risk both in the presence and absence of these characteristics. We conclude that information on other known risk factors for endometrial cancer provides little or no guidance as to which patients to select in the perimenopause.

Outcome of pregnancies following the use of oral contraceptives

The use of oral contraception by women doctors on the Medical Register for England and Wales in 1975 was studied and related to the outcome of their pregnancies. Nearly two thirds had used oral contraception at some time, but less than one third of their pregnancies had followed its use. Users tended to be younger at the time of the survey and to smoke in pregnancy more often. After allowing for these associations a poor outcome was just slightly more common in pregnancies occurring after OC use, particularly in conceptions occurring within a month or after a year of cessation. In contrast conceptions occurring in the 2nd or 3rd month after cessation had an unusually favourable outcome. It therefore seems likely that at least some of this weak association between oral contraception and poor outcome may be explained by factors that determine the length of time it takes to conceive. Overall it seems that any real risk to pregnancies conceived after cessation of oral contraception must be very small and outweighed by the undoubted advantages of its use.

Increased blood viscosity in young women using oral contraceptives

Blood viscosity and its major determinants (hematocrit, plasma fibrinogen, and plasma viscosity) were measured in 25 men, 25 women who were not using oral contraceptives, and 25 women who had been using oral contraceptives for at least 3 months. Mean blood viscosity and hematocrit were significantly higher in women using oral contraceptives than in women who were not (p < 0.001), and use of oral contraceptives abolished the normal sex difference in blood viscosity and hematocrit. After correction to a standard hematocrit of 45%, blood viscosity was still higher in users or oral contraceptives, as was plasma fibrinogen (p < 0.05). Plasma viscosity was not significantly increased in users of oral contraceptives.

Blood coagulation and idiopathic thromboembolism among fertile women

A case-control study of fibrinolytic activity and antithrombin-III (AT-III) was conducted comparing 16 women within the childbearing ages who had a recent history of idiopathic thromboembolism to 29 age- and race-matched female controls without a history of thromboembolism. All subjects had stopped using oral contraceptives at least 12 months prior to study. No difference in AT-III was evident between cases and controls. The mean fibrinolytic response to venous occlusion in cases was significantly lower; however, baseline fibrinolysis was essentially identical. These data demonstrated a bimodal distribution of fibrinolytic response among controls. By dichotomizing fibrinolytic response between the two modes in the controls, we estimated that the rate of low fibrinolytic response was 6 times as frequent in cases as controls. Thus, low fibrinolytic response may signal a natural predisposition to thromboembolism which could be triggered by use of synthetic estrogens.

Alcohol, smoking, and incidence of spontaneous abortions in the first and second trimester

32,019 women completed a questionnaire on alcohol use at their first antenatal visit; thereafter they were followed to assess the incidence of spontaneous abortions. 51.7% reported drinking no alcohol in early pregnancy; 44.7% had less than 1 drink daily; and 2.4, 0.4, and 0.1% had an average of 1-2, 3-5, or more than 6 drinks respectively. Life-table analysis showed that the age-adjusted relative risks of second-trimester losses (15-27 weeks) were 1.03 (not significant: ns), 1.98 (p < .01), and 3.53 (p < .01) for women taking less than 1, 1-2, and more than 3 drinks daily, compared with non-drinkers. The corresponding relative risks for first-trimester losses (5-14 weeks) were 1.12 (ns), 1.15(ns), and 1.15(ns). Smokers had relative risks of 1.01(ns) and 1.21(ns) in the first and second trimesters, compared with non-smokers. The increased risk of second-trimester miscarriage in drinkers was not explained by age, parity, race, marital status, smoking, or the number of previous spontaneous or induced abortions. Thus alcohol may harm human fetuses not only when it is abused but also when taken in moderation.

Fetal growth retardation in cigarette-smoking mothers is not due to decreased maternal food intake

To determine whether the fetal growth-retarding effect of maternal cigarette smoking could be due to a lower dietary intake in smokers than in nonsmokers, the energy and nutrient intake of 302 smoking and 234 nonsmoking women were assessed toward the end of the last trimester of pregnancy. The women were from two socioeconomic groups which differed greatly in age, height, education, family income, racial origin, and pregnancy weight gain. Within each group, smokers had significantly smaller infants, but pregnancy weight gain was not different. Daily dietary intake of the smokers was not less than that of the nonsmokers; in fact, for some nutrients it was significantly greater. Therefore, fetal growth retardation due to smoking is not caused by the mother's diminished intake of food.

Fatal myocardial infarction and the role of oral contraceptives

The association between use of oral contraceptives (OC) and death from myocardial infarction (MI) in young women was investigated in a collaborative case-control study conducted in the five largest metropolitan areas in the US. Potential cases were identified from computer tapes of the National Center for Health Statistics. Controls were selected from among women who died from, or were hospitalized for, acute conditions other than heart disease or from accidents, and were matched to cases on age, geographic area, and year of death. Information on cause of death, personal characteristics, OC use, and the presence of conditions predisposing to MI was obtained from interviews with relatives and abstracts of hospital, clinic and physician records. Odds ratios as approximations to relative risks for fatal MI in relation to OC use, and the associated 95% confidence limits, were calculated overall and for subgroups determined by demographic and health history characteristics. Odds ratios in the total study population were not significantly different from one. However, odds ratios significantly different from one were found when attention was restricted to white subjects without contraindications to OC use, andincluding only those cases whose deaths were attributed to MI with the greatest degree of certainty. Smoking was found to be a significant risk factor for fatal MI.

Respiratory disease mortality in New Mexico's American Indians and Hispanics

To determine the effect of ethnic group on respiratory disease occurrence, average annual sex, ethnic, and disease specific mortality rates for the period of 1969 to 1977 were calculated for New Mexico's American Indian, Hispanic, and Anglo populations. Incidence data were available for respiratory tract cancer. This study corroborates previous findings of reduced mortality from lung cancer in American Indians of both sexes and in Hispanic males. American Indian mortality from tuberculosis and from influenza and pneumonia was high. Hispanic males and American Indians of both sexes showed low mortality rates for chronic obstructive pulmonary disease (COPD). Differing cigarette usage is the most obvious explanation for the variations in COPD and lung cancer occurrence with ethnic group.

Patterns of drug use amongst Malaysian secondary schoolchildren

A representative sampling of the secondary school population of two states of Malaysia (sample size 16166) indicated that 11% of students had had experience of drug use. Use of a single drug was the common pattern, with cannabis reported most often by older students, and sedatives most often by younger students. A quarter of those who had used drugs reported experience with four or more substances and were likely to have progressed rapidly to heroin. This progression may be facilitated by the ready availability of heroin and the local tradition of smoking or inhaling rather than injecting opiates. Descriptions of drug migration patterns based on Western samples are not fully appropriate worldwide, because the youthful abuser is much influenced both by local market forces and by cultural traditions, even though the epidemic of youthful drug abuse is itself worldwide.

A comparison of trends of coronary heart disease mortality in Australia, USA and England and Wales with reference to three major risk factors-hypertension, cigarette smoking and diet

A comparison has been made of the recent changes in coronary heart disease mortality in Australia, the USA, and in the United Kingdom (England and Wales). Sharp declines in mortality dating from 1966 in Australia and from 1968 in the USA in both sexes contrast with a persistent increase in men in England and Wales until 1972 (after which a sight fall occurred) and a consistent slight fall in women since 1950. An investigation has been made of changes in 3 major risk factors-hypertension, cigarette smoking and diet in the 3 countries in an attempt to determine to what extent such changes might correlate with the different patterns of mortality. There has been a progressive and similar fall in mortality due to hypertension in both sexes in all 3 countries since 1950. There was a rise in cigarette smoking in all 3 countries from 1947 followed by a fall in the USA from 1963 and a more recent fall in men in Australia. There has been a levelling off of smoking in the United Kingdom in middle-aged and older men but not in women where smoking rates have increased from 1950 since when there has been a progressive slight fall in overall coronary heart disease mortality (although there is evidence of a recent rise in younger women.) Changes in dietary constituents (meat, eggs, milk and cheese, butter or margarine) have been examined by reference to aggregate consumption data. In Australia and the USA increases in vegetable fat consumption have occurred since 1950 with a reduction in animal fat in Australia but not in the USA. In the United Kingdom increases in vegetable fat have not been observed while there has been some increase in animal fat. It is concluded that the different patterns of coronary heart disease mortality in the 3 countries do correlate to some extent with changes in diet and cigarette smoking.

Variation of ethinylestradiol blood levels among healthy women using oral contraceptives

Data concerning ethinylestradiol (EE) blood levels among 93 healthy women using oral contraceptives are presented. Seventy-two per cent of the observed variation in EE blood levels was unexplainable on the basis of time since ingestion of the last oral contraceptive, day of menstrual cycle, race, age, weight, height, blood pressure, cigarette consumption, alcohol consumption, diurnal variation, or lifetime use of oral contraceptives.

Diminished fetal reactivity with smoking

The fetal activity-acceleration determination (FAD), or nonstress test, has been demonstrated to be an effective method for the antepartum assessment of fetal status in high-risk pregnancies. A reactive or negative test has been equated with fetal well-being, while fetal compromise has been related to a nonreactive or positive FAD. The present investigation was designed to determine the effects of chronic cigarette smoking on fetal reactivity as measured by the FAD. Increased fetal reactivity might be expected from recent investigations of the acute effects of cigarette smoking and 350 nonsmoking pregnant women with high-risk pregnancies, nonreactive or positive FAD's were demonstrated to be significantly higher in the smoking group (chi 2=8.9950; p less than 0.005).

[Lung cancer mortality and cigarette smoking in Europe, North America, Japan, and Australia: regional differences and chronological development]

Trends and regional differences in lung cancer mortality and cigarette smoking are examined for 26 developed countries. "In 1975, lung cancer mortality figures for females aged 55 to 64 years...showed 12 to 60 deaths per 100,000 inhabitants, for males 60 to 270 deaths. In nearly all countries the mortality rates of males have been increasing since 1958.... For females the rise in lung cancer mortality is particularly steep...." An increase in cigarette smoking between 1935 and 1973 is also noted, and it is found that "the ranking of the countries by cigarette consumption essentially corresponds to that by lung cancer mortality." (summary in ENG)

Increased risk of thrombosis due to oral contraceptives: a further report

In a previously reported case-control study of the relationship between oral contraceptives and thromboembolism, there were 461 cases and 1302 controls, individually matched on age, race, marital status, hospital, and date of admission. Initially, the control patients had not been matched with the cases for the presence or absence of six factors thought to predispose to or precipitate thromboembolic disease. The present paper reports the effects of taking into consideration these factors in the controls. Two methods of analysis (matched set, and logistic regression) gave closely similar results. Where the case series consisted of idiopathic cases, the revised estimate of the relative risk was reduced from 7.2 to 4.7 by these procedures; for predisposed cases, it was increased from 1.2 to 2.2. The explanation suggested in the previous report for the failure to find an increased risk for cases with predisposition receives support from these findings. Variation in the relative risk was examined for four separate diagnostic categories: venous thrombosis alone, pulmonary embolism alone, venous thrombosis and pulmonary embolism together, and myocardial infarction. The relative risk estimates were greater than unity for each thrombosis category for both predisposed and non-predisposed cases. The relative risk was not found to vary significantly according to age or smoking status.

Use of contraceptives prior to and after conception and exposure to other fetal hazards

In a large prospective study, set up to determine whether reproductive outcomes are affected by prior contraceptive use, 34,344 women were recruited at their first antenatal visit and followed until pregnancy termination. This paper summarizes the study methods and describes the demographic differences between subjects who used various contraceptives shortly before conception, and those who experienced contraceptive failures. Thirty percent of the women had used oral contraceptives (OCs) during the 5 months prior to conception and 2.4% had continued using them after their LMP. IUDs had been used by 5.8% of women before conception and 1.1% after. If these rates are also true for the whole population of the U.S., they indicate that approximately 70,000 babies are born each year following pill-failures and 30,000 following failures of IUD's. Exposure to other fetal hazards was common, with 48% of pregnant women drinking alcohol, 28% smoking, and 15% receiving diagnostic X-rays. OC use was more common among smokers and drinkers, and OC failures were significantly associated with the use of anti-epileptics, aspirin, and with exposure to radiation.

Effects of subjects' sex, and intake of tobacco, alcohol and oral contraceptives on plasma phenytoin levels

1. Steady state plasma phenytoin levels in 210 epileptic patients were studied by computerized analysis of covariance to determine whether the subject's sex, alcohol intake, tobacco smoking or use of oral contraceptives influenced the relation between plasma drug level and drug dose. 2. Sex, tobacco smoking and alcohol usage had no statistically significant effect. There was a trend towards higher phenytoin levels relative to drug dose in oral contraceptive users. 3. This finding prompted an additional study of plasma phenytoin levels in 40 oral contraceptive users and 135 aged matched non-users. Analysis of covariance again showed higher plasma phenytoin levels relative to drug dose in users of oral contraceptives (P = 0.061). 4. This finding raised the possibility that the relation between plasma phenytoin level and drug dose differed between males and females who did not use oral contraceptives. However, when the relation between plasma phenytoin levels and drug dose was compared in 159 females who did not use oral contraceptives and 101 males (both groups aged 15 to 70 years) no statistically significant difference was found.

Frustrated fertility: a population paradox

This Bulletin examines the causes of subfecundity -- the diminished ability to reproduce -- and its effect today and in the past on the fertility, or actual reproductive performance, of individuals and, hence, populations. By definition, all real populations are subfecund since all experience some degree of involuntary biological factors affecting coitus, conception, or the ability to carry a conceptus to live birth which reduces their fecundity below the estimated biological population maximum of 15 children per woman. Affecting both men and women, these factors fall into 5 categories: genetic factors such as blood group incompatibilities and inherited sickle cell anemia or diabetes; psychopathology, including psychic stress and behavioral disorders (e.g., drug and alcohol abuse); infectious diseases such as gonorrhea, malaria, tuberculosis, and postabortion infection; malnutrrition, including the chronic undernutrition of the 3rd World and the overnutrition of developed societies; and hazards posed by increasing amounts of radiation and toxic chemicals in the environment. Reducing subfecundity requires improved living conditions, avoidance of or protection from known hazards, and adoption of medical advances which now can help 40 to 60% of subfecund couples. But even in the U.S. fertility would certainly rise among the 15% of couples now estimated to be involuntarily childless and the 10% who have fewer children than they want, and among disadvantaged groups, and teenagers.

The mechanism of coronary artery spasm: roles of oxygen, prostaglandins, sex hormones and smoking

A reduced oxygen supply to the heart causes coronary vasodilatation in the first instance. But if the hypoxia is severe or prolonged, the dilatation passes off and coronary vasospasm develops leading to a vicious circle with a further reduction of myocardial oxygenation. The spasm is associated with increased outflow of prostaglandin (PG)-like material and can be prevented or reversed by inhibitors of PG synthesis such as indomethacin or antagonists of PG action such as chloroquine. The spasm does not appear to be caused by thromboxane (TX) A2 since selective inhibitors of TXA2 synthesis enhance the hypoxic spasm and by themselves can cause spasm even in oxygenated hearts. The mechanism may be related to loss of negative feedback control of the PG pathway by TXA2. Oxygen may enhance TXA2 production and reduce formation of vasoconstrictor PGs, while smoking, because of the formation of carboxyhaemoglobin, may have the opposite effect. Oestradiol and testosterone do not influence the hypoxic spasm but progesterone at physiological concentrations blocks it completely. Progesterone may be the protective female hormone and the increased susceptibility to myocardial infarction in women on oral contraceptives may be related to reduced formation of endogenous progesterone.

[The effect of tobacco and alcohol on pregnancy course and child development]

Smoking during pregnancy may cause small-for-date babies, severeness and frequency depending on the number of cigarettes per day. Regular and heavy smoking appearently increases perinatal mortality. A similar correlation and additionally an increased rate of newborns with major abnormalities was observed when the father regularly smoked 10 and more cigarettes per day, even then when the mother was a non-smoker. The mechanism involved is unclear. Based upon present information one may favour the view that smoking of the father impairs spermiogenesis rather than "passive" smoking of the mother. Regular intake of liquor by the mother is well correlated with a shortened duration of pregnancy--that means an increased rate of abortion and prematurity. The consequences and responsibilities in the frame of family planning and prenatal care are discussed. The results referred to were attained mainly by a prospective study "Course of pregnancy and child development" supported by the German Research Foundation (Deutsche Forschungsgemeinschaft).

[Tobacco, mortality and morbidity of atherosclerotic cardiovascular diseases--a prospective study in Paris]

In the Paris Prospective Study, after a 6,5 year follow-up, mortality and atherosclerotic disease incidence are studied according to the tobacco consumption measured at entry among 7746 middle-aged men in the same administrative group. Mortality is 3 times higher among smokers; the excess mortality of smokers concerns particularly cancers, especially cancers of the upper part of the digestive tube or lung cancers and coronary heart disease. The incidences of leg atherosclerosis and of hard coronary diseases increase very much with the quantity smoked and inhaled. The cigarette consumption is linked with the development of coronary diseases independently of other risk factors; it is taken into account in a five risk factor combination which gives the best estimation of individual risk of future disease. The theoretical effects of the reduction of cigarette consumption on the individual risk or on the incidence of coronary diseases are given. A multifactorial prevention with a small reduction of the level of several risk factors might reduce that incidence in the population.

Pituitary adenoma and oral contraceptives: a case-control study

A search of the centralized data resource available at the Mayo Clinic for all cases of pituitary adenoma diagnosed in the population of Olmstead County, Minnesota, disclosed an increasing incidence of this tumor in women of childbearing age. The sex, age, and temporal relationships suggest that, if this increase is real, oral contraceptives should be considered as one of the possible etiologic factors. A case-control study, however, did not reveal an association of prior use of oral contraceptives with pituitary tumor--relative risk, 0.5; 95% confidence interval, 0.1 to 2.2. No association was found with other possible risk factors, i.e., prior head injury, radiation therapy, seizures, and smoking. Thus, unless other etiologic agents can be identified, it appears that the increasing incidence is due to advances in diagnostic and surgical technology rather than to a specific etiologic factor.

Pregnancy complications following legally induced abortion

The frequency of pregnancy and delivery complications in women whose previous pregnancy had been terminated by a legally induced abortion is evaluated in a prospective and a retrospective study. Bleeding before 28 weeks of gestation and retention of placenta or placental tissue occurred more frequently after legal abortion that in a control group matched for age, parity, and socio-economic status. Other pregnancy and delivery complications did not occur more frequently after legal abortion. It is of particular interest that the study could not demonstrate an increased frequency of low birth weight among women whose previous pregnancy had been terminated by legal abortion.