Hormone replacement therapy and the risk of myocardial infarction in women with coronary risk factors

To assess the risk of myocardial infarction in users of post-menopausal hormone replacement therapy who are at high risk of coronary disease because of hypertension, diabetes mellitus, or smoking, we used data from a previously published case-control study of women 45-74 years. After adjustment for age, ethnicity, and education, the odds ratio for myocardial infarction in current users of hormone replacement therapy was 0.9 (95% confidence interval (CI) = 0.5-1.6) in women with no major coronary risk factors, 0.8 (95% CI = 0.5-1.8) in women with one risk factor, and 1.1 (95% CI = 0.5-2.2) in women with two risk factors.

Hospitalization for suicide attempt and completed suicide: epidemiological features in a managed care population

BACKGROUND

Understanding factors that contribute to high suicide risk holds important implications for prevention. We aimed to examine the sociodemographic and medical predictors of attempted suicide (severe enough to require hospitalization) and of completed suicide in a large population-based sample from a health maintenance organization (HMO) in northern California, USA.

METHOD

We designed a cohort study, including 87,257 women and 70,570 men aged 15 through 89 years old at baseline (in 1977-1985) with follow-up for hospitalizations and mortality through the end of 1993.

RESULTS

After a median of 10 years, 169 first hospitalizations for attempted suicide (111 among women, 58 among men) and 319 completed suicides (101 among women, 218 among men) were identified. There was a greater incidence of hospitalization for suicide attempt in women than in men and, conversely, a greater incidence of completed suicide in men than in women. The predominant methods of attempted and completed suicides were ingestion of psychotropic agents and use of firearms, respectively. In gender-specific multivariate analysis of hospitalization for suicide attempt, statistically significant associations were seen for age 15-24 years (women), 65-89 years (men), white race (women), 12th grade or less education (both genders), technical/business school education (men), never being married (men), history of emotional problems (both genders), history of family problems (women), history of job problems (men) and presence of one or more comorbidities (men). The independent predictors of completed suicide were: age 15-24 years (both genders), Asian race (women), Caucasian race (both genders), never being married (both genders), being separated/divorced (women), prior inpatient hospitalization for suicide attempt (both genders) and history of emotional problems (both genders).

CONCLUSION

These findings could help health professionals be more effective in the prevention of suicide morbidity and mortality.

Calcification of the aortic arch: risk factors and association with coronary heart disease, stroke, and peripheral vascular disease

CONTEXT

Calcium deposits in coronary and extracoronary arterial beds may indicate the extent of atherosclerosis. However, the incremental predictive value of vascular calcification, beyond traditional coronary risk factors, is not clearly established.

OBJECTIVE

To evaluate risk factors for aortic arch calcification and its long-term association with cardiovascular diseases in a population-based sample.

DESIGN AND SETTING

Cohort study conducted at a health maintenance organization in northern California.

PARTICIPANTS

A total of 60,393 women and 55,916 men, aged 30 to 89 years at baseline who attended multiphasic health checkups between 1964 and 1973 and for whom incidence of hospitalizations and/or mortality data were ascertained using discharge diagnosis codes and death records through December 31, 1997 (median follow-up, 28 years).

MAIN OUTCOME MEASURE

Hospitalization for or death due to coronary heart disease, ischemic stroke, hemorrhagic stroke, or peripheral vascular disease, as associated with aortic arch calcification found on chest radiograph at checkup from 1964-1973.

RESULTS

Aortic arch calcification was present in 1.9% of men and 2.6% of women. It was independently associated with older age, no college education, current smoking, and hypertension in both sexes, but it was inversely related to body mass index and family history of myocardial infarction. In women, aortic arch calcification was also associated with black race and elevated serum cholesterol level. After adjustment for age, educational attainment, race/ethnicity, cigarette smoking, alcohol consumption, body mass index, serum cholesterol level, hypertension, diabetes, and family history of myocardial infarction, aortic arch calcification was associated with an increased risk of coronary heart disease (in men, relative risk [RR], 1.27; 95% confidence interval [CI], 1.11-1.45; in women, RR, 1. 22; 95% CI, 1.07-1.38). Among women, it was also independently associated with a 1.46-fold increased risk of ischemic stroke (95% CI, 1.28-1.67).

CONCLUSION

In our population-based cohort, aortic arch calcification was independently related to coronary heart disease risk in both sexes as well as to ischemic stroke risk in women. JAMA. 2000;283:2810-2815

Association of hostility with coronary artery calcification in young adults: the CARDIA study. Coronary Artery Risk Development in Young Adults

CONTEXT

Psychosocial factors, including personality and character traits, may play a role in the development and expression of coronary artery disease.

OBJECTIVE

To evaluate whether hostility, a previously reported predictor of clinical coronary artery disease, is associated with coronary calcification, which is a marker of subclinical atherosclerosis.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

Volunteer subsample from Chicago, Ill, and Oakland, Calif, consisting of 374 white and black men and women, aged 18 to 30 years at baseline, who participated in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Cook-Medley hostility assessment data were collected at baseline from 1985 to 1986 and at year 5 examinations from 1990 to 1992. After the 10-year examinations in the 1995-1996 year, electron-beam computed tomographic scans were performed.

MAIN OUTCOME MEASURES

Presence of any detectable coronary artery calcification (coronary calcium score >0), and coronary artery calcium scores of 20 or higher.

RESULTS

In logistic regression analysis adjusting for age, sex, race, and field center comparing those with hostility scores above and below the median of the distribution of the present sample, the odds ratio of having any coronary calcification was 2.57 (95% confidence interval, 1.31-5.22), and the odds ratio of having a calcium score of 20 or higher was 9.56 (95% confidence interval, 2.29-65.9) for calcium scores of 20 or higher. The associations with any coronary artery calcification persisted after adjusting for demographic, lifestyle, and physiological variables. Results using a cynical distrust subscale were somewhat weaker than for those using the global hostility score. Power was inadequate to perform sex- or race-specific analyses.

CONCLUSION

These results suggest that a high hostility level may predispose young adults to coronary artery calcification. JAMA. 2000;283:2546-2551

Occupational attainment, smoking, alcohol intake, and marijuana use: ethnic-gender differences in the CARDIA study

OBJECTIVES

To evaluate the prospective interrelationship of smoking, alcohol intake, marijuana use, and educational and occupational attainment of Black and White young adults.

METHODS

Logistic or mixed model linear regression were used to evaluate relationships between self-reported substance use, ethnicity, gender, college graduation, and four measures of occupational attainment.

RESULTS

College graduation in the next 10 years was negatively associated with smoking and marijuana use, but not daily alcohol consumption in all ethnic and gender groups. In Whites, marijuana use was associated with less prestigious occupations and lower family income, while smoking was unrelated and moderate daily drinking was positively associated. In Blacks, marijuana use was generally unrelated to occupational measures, while smoking and daily alcohol consumption were negatively associated.

CONCLUSIONS

Relationships between smoking, marijuana use, daily drinking, and occupational attainment were not universally negative in this age group. Substance use, particularly smoking, is associated with reduced occupational attainment in Blacks compared with Whites after considering sociodemographic factors potentially limiting educational progression and occupational attainment.

Cigarette smoking, alcohol consumption, and risk of ARDS: a 15-year cohort study in a managed care setting

STUDY OBJECTIVE

To examine the association of cigarette smoking and alcohol consumption with hospital presentation of ARDS in a well-defined, multiethnic population.

DESIGN

Retrospective cohort study.

SETTING

Health maintenance organization in Northern California.

PARTICIPANTS

A total of 121,012 health plan subscribers (54.2% women), aged 25 to 89 years.

OUTCOME MEASURE

Hospital presentation of ARDS (validated by medical chart review) from baseline in 1979 to 1985 through the end of 1993 (median, 9.9 years).

RESULTS

There were 56 cases of ARDS (33 in men, 23 in women). The case fatality rate was 39% in both genders. ARDS was independently related to increasing age (rate ratio of 10 years, 1.38; 95% confidence interval [CI], 1.12 to 1.71), to current smoking of < 20 cigarettes/d (rate ratio vs never cigarette smokers, 2.85; 95% CI, 1. 23 to 6.60), and to current cigarette smoking of > or = 20 cigarettes/d (rate ratio vs never smokers, 4.59; 95% CI, 2.13 to 9.88). No association was observed between alcohol consumption and ARDS.

CONCLUSIONS

The results of this study suggest a relationship (with evidence of dose-response effect) between cigarette smoking and ARDS. Assuming a causal relationship, approximately 50% of ARDS cases were attributable to cigarette smoking.

Effect of cigar smoking on the risk of cardiovascular disease, chronic obstructive pulmonary disease, and cancer in men

BACKGROUND

The sale of cigars in the United States has been increasing for the past six years. Cigar smoking is a known risk factor for certain cancers and for chronic obstructive pulmonary disease (COPD). However, unlike the relation between cigarette smoking and cardiovascular disease, the association between cigar smoking and cardiovascular disease has not been clearly established.

METHODS

We performed a cohort study among 17,774 men 30 to 85 years of age at base line (from 1964 through 1973) who were enrolled in the Kaiser Permanente health plan and who reported that they had never smoked cigarettes and did not currently smoke a pipe. Those who smoked cigars (1546 men) and those who did not (16,228) were followed from 1971 through the end of 1995 for a first hospitalization for or death from a major cardiovascular disease or COPD, and through the end of 1996 for a diagnosis of cancer.

RESULTS

In multivariate analysis, cigar smokers, as compared with nonsmokers, were at higher risk for coronary heart disease (relative risk, 1.27; 95 percent confidence interval, 1.12 to 1.45), COPD (relative risk, 1.45; 95 percent confidence interval, 1.10 to 1.91), and cancers of the upper aerodigestive tract (relative risk, 2.02; 95 percent confidence interval, 1.01 to 4.06) and lung (relative risk, 2.14; 95 percent confidence interval, 1.12 to 4.11), with evidence of dose-response effects. There appeared to be a synergistic relation between cigar smoking and alcohol consumption with respect to the risk of oropharyngeal cancers and cancers of the upper aerodigestive tract.

CONCLUSIONS

Independently of other risk factors, regular cigar smoking can increase the risk of coronary heart disease, COPD, and cancers of the upper aerodigestive tract and lung.

Association of total and central adiposity measures with fasting insulin in a biracial population of young adults with normal glucose tolerance: the CARDIA study

OBJECTIVE

To determine the association of computed tomography (CT)-measured visceral adipose tissue (AT) and other measures of adiposity with fasting insulin in a biracial (African American and Caucasian) study population of young adults.

RESEARCH METHODS AND PROCEDURES

The study population consisted of 251 young adults with normal glucose tolerance (NGT), ages 28-40 years, who were volunteers from the Birmingham, Alabama, and Oakland, California centers of the Coronary Artery Risk Development in Young Adults (CARDIA) study.

RESULTS

In regression models with total adiposity measures (body mass index or dual-energy X-ray absorptiometry-measured percent fat), visceral AT (measured as a cross-sectional area in cm2) was generally a stronger predictor of insulin than overall adiposity in all race/gender groups (partial correlation coefficients ranging from 0.31 to 0.47) except for black men, in whom the associations were nonsignificant. Partial correlation coefficients between waist circumference and insulin, controlling for percent fat, were nearly identical to those between visceral AT and insulin in women and in white men. Analyses performed on 2060 NGT CARDIA subjects who were not in this study of visceral AT showed significant correlations of waist circumference with insulin in all race/gender groups, including black men, and that black men in the visceral AT study group were significantly leaner than other black male CARDIA subjects.

DISCUSSION

We conclude that visceral AT was associated with fasting insulin in NGT participants in three of the four race/gender groups (black men excepted) and that waist circumference was a good surrogate for visceral AT in examining associations of central adiposity with fasting insulin.

Differences in calcium metabolism between black and white men and women

To determine whether environmental factors influence racial differences in calcium metabolism, the authors evaluated the influence of three factors (season, length of sunlight exposure, and diet) on calciotropic hormones, renal calcium excretion, and markers of bone turnover in an ambulatory population aged 25-36 years. Included were 109 black men, 114 white men, 95 black women, and 84 white women. Compared with white subjects, black subjects of both genders showed lower levels of serum 25-hydroxyvitamin D (25-OHD) and higher levels of serum 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. The mean winter levels of 25-OHD were 19 to 29% lower than the summer levels in all groups. The urinary calcium excretion was 26% lower in black men than in white men and was 36% lower in black women than in white women. The parathyroid hormone levels were 29% higher in black women than in white women, but no statistically significant racial differences in parathyroid hormone levels were seen in men. Bone turnover markers (serum osteocalcin, bone-specific alkaline phosphatase, urinary pyridinoline cross-link excretion) did not show consistent racial differences. Racial and gender differences in calcium excretion did not significantly correlate with differences in lifestyle or with levels of the calciotropic hormones. Environmental factors such as diet and sunlight exposure do not appear to influence racial differences in the levels of the calciotropic hormones or renal calcium excretion.

Racial differences in amounts of visceral adipose tissue in young adults: the CARDIA (Coronary Artery Risk Development in Young Adults) study

BACKGROUND

In several white populations, visceral adipose tissue (VAT) is a risk factor for development of type 2 diabetes and dyslipidemia. VAT can be accurately assessed by computed topography or magnetic resonance imaging, but is also estimated from anthropometric variables, such as waist-to-hip ratio, waist circumference, or sagittal diameter. To date, anthropometric variables have been used largely in whites and inadequate data are available to evaluate the validity of these variables in other groups.

OBJECTIVES

The objectives of this study were to 1) determine whether amount of VAT in relation to total body fatness differs in different race and sex groups and 2) determine which anthropometric variables predict amount of VAT in different race and sex groups.

DESIGN

We determined the amount and location of body fat, including assessment of VAT by computed tomography, in young adult white and black men and women participating in the 10-y follow-up of the CARDIA (Coronary Artery Risk Development in Young Adults) Study.

RESULTS

Black men had less visceral fat (73.1+/-35.9 cm2) than white men (99.3+/-40 cm2), even when VAT was corrected for total body fatness. Black women were more obese than white women and thus had more visceral fat (75.1+/-37.5 compared with 58.6+/-35.9 cm2, respectively). This difference disappeared when corrected for total body fatness.

CONCLUSIONS

Both waist circumference and sagittal diameter were good predictors of VAT in all groups. However, the nature of this relation differed such that race- and sex-specific equations will likely be required to estimate VAT from waist circumference or sagittal diameter.

Seven-year changes in physical fitness, physical activity, and lipid profile in the CARDIA study. Coronary Artery Risk Development in Young Adults

PURPOSE

To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships.

METHODS

The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California.

RESULTS

All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P < 0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates.

CONCLUSIONS

Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.

Stroke and use of low-dose oral contraceptives in young women: a pooled analysis of two US studies

BACKGROUND AND PURPOSE

The available data on low-dose oral contraceptive pill (OCP) use and stroke risk in US women are limited by small numbers. We sought more precise estimates by conducting a pooled analysis of data from 2 US population-based case-control studies.

METHODS

We analyzed interview data from 175 ischemic stroke cases, 198 hemorrhagic stroke cases, and 1191 control subjects 18 to 44 years of age.

RESULTS

For ischemic stroke, the pooled odds ratio (pOR) adjusted for stroke risk factors for current use of low-dose OCPs compared with women who had never used OCP (never users) was 0.66 (95% confidence interval [CI], 0.29 to 1.47) and compared with women not currently using OCPs (nonusers) the pOR was 1.09 (95% CI, 0.54 to 2.21). For hemorrhagic stroke, the pOR for current use of low-dose OCPs compared with never users was 0.95 (95% CI, 0.46 to 1.93) and compared with nonusers the pOR was 1.11 (95% CI, 0.61 to 2.01). The pORs for current low-dose OCP use and either stroke type were not elevated among women who were >/=35 years, cigarette smokers, obese, or not receiving medical therapy for hypertension. pORs for current low-dose OCP use were 2.08 (95% CI, 1. 19 to 3.65) for ischemic stroke and 2.15 (95% CI, 0.85 to 5.45) for hemorrhagic stroke among women reporting a history of migraine but were not elevated among women without such a history. Past OCP use (irrespective of formulation) was inversely related to ischemic stroke but unrelated to hemorrhagic stroke.

CONCLUSIONS

Women who use low-dose OCPs are, in the aggregate, not at increased risk of stroke. Studies are needed to clarify the risk of stroke among users who may be susceptible on the basis of age, smoking, obesity, hypertension, or migraine history.

Stroke and cocaine or amphetamine use

The association of cocaine and amphetamine use with hemorrhagic and ischemic stroke is based almost solely on data from case series. The limited number of epidemiologic studies of stroke and use of cocaine and/or amphetamine have been done in settings that serve mostly the poor and/or minorities. This case-control study was conducted in the defined population comprising members of Kaiser Permanente of Northern and Southern California. We attempted to identify all incident strokes in women ages 15-44 years during a 3-year period using hospital admission and discharge records, emergency department logs, and payment requests for out-of-plan hospitalizations. We selected controls, matched on age and facility of usual care, at random from healthy members of the health plan. We obtained information in face-to-face interviews. There were 347 confirmed stroke cases and 1,021 controls. The univariate matched odds ratio for stroke in women who admitted to using cocaine and/or amphetamine was 8.5 (95% confidence interval = 3.6-20.0). After further adjustment for potential confounders, the odds ratio in women who reported using cocaine and/or amphetamine was 7.0 (95% confidence interval = 2.8-17.9). The use of cocaine and/or amphetamine is a strong risk factor for stroke in this socioeconomically heterogeneous, insured urban population.

Cohort study of serum total cholesterol and in-hospital incidence of infectious diseases

A multiethnic cohort of adult members of the Kaiser Permanente Medical Care Program (55300 men and 65271 women) was followed for 15 years (1979-93) to assess the association between total cholesterol and risk of infections (other than respiratory and HIV) diagnosed in the in-patient setting. Using multivariate Cox regression, total cholesterol was inversely and significantly related to urinary tract, venereal, musculo-skeletal, and all infections among men; and to urinary tract, all genito-urinary, septicaemia or bacteraemia, miscellaneous viral site unspecified, and all infections among women. The reduction of risk of all infections associated with a 1 S.D. increase in total cholesterol was 8% in both men (95% CI, 4-12 %) and women (95% CI, 5-11%). For urinary tract infections among men, as for septicaemia or bacteraemia and nervous system infections among women, the risk relation was restricted to persons aged 55-89 years. Nervous system infections were positively related to total cholesterol among women aged 25-54. In both genders, the significant inverse association with all infections persisted after excluding the first 5 years of follow-up. Collectively, these data are suggestive of an inverse association, although not entirely consistent, between total cholesterol and incidence of infections either requiring hospitalization or acquired in the hospital. Further research is needed to elucidate whether these associations are biologically plausible or represent uncontrolled confounding by unmeasured risk factors.

Myocardial infarction and use of low-dose oral contraceptives: a pooled analysis of 2 US studies

BACKGROUND

Population-based case-control studies to assess the relationship of low-dose oral contraceptive (OC) use with myocardial infarction (MI) were performed at 2 sites in the United States (California and Washington state). The purpose of the present study was to estimate risk of MI in relation to use of low-dose OCs in a pooled analysis combining results from the 2 sites.

METHODS AND RESULTS

The study included as cases women aged 18 to 44 years with incident MI who had no prior history of ischemic heart disease or cerebrovascular disease. Women in the case and control groups were interviewed in person regarding OC use and cardiovascular risk factors. The analysis included 271 MI cases and 993 controls. Compared with noncurrent users, the adjusted pooled odds ratio for MI in current OC users was 0.94 (95% CI, 0.44, 2.20) after adjustment for major risk factors and sociodemographic factors. Compared with never users, the adjusted pooled odds ratio for MI was 0.56 (0.21, 1.49) in current OC users and 0.54 (0.31, 0.95) in past OC users. Among past OC users, duration and recency of use were unrelated to MI risk as was current hormone replacement therapy. There was no evidence of interaction between OC use and age, presence of cardiovascular risk factors (hypercholesterolemia, hypertension, diabetes), obesity, or smoking.

CONCLUSIONS

We conclude that low-dose OCs as used in these populations are safe with respect to risk of MI in women.

Racial discrimination and skin color in the CARDIA study: implications for public health research. Coronary Artery Risk Development in Young Adults

OBJECTIVES

This study assessed whether skin color and ways of handling anger can serve as markers for experiences of racial discrimination and responses to unfair treatment in public health research.

METHODS

Survey data on 1844 Black women and Black men (24 to 42 years old), collected in the year 5 (1990-1991) and year 7 (1992-1993) examinations of the Coronary Artery Risk Development in Young Adults (CARDIA) study, were examined.

RESULTS

Skin color was not associated with self-reported experiences of racial discrimination in 5 of 7 specified situations (getting a job, at work, getting housing, getting medical care, in a public setting). Only moderate associations existed between darker skin color and being working class, having low income or low education, and being male (risk ratios under 2). Comparably moderate associations existed between internalizing anger and typically responding to unfair treatment as a fact of life or keeping such treatment to oneself.

CONCLUSIONS

Self-reported experiences of racial discrimination and responses to unfair treatment should be measured directly in public health research; data on skin color and ways of handling anger are not sufficient.

Marijuana use and medically attended injury events

STUDY OBJECTIVE

This study evaluated the relation between self-reported marijuana use and 3-year incidence of injury.

METHODS

We conducted a retrospective cohort study of adult Kaiser Permanente Medical Care Program members who underwent multiphasic health examinations between 1979 and 1986 (n=4,462). Injury-related outpatient visits, hospitalizations, and fatalities within 3 years of examination were determined.

RESULTS

Outpatient injury events totaled 2,524; 1,611 participants (36%) had at least 1 injury-related outpatient visit. Injury-related hospitalizations (n=22) and fatalities (n=3) were rare. Among men, there was no consistent relation between marijuana use and injury incidence for either former users (rate ratio, 1.15; 95% confidence interval [CI], .97 to 1.36) or current users (rate ratio, 0.97; 95% CI, .81 to 1.17), compared with those who had never used marijuana. Among women, former and current users showed little difference in their rate of later injury compared with never users; the rate ratios were 1.05 (95% CI, .87 to 1.26) and 1.20 (95% CI, 1.00 to 1.44), respectively. No statistically significant associations were noted between marijuana use and cause-specific injury incidence in men or women.

CONCLUSION

Among members of a health maintenance organization, self-reported marijuana use in adult men or women was not associated with outpatient injury within 3 years of marijuana use ascertainment.

Norplant implants and cardiovascular disease

A 1995 publication on serious adverse events in users of Norplant implants submitted to the Food and Drug Administration's MedWatch Spontaneous Reporting System reported 14 hospitalizations for stroke in Norplant users. This number was higher than expected. This is a report on the association of current use of Norplant implants with stroke and myocardial infarction (MI) based on a pooled analysis of data from two population-based, case-control studies conducted in the US. All data collection for these two studies occurred after approval of Norplant implants for marketing in the US in December 1990. The methods of the individual studies are detailed in prior publications.

Oral contraceptive use and myocardial infarction

Epidemiologic studies of current oral contraceptive (OC) use and myocardial infarction (MI) have been contradictory and confusing. This comprehensive review of the epidemiologic literature attempts to draw conclusions about the risk of myocardial infarction in oral contraceptive users, focusing on recent, methodologically rigorous studies of the topic. Recent studies are consistent in showing a higher relative risk of MI in current OC users who smoke compared with current OC users who do not smoke. Studies in aggregate suggest that the relative risk of MI is higher in current OC users with hypertension than in current OC users without hypertension. Recent studies do not show a relationship between higher estrogen dose and higher risk of MI, but the effect of estrogen dose and progestogen type and dose are difficult to separate. The limited data on the risk of MI in current users of low estrogen OC do not allow a firm conclusion about the possibility that progestogen type might affect the risk of MI in current users. Past OC use does not increase or decrease the risk of MI.

Seven-year change in graded exercise treadmill test performance in young adults in the CARDIA study. Cardiovascular Risk Factors in Young Adults

PURPOSE

Most studies of physical fitness change have been relatively small, not population-based, and lacking in women and nonwhites. The purpose of this analysis was to evaluate the 7-yr change in physical fitness in a biracial (black and white) population of young men and women.

METHODS

We evaluated change in exercise treadmill test performance in a biracial (black and white) population of 1,962 young adults, ages 18-30 yr at baseline, who completed symptom-limited graded exercise treadmill tests at the baseline (1985-1986) and year 7 (1992-1993) examinations of the CARDIA study.

RESULTS

Mean test duration decreased 58 s (9.5%) over 7 yr (black men, 13.6% decrease, white men, 7.4%; black women, 11.1%; white women, 7.0%). Mean time to heart rate 130 (WL130), a measure of submaximal performance, decreased 31 s (11.3%) (black men, 16.9%; white men, 10.0%; black women, 12.3%; white women, 6.1%). Baseline body mass index (BMI) and physical activity were not statistically significant predictors of test duration change in any race-gender group, but change in BMI and activity were. Seven-year weight gain >20 lbs (31% of cohort) was associated with a large decrease in fitness (18.5% decrease in mean duration, 21.8% decrease in WL130).

CONCLUSION

These data suggest that fitness declines during young adulthood in blacks and whites and that fitness changes are related to changes in weight and physical activity.

Association between serum total cholesterol and HIV infection in a high-risk cohort of young men

Low serum total cholesterol (TC) is associated with a variety of nonatherosclerotic diseases, but the association of TC with infectious disease has been little studied. In this study, we examined the relationship between serum TC and HIV infection in members of a large health maintenance organization in Northern California. The cohort consisted of 2446 unmarried young men 15 to 49 years of age at high risk of HIV infection, defined as self-reported history of sexually transmitted disease or liver disease. Baseline measurements were taken between 1979 and 1985, and subjects were passively followed for HIV infection until the end of 1993 (average length of follow-up, 7.7 years). From a multivariate-adjusted Cox regression, the rate ratio (RR) of HIV infection was 1.66 (95% CI = 1.07, 2.56) for men with serum TC levels <160 mg/dl compared with those with TC levels between 160 and 199 mg/dl. Similar excess risk of AIDS and AIDS-related death was observed. These findings suggest that low serum TC levels should be considered a marker of increased risk of HIV infection in men already at heightened risk of HIV infection.

Ischemic stroke and use of estrogen and estrogen/progestogen as hormone replacement therapy

BACKGROUND AND PURPOSE

Information about the risk of stroke in current postmenopausal hormone users is limited.

METHODS

In this case-control study, women aged 45 to 74 years hospitalized with a fatal or nonfatal stroke in any of 10 Northern California Kaiser Permanente facilities during the period November 1991 to November 1994 were identified as cases. Controls were selected at random from female Health Plan members. Data regarding use of estrogen plus progestogen or estrogen alone were obtained in interviews.

RESULTS

The analysis was based on nonproxy responses from 349 cases of ischemic stroke and 349 matched control subjects. After adjustment for confounders, the odds ratio for ischemic stroke in current hormone users was 1.03 (95% confidence interval, 0.65 to 1.65). The odds ratios for ischemic stroke in current hormone users showed no clear trend of increasing or decreasing risk in relation to duration of hormone use. The odds ratio for ischemic stroke in past hormone users was 0.84 (95% confidence interval, 0.54 to 1.32).

CONCLUSIONS

In this study postmenopausal hormone use was not associated with an increase or decrease in the risk of ischemic stroke, a finding that is consistent with the body of literature on this topic.

Characteristics of falls and risk of hip fracture in elderly men

The steep rise in hip fracture incidence rates with age is not fully explained by an increase in the frequency of falls or by reduction in bone mineral density, suggesting that circumstances of falls may also affect the risk of hip fracture. Previous studies conducted mainly among women have identified the importance of the orientation of a fall in the etiology of hip fracture. In this case-control study among men of 45 years and older, we evaluated how the circumstances of falls affect the risk of hip fracture. We compared 214 cases with hip fracture due to a fall with 86 controls who had fallen within the past year but did not sustain a hip fracture. As expected, in multivariable age-adjusted analyses men who reported hitting the hip/thigh in a fall had a markedly elevated risk of hip fracture (OR = 97.8; 95% CI = 31.7-302). Hitting the knee in a fall was associated with reduced risk (OR = 0.24; 95% CI = 0.09-0.67). Other factors that were associated with reduced risk of hip fracture among men who fell were more hours of physical activity in the past year (OR = 0.84; 95% CI = 0.73-0.97, for each additional 4 h per week), a greater body mass index (OR = 0.60; 95% CI = 0.40-0.90, for each additional 4 kg/m2), and a history of a fracture when age 45 years or older (OR = 0.26; 95% CI = 0.10-0.69). Reported lower limb dysfunction was associated with increased risk of hip fracture (OR = 6.41; 95% CI = 2.09-19.6) among fallers. The increased risk associated with hitting the hip/thigh in a fall and the reduced risk associated with high body mass index suggest that preventive efforts for older men at high risk might include protective hip pads to reduce the force on the hip in a fall. Exercise and strength training programs may also reduce the risk of hip fracture among men who fall.

Serum total cholesterol and risk of hospitalization, and death from respiratory disease

BACKGROUND

In earlier studies, serum total cholesterol was inversely associated with death due to respiratory diseases.

METHODS

Relationships of cholesterol with risk of respiratory diseases were examined between 1978 and 1993 in a health maintenance organization in Northern California (48,188 men, 55,276 women, about 60% white, age range 25-89). Incident and fatal endpoints were ascertained using hospital discharge diagnostic codes and underlying cause of death, respectively.

RESULTS

An inverse association of cholesterol level with pneumonia/influenza hospitalization was found among men and women except that, contrary to hypothesis, a positive association was seen in women under 55 years of age. Inconsistent inverse associations were found in men, but not women, between cholesterol level and hospitalization for chronic obstructive pulmonary disease (COPD). Hospitalization for asthma was unrelated to cholesterol level. An inverse association existed between cholesterol level and hospitalization for miscellaneous respiratory diseases among men, but not women. Exclusion of early hospitalizations tended to attenuate risk for cholesterol level below 4.14 mmol/l, but not the risk gradient across higher cholesterol levels. For deaths, cholesterol level was statistically significantly inversely associated only with COPD.

CONCLUSIONS

Cholesterol had graded inverse associations with some respiratory diseases, but not others, tending to be stronger in men than in women, and in older than in younger participants. Associations varied for hospitalizations compared to deaths. More epidemiological and basic research is needed to elucidate the potential mechanisms underlying the observed associations.