Low-dose aspirin for migraine prophylaxis in women

Although migraine is more common among women than men, the only two large, randomized trials of low-dose aspirin for migraine prophylaxis have been conducted in men. As part of the Women's Health Study, an ongoing randomized trial of low-dose aspirin and vitamin E among 39 876 female health professionals aged 45 and older, 1001 women with frequent migraine attacks were assigned to 100 mg of aspirin every other day (n = 525) or aspirin placebo (n = 476). Migraine frequency, as well as severity, duration, and degree of incapacitation, were assessed by self-report on questionnaires 12 months and 36 months after randomization, and also by monthly diaries kept before and after randomization. Women assigned to aspirin reported small and consistent decreases in migraine frequency (59.6% vs. 56.4% assigned to placebo reporting improvement at 36 months; odds ratio 1.13, 95% confidence interval, 0.86--1.48), as well as decreases in severity, duration, and migraine-related incapacitation. These reductions were not, however, statistically significant. These data are compatible with a small treatment effect of low-dose aspirin in the prophylaxis of migraine among middle-aged women.

Physical activity and coronary heart disease in women: is "no pain, no gain" passé?

CONTEXT

Physically active women have lower coronary heart disease (CHD) rates than inactive women. However, whether the association differs by intensity of activity or in women at high risk for CHD is unclear.

OBJECTIVE

To examine the relation between physical activity, specifically investigating walking (a light-to-moderate activity depending on pace), and CHD among women, including those at high risk for CHD.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study of 39 372 healthy female health professionals aged 45 years or older, enrolled throughout the United States between September 1992 and May 1995, with follow-up to March 1999. Recreational activities, including walking and stair climbing, were reported at study entry.

MAIN OUTCOME MEASURE

Correlation of CHD with energy expended on all activities, vigorous activities, and walking.

RESULTS

A total of 244 cases of CHD occurred. Adjusting for potential confounders, the relative risks (RRs) of CHD for less than 200, 200-599, 600-1499, and 1500 or more kcal/wk expended on all activities were 1.00 (referent), 0.79 (95% confidence interval [CI], 0.56-1.12), 0.55 (95% CI, 0.37-0.82), and 0.75 (95% CI, 0.50-1.12), respectively (P for linear trend =.03). Vigorous activities were associated with lower risk (RR, 0.63; 95% CI, 0.38-1.04 comparing highest and lowest categories). Walking also predicted lower risk among women without vigorous activities. Among these women, the multivariate RRs for walking 1 to 59 min/wk, 1.0 to 1.5 h/wk, and 2 or more h/wk, compared with no regular walking, were 0.86 (95% CI, 0.57-1.29), 0.49 (95% CI, 0.28-0.86), and 0.48 (95% CI, 0.29-0.78), respectively. For walking paces of less than 3.2 km/h (2.0 mph), 3.2 to 4.7 km/h (2.0-2.9 mph), and 4.8 km/h (3.0 mph) or more, compared with no regular walking, RRs were 0.56 (95% CI, 0.32-0.97), 0.71 (95% CI, 0.47-1.05), and 0.52 (95% CI, 0.30-0.90), respectively. When analyzed simultaneously, time spent walking (P for linear trend =.01) but not walking pace (P for linear trend =.55) predicted lower risk. The inverse association between physical activity and CHD risk did not differ by weight or cholesterol levels (P for interaction =.95 and.71, respectively), but there were significant interactions by smoking and hypertension status. Physical activity was inversely related to risk in current smokers but not hypertensive women (P for interaction =.01 and.001, respectively).

CONCLUSIONS

These data indicate that even light-to-moderate activity is associated with lower CHD rates in women. At least 1 hour of walking per week predicted lower risk. The inverse association with physical activity was also present in women at high risk for CHD, including those who were overweight, had increased cholesterol levels, or were smokers.

Intake of vegetables rich in carotenoids and risk of coronary heart disease in men: The Physicians' Health Study

BACKGROUND

Previous studies of diet and coronary heart disease (CHD) have focused on intake of nutrients rather than whole foods. Because of the findings that dietary fibre, folate and antioxidants may be protective for CHD, increased intake of vegetables has been recommended. However, due to the chemical and physical complexity of vegetables, the effects of individual nutrients may differ if eaten as whole foods. Moreover, little is known about the direct association between vegetable intake and risk of CHD.

METHODS

We prospectively evaluated the relation between vegetable intake and CHD risk in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among 22 071 US male physicians aged 40-84 years in 1982. In this analysis, we included 15 220 men without heart disease, stroke or cancer at baseline who provided information on their vegetable intake at baseline, and in the 2nd, 4th and 6th years of follow-up using a simple semiquantitative food frequency questionnaire including eight vegetables. We confirmed 1148 incident cases of CHD (387 incident cases of myocardial infarction and 761 incident cases of coronary artery bypass grafting or percutaneous transluminal coronary angioplasty) during 12 years of follow-up.

RESULTS

After adjusting for age, randomized treatment, body mass index (BMI), smoking, alcohol intake, physical activity, history of diabetes, history of hypertension, history of high cholesterol, and use of multivitamins, men who consumed at least 2.5 servings/day of vegetables had a relative risk (RR) of 0.77 (95% CI : 0.60-0.98) for CHD, compared with men in the lowest category (<1 serving/day). Adjusting for the same covariates in an analysis of the overall trend that considered intake of vegetables as a continuous variable, we found a RR of 0.83 (95% CI : 0.71-0.98) for risk of CHD for each additional serving/day of vegetables. The inverse relation between vegetable intake and CHD risk was more evident among men with a BMI > or =25 (RR = 0.71, 95% CI : 0.51-0.99) or current smokers (RR = 0.40, 95% CI : 0.18-0.86) comparing highest to the lowest categories of intake.

CONCLUSIONS

Our results suggest an inverse association between vegetable intake and risk of CHD. These prospective data support current dietary guidelines to increase vegetable intake for the prevention of CHD.

Soluble P-selectin and the risk of future cardiovascular events

BACKGROUND

P-selectin, a cell-surface adhesion molecule involved in leukocyte rolling and attachment, has been hypothesized to play a role in the initiation of atherosclerosis. However, little clinical data are available evaluating the role of soluble P-selectin in determining vascular risk.

METHODS AND RESULTS

In a large-scale prospective study of apparently healthy women, we measured baseline plasma concentration of soluble P-selectin among 115 participants who subsequently developed cardiovascular events and among 230 age- and smoking-matched participants who remained free of disease during 3.5 years of follow-up. Overall, mean levels of soluble P-selectin were significantly higher at baseline among women who subsequently experienced cardiovascular events compared with those who did not (83.2 versus 69.3 ng/mL; P:=0.003). The risk of future cardiovascular events increased with increasing quartiles of soluble P-selectin (P:=0.02), such that women in the highest quartile at study entry had an age- and smoking-matched relative risk 2.2 times higher than those in the lowest quartile (95% confidence interval, 1.2 to 4.2; P:=0.01). This effect was independent of traditional risk factors. For each quartile increase in soluble P-selectin, the risk of future cardiovascular events increased 28% (P:=0.03) after additional adjustment for obesity, hypertension, hyperlipidemia, diabetes, and exercise frequency. The highest risks were observed among women with the very highest levels of P-selectin (>137.3 ng/mL, the 95th percentile cut point of the control distribution).

CONCLUSIONS

Soluble P-selectin levels are elevated among apparently healthy women at risk for future vascular events.

Diabetes and all-cause and coronary heart disease mortality among US male physicians

BACKGROUND

While diabetes has long been associated with increased risk of coronary heart disease (CHD), the magnitude of risk of diabetes-related CHD is uncertain.

OBJECTIVE

To evaluate the impact of diabetes and prior CHD on all-cause and CHD mortality.

METHODS

In a prospective cohort study of 91 285 US male physicians aged 40 to 84 years, participants were divided into 4 groups: (1) a reference group of 82 247 men free of both diabetes and CHD (previous myocardial infarction and/or angina) at baseline, (2) 2317 men with a history of diabetes but not CHD, (3) 5906 men with a history of CHD but not diabetes, and (4) 815 men with a history of both diabetes and CHD. Rates of all-cause and CHD mortality were compared in these groups.

RESULTS

Over 5 years (49 7952 person-years of follow-up), 3627 deaths from all causes were documented, including 1242 deaths from CHD. Compared with men with no diabetes or CHD, the age-adjusted relative risk of death from any cause was 2.3 (95% confidence interval [CI], 2.0-2.6) among men with diabetes and without CHD, 2.2 (95% CI, 2.0-2.4) among men with CHD and without diabetes, and 4.7 (95% CI, 4.0-5.4) among men with both diabetes and CHD. The relative risk of CHD death was 3.3 (95% CI, 2.6-4.1) among men with diabetes and without CHD, 5.6 (95% CI, 4.9-6.3) among men with CHD and without diabetes, and 12.0 (95% CI, 9.9-14.6) among men with both diabetes and CHD. Multivariate adjustment for body mass index, smoking status, alcohol intake, and physical activity as well as stratification by these variables did not materially alter these associations.

CONCLUSIONS

These prospective data indicate that diabetes is associated with a substantial increase in all-cause and CHD mortality. For all-cause mortality, the magnitude of excess risk conferred by diabetes is similar to that conferred by a history of CHD; for mortality from CHD, a history of CHD is a more potent predictor of death. The presence of both diabetes and CHD, however, identifies a particularly high-risk group.

Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study

BACKGROUND

Prospective data relating fruit and vegetable intake to cardiovascular disease (CVD) risk are sparse, particularly for women.

OBJECTIVE

In a large, prospective cohort of women, we examined the hypothesis that higher fruit and vegetable intake reduces CVD risk.

DESIGN

In 1993 we assessed fruit and vegetable intake among 39876 female health professionals with no previous history of CVD or cancer by use of a detailed food-frequency questionnaire. We subsequently followed these women for an average of 5 y for incidence of nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, or death due to CVD.

RESULTS

During 195647 person-years of follow-up, we documented 418 incident cases of CVD including 126 MIs. After adjustment for age, randomized treatment status, and smoking, we observed a significant inverse association between fruit and vegetable intake and CVD risk. For increasing quintiles of total fruit and vegetable intake (median servings/d: 2. 6, 4.1, 5.5, 7.1, and 10.2), the corresponding relative risks (RRs) were 1.0 (reference), 0.78, 0.72, 0.68, and 0.68 (95% CI comparing the 2 extreme quintiles: 0.51, 0.92; P: for trend = 0.01). An inverse, though not statistically significant, trend remained after additional adjustment for other known CVD risk factors, with RRs of 1.0, 0.75, 0.83, 0.80, and 0.85 (95% CI for extreme quintiles: 0.61, 1.17). After excluding participants with a self-reported history of diabetes, hypertension, or high cholesterol at baseline, the multivariate-adjusted RR was 0.45 when extreme quintiles were compared (95% CI: 0.22, 0.91; P: for trend = 0.09). Higher fruit and vegetable intake was also associated with a lower risk of MI, with an adjusted RR of 0.62 for extreme quintiles (95% CI: 0.37, 1.04; P: for trend = 0.07).

CONCLUSION

These data suggest that higher intake of fruit and vegetables may be protective against CVD and support current dietary guidelines to increase fruit and vegetable intake.

Smoking cessation and risk of age-related cataract in men

CONTEXT

Although cigarette smoking has been shown to be a risk factor for age-related cataract, data are inconclusive on the risk of cataract in individuals who quit smoking.

OBJECTIVE

To examine the association between smoking cessation and incidence of age-related cataract.

DESIGN

Prospective cohort study conducted from 1982 through 1997, with an average follow-up of 13.6 years.

SETTING AND PARTICIPANTS

A total of 20,907 US male physicians participating in the Physicians' Health Study I who did not have a diagnosis of age-related cataract at baseline and had reported their level of smoking at baseline.

MAIN OUTCOME MEASURES

Incident age-related cataract defined as self-report confirmed by medical record review, diagnosed after study randomization and responsible for vision loss to 20/30 or worse, and surgical extraction of incident age-related cataract, in relation to smoking status and years since quitting smoking.

RESULTS

At baseline, 11% were current smokers, 39% were past smokers, and 50% were never smokers. Average reported cumulative dose of smoking at baseline was approximately 2-fold greater in current than in past smokers (35.8 vs 20.5 pack-years). Two thousand seventy-four incident cases of age-related cataract and 1193 cataract extractions were confirmed during follow-up. Compared with current smokers, multivariate relative risks (RRs) of cataract in past smokers who quit smoking fewer than 10 years, 10 to fewer than 20 years, and 20 or more years before the study were 0.79 (95% confidence interval [CI], 0.64-0.98), 0.73 (95% CI, 0.61-0.88), and 0.74 (95% CI, 0.63-0.87), respectively, after adjustment for other risk factors for cataract and age at smoking inception. The RR for never smokers was 0.64 (95% CI, 0.54-0.76). The reduced risk in past smokers was principally due to a lower total cumulative dose (RR of cataract for increase of 10 pack-years of smoking, 1.07; 95% CI, 1.04-1.10). A benefit of stopping smoking independent of cumulative dose was suggested in some analyses. Results for cataract extraction were similar.

CONCLUSION

These prospective data indicate that while some smoking-related damage to the lens may be reversible, smoking cessation reduces the risk of cataract primarily by limiting total dose-related damage to the lens. JAMA. 2000;284:713-716

Alcohol consumption and risk of coronary heart disease by diabetes status

BACKGROUND

An inverse association between moderate alcohol consumption and coronary heart disease (CHD) has been observed in several epidemiological studies. To assess whether a similar association exists among diabetics, we examined the relation between light to moderate alcohol consumption and CHD in men with and without diabetes mellitus in a prospective cohort study.

METHODS AND RESULTS

A total of 87 938 US physicians (2790 with diagnosed diabetes mellitus) who were invited to participate in the Physicians' Health Study and were free of myocardial infarction, stroke, cancer, or liver disease at baseline were followed for an average of 5.5 years for death with CHD as the underlying cause. During 480 876 person-years of follow-up, 850 deaths caused by CHD were documented: 717 deaths among nondiabetic men and 133 deaths among diabetic men. Among men without diabetes at baseline, the relative risk estimates for those reporting rarely/never, monthly, weekly, and daily alcohol consumption were 1.00 (referent), 1.02, 0. 82, and 0.61 (95% CI 0.49 to 0.78; P for trend <0.0001) after adjustment for age, aspirin use, smoking, physical activity, body mass index, and history of angina, hypertension, and high cholesterol. Among men with diabetes at baseline, the relative risk estimates were 1.00 (referent), 1.11, 0.67, and 0.42 (95% CI 0.23 to 0.77; P for trend=0.0019).

CONCLUSIONS

These results suggest that light to moderate alcohol consumption is associated with similar risk reductions in CHD among diabetic and nondiabetic men.

Effects of beta-carotene supplementation on cancer incidence by baseline characteristics in the Physicians' Health Study (United States)

OBJECTIVES

The Physicians' Health Study (PHS) was a randomized trial of beta-carotene (50 mg, alternate days) and aspirin in primary prevention of cancer and cardiovascular disease among 22,071 US male physicians. This report updates results for beta-carotene and examines effect modification by baseline characteristics.

METHODS

Beta-carotene's effect on cancer over nearly 13 years was examined overall and within subgroups defined by baseline characteristics using proportional-hazards models.

RESULTS

2667 incident cancers were confirmed, with 1117 prostate, 267 colon, and 178 lung cancers. There were no significant differences with supplementation in total (relative risk (RR) = 1.0, 95% confidence interval (CI) = 0.9-1.0); prostate (RR = 1.0, 95% CI = 0.9-1.1); colon (RR = 0.9, 95% CI = 0.7-1.2); or lung (RR = 0.9, 95% CI = 0.7-1.2) cancer, and no differences over time. In subgroup analyses, total cancer was modestly reduced with supplementation among those aged 70+ years (RR = 0.8, 95% CI = 0.7-1.0), daily drinkers of alcohol (RR = 0.9, 95% CI = 0.8-1.0), and those in the highest BMI quartile (RR = 0.9, 95% CI = 0.7-1.0). Prostate cancer was reduced with supplementation among those in the highest BMI quartile (RR = 0.8, 95% CI = 0.6-1.0), and colon cancer was reduced among daily drinkers of alcohol (RR = 0.5, 95% CI = 0.3-0.8).

CONCLUSIONS

The PHS found no overall effect of beta-carotene on total cancer, or the three most common site-specific cancers. The possibility of risk reduction within specific subgroups remains.

Demographic predictors of eye care utilization among women

BACKGROUND

Visual impairment may be preventable or treatable with timely intervention. Differences in the use of eye care services may play a role in fostering the racial and socioeconomic gap in the burden of visual impairment in the United States.

OBJECTIVE

The objective of this study was to examine the frequency of eye examinations in women and how this varies with age, race, marital status, geographic region, profession, education, and income.

SUBJECTS AND METHODS

We used logistic regression models to examine data obtained by mailed questionnaires from 39,876 female health professionals participating in the Women's Health Study.

RESULTS

Most women (83%) had an eye examination within the past 2 years. The likelihood of having an eye examination in the past 2 years increased with age (odds ratio [OR] = 2.59 for age > or =75 years versus those <50 years; P [trend] <0.0001), higher education (OR = 1.27 for master's degree versus licensed nurse training; P [trend] = 0.0004), and higher household income (OR = 1.85 for > or =$100,000 versus <$10,000; P [trend] <0.0001). Women from the south were less likely to have had an eye examination than those from the west (OR = 0.92; P = 0.03). Compared with whites, Asian/Pacific Islanders were less likely (OR = 0.76; P = 0.02) and blacks more likely (OR = 1.27; P = 0.02) to have had an eye examination within 2 years.

CONCLUSIONS

Age, education, income, race/ethnicity, and region of residence were independent predictors of having had an eye examination in the past 2 years. Known medical and ocular problems appeared to explain the association with age but not the other findings, although the clinical significance of these associations was not determined in the present study. Additional research on determinants of eye care-seeking behavior could help in devising new strategies to encourage preventive behaviors, especially among groups at higher risk of visual impairment.

Baseline self-reported cataract and subsequent mortality in Physicians' Health Study I

PURPOSE

To examine whether a reported history of cataract, a possible marker of aging, is associated with future mortality.

METHODS

Participants were 18,669 of the 22,071 U.S. male physicians enrolled in the Physicians' Health Study I who had complete information at study entry, including self-report of presence or absence of baseline cataract. Participants were without a previous history of myocardial infarction, stroke, transient cerebral ischemia, or cancer (except non-melanoma skin cancer). Reported deaths were confirmed by an End Points Committee of physicians.

RESULTS

A total of 581 participants reported a personal history of cataract at baseline. During an average of 12.4 years of follow-up, there were 1,514 deaths including 496 due to cardiovascular (CV) and 1,018 due to non-CV causes. After adjustment for differences in age, men who reported cataract at baseline had a non-significant 9% increased risk of death from any cause compared to men who did not report cataract (RR, 1.09; 95% CI, 0.91-1.30). The RRs were 1.03 (95% CI, 0.75-1.41) for CV death and 1.12 (95% CI, 0.90-1.40) for non-CV death. Adjustment for other risk factors had little effect on these estimates. Similar results were obtained in analyses conducted separately among those with and without self-reported diabetes at baseline.

CONCLUSIONS

These results from a population of generally healthy physicians indicate that a report of a history of cataract is not associated with any material increase in mortality after adjustment for differences in age between men with and without cataract. Additional investigation of this cohort is in progress to determine whether incident age-related cataracts as well as their subtypes, confirmed by medical record review, are associated with increased mortality.

Self-selected posttrial aspirin use and subsequent cardiovascular disease and mortality in the physicians' health study

BACKGROUND

The randomized aspirin component of the Physicians' Health Study (PHS) was terminated early, after 5 years, primarily because of the emergence of a statistically extreme (P<.00001) 44% reduction of first myocardial infarction (MI) among those assigned to aspirin. As a result, there were insufficient numbers of strokes or cardiovascular disease (CVD)-related deaths to evaluate these end points definitively.

METHODS

Data on self-selected aspirin use were collected until the beta carotene component ended as scheduled after 12 years. Posttrial use of aspirin was assessed at the 7-year follow-up among 18 496 participants with no previous reported CVD. Randomized and posttrial observational results in the PHS were compared, and differences between those self-selecting aspirin and those not were examined.

RESULTS

At 7 years, 59.5% of participants without CVD reported self-selected aspirin use for at least 180 d/y, and 20.8% for 0 to 13 d/y. Use was significantly associated with family history of MI, hypertension, elevated cholesterol levels, body mass index, alcohol consumption, exercise, and use of vitamin E supplements. In multivariate analyses, self-selected aspirin use for at least 180 vs 0 to 13 d/y was associated with lower risk for subsequent MI (relative risk [RR], 0.72; 95% confidence interval [CI], 0.55-0.95), no relation with stroke (RR, 1.02; 95% CI, 0.74-1.39), and significant reductions in CVD-related (RR, 0.65; CI, 0.47-0.89) and total mortality (RR, 0.64; CI, 0.54-0.77).

CONCLUSION

These associations between self-selected aspirin use and CVD risk factors increase the likelihood of residual confounding and emphasize the need for large-scale randomized trials, such as the ongoing Women's Health Study, to detect reliably the most plausible small to moderate effects of aspirin in the primary prevention of stroke and CVD-related death.

C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women

BACKGROUND

Since inflammation is believed to have a role in the pathogenesis of cardiovascular events, measurement of markers of inflammation has been proposed as a method to improve the prediction of the risk of these events.

METHODS

We conducted a prospective, nested case-control study among 28,263 apparently healthy postmenopausal women over a mean follow-up period of three years to assess the risk of cardiovascular events associated with base-line levels of markers of inflammation. The markers included high-sensitivity C-reactive protein (hs-CRP), serum amyloid A, interleukin-6, and soluble intercellular adhesion molecule type 1 (sICAM-1). We also studied homocysteine and a variety of lipid and lipoprotein measurements. Cardiovascular events were defined as death from coronary heart disease, nonfatal myocardial infarction or stroke, or the need for coronary-revascularization procedures.

RESULTS

Of the 12 markers measured, hs-CRP was the strongest univariate predictor of the risk of cardiovascular events; the relative risk of events for women in the highest as compared with the lowest quartile for this marker was 4.4 (95 percent confidence interval, 2.2 to 8.9). Other markers significantly associated with the risk of cardiovascular events were serum amyloid A (relative risk for the highest as compared with the lowest quartile, 3.0), sICAM-1 (2.6), interleukin-6 (2.2), homocysteine (2.0), total cholesterol (2.4), LDL cholesterol (2.4), apolipoprotein B-100 (3.4), HDL cholesterol (0.3), and the ratio of total cholesterol to HDL cholesterol (3.4). Prediction models that incorporated markers of inflammation in addition to lipids were significantly better at predicting risk than models based on lipid levels alone (P<0.001). The levels of hs-CRP and serum amyloid A were significant predictors of risk even in the subgroup of women with LDL cholesterol levels below 130 mg per deciliter (3.4 mmol per liter), the target for primary prevention established by the National Cholesterol Education Program. In multivariate analyses, the only plasma markers that independently predicted risk were hs-CRP (relative risk for the highest as compared with the lowest quartile, 1.5; 95 percent confidence interval, 1.1 to 2.1) and the ratio of total cholesterol to HDL cholesterol (relative risk, 1.4; 95 percent confidence interval, 1.1 to 1.9).

CONCLUSIONS

The addition of the measurement of C-reactive protein to screening based on lipid levels may provide an improved method of identifying persons at risk for cardiovascular events.

A prospective study of physical activity and risk of prostate cancer in US physicians

BACKGROUND

Exercise can suppress androgen production and may thus decrease the risk of prostate cancer. However, findings from epidemiological studies assessing physical activity and risk of prostate cancer are inconsistent.

METHODS

We prospectively examined the association between physical activity and prostate cancer risk in the Physicians' Health Study (PHS), a randomized trial of low-dose aspirin and beta-carotene among 22,071 men aged 40-84 without self-reported myocardial infarction, stroke and cancer. At baseline in 1982, men were asked about the frequency of exercise vigorous enough to work up a sweat. Physical activity was assessed in a similar fashion again at 36 months of follow-up.

RESULTS

During 11.1 years of follow-up (258 779 person-years), 982 cases of prostate cancer occurred and were confirmed by medical record review. After adjustment for potential confounding factors (including age, height, randomized treatment assignment, smoking status, alcohol intake, use of multivitamins, history of diabetes, history of hypertension and history of high cholesterol), the relative risks for prostate cancer associated with exercise vigorous enough to work up a sweat were 1.0 (referent) for frequency less than once per week, 1.02 (95% CI: 0.82-1.26) for once per week, 1.07 (95% CI: 0.90-1.27) for 2-4 times per week, and 1.11 (95% CI: 0.90-1.36) for 5+ times per week. Across all subgroups of men categorized by age, body mass index, smoking status, alcohol intake, use of multivitamins, history of diabetes, history of hypertension and history of high cholesterol, there were no significant associations between frequency of exercise vigorous enough to work up a sweat and prostate cancer risk. After excluding cases of prostate cancer that occurred during the first 36 months of follow-up, again, there was no significant association. Combining physical activity assessments at baseline and at 36 months also yielded no significant association with prostate cancer risk.

CONCLUSIONS

These observational data from the Physicians' Health Study do not support the hypothesis that increased physical activity reduces the risk of prostate cancer.

Light-to-moderate alcohol consumption and mortality in the Physicians' Health Study enrollment cohort

OBJECTIVES

This study examined the relationship between light-to-moderate alcohol consumption and cause-specific mortality.

BACKGROUND

Previous studies suggest a J-shaped relation between alcohol and total mortality in men. A decrease in cardiovascular disease (CVD) mortality without a significant increase in other causes of mortality may explain the overall risk reduction at light-to-moderate levels.

METHODS

We conducted a prospective cohort study of 89,299 U.S. men from the Physicians' Health Study enrollment cohort who were 40 to 84 years old in 1982 and free of known myocardial infarction, stroke, cancer or liver disease at baseline. Usual alcohol consumption was estimated by a limited food frequency questionnaire.

RESULTS

There were 3,216 deaths over 5.5 years of follow-up. We observed a U-shaped relationship between alcohol consumption and total mortality. Compared with rarely/never drinkers, consumers of 1, 2 to 4 and 5 to 6 drinks per week and 1 drink per day had significant reductions in risk of death (multivariate relative risks [RRs] of 0.74, 0.77, 0.78 and 0.82, respectively) with no overall benefit or harm detected at the > or =2 drinks per day level (RR = 0.95; 95% confidence interval (CI), 0.79 to 1.14). The relationship with CVD mortality was inverse or L-shaped with apparent risk reductions even in the highest category of > or =2 drinks per day (RR = 0.76; 95% CI, 0.57 to 1.01). We found no clear harm or benefit for total or common site-specific cancers. For remaining other cancers, there was a nonsignificant 28% increased risk for those consuming > or =2 drinks per day.

CONCLUSIONS

These data support a U-shaped relation between alcohol and total mortality among light-to-moderate drinking men. The U-shaped curve may reflect an inverse association for CVD mortality, no association for common site-specific cancers and a possible positive association for less common cancers.

Baseline characteristics of participants in the Women's Health Study

The Women's Health Study (WHS) is a randomized, double-blind, placebo-controlled trial designed to evaluate the balance of benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer in women. A total of 39,876 female health professionals, age 45 years or older and without a history of cardiovascular disease or cancer (other than nonmelanoma skin cancer), were randomized in a 2x2 factorial design to one of four treatment groups: active aspirin and vitamin E placebo, aspirin placebo and active vitamin E, both active agents, or both placebos. The process of randomization was successful, as evidenced by the equal distribution of a large number of baseline demographic, lifestyle, and health history characteristics among the four treatment groups. Similar distribution of known potential confounders, as well as the large sample size, provides reassuring evidence that unmeasured or unknown potential confounders are also equally distributed. As expected in a clinical trial, the women in the study are healthier in some respects than the general population, but they have very comparable rates of obesity, hypertension, and elevated cholesterol. With adequate duration of treatment and follow-up, this trial will provide important and relevant information on the balance of benefits and risks of aspirin and vitamin E supplementation in the primary prevention of cardiovascular disease and cancer in women.

Clinical utility of lipid and lipoprotein levels during hospitalization for acute myocardial infarction

The management of dyslipidemia after myocardial infarction (MI) is an important aspect of post-myocardial infarction care. However, acute changes in the lipid profile immediately following myocardial infarction have resulted in uncertainty regarding the clinical utility of lipid levels assessed during hospitalization for MI. We studied the effect of the timing of plasma lipid assessment among 294 patients who presented with MI to determine whether the differences between the serum lipid values in-hospital when compared with post-discharge values (generally 2-3 months after MI) would have a substantial impact on the decision to initiate lipid-lowering therapy. We found that the mean total and LDL cholesterol levels were significantly lower in-hospital when compared with generally 2-3 months later. However, patients whose lipids were measured within 48 h of presentation did not have significantly different values compared with generally 2-3 months post-discharge. Moreover, despite slightly lower in-hospital levels, 83.7% of patients were above the National Cholesterol Education Program target LDL for secondary prevention and 57.6% met the criteria for drug therapy based on in-hospital assessment. Total and LDL cholesterol levels fall modestly after an acute MI; however, from a clinical perspective, in-hospital levels can be used to guide decisions regarding lipid-lowering therapy which can begin in the immediate post-MI setting. In-hospital levels approximate post-MI levels, particularly if drawn within 48 h of presentation. All patients with acute myocardial infarction should have complete lipid profiles measured prior to discharge.

Beta-carotene supplementation and incidence of cancer and cardiovascular disease: the Women's Health Study

BACKGROUND

In observational studies, individuals with high intakes of fruits and vegetables containing beta-carotene experience lower risks of developing cancer. However, the few randomized trials of beta-carotene supplementation show no overall benefits; some even suggest harm. This trial was designed to test the effects of beta-carotene supplementation in women.

METHODS

The Women's Health Study is a randomized, double-blind, placebo-controlled trial originally testing aspirin, vitamin E, and beta-carotene in the prevention of cancer and cardiovascular disease among 39 876 women aged 45 years or older. The beta-carotene component was terminated early after a median treatment duration of 2.1 years (range = 0.00-2. 72 years). Statistical tests were two-sided.

RESULTS

Among women randomly assigned to receive beta-carotene (50 mg on alternate days; n = 19 939) or placebo (n =19 937), there were no statistically significant differences in incidence of cancer, cardiovascular disease, or total mortality after a median of 4.1 years (2.1 years' treatment plus another 2.0 years' follow-up). There were 378 cancers in the beta-carotene group and 369 cancers in the placebo group (relative risk [RR] = 1.03; 95% confidence interval [CI] = 0.89-1. 18). There were no statistically significant differences for any site-specific cancer or during years 1 and 2 combined and years 3 and up combined. For cardiovascular disease, there were no statistically significant differences for myocardial infarction (42 in the beta-carotene group versus 50 in the placebo group), stroke (61 versus 43), deaths from cardiovascular causes (14 versus 12), or the combined end point of these three events (116 versus 102; among women with more than one event, only the first was counted). Deaths from any cause were similar in the two groups (59 versus 55). Among smokers at baseline (13% of all women), there were no statistically significant differences in overall incidence of cancer (RR = 1.11; 95% CI = 0.78-1.58) or cardiovascular disease (RR = 1.01; 95% CI = 0. 62-1.63).

CONCLUSION

Among apparently healthy women, there was no benefit or harm from beta-carotene supplementation for a limited period on the incidence of cancer and of cardiovascular disease.

Light-to-moderate alcohol consumption and the risk of stroke among U.S. male physicians

BACKGROUND

Several studies have shown U- or J-shaped relations between alcohol consumption and the risk of stroke. We evaluated the effect of light-to-moderate alcohol intake on the risk of stroke, with separate analyses of ischemic stroke and hemorrhagic stroke.

METHODS

Our analyses were based on a prospective cohort study of 22,071 male physicians, 40 to 84 years old, who were participating in the Physicians' Health Study. At base line, the participants reported that they had no history of stroke, transient ischemic attack, or myocardial infarction and were free of cancer. Alcohol intake, reported by 21,870 participants at base line, ranged from none or almost none to two or more drinks per day.

RESULTS

During an average of 12.2 years of follow-up, 679 strokes were reported. As compared with participants who had less than one drink per week, those who drank more had a reduced overall risk of stroke (relative risk, 0.79; 95 percent confidence interval, 0.66 to 0.94) and a reduced risk of ischemic stroke (relative risk, 0.77; 95 percent confidence interval, 0.63 to 0.94). There was no statistically significant association between alcohol consumption and hemorrhagic stroke. The overall relative risks of stroke for the men who had one drink per week, two to four drinks per week, five or six drinks per week, or one or more drinks per day were 0.78 (95 percent confidence interval, 0.59 to 1.04), 0.75 (95 percent confidence interval, 0.58 to 0.96), 0.83 (95 percent confidence interval, 0.62 to 1.11), and 0.80 (95 percent confidence interval, 0.64 to 0.99), respectively, in an analysis in which we controlled for major risk factors for stroke.

CONCLUSIONS

Light-to-moderate alcohol consumption reduced the overall risk of stroke and the risk of ischemic stroke in men. The benefit is apparent with as little as one drink per week. Greater consumption, up to one drink per day, does not increase the observed benefit.

Beta-carotene supplementation for patients with low baseline levels and decreased risks of total and prostate carcinoma

BACKGROUND

The Physicians' Health Study was a randomized, double-blind, placebo-controlled trial using a 2x2 factorial design including supplementation with beta-carotene (50 mg every other day) in the primary prevention of cancer among 22,071 U.S. male physicians ages 40-84 years at randomization. Before randomization, the authors collected baseline blood specimens to determine whether any benefit was greater among or confined to those with low baseline levels of beta-carotene.

METHODS

Baseline blood samples were collected from 14,916 participants. These samples were assayed, according to a nested case-control design, from 1439 men subsequently diagnosed with cancer over 12 years of follow-up (631 with prostate carcinoma) and 2204 controls matched by age and smoking habits.

RESULTS

Men in the lowest quartile for plasma beta-carotene at baseline had a marginally significant (P = 0.07) increased risk of cancer compared with those in the highest quartile (relative risk [RR] = 1.30, 95% confidence interval [CI], 0.98-1.74). Men in the lowest quartile assigned at random to beta-carotene supplementation had a possible but nonsignificant decrease in overall cancer risk (RR = 0.83, 95% CI, 0.63-1.09) compared with those assigned to placebo. This was primarily due to a significant reduction in the risk of prostate carcinoma (RR = 0.68, 95% CI, 0. 46-0.99) in this group. After the first 2 years of follow-up were excluded, the results were virtually unchanged.

CONCLUSIONS

These prespecified subgroup analyses appeared to support the idea that beta-carotene supplementation may reduce risk of prostate carcinoma among those with low baseline levels. Further follow-up of this population will help determine whether these findings are valid.

Baseline IgG antibody titers to Chlamydia pneumoniae, Helicobacter pylori, herpes simplex virus, and cytomegalovirus and the risk for cardiovascular disease in women

BACKGROUND

Results of cross-sectional and retrospective studies have suggested that chronic infection may be a risk factor for cardiovascular disease. However, prospective data evaluating the relation between baseline antibody titers against various plausible agents and risk for cardiovascular disease are sparse, particularly among women.

OBJECTIVE

To determine whether previous exposure to Chlamydia pneumoniae, Helicobacter pylori, herpes simplex virus, or cytomegalovirus is associated with increased risk for cardiovascular events.

DESIGN

Prospective, nested, case-control study.

SETTING

Women's Health Study.

PARTICIPANTS

Apparently healthy postmenopausal women.

MEASUREMENTS

IgG antibody titers against C. pneumoniae, H. pylori, herpes simplex virus, and cytomegalovirus were measured in baseline blood samples obtained from 122 study participants who subsequently reported a first cardiovascular event (case-patients) and 244 participants matched for age and smoking status who did not report a cardiovascular event (controls) during 3 years of follow-up.

RESULTS

Little evidence was found of an association between risk for cardiovascular events and baseline IgG seropositivity for antibodies against C. pneumoniae (rate ratio, 1.1 [95% CI, 0.7 to 1.8]), H. pylori (rate ratio, 0.90 [CI, 0.6 to 1.4]), herpes simplex virus (rate ratio, 1.2 [CI, 0.6 to 2.1]), and cytomegalovirus (rate ratio, 0.9 [CI, 0.6 to 1.5]). In addition, there was little evidence of an association between a participant's total number of infections and subsequent cardiovascular risk (P > 0.2).

CONCLUSION

In apparently healthy postmenopausal women, little evidence was found that previous infection, as measured by IgG antibody titers to C. pneumoniae, H. pylori, herpes simplex virus, and cytomegalovirus, is associated with subsequent risk for cardiovascular disease.

Relation between systemic hypertension and blood lipids on the risk of myocardial infarction

We sought to evaluate the potential interactions between systemic hypertension and blood lipids on the risk of myocardial infarction (MI). Recent evidence suggests that hypertension may interact with other risk factors such as dyslipidemia in the development of coronary heart disease. However, the precise nature of that interrelation remains unclear. We selected 340 cases of first MI and an equal number of age-, sex-, and community-matched controls. Data were collected on a large number of coronary risk factors, and fasting blood samples were obtained. Logistic regression was used to calculate the odds ratio (OR) of nonfatal MI. The age- and sex-adjusted OR of MI was 1.61 (95% confidence interval [CI] 1.15 to 2.25) among treated hypertensives compared with nonhypertensives. Further adjustment for coronary risk factors did not materially alter the results (OR 1.67, 95% CI 1.16 to 2.41). To explore the interrelations among hypertension, lipids, and risk of MI, each lipoprotein parameter was individually added to the risk factor-adjusted multivariate model. The apparent risk associated with hypertension was substantially attenuated by the addition of either high-density lipoprotein cholesterol (OR 1.25, 95% CI 0.82 to 1.90) or triglycerides (OR 1.37, 95% CI 0.91 to 2.05). No significant interactions were found between hypertension and any lipoprotein parameter. These data indicate that the risk of MI associated with treated hypertension may have a lipid mechanism involving high-density lipoprotein cholesterol and/or triglycerides.

Long-term beta-carotene supplementation and risk of type 2 diabetes mellitus: a randomized controlled trial

CONTEXT

Recent data suggest a protective role of carotenoids in the development of type 2 diabetes mellitus (DM), possibly via an antioxidant effect, but no randomized trial has directly assessed the efficacy of beta-carotene to prevent DM.

OBJECTIVE

To determine whether long-term beta-carotene supplementation reduces the risk of developing type 2 DM.

DESIGN, SETTING, AND PARTICIPANTS

A total of 22, 071 healthy US male physicians aged 40 to 84 years in a randomized, double- blind, placebo-controlled trial, from 1982 to 1995. More than 99% of the participants had complete follow-up (median duration, 12 years).

INTERVENTION

Subjects were randomly assigned to receive beta-carotene (50 mg on alternate days) or placebo.

MAIN OUTCOME MEASURE

Incidence of type 2 DM.

RESULTS

A total of 10, 756 subjects were assigned to beta-carotene and 10, 712 to placebo. Incidence of type 2 DM did not differ between groups: 396 men in the beta-carotene group and 402 men in the placebo group developed type 2 DM (relative risk, 0.98; 95% confidence interval, 0.85-1.12). The lack of association between beta-carotene supplementation and incidence of type 2 DM persisted despite multivariate adjustment. There was no evidence of benefit when the period of risk was subdivided into years of follow-up or increasing duration of treatment.

CONCLUSION

In this trial of apparently healthy men, supplementation with beta-carotene for an average of 12 years had no effect on the risk of subsequent type 2 DM.

Comparison of self-reported diagnosis of connective tissue disease with medical records in female health professionals: the Women's Health Cohort Study

To compare self-report of connective tissue disease (CTD) with medical records, subjects were selected from 395,543 female health professionals with and without breast implants who reported CTD on mailed questionnaires from 1992 to 1995. The authors identified 220 women with breast implants (exposed) who self-reported CTD and a random sample of 879 women without breast implants (unexposed) who also self-reported CTD, matched by age and date of diagnosis. Medical records were reviewed using classification criteria from the American College of Rheumatology or other published criteria. After up to three requests and a telephone call, 27.7% of the women provided consent for medical record review. Exposed women appeared somewhat more likely (33.2% vs. 26.3%, p = 0.04) to provide consent. Using medical record reviews for 90% of the women who provided consent, confirmation rates of definite CTD were similar among the exposed and unexposed (22.7% vs. 24.0%, p = 0.83). This study demonstrates the difficulty of obtaining consent for medical record review of CTD reported to have occurred years ago in women with and without breast implants. Confirmation rates were low but were similar in exposed and unexposed. Despite the fact that the study had low participation rates, the data suggest that relative risk estimates for any definite CTD among women with breast implants compared with women without breast implants would be similar in analyses of self-reported or medical record-confirmed cases.

Hormone replacement therapy and increased plasma concentration of C-reactive protein

BACKGROUND

It has been hypothesized that postmenopausal hormone replacement therapy (HRT) may increase levels of C-reactive protein (CRP), a marker of inflammation associated with increased risk of future cardiovascular events. However, data evaluating this hypothesis are sparse and limited to older women.

METHODS AND RESULTS

CRP levels were evaluated in a cross-sectional survey of 493 healthy postmenopausal women; mean age was 51 years. Overall, median CRP levels were 2 times higher among women taking HRT than among women not taking HRT (0.27 versus 0.14 mg/dL; P=0.001). This difference was present in all subgroups evaluated, including those with no history of hypertension, hyperlipidemia, obesity, diabetes, or cigarette consumption or a family history of premature coronary artery disease (all P< 0.01). Compared with nonusers of HRT, median CRP levels were higher among women using estrogen alone (P=0.003) and women using estrogen plus progesterone (P=0.03); however, there was no significant difference in CRP levels between users of different HRT preparations. In multivariate analysis, the relationship between HRT use and CRP remained significant after control for body mass index, age, diabetes, hypertension, hyperlipidemia, alcohol use, and cigarette consumption (P=0.001).

CONCLUSIONS

In this cross-sectional survey, CRP levels were increased among apparently healthy postmenopausal women taking HRT. The potential impact of HRT on inflammatory parameters should be investigated in ongoing clinical trials.

Homocysteine and risk of cardiovascular disease among postmenopausal women

CONTEXT

Individuals with elevated levels of homocysteine tend to have higher prevalence of cardiovascular disease. However, prospective studies of homocysteine are inconsistent and data among women are limited.

OBJECTIVE

To determine whether elevated homocysteine levels in healthy postmenopausal women predict risk of developing cardiovascular disease.

DESIGN

Prospective, nested case-control study with a mean 3-year follow-up.

SETTING

The Women's Health Study, an ongoing US primary prevention trial initiated in 1993.

PARTICIPANTS

From a total cohort of 28,263 postmenopausal women with no history of cardiovascular disease or cancer at baseline, 122 women who subsequently experienced cardiovascular events were defined as cases, and 244 age- and smoking status-matched women who remained free of disease during follow-up were defined as controls.

MAIN OUTCOME MEASURES

Incidence of death due to cardiovascular disease, nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft by baseline homocysteine level.

RESULTS

Of the 122 cases, there were 85 events of MI or stroke and 37 coronary revascularizations. Case subjects had significantly higher baseline homocysteine levels than controls (14.1 vs 12.4 micromol/L; P = .02). Subjects with homocysteine levels in the highest quartile had a 2-fold increase in risk of any cardiovascular event (relative risk [RR], 2.0; 95% confidence interval [CI], 1.1-3.8). This effect was largely due to an excess of cases with high levels of homocysteine; the RR for those with homocysteine levels at or higher than the 95th percentile (20.7 micromol/L) was 2.6 (95% CI, 1.1-5.7). Risk estimates were independent of traditional risk factors and were greatest for the end points of MI and stroke (RR for those with baseline homocysteine levels in the top quartile, 2.2; 95% CI, 1.1-4.6). Self-reported multivitamin supplement use at study entry was associated with significantly reduced levels of homocysteine (P<.001). However, the association between increasing quartile of homocysteine level and risk of MI or stroke remained significant in analyses controlling for baseline multivitamin supplement use (P = .003 for trend), and subgroup analyses limited to women who were (P = .02 for trend) or were not (P = .04 for trend) taking multivitamin supplements.

CONCLUSIONS

Among healthy postmenopausal US women, elevated levels of homocysteine moderately increased the risk of future cardiovascular disease. Whether lowering the homocysteine level reduces risk of cardiovascular events requires testing in randomized controlled trials.

A retrospective cohort study of cigarette smoking and risk of rheumatoid arthritis in female health professionals

OBJECTIVE

To study the association of cigarette smoking with risk of rheumatoid arthritis (RA), among 377,481 female health professionals in the Women's Health Cohort Study.

METHODS

Subjects completed mailed questionnaires regarding demographics, health habits, including cigarette smoking history, and medical history, including RA diagnosis made by a physician and date of diagnosis. Of 7,697 women who self-reported RA, 3,416 reported seropositive RA. Cox proportional hazards regression models were used to retrospectively assess the associations of smoking intensity and duration with the risk of developing RA or seropositive RA. Cigarette smoking status was treated as a time-varying exposure in these regression models.

RESULTS

In multivariate analyses controlling for age, race, education, age at menarche, pregnancy history, menopausal status, and postmenopausal hormone use, duration of smoking was associated with a significantly increased risk of both RA and seropositive RA (both P < 0.01 for trend), after adjusting for smoking intensity. Women who smoked > or =25 cigarettes/day for more than 20 years experienced a 39% increased risk of RA and 49% increased risk of seropositive RA. However, smoking intensity (number of cigarettes/day) was unrelated to risk of RA or seropositive RA (both P = 0.3 for trend), after adjusting for duration of smoking.

CONCLUSION

Duration, but not intensity, of cigarette smoking is associated with a modest increased risk of RA in women.

A prospective study of alcohol consumption and the risk of age-related macular degeneration

PURPOSE

Vascular risk factors, including alcohol intake, have been hypothesized to play a role in the development of age-related macular degeneration (AMD). We examined the relationship of alcohol intake with AMD in the Physicians' Health Study (PHS).

METHODS

The PHS was a randomized trial of aspirin and beta-carotene among 22,071 U.S. male physicians age 40 to 84 years at entry. A total of 21,041 physicians with complete data on alcohol consumption and no AMD at baseline were included in this analysis. Proportional hazards models were used to estimate relative risks (RR) and 95% confidence interval (CI).

RESULTS

During an average follow-up period of 12.5 years, 278 physicians were confirmed by medical record review to have incident AMD resulting in vision loss ( acuity 20/30 or worse). After adjusting for age, randomized treatment assignment, and other potential risk factors, the RR for > or = 1 drink/week versus < 1 drink/week was 0.97 (CI: 0.78-1.21). For categories of alcohol intake, the RRs for those reporting alcohol consumption of < 1 drink/week, 1 drink/week, 2-4 drinks/week, 5-6 drinks/week, and > or = 1 drink/day were 1.00 (referent), 1.00 (0.65-1.55), 0.68 (0.44-1.04), 1.32 (0.89-1.95), and 1.27 (0.93-1.73), respectively.

CONCLUSIONS

These prospective data indicate that alcohol intake is not appreciably associated with the risk of incident AMD. However, the width of the confidence intervals are compatible with a possible small effect (reduction or increase) in risk for low to moderate levels of alcohol intake, which warrant further investigation.

Prospective cohort study of antioxidant vitamin supplement use and the risk of age-related maculopathy

In a prospective cohort study, the authors examined whether self-selection for antioxidant vitamin supplement use affects the incidence of age-related maculopathy. The study population consisted of 21,120 US male physician participants in the Physicians' Health Study I who did not have a diagnosis of age-related maculopathy at baseline (1982). During an average of 12.5 person-years of follow-up, a total of 279 incident cases of age-related maculopathy with vision loss to 20/30 or worse were confirmed by medical record review. In multivariate analysis, as compared with nonusers of supplements, persons who used vitamin E supplements had a possible but nonsignificant 13% reduced risk of age-related maculopathy (relative risk = 0.87, 95 percent confidence interval (CI) 0.53-1.43), while users of multivitamins had a possible but nonsignificant 10% reduced risk (relative risk = 0.90, 95% CI 0.68-1.19). Users of vitamin C supplements had a relative risk of 1.03 (95% CI 0.71-1.50). These observational data suggest that among persons who self-select for supplemental use of antioxidant vitamin C or E or multivitamins, large reductions in the risk of age-related maculopathy are unlikely. Randomized trial data are accumulating to enable reliable detection of the existence of more plausible small-to-moderate benefits of these agents alone and in combination on age-related maculopathy.

Alcohol intake, lipids and risks of myocardial infarction

The health effects of alcohol consumption remain complex for several reasons: the risks and benefits accrue over many years, assessment of drinking is generally based on self-report, drinking habits change over time and studies estimate average daily drinking disregarding how or when the beverage was consumed. In addition, alcohol consumption is associated with lifestyle factors which may confound relationship with disease. Despite these methodological difficulties, epidemiological studies are surprisingly consistent, showing that light to moderate intake is associated with a lower risk of total mortality compared with those who drink heavily or do not drink at all. Thus there is a J-shaped association of alcohol intake with risk of total mortality whose basis is likely to be the effect of summing the cause-specific effects at the various drinking levels. Studies using a diversity of methods and populations have consistently reported an inverse relationship between coronary heart disease and light to moderate drinking, with the depth and width of the J-shaped mortality curve depending on the underlying risk of coronary heart disease for that population. The higher risk of death at heavy drinking levels is due to increased risk of cancer, liver diseases, cardiomyopathy and stroke. The precise mechanisms behind these effects of alcohol are only now beginning to be understood. The most plausible mechanism by which alcohol reduces the risk of coronary heart disease is by its effects on blood lipids, particularly increases in high density lipoprotein (HDL) cholesterol: about 50% of the risk reduction attributable to alcohol is explained by changes in total HDL. Further support for the HDL hypothesis comes from the lack of a differential effect of alcohol by beverage type. While the association of alcohol and cardiovascular disease is likely to be causal, any public health recommendations must consider the complexity of alcohol's metabolic, physiological and psychological effects.

Beta-carotene supplementation: a good thing, a bad thing, or nothing?

Available data from several completed large-scale randomized trials indicate that beta-carotene supplementation for durations up to 12 years has no overall benefit in well-nourished populations on the incidence of cardiovascular disease or the middle-to-late stages of carcinogenesis. Several important questions, however, remain unanswered. The post-trial follow-up of completed trials, together with the results of several ongoing trials of beta-carotene supplementation, will contribute reliable information to the totality of evidence from basic research, animal studies, observational epidemiologic studies, and completed trials, thus allowing more rational clinical decisions for individual patients and policy decisions for the health of the general public.

Coffee and tea intake and the risk of myocardial infarction

The authors investigated the association of caffeinated coffee, decaffeinated coffee, and tea with myocardial infarction in a study of 340 cases and age-, sex-, and community-matched controls. The odds ratio for drinking > or = 4 cups/day of caffeinated coffee versus drinking < or = 1 cup/week was 0.84 (95% confidence interval (CI) 0.49-1.42) after adjustment for coronary risk factors (1 cup = 237 ml). The odds ratio for drinking > 1 cup/day of decaffeinated coffee versus nondrinkers was 1.25 (95% CI 0.76-2.04). For tea, the odds ratio for drinking > or = 1 cup/day versus nondrinkers was 0.56 (95% CI 0.35-0.90). In these data, only tea was associated with a lower risk of myocardial infarction.

Exercise and risk of stroke in male physicians

BACKGROUND AND PURPOSE

From a physiological perspective, physical activity might be expected to decrease the risk of developing stroke. However, epidemiological studies of physical activity and stroke risk have yielded divergent findings. We therefore sought to examine the association between exercise and stroke risk.

METHODS

This was a prospective cohort study of 21 823 men, followed up for an average of 11.1 years. Participants were from the Physicians' Health Study, a randomized trial of low-dose aspirin and beta carotene. Men, aged 40 to 84 years at baseline, were free of self-reported myocardial infarction, stroke, transient ischemic attack, and cancer. At baseline, they reported on the frequency of exercise vigorous enough to work up a sweat. Stroke occurrence was reported by participants and confirmed after medical record review (n=533). We used Cox proportional hazards regression to analyze the data.

RESULTS

With adjustment for age, treatment assignment, smoking, alcohol intake, history of angina, and parental history of myocardial infarction, the relative risks of total stroke associated with vigorous exercise <1 time, 1 time, 2 to 4 times, and >/=5 times per week at baseline were 1.00 (referent), 0.79 (95% confidence interval [CI], 0.61 to 1. 03), 0.80 (95% CI, 0.65 to 0.99), and 0.79 (95% CI, 0.61 to 1.03), respectively; P for trend=0.04. In subgroup analyses, the inverse association appeared stronger with hemorrhagic than ischemic stroke. When we additionally adjusted for body mass index, history of hypertension, high cholesterol, and diabetes mellitus, corresponding relative risks for total stroke were 1.00 (referent), 0.81 (95% CI, 0.61 to 1.07), 0.88 (95% CI, 0.70 to 1.10), and 0.86 (95% CI, 0.65 to 1.13), respectively; P for trend=0.25.

CONCLUSIONS

Exercise vigorous enough to work up a sweat is associated with decreased stroke risk in men. In the present study, the inverse association with physical activity appeared to be mediated through beneficial effects on body weight, blood pressure, serum cholesterol, and glucose tolerance. Apart from its favorable influences on these variables, physical activity had no significant residual association with stroke incidence.

Type of alcoholic beverage and risk of myocardial infarction

We examined the relation of alcoholic beverage type and risk of myocardial infarction (MI) in a case-control study among 340 cases of MI and an equal number of age-, sex-, and community-matched controls. Alcohol consumption was estimated using a food frequency questionnaire, with alcohol drinkers defined as those consuming > or = 1/2 drink/day on average of any alcoholic beverage. Beer, wine, and liquor drinkers had at least half of their consumption from 1 beverage type. Fasting venous blood samples were obtained and analyzed for lipid profiles. Compared with nondrinkers, after adjustment for age and sex, reductions in risk of MI were similar for regular drinkers of any type of alcoholic beverage (relative risk [RR] 0.54; 95% confidence interval [CI] 0.37 to 0.79; p = 0.001), beer (RR 0.55; 95% CI 0.31 to 0.97; p <0.05), wine (RR 0.48; 95% CI 0.27 to 0.87; p <0.05), and liquor (RR 0.59; 95% CI 0.38 to 0.91; p <0.05) drinkers. Comparable benefits remained apparent even after multivariate adjustment for a wide range of nonlipid coronary risk factors. High-density lipoprotein (HDL) levels were significantly higher in all 4 beverage categories when compared with levels in nondrinkers, and as expected, adjustment for total HDL, a major direct effect of alcohol, substantially attenuated the protective effect in all 4 beverage categories. Relative risks were 0.94 for any beverage, 1.09 for beer, 0.97 for wine, and 0.83 for liquor after further adjustment. This strongly suggests that the protective effect of each beverage type is, in large part, mediated by increased HDL. These data indicate that regular consumption of small to moderate amounts of alcoholic beverages, regardless of the type, reduces the risk of MI, and further suggest that there is benefit, in large part, from increases in HDL levels.

Mortality and light to moderate alcohol consumption after myocardial infarction

BACKGROUND

Although heavy alcohol consumption increases total mortality, light to moderate consumption decreases cardiovascular and all-cause mortality in apparently healthy people. Since data are sparse on the relation of light to moderate alcohol intake to mortality in patients with previous myocardial infarction, we did a prospective study of mortality in men.

METHOD

Of 90,150 men in the Physicians' Health Study enrollment cohort who provided information on alcohol intake and who had no history of cancer, stroke, or liver disease, 5358 had a previous myocardial infarction. We estimated alcohol consumption by food-frequency questionnaire.

FINDINGS

During a mean follow-up of 5 years, 920 men died. After adjustment for several potential confounders, moderate alcohol intake was associated with a significant decrease in total mortality (p=0.016). Compared with men who rarely or never drank alcohol, those who drank one to four drinks per month had a relative risk for total mortality of 0.85 (95% CI 0.69-1.05); for two to four drinks per week, the relative risk was 0.72 (0.58-0.89); for one drink per day 0.79 (0.64-9.96); and for two or more drinks per day 0.84 (0.55-1.26).

INTERPRETATION

Men with previous myocardial infarction who consume small to moderate amounts of alcohol have a lower total mortality.

Low-dose aspirin and risk of cataract and subtypes in a randomized trial of U.S. physicians

PURPOSE

To examine whether low-dose aspirin (325 mg on alternate days) reduces the risk of age-related cataract and subtypes. This report extends previous findings, including both subtypes and additional newly identified incident cases since the earlier report.

METHODS

All 20,979 participants in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among U.S. male physicians age 40-84 in 1982, who did not report cataract at baseline were included. Average follow-up was five years. The main outcome measure was incident, age-related cataract responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report confirmed by medical record review.

RESULTS

501 age-related cataracts were diagnosed during follow-up, including 416 with nuclear sclerosis and 212 with a posterior subcapsular component; 318 cataracts progressed to surgical extraction. Overall, there were 245 cataracts in the aspirin group and 256 in the placebo group (relative risk [RR], 0.94; 95% confidence interval [CI], 0.79 to 1.13; P = 0.52). Cataract extractions were 19% less frequent in the aspirin than in the placebo group (RR, 0.81; 95% CI, 0.65 to 1.01; P = 0.06). In subgroup analyses of subtypes, aspirin takers had a lower risk of posterior subcapsular cataract (RR, 0.74; 95% CI, 0.57 to 0.98; P = 0.03) but not nuclear sclerosis (RR, 0.96; 95% CI, 0.79 to 1.16; P = 0.65) cataract.

CONCLUSIONS

Overall, these randomized trial data tend to exclude a large benefit of five years of low-dose aspirin therapy on cataract development and extraction. The data are compatible with a modest benefit on cataract extraction for this duration of aspirin therapy. Subgroup analyses raise the possibility of a modest, but potentially important, protective effect of aspirin on posterior subcapsular cataract, a particularly disabling subtype.

Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women

BACKGROUND

C-reactive protein (CRP) predicts risk of myocardial infarction (MI) and stroke among apparently healthy men, but in women, virtually no data are available.

METHODS AND RESULTS

CRP was measured in baseline blood samples from 122 apparently healthy participants in the Women's Health Study who subsequently suffered a first cardiovascular event and from 244 age- and smoking-matched control subjects who remained free of cardiovascular disease during a 3-year follow-up period. Women who developed cardiovascular events had higher baseline CRP levels than control subjects (P=0.0001), such that those with the highest levels at baseline had a 5-fold increase in risk of any vascular event (RR=4.8; 95% CI, 2.3 to 10.1; P=0.0001) and a 7-fold increase in risk of MI or stroke (RR=7.3; 95% CI, 2.7 to 19.9; P=0.0001). Risk estimates were independent of other risk factors, and prediction models that included CRP provided a better method to predict risk than models that excluded CRP (all P values <0.01). In stratified analyses, CRP was a predictor among subgroups of women with low as well as high risk as defined by other cardiovascular risk factors.

CONCLUSIONS

In these prospective data among women, CRP is a strong independent risk factor for cardiovascular disease that adds to the predictive value of risk models based on usual factors alone. (Circulation. 1998;98:731-733.)

Factor V Leiden mutation as a risk factor for recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss may result from hypercoagulability.

OBJECTIVE

To determine whether women with factor V Leiden mutation, a common inherited defect of coagulation, are at increased risk for recurrent pregnancy loss.

DESIGN

Case-control study.

SETTING

University hospital.

PATIENTS

113 consecutive women referred for evaluation of recurrent spontaneous abortion (case-patients) and 437 postmenopausal women with at least one successful pregnancy and no history of pregnancy loss (controls). An additional survey of 387 postmenopausal women with at least one pregnancy loss was also conducted.

MEASUREMENTS

Prevalence of factor V Leiden mutation determined by a second-generation screening test for resistance to activated protein C with genetic confirmation of all borderline and low-value results.

RESULTS

Prevalence of the factor V Leiden mutation was greater among case-patients (8.0%) than among controls (3.7%) (odds ratio, 2.3 [95% CI, 1.0 to 5.2]; P = 0.050). In the subgroup of case-patients with three or more pregnancy losses and no successful pregnancies, prevalence of the mutation was 9.0% (odds ratio, 2.6 [CI, 1.0 to 6.7]; P = 0.048). Among the additional women surveyed, the prevalence of the mutation in those with three or more pregnancy losses (7.5%) was almost identical to that in case-patients. Thus, in all evaluated women with several pregnancy losses, the prevalence of factor V Leiden was increased 2.2-fold (P = 0.026).

CONCLUSION

These data are compatible with the hypothesis that factor V Leiden mutation may play a role in some cases of unexplained recurrent pregnancy loss.

Aspirin use and colorectal cancer: post-trial follow-up data from the Physicians' Health Study

BACKGROUND

In contrast to most observational studies, the randomized Physicians' Health Study found no association between aspirin use and colorectal cancer after 5 years.

OBJECTIVE

To determine the effect of randomly assigned aspirin treatment and self-selected aspirin use on the incidence of colorectal cancer after 12 years and to identify factors influencing the self-selection of regular aspirin use.

DESIGN

Randomized clinical trial and prospective cohort study.

SETTING

Male physicians throughout the United States.

PATIENTS

22071 healthy male physicians who were 40 to 84 years of age in 1982.

INTERVENTION

325 mg of aspirin every other day. In 1988, the aspirin arm of the randomized trial was stopped early. Participants then chose to receive either aspirin or placebo for the rest of the study.

MEASUREMENTS

Annual questionnaires asking about aspirin use and other variables, including occurrence of cancer.

RESULTS

Colorectal cancer was diagnosed in 341 patients during the study period. Over 12 years of follow-up, random assignment to aspirin was associated with a relative risk for colorectal cancer of 1.03 (95% CI, 0.83 to 1.28). Various gastrointestinal symptoms and diagnoses were strong predictors of less frequent aspirin use in 1988. The relative risk for colorectal cancer in persons who used aspirin frequently after 1988 was 1.07 (CI, 0.75 to 1.53).

CONCLUSIONS

In the Physicians' Health Study, both randomized and observational analyses indicate that there is no association between the use of aspirin and the incidence of colorectal cancer. The low dose of aspirin used and the short treatment period may account for the null findings. However, other characteristics associated with the use of aspirin in observational studies remain a plausible alternative explanation.

Fasting triglycerides, high-density lipoprotein, and risk of myocardial infarction

BACKGROUND

Recent data suggest that triglyceride-rich lipoproteins may play a role in atherogenesis. However, whether triglycerides, as a marker for these lipoproteins, represent an independent risk factor for coronary heart disease remains unclear, despite extensive research. Several methodological issues have limited the interpretability of the existing data.

METHODS AND RESULTS

We examined the interrelationships of fasting triglycerides, other lipid parameters, and nonlipid risk factors with risk of myocardial infarction among 340 cases and an equal number of age-, sex-, and community-matched control subjects. Cases were men or women of <76 years of age with no prior history of coronary disease who were discharged from one of six Boston area hospitals with the diagnosis of a confirmed myocardial infarction. In crude analyses, we observed a significant association of elevated fasting triglycerides with risk of myocardial infarction (relative risk [RR] in the highest compared with the lowest quartile=6.8; 95% confidence interval [CI]=3.8 to 12.1; P for trend <.001). Results were not materially altered after control for nonlipid coronary risk factors. As expected, the relationship was attenuated after adjustment for HDL but remained statistically significant (RR in the highest quartile=2.7; 95% confidence interval [CI]=1.4 to 5.5; P for trend=.016). Furthermore, the ratio of triglycerides to HDL was a strong predictor of myocardial infarction (RR in the highest compared with the lowest quartile=16.0; 95% CI=7.7 to 33.1; P for trend <.001).

CONCLUSIONS

Our data indicate that fasting triglycerides, as a marker for triglyceride-rich lipoproteins, may provide valuable information about the atherogenic potential of the lipoprotein profile, particularly when considered in context of HDL levels.

Physical activity and risk of colon cancer: the Physicians' Health Study (United States)

Previous studies indicate that physical activity is related inversely to colon cancer risk. However, details regarding that association--whether a dose-response relation exists, whether the relation differs between non-obese and obese persons, the effect of long-term physical activity--are unclear. We examined these issues in the Physicians' Health Study (United States). Physical activity was assessed at baseline among 21,807 men, aged 40 to 84 years, and again 36 months later. Men were followed for an average of 10.9 years (from baseline) during which 217 developed colon cancer. After adjusting for potential confounders (including age, obesity, and alcohol intake), the relative risks for colon cancer associated with vigorous exercise in times per week (< 1, 1, 2-4, 5+, at baseline) were 1.0 (referent); 1.1 (95% confidence interval [CI] = 0.7-1.7); 1.2 (CI = 0.8-1.6); and 1.1 (CI = 0.7-1.6), respectively; P trend = 0.6. Physical activity was not associated significantly with colon cancer risk either among non-obese or obese men. When we used physical activity assessments at baseline as well as at 36 months, physical activity again was unrelated to colon cancer risk. These data do not support the hypothesis that physical activity reduces the risk of colon cancer. Plausible alternate explanations for the null finding include misclassification of physical activity and the potential for increased surveillance for colon cancer ('screening effect') among those physically active.

Ethnic distribution of factor V Leiden in 4047 men and women. Implications for venous thromboembolism screening

OBJECTIVE

To estimate ethnic-specific prevalence rates of factor V Leiden, an inherited defect of hemostasis associated with risk of venous thrombosis.

DESIGN

Survey of 4047 American men and women participating in the Physicians' Health Study (PHS) or in the Women's Health Study (WHS). All study participants were free of myocardial infarction, stroke, or venous thrombosis.

MAIN OUTCOME MEASURE

Prevalence of G1691A Leiden mutation in the gene coding for coagulation factor V was determined in the PHS group using polymerase chain reaction techniques and, in the WHS group, a second-generation activated protein C (APC)-resistance screening test with genetic confirmation of all borderline and low-value results.

RESULTS

In 2468 Caucasian Americans, carrier frequency of factor V Leiden was 5.27% (95% confidence interval [CI], 4.42%-6.22%). Carrier frequency was 2.21% in 407 Hispanic Americans, 1.23% in 650 African Americans, 0.45% in 442 Asian Americans, and 1.25% in 80 Native Americans. Thus, prevalence of factor V Leiden was less among minority subjects (P=.001). Carrier frequencies were similar in Caucasian men and women (5.53% vs 4.85% respectively, P=.5).

CONCLUSION

These data indicate that prevalence of factor V Leiden is greater among Caucasians than minority Americans. These data have implications for clinicians considering whether to screen for factor V Leiden in high-risk groups such as those with prior venous thromboses or coexistent defects of anticoagulation and women at risk for postpartum thrombosis or seeking oral contraceptives.

Moderate alcohol consumption and risk for angina pectoris or myocardial infarction in U.S. male physicians

BACKGROUND

Although previous studies have found that moderate alcohol intake decreases the risk for myocardial infarction, many clinicians question the validity of this finding. Furthermore, the relation of moderate drinking to the risk for other events, such as angina pectoris, is not known.

OBJECTIVE

To determine whether moderate alcohol intake decreases the risk for angina pectoris or myocardial infarction in apparently healthy men.

DESIGN

Prospective cohort study.

SETTING

United States.

PARTICIPANTS

22,071 apparently healthy male physicians who were 40 to 84 years of age between 1981 and 1984.

MEASUREMENTS

Responses to annual questionnaires.

RESULTS

Through 1994, 1368 cases of new-onset angina and 690 cases of myocardial infarction had been documented. In multivariate analyses that controlled for several potential confounders, alcohol intake was strongly and inversely associated with the risk for each event (P for trend < 0.001). Compared with men who consumed less than one drink per week, those who consumed one drink per day had relative risks of 0.69 (95% CI, 0.59 to 0.81) for angina and 0.65 (CI, 0.52 to 0.81) for myocardial infarction. These associations were seen when either nondrinkers or occasional drinkers were used as the reference group.

CONCLUSIONS

Moderate drinking decreases the risk for angina pectoris and myocardial infarction in apparently healthy men.