Biomedical subjects

M J Stampfer

Publications and source records attributed to M J Stampfer.

At least 145 records · Page 8Linked to original sources

PubMed1999

Prospective study of calcium, potassium, and magnesium intake and risk of stroke in women.

BACKGROUND AND PURPOSE: High intakes of calcium, potassium, and magnesium have been hypothesized to reduce risks of cardiovascular disease, but only a few prospective studies have examined intakes of these cations in relation to risk of stroke. METHODS: In 1980, 85 764 women in the Nurses' Health Study cohort, aged 34 to 59 years and free of diagnosed cardiovascular disease and cancer, completed dietary questionnaires from which we calculated intakes of calcium, potassium, and magnesium. By 1994, after 1.16 million person-years of follow-up, 690 incident strokes (129 subarachnoid hemorrhages, 74 intraparenchymal hemorrhages, 386 ischemic strokes, and 101 strokes of undetermined type) had been documented. RESULTS: Intakes of calcium, potassium, and magnesium were each inversely associated with age- and smoking-adjusted relative risks of ischemic stroke, excluding embolic infarction of nonatherogenic origin (n=347). Adjustment for other cardiovascular risk factors, including history of hypertension, attenuated these associations, particularly for magnesium intake. In a multivariate analysis, women in the highest quintile of calcium intake had an adjusted relative risk of ischemic stroke of 0.69 (95% CI, 0.50 to 0.95; P for trend=0.03) compared with those in the lowest quintile; for potassium intake the corresponding relative risk was 0.72 (95% CI, 0.51 to 1.01; P for trend=0.10). Further simultaneous adjustment for calcium and potassium intake suggested an independent association for calcium intake. The association of risk with calcium intake did not appear to be log linear; the increase in risk was limited to the lowest quintile of intake, and intakes > approximately 600 mg/d did not appear to reduce risk of stroke further. The inverse association with calcium intake was stronger for dairy than for nondairy calcium intake. Intakes of calcium, potassium, and magnesium were not related to risk of other stroke subtypes. CONCLUSIONS: Low calcium intake, and perhaps low potassium intake, may contribute to increased risk of ischemic stroke in middle-aged American women. It remains possible that women in the lowest quintile of calcium intake had unknown characteristics that made them susceptible to ischemic stroke.

Adult↗

PubMed1999

Intake of vitamins B6 and C and the risk of kidney stones in women.

Urinary oxalate is an important determinant of calcium oxalate kidney stone formation. High doses of vitamin B6 may decrease oxalate production, whereas vitamin C can be metabolized to oxalate. This study was conducted to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. The relation between the intake of vitamins B6 and C and the risk of symptomatic kidney stones were prospectively studied in a cohort of 85,557 women with no history of kidney stones. Semiquantitative food-frequency questionnaires were used to assess vitamin consumption from both foods and supplements. A total of 1078 incident cases of kidney stones was documented during the 14-yr follow-up period. A high intake of vitamin B6 was inversely associated with risk of stone formation. After adjusting for other dietary factors, the relative risk of incident stone formation for women in the highest category of B6 intake (> or =40 mg/d) compared with the lowest category (<3 mg/d) was 0.66 (95% confidence interval, 0.44 to 0.98). In contrast, vitamin C intake was not associated with risk. The multivariate relative risk for women in the highest category of vitamin C intake (> or =1500 mg/d) compared with the lowest category (<250 mg/d) was 1.06 (95% confidence interval, 0.69 to 1.64). Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted.

Adult↗

PubMed1999

Smoking and risk of total and fatal prostate cancer in United States health professionals.

Studies that have examined the relationship between cigarette use and prostate cancer incidence have yielded inconsistent results, although most studies have suggested that smoking is related to the occurrence of fatal prostate cancer. We evaluated prospectively the relationship between cigarette smoking and total, distant metastatic, and fatal prostate cancer in 47,781 male health professionals throughout the United States followed with questionnaires. From 1986 to 1994, we documented 1369 men with prostate cancer (excluding stage A1). One hundred fifty-two of the men had distant metastatic disease at diagnosis, and 103 fatal cases occurred from 1986 to 1994. Early (before age 30), late (within recent 10 years), and lifetime cumulative smoking history were unrelated to risk of total prostate cancer. However, men who had smoked 15 or more pack-years of cigarettes within the preceding 10 years were at higher risk of distant metastatic prostate cancer [multivariate relative risk (RR), 1.81; 95% confidence interval (CI), 1.05-3.11; P (trend), 0.03] and fatal prostate cancer [RR, 2.06; CI, 1.08-3.90; P (trend), 0.02] relative to nonsmokers. Within 10 years after quitting, the excess risk among smokers is eliminated. The higher rate of fatal prostate cancer among smokers did not appear to result from confounding by diet or other lifestyle factors, different screening behavior between smokers and nonsmokers, or from other smoking-related comorbidities. Our results indicate that although smoking was unrelated to prostate cancer incidence, recent tobacco use had a substantial impact on the occurrence of fatal prostate cancer.

Adult↗

PubMed1999

Prospective study of alcohol consumption patterns in relation to symptomatic gallstone disease in men.

Although the association between alcohol intake and gallstone disease has been characterized previously, the relation between alcohol consumption patterns, specific types of alcoholic beverages, and risk for cholelithiasis has not been addressed systematically. These issues were examined prospectively in a cohort of men who were free from symptomatic gallstone disease in 1986 and were followed to 1996. During follow-up, 2.4% of the men reported newly symptomatic gallstones that were diagnosed by ultrasonography or x-ray, or a cholecystectomy. After adjusting for other known or suspected risk factors, an increase in the amount of alcohol consumed was associated with a decreased risk of symptomatic gallstone disease. An increase in frequency of alcohol consumption also was related to decreased risk. Combining the reports of quantity and frequency of alcohol intake, a consumption pattern that reflected frequent intake (5-7 days/week) of any given amount of alcohol was associated with a decreased risk, as compared with nondrinkers. In contrast, infrequent alcohol intake (1-2 days/week) showed no significant association with risk. All alcoholic beverage types were inversely associated with risk of symptomatic gallstone disease, independent of patterns of consumption. These results suggest that frequent, moderate intake of alcohol decreases the risk for symptomatic gallstone disease, in contrast to infrequent or episodic alcohol intake. Recommendations regarding the benefit of moderate quantities of alcohol for gallstone discase should be weighed against the potential health hazards of alcohol consumption.

Adult↗

PubMed1999

Incidence rates and risk factors for acute urinary retention: the health professionals followup study.

PURPOSE: We define incidence rates and risk factors for acute urinary retention. MATERIALS AND METHODS: In 1992, 41,276 United States male health professionals 45 to 83 years old self-reported baseline health data and American Urological Association symptom index scores. In 1995 a subset reported the year of any episode of acute urinary retention requiring catheterization. Of 8,418 respondents 6,100 without a history of prostate cancer, prostatectomy or acute urinary retention before 1992 provided data. Incidence rates from 1992 to 1995 were calculated and risk factors were assessed using logistic regression. RESULTS: During 15,851 person-years of followup 82 men reported an episode of acute urinary retention (sampling weighted incidence 4.5/1,000 person-years, 95% confidence intervals 3.1 to 6.2). Rates increased with age and baseline symptom severity. In men with symptom score 0 to 7 (none or mild lower urinary tract symptoms) the incidence of acute urinary retention increased from 0.4/1,000 person-years for those 45 to 49 years old to 7.9/1,000 person-years for those 70 to 83 years old. In men with symptom score 8 to 35 (moderate or severe lower urinary tract symptoms) rates increased from 3.3/1,000 person-years for those 45 to 49 years old to 11.3/1,000 person-years for those 70 to 83 years old. Men with a clinical diagnosis of benign prostatic hyperplasia and a symptom score 8 or greater had the highest rates (age adjusted incidence 13.7/1,000 person-years). All 7 lower urinary tract symptoms comprising the American Urological Association symptom index individually predicted acute urinary retention (age adjusted odds ratio 1.8 to 2.9 for symptoms occurring more than 25% of the time during the last month). The sensation of incomplete bladder emptying, having to void again after less than 2 hours and a weak urinary stream were the best independent symptom predictors. Use of medications with adrenergic or anticholinergic side effects also predicted acute urinary retention. CONCLUSIONS: Acute urinary retention occurred relatively infrequently but older age, moderate or severe lower urinary tract symptoms, a diagnosis of benign prostatic hyperplasia and specific drug therapies significantly increased the risk of occurrence.

Acute Disease↗

PubMed1999

Postmenopausal hormone therapy and risk of cardiovascular disease and hip fracture in a cohort of Swedish women.

Postmenopausal estrogen use is associated with a reduced risk of heart disease and hip fracture; in observational studies, different behaviors among hormone users and nonusers may partially explain these results. We examined risk of cardiovascular disease and hip fracture with medium-potency compared with low-potency or short-term estrogen use, and the effect of added progestin, among 9,236 women in Uppsala, Sweden, who responded to a mailed questionnaire in 1987-1988. Using population registries, we identified 213 cases of myocardial infarction, 289 strokes, and 114 hip fractures from 1987-1995. We found a reduced risk of myocardial infarction for medium-potency compared with low-potency or short-term estrogen use (relative risk = 0.75, 95% confidence interval (CI) = 0.56-0.99), with a similar decrease in the subgroup that took estrogens with progestin (RR = 0.69, 95% CI = 0.45-0.90). There was no relation of medium-potency estrogen to stroke (RR = 0.91, 95% CI = 0.71-1.17, and RR = 0.81, 95% CI = 0.61-1.10 for the subgroup taking progestin), and no effect of duration on either heart disease or stroke. We observed a reduction in hip fractures for medium-potency use (RR = 0.65, 95% CI = 0.45-0.95), and for use of combined estrogen-progestin therapy (RR = 0.64, 95% CI = 0.41-1.00). These data support a decreased risk of heart disease and hip fracture for medium-potency estrogen use alone or with progestin; self-selection to hormone use cannot explain these reductions.

Cardiovascular Diseases↗

PubMed1999

A polymorphism of the methionine synthase gene: association with plasma folate, vitamin B12, homocyst(e)ine, and colorectal cancer risk.

We previously reported (J. Chen et al., Cancer Res., 56: 4862-4864, 1996; J. Ma et al., Cancer Res., 57: 1098-1102, 1997) that a 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism (677C-->T, ala-->val) was associated with lower risk of colorectal cancer. In this study, we examined the relationship of a polymorphism (2756A-->G, asp-->gly) in the gene (MTR) for methionine synthase, another important enzyme in the same folate/methionine/homocyst(e)ine metabolic pathway, with risk of colorectal cancer among 356 cases and 476 cancer-free controls. The frequency of the homozygous variant genotype (gly/gly) was slightly lower among cases (3%) than controls (5%). The odds ratio for the gly/gly genotype was 0.59 [95% confidence interval (CI), 0.27-1.27] compared with those with the homozygous wild type (asp/asp). There were no significant differences in plasma levels of folate, vitamin B12, and homocyst(e)ine (tHcy) among the MTR genotypes, in contrast to the MTHFR polymorphism. However, similar to the interaction observed for the MTHFR polymorphism among men who consumed less than 1 alcoholic drink/day, those with the gly/gly genotype had a lower risk of colorectal cancer with an odds ratio of 0.27 (95% CI, 0.09-0.81) compared with those with the asp/asp genotype. The possible association of the MTR polymorphism with lower risk of colorectal cancer especially among those with low alcohol consumption, in the same direction as for the MTHFR polymorphism, is intriguing. However, our study had limited statistical power because of the low frequency of the MTR variant genotype, which is reflected in the wide CIs. Hence, these findings need to be confirmed in larger populations.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed1999

A prospective study of vitamin supplement intake and cataract extraction among U.S. women.

We prospectively examined the association between vitamin supplement intake and the incidence of cataract extraction during 12 years of follow-up in a cohort of 47,152 female nurses. Women were 45 years or older and free of diagnosed cancer in 1980; others were added as they reached 45 years of age, for a total of 73,956 women. During 720,082 years of follow-up, 1,377 senile cataracts were diagnosed and extracted. Those who used multivitamins or separate supplements of vitamin C, E, or A did not have decreased risks of cataract as compared with nonusers even for use of 10 or more years. After adjusting for cataract risk factors, including cigarette smoking, body mass index, and diabetes mellitus, users of vitamin C supplements for 10 or more years had a relative risk (RR) of 0.95 [95% confidence interval (CI) = 0.76-1.20]. Associations were stronger among long-term vitamin C supplement users who were never-smokers (RR = 0.71; 95% CI = 0.47-1.08) and less than 60 years of age (RR = 0.72; 95% CI = 0.49-1.04). These findings suggest that there is little overall benefit of long-term use of vitamin supplements for risk of cataracts requiring extraction.

Adult↗

PubMed1999

Supplemental vitamin E intake and prostate cancer risk in a large cohort of men in the United States.

A clinical trial of vitamin E and beta-carotene supplementation for lung cancer prevention among male smokers in Finland recently reported an unexpected, strong protective effect of vitamin E against prostate cancer incidence and mortality. Our objective was to prospectively examine supplemental vitamin E intake and prostate cancer risk in a distinct U.S. population. In 1986, we identified 47,780 U.S. male health professionals, free from diagnosed cancer, who completed a dietary and lifestyle questionnaire; supplemental vitamin E and prostate cancer incidence were updated biennially through 1996. We estimated relative risks (RRs) from multivariate pooled logistic regression models. There were 1896 total (non-stage A1), 522 extraprostatic, and 232 metastatic or fatal incident prostate cancer cases diagnosed between 1986-1996. Men consuming at least 100 IU of supplemental vitamin E daily had multivariate RRs of 1.07 (95% confidence interval [CI], 0.95-1.20) for total and 1.14 (95% CI, 0.82-1.59) for metastatic or fatal prostate cancer compared with those consuming none. Current use, dosage, and total duration of use of specific vitamin E supplements or multivitamins were not associated with risk. However, among current smokers and recent quitters, those who consumed at least 100 IU of supplemental vitamin E per day had a RR of 0.44 (95% CI, 0.18-1.07) for metastatic or fatal prostate cancer compared with nonusers. Thus, supplemental vitamin E was not associated with prostate cancer risk generally, but a suggestive inverse association between supplemental vitamin E and risk of metastatic or fatal prostate cancer among current smokers and recent quitters was consistent with the Finnish trial among smokers and warrants further investigation.

Adult↗

PubMed1999

Alcohol consumption in relation to breast cancer risk in a cohort of United States women 25-42 years of age.

We evaluated current and past alcohol consumption prospectively in relation to breast cancer risk among 116,671 women ages 25-42 years old at enrollment in 1989. During 6 years of follow-up, 445 cases of invasive breast cancer were identified. For alcohol consumption in the previous year, the multivariate relative risk associated with more than 20 g/day (approximately 10 drinks/week) was 1.23 (95% confidence interval, 0.68-2.21); the P for trend was 0.85. For average lifetime alcohol consumption, the multivariate relative risk associated with consumption of 10 or more drinks/week was 1.20 (95% confidence interval, 0.69-2.11); the P for trend was 0.18. We examined drinking in several time periods of life; only drinking at ages 23-30 was significantly positively associated with risk. Although this may represent a chance finding, it merits further study. Because drinking levels in this population were low, we had limited information on heavier drinking. Our results suggest that there is unlikely to be a large effect of moderate alcohol consumption on breast cancer risk among young women, although a modest effect cannot be excluded. The association between alcohol consumption and breast cancer is unlikely to be substantially stronger among premenopausal women than among postmenopausal women.

Adolescent↗

PubMed1999

Epidemiology of interstitial cystitis: a population based study.

PURPOSE: Interstitial cystitis is a chronic and debilitating syndrome but surprisingly little is known about its epidemiology. This study was designed to estimate the prevalence of interstitial cystitis among women in the United States. MATERIALS AND METHODS: Female participants in the Nurses' Health Study (NHS) I and II (184,583) were asked by mailed questionnaires whether they had ever been diagnosed with interstitial cystitis. We requested and reviewed medical records of women self-reporting interstitial cystitis. The accuracy of self-reports was evaluated using standardized criteria. RESULTS: Among the 93,428 women who responded to the NHS II questionnaire and 91,155 women who responded to the NHS I questionnaire 1,354 (1.4%) and 357 (0.4%), respectively, self-reported interstitial cystitis. Based on medical record review 63 cases of interstitial cystitis were confirmed in NHS II and 47 in NHS I. The prevalence of interstitial cystitis was 67/100,000 women in NHS II and 52/100,000 in NHS I. There was no substantial variation in prevalence by age. CONCLUSIONS: The prevalence of interstitial cystitis in the United States is more than 50% greater than previously reported and 3-fold greater than that reported in Europe.

Adult↗

PubMed1998

Abdominal adiposity and coronary heart disease in women.

CONTEXT: Obesity is a well-established risk factor for coronary heart disease (CHD), but whether regional fat distribution contributes independently to risk remains unclear. OBJECTIVE: To compare waist-hip ratio (WHR) and waist circumference in determining risk of CHD in women. DESIGN AND SETTING: Prospective cohort study among US female registered nurses participating in the Nurses' Health Study conducted between 1986, when the nurses completed a questionnaire, and follow-up in June 1994. PARTICIPANTS: A total of 44702 women aged 40 to 65 years who provided waist and hip circumferences and were free of prior CHD, stroke, or cancer in 1986. MAIN OUTCOME MEASURES: Incidence of CHD (nonfatal myocardial infarction or CHD death). RESULTS: During 8 years of follow-up 320 CHD events (251 myocardial infarctions and 69 CHD deaths) were documented. Higher WHR and greater waist circumference were independently associated with a significantly increased age-adjusted risk of CHD. After adjusting for body mass index (BMI) (defined as weight in kilograms divided by the square of height in meters) and other cardiac risk factors, women with a WHR of 0.88 or higher had a relative risk (RR) of 3.25 (95% confidence interval [CI], 1.78-5.95) for CHD compared with women with a WHR of less than 0.72. A waist circumference of 96.5 cm (38 in) or more was associated with an RR of 3.06 (95% CI, 1.54-6.10). The WHR and waist circumference were independently strongly associated with increased risk of CHD also among women with a BMI of 25 kg/m2 or less. After adjustment for reported hypertension, diabetes, and high cholesterol level, a WHR of 0.76 or higher or waist circumference of 76.2 cm (30 in) or more was associated with more than a 2-fold higher risk of CHD. CONCLUSIONS: The WHR and waist circumference are independently associated with risk of CHD in women.

Abdomen↗

PubMed1998

Physical activity and benign prostatic hyperplasia.

BACKGROUND: Benign prostatic hyperplasia (BPH) leading to prostatic enlargement and lower urinary tract symptoms is highly prevalent among older men. Sympathetic nervous system activity, which is decreased by physical activity, is associated with increased prostatic smooth-muscle tone and prostatic symptoms. Therefore, we assessed whether physical activity leads to fewer lower urinary tract symptoms in the Health Professionals Follow-up Study. METHODS: We observed men who were aged 40 to 75 years at baseline in 1986 for subsequent incidence of surgery for BPH. The men were free of diagnosed cancer, including prostate cancer at baseline and during follow-up, had not had a radical prostatectomy, and provided data on physical activity. Cases were men who under-went BPH surgery between 1986 and 1994 (n = 1890) or, among those who did not have surgery, who scored 15 or more points of 35 (n = 1853) on 7 questions about lower urinary tract symptoms modified from the American Urological Association Symptom Index. Noncases were men who scored 7 points or less (n = 21745). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from multiple logistic regression models. RESULTS: After controlling for age, race or ethnicity, alcohol consumption, and smoking, physical activity was inversely related with total BPH (extreme quintiles: OR, 0.75; 95% CI, 0.67-0.85; P for trend, <.001), surgery for BPH (OR, 0.76; 95% CI, 0.64-0.90; P for trend, <.001), and symptomatic BPH (OR, 0.75; 95% CI, 0.64-0.87; P for trend, <.001). Walking, the most prevalent activity, was inversely related to BPH risk; men who walked 2 to 3 h/wk had a 25% lower risk of total BPH. CONCLUSION: Our results indicate that more physically active men have a lower frequency of lower urinary tract symptoms.

Adult↗

PubMed1998

A prospective study of physical activity and prostate cancer in male health professionals.

Because the role of exercise in prostate cancer is unclear, we examined the relationship between leisure time physical activity and risk of prostate cancer in the Health Professionals Follow-up Study, a prospective cohort study of male health professionals in the United States. In 1986, 47,542 men 40-75 years of age and free of cancer responded to a mailed questionnaire that included an assessment of physical activity. The reported average time per week spent on each of a variety of nonoccupational activities was multiplied by its typical energy expenditure requirements expressed in metabolic equivalents (METs) and summed to yield a total weekly MET-hour score. We also examined MET-hours from all vigorous activities, defined as those requiring energy expenditures of six or more METs, and nonvigorous activities. From 1986 until January 31, 1994, we identified 1362 incident cases of total prostate cancer (excluding stage A1), 419 advanced (extraprostatic) cases, and 200 metastatic cases. No relationship with total or advanced prostate cancer was evident for total, vigorous, and nonvigorous physical activity. For metastatic prostate cancer, we also found no linear trends for these activities, but did observe a significantly lower risk in the highest category of vigorous activity (multivariate relative risk = 0.46; 95% confidence interval = 0.24-0.89 for > 25 versus 0 MET-hours), controlling for age, vasectomy, history of diabetes, height, smoking, and dietary factors. This highest category included 15% of the population and reflects at least 3 h/week of participation in vigorous activities. Differences in disease surveillance according to activity level could not account for our findings. The results from this cohort indicate that physical activity is unlikely to influence the incidence of total prostate cancer appreciably; however, the suggestion of a lower risk of metastatic prostate cancer in men engaging in high levels of vigorous activities warrants further study.

Adult↗

PubMed1998

Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study.

OBJECTIVE: To examine the relation between nut consumption and risk of coronary heart disease in a cohort of women from the Nurses' Health Study. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study. SUBJECTS: 86 016 women from 34 to 59 years of age without previously diagnosed coronary heart disease, stroke, or cancer at baseline in 1980. MAIN OUTCOME MEASURES: Major coronary heart disease including non-fatal myocardial infarction and fatal coronary heart disease. RESULTS: 1255 major coronary disease events (861 cases of non-fatal myocardial infarction and 394 cases of fatal coronary heart disease) occurred during 14 years of follow up. After adjusting for age, smoking, and other known risk factors for coronary heart disease, women who ate more than five units of nuts (one unit equivalent to 1 oz of nuts) a week (frequent consumption) had a significantly lower risk of total coronary heart disease (relative risk 0.65, 95% confidence interval 0.47 to 0.89, P for trend=0.0009) than women who never ate nuts or who ate less than one unit a month (rare consumption). The magnitude of risk reduction was similar for both fatal coronary heart disease (0.61, 0.35 to 1.05, P for trend=0.007) and non-fatal myocardial infarction (0.68, 0.47 to 1.00, P for trend=0.04). Further adjustment for intakes of dietary fats, fibre, vegetables, and fruits did not alter these results. The inverse association persisted in subgroups stratified by levels of smoking,use of alcohol, use of multivitamin and vitamin E supplements, body mass index, exercise, and intake of vegetables or fruits. CONCLUSIONS: Frequent nut consumption was associated with a reduced risk of both fatal coronary heart disease and non-fatal myocardial infarction. These data, and those from other epidemiological and clinical studies, support a role for nuts in reducing the risk of coronary heart disease.

Adult↗

PubMed1998

Calcium channel blockers, cancer incidence, and cancer mortality in a cohort of U.S. women: the nurses' health study.

BACKGROUND: Some studies have suggested that the use of calcium channel blockers may increase the risk of cancer. A possible association of the use of calcium channel blockers with cancer incidence and cancer mortality was addressed using data from the Nurses' Health Study. METHODS: In this study, a total of 18,635 female nurses reported regularly taking at least 1 of 4 cardiovascular medications in 1988: diuretics, beta-blockers, calcium channel blockers, and/or angiotensin-converting enzyme (ACE) inhibitors. Cancer incidence and cancer deaths were ascertained until 1994. RESULTS: During 6 years of follow-up, 852 women were newly diagnosed with cancer and 335 women died of cancer. Women who reported the use of calcium channel blockers had no increased risk of newly diagnosed cancer compared with those taking other cardiovascular drugs (relative risk=1.02; 95% CI 0.83-1.26). The relative risk of dying from cancer associated with the self-reported use of calcium channel blockers was 1.25 (95% CI 0.91-1.72). Relative risks were adjusted for the following self-reported factors: age; weight; height; cholesterol level; systolic and diastolic blood pressure; smoking; alcohol intake; physical activity; menopausal status; postmenopausal hormone use; aspirin use; and history of diabetes, cancer, stroke, myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty, angina, and hypertension. Regarding site specific cancer incidence and mortality, only lung cancer incidence was somewhat increased (RR=1.61; 95% CI 0.88-2.96). CONCLUSIONS: These data suggest no important increase in overall cancer incidence or cancer mortality related to the self-reported use of calcium channel blockers.

Adrenergic beta-Antagonists↗

PubMed1998

Multivitamin use, folate, and colon cancer in women in the Nurses' Health Study.

BACKGROUND: High intake of folate may reduce risk for colon cancer, but the dosage and duration relations and the impact of dietary compared with supplementary sources are not well understood. OBJECTIVE: To evaluate the relation between folate intake and incidence of colon cancer. DESIGN: Prospective cohort study. SETTING: 88,756 women from the Nurses' Health Study who were free of cancer in 1980 and provided updated assessments of diet, including multivitamin supplement use, from 1980 to 1994. PATIENTS: 442 women with new cases of colon cancer. MEASUREMENTS: Multivariate relative risk (RR) and 95% CIs for colon cancer in relation to energy-adjusted folate intake. RESULTS: Higher energy-adjusted folate intake in 1980 was related to a lower risk for colon cancer (RR, 0.69 [95% CI, 0.52 to 0.93] for intake > 400 microg/d compared with intake < or = 200 microg/d) after controlling for age; family history of colorectal cancer; aspirin use; smoking; body mass; physical activity; and intakes of red meat, alcohol, methionine, and fiber. When intake of vitamins A, C, D, and E and intake of calcium were also controlled for, results were similar. Women who used multivitamins containing folic acid had no benefit with respect to colon cancer after 4 years of use (RR, 1.02) and had only nonsignificant risk reductions after 5 to 9 (RR, 0.83) or 10 to 14 years of use (RR, 0.80). After 15 years of use, however, risk was markedly lower (RR, 0.25 [CI, 0.13 to 0.51]), representing 15 instead of 68 new cases of colon cancer per 10,000 women 55 to 69 years of age. Folate from dietary sources alone was related to a modest reduction in risk for colon cancer, and the benefit of long-term multivitamin use was present across all levels of dietary intakes. CONCLUSIONS: Long-term use of multivitamins may substantially reduce risk for colon cancer. This effect may be related to the folic acid contained in multivitamins.

Adult↗

PubMed1998

Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men.

BACKGROUND: Animal experiments and epidemiological studies have suggested that high potassium intake may reduce the risk of stroke, but the evidence is inconclusive, and the role of other nutrients in potassium-rich foods remains unknown. METHODS AND RESULTS: We examined the association of potassium and related nutrients with risk of stroke among 43 738 US men, 40 to 75 years old, without diagnosed cardiovascular diseases or diabetes, who completed a semiquantitative food frequency questionnaire in 1986. During 8 years of follow-up, 328 strokes (210 ischemic, 70 hemorrhagic, 48 unspecified) were documented. The multivariate relative risk of stroke of any type for men in the top fifth of potassium intake (median intake, 4.3 g/d) versus those in the bottom (median, 2.4 g/d) was 0.62 (95% CI, 0.43, 0.88; P for trend=0.007). Results for ischemic stroke alone were similar. Intakes of cereal fiber and magnesium, but not of calcium, were also inversely associated with risk of total stroke. These inverse associations were all stronger in hypertensive than normotensive men and were not materially altered by adjustment for blood pressure levels. Use of potassium supplements was also inversely related to risk of stroke, particularly among men taking diuretics (relative risk, 0.36; 95% CI, 0.18, 0.72). CONCLUSIONS: Although these data do not prove a causal relationship, they are consistent with the hypothesis that diets rich in potassium, magnesium, and cereal fiber reduce the risk of stroke, particularly among hypertensive men. Potassium supplements may also be beneficial, but because of potential risks, use should be carefully monitored and restricted to men taking potassium-losing diuretics.

Adult↗