Relative Risks For Quintiles Research Articles

Premenopausal dietary fat in relation to pre- and post-menopausal breast cancer

We examined the association between fat intake and breast cancer incidence in the Nurses' Health Study II. We followed 88,804 women aged 26-45 years from 1991 to 2011 and documented incident breast cancers. Dietary fat, assessed by questionnaires in 1991, was examined in relation to total, premenopausal, and postmenopausal breast cancers. Multivariable-adjusted Cox proportional hazards models were used to estimate relative risk (RR) and 95 % confidence intervals (95 % CI). During 20 years of follow-up, 2,830 incident invasive breast cancer cases were diagnosed. Total fat intake was not associated with risk of breast cancer overall. After adjustment for demographic, anthropometric, lifestyle, and dietary factors, a positive association was observed between animal fat intake and breast cancer overall (RR for highest vs lowest quintile, 1.18; 95 % CI 1.04-1.33; P trend = 0.01). A positive association with animal fat intake was also seen among premenopausal women, but not among postmenopausal women. Higher intakes of saturated fat and monounsaturated fat were each associated with modestly higher breast cancer risk among all women, and higher cholesterol intake was associated with higher premenopausal breast cancer risk. However, the associations of saturated fat, monounsaturated fat and animal fat, were attenuated and non-significant after adjustment for red meat intake. Intakes of other types of fat including vegetable fat, dairy fat, polyunsaturated fat, and trans fat were not associated with breast cancer risk. Our finding suggests a positive association between early adult intake of animal fat and breast cancer risk.

Consumption of Dairy Products and Risk of Parkinson's Disease

The authors prospectively investigated the association between intake of dairy products and risk of Parkinson's disease among 57,689 men and 73,175 women from the American Cancer Society's Cancer Prevention Study II Nutrition Cohort. A total of 250 men and 138 women with Parkinson's disease were identified during follow-up (1992-2001). Dairy product consumption was positively associated with risk of Parkinson's disease: Compared with the lowest intake quintile, the corresponding relative risks for quintiles 2-5 were 1.4, 1.4, 1.4, and 1.6 (95 percent confidence interval (CI): 1.1, 2.2; p for trend = 0.05). A higher risk among dairy product consumers was found in both men and women, although the association in women appeared nonlinear. Meta-analysis of all prospective studies confirmed a moderately elevated risk of Parkinson's disease among persons with high dairy product consumption: For extreme intake categories, relative risks were 1.6 (95 percent CI: 1.3, 2.0) for both sexes, 1.8 for men (95 percent CI: 1.4, 2.4), and 1.3 for women (95 percent CI: 0.8, 2.1). These data suggest that dairy consumption may increase the risk of Parkinson's disease, particularly in men. More studies are needed to further examine these findings and to explore underlying mechanisms.

Folate, vitamin B12 and postmenopausal breast cancer in a prospective study of French women

Adequate folate intake may be important for breast cancer prevention. Its protective effect may be influenced by factors associated with folate metabolism. We sought to evaluate folate intake in relation to breast cancer risk and examine whether the relation is affected by alcohol and intake of vitamin B(2) and B(12). A prospective cohort analysis of folate intake was conducted among 62,739 postmenopausal women in the French E3N cohort who had completed a validated food frequency questionnaire in 1993. During nine years' follow-up, 1,812 cases of pathology-confirmed breast cancer were documented through follow-up questionnaires. Nutrients were categorized in quintiles and energy-adjusted using the regression-residual method. Cox model-derived relative risks (RRs) were adjusted for known breast cancer determinants. The multivariate RR for extreme quintiles of folate intake was 0.78 (95% CI: 0.67-0.90; p-trend = 0.001) [Median intake for Q(1) = 296 microg/day and Q(5) = 522 microg/day]. There was no evidence to support effect modification by alcohol or B(2) intake. The decreasing trend was most marked in women with higher folate and vitamin B(12 )intake. However, test for interaction was not statistically significant (p = 0.29). High folate intake was associated with decreased breast cancer risk. Vitamin B(12) intake may modify this association.

Coffee Consumption and Coronary Heart Disease in Men and Women

We examined the association between long-term habitual coffee consumption and risk of coronary heart disease (CHD). We performed a prospective cohort study with 44,005 men and 84,488 women without history of cardiovascular disease or cancer. Coffee consumption was first assessed in 1986 for men and in 1980 for women and then repeatedly every 2 to 4 years; the follow-up continued through 2000. We documented 2173 incident cases of coronary heart disease (1449 nonfatal myocardial infarctions and 724 fatal cases of CHD) among men and 2254 cases (1561 nonfatal myocardial infarctions and 693 fatal cases of CHD) among women. Among men, after adjustment for age, smoking, and other CHD risk factors, the relative risks (RRs) of CHD across categories of cumulative coffee consumption (<1 cup/mo, 1 cup/mo to 4 cups/wk, 5 to 7 cups/wk, 2 to 3 cups/d, 4 to 5 cups/d, and > or =6 cups/d) were 1.0, 1.04 (95% confidence interval 0.91 to 1.17), 1.02 (0.91 to 1.15), 0.97 (0.86 to 1.11), 1.07 (0.88 to 1.31), and 0.72 (0.49 to 1.07; P for trend=0.41); among women, the RRs were 1.0, 0.97 (0.83 to 1.14), 1.02 (0.90 to 1.17), 0.84 (0.74 to 0.97), 0.99 (0.83 to 1.17), and 0.87 (0.68 to 1.11; P for trend=0.08). Stratification by smoking status, alcohol consumption, history of type 2 diabetes mellitus, and body mass index gave similar results. Similarly, we found no effect when the most recent coffee consumption was examined. RRs for quintiles of caffeine intake varied from 0.97 (0.84 to 1.10) in the second quintile to 0.97 (0.84 to 1.11) in the highest quintile (P for trend=0.82) in men and from 1.02 (0.90 to 1.16) to 0.97 (0.85 to 1.11; P for trend=0.37) in women. These data do not provide any evidence that coffee consumption increases the risk of CHD.

Apolipoprotein(a) size and lipoprotein(a) concentration and future risk of angina pectoris with evidence of severe coronary atherosclerosis in men: The Physicians' Health Study.

The relationship of lipoprotein (a) [Lp(a)] concentrations with risk of coronary heart disease needs clarification, especially for threshold values for increased risk and for possible interactions with LDL-cholesterol concentrations and apolipoprotein (a) [apo(a)] size polymorphism. This study was designed to examine the ability of baseline Lp(a) concentration and apo(a) size to predict future severe angina pectoris in apparently healthy men. Baseline Lp(a) concentration and apo(a) size were determined in 195 men who subsequently developed angina and in 195 men who remained free of cardiovascular disease for 5 years. Cases had higher median Lp(a) concentrations than did controls (30.6 vs 22.5 nmol/L; P = 0.02). Lp(a) concentration was predictive of angina [relative risk (RR) from lowest to highest quintiles: 1.0, 1.5, 1.0, 1.8, and 2.6; P for trend = 0.015]. The increased risk was approximately 4-fold (95% confidence interval, 1.4- to 11-fold) among men who had Lp(a) above the 95th percentile (>158 nmol/L). Men with Lp(a) concentrations in the highest quintile and LDL-cholesterol concentrations >1600 mg/L had a 12-fold increased risk (95% confidence interval, 1.5- to 43-fold). Small apo(a) size isoforms also significantly predicted risk of angina (RR for lowest quintile = 4.1; P for trend = 0.004). When the independent effect of Lp(a) concentration and apo(a) size was assessed by including them in the same multivariate model, only the association between apo(a) size and risk remained significant. High Lp(a) predicts risk of angina, and the risk is substantially increased with high concomitant LDL-cholesterol. Small apo(a) size predicts angina with greater strength and independence than Lp(a) concentration.

A prospective study of tomato products, lycopene, and prostate cancer risk.

Some data, including our findings from the Health Professionals Follow-Up Study (HPFS) from 1986 through January 31, 1992, suggest that frequent intake of tomato products or lycopene, a carotenoid from tomatoes, is associated with reduced risk of prostate cancer. Overall, however, the data are inconclusive. We evaluated additional data from the HPFS to determine if the association would persist. We ascertained prostate cancer cases from 1986 through January 31, 1998, among 47 365 HPFS participants who completed dietary questionnaires in 1986, 1990, and 1994. We used pooled logistic regression to compute multivariate relative risks (RR) and 95% confidence intervals (CIs). All statistical tests were two-sided. From 1986 through January 31, 1998, 2481 men in the study developed prostate cancer. Results for the period from 1992 through 1998 confirmed our previous findings---that frequent tomato or lycopene intake was associated with a reduced risk of prostate cancer. Similarly, for the entire period of 1986 through 1998, using the cumulative average of the three dietary questionnaires, lycopene intake was associated with reduced risk of prostate cancer (RR for high versus low quintiles = 0.84; 95% CI = 0.73 to 0.96; P(trend) =.003); intake of tomato sauce, the primary source of bioavailable lycopene, was associated with an even greater reduction in prostate cancer risk (RR for 2+ servings/week versus <1 serving/month = 0.77; 95% CI = 0.66 to 0.90; P(trend)<.001), especially for extraprostatic cancers (RR = 0.65; 95% CI = 0.42 to 0.99). These associations persisted in analyses controlling for fruit and vegetable consumption and for olive oil use (a marker for Mediterranean diet) and were observed separately in men of Southern European or other Caucasian ancestry. Frequent consumption of tomato products is associated with a lower risk of prostate cancer. The magnitude of the association was moderate enough that it could be missed in a small study or one with substantial errors in measurement or based on a single dietary assessment.

Association of fractures with caffeine and alcohol in postmenopausal women: the Iowa Women's Health Study.

To assess whether alcoholic and caffeinated beverages are associated with risk of fractures in women. Population-based sample surveyed by post. A total of 34 703 postmenopausal Iowan women aged 55-69 years were surveyed. A cohort of women reported alcoholic and caffeinated beverage intake and were followed for 6.5 years for fracture occurrence. Relative risks (RR) and 95% confidence intervals (CI) were computed using Cox proportional hazards regression. Covariates included age, tobacco use, physical activity, body mass index (BMI), waist to hip ratio (WHR), oestrogen use and calcium intake. At least one fracture was reported by 4378 women (389 upper arm, 288 forearm, 1128 wrist, 275 hip, 416 vertebral and 2920 other fractures). The adjusted RR for highest versus lowest caffeine intake quintiles was 1.09 (95% CI 0.99-1.21) for combined fracture sites. Wrist fractures were associated positively (RR for extreme quintiles 1.37, 95% CI 1.11-1.69) and upper arm fractures were negatively associated (RR 0.67, 95% CI 0.48-0.94) with caffeine intake. The age-adjusted RR of total fractures for highest versus lowest frequency of beer usage was 1.55 (95% CI 1.25-1.92) and for liquor was 1.25 (95% CI 1.03-1.54). No other association was found between any specific fracture site and alcohol intake. We found a modest increase in fracture risk associated with highest caffeine intake, varying by site. Alcohol intake was low, but it also showed a weak positive association with fracture risk.

Air pollution and daily mortality in Philadelphia.

Many recent analyses have reported associations between air pollution and mortality in U.S. cities. In this paper, we present the results of regression analyses of daily mortality in Philadelphia during the period 1973-1988. Pollution variables included in the analyses were total suspended particulates (TSP), sulfur dioxide, and ozone. We controlled for the effects of weather on mortality by analyzing mortality separately for each season and explicityly including quintiles of temperature in the regression models. In regression models that consider weather and pollution variables simultaneously, daily mortality is associated with hot days in summer [relative risk (RR) for highest quintile of temperature = 1.07; 95% confidence interval (CI) = 1.04-1.10], and with cold days in spring (RR for lowest quintile of temperature = 1.07; 95% CI = 1.04-1.10), fall (RR for lowest quintile of temperature = 1.05; 95% CI = 1.02-1.08), and winter (RR for lowest quintile of temperature = 1.04; 95% CI = 1.01-1.07). When all three pollution covariates and weather are considered simultaneously in the regression model, ozone is associated with mortality in summer (RR = 1.15; 95% CI = 1.07-1.24) and sulfur dioxide is associated with mortality in spring (RR = 1.19; 95% CI = 1.06-1.33), fall (RR = 1.14; 95% CI = 1.00-1.29), and winter (RR = 1.21; 95% CI = 1.09-1.35), where the relative risks are for incremental changes of 100 parts per billion in ozone and sulfur dioxide on the previous day.(ABSTRACT TRUNCATED AT 250 WORDS)