Long- and short-term weight change and incident coronary heart disease and ischemic stroke: the Atherosclerosis Risk in Communities Study.

Weight gain increases the prevalence of obesity, a risk factor for cardiovascular disease. Nevertheless, unintentional weight loss can be a harbinger of health problems. The Atherosclerosis Risk in Communities Study (1987-2009) included 15,792 US adults aged 45-64 years at baseline and was used to compare associations of long-term (30 years) and short-term (3 years) weight change with the risks of coronary heart disease (CHD) and ischemic stroke. Age-, gender-, and race-standardized incidence rates were 4.9 (95% confidence interval (CI): 4.6, 5.2) per 1,000 person-years for CHD and 2.5 (95% CI: 2.3, 2.8) per 1,000 person-years for stroke. After controlling for baseline body mass index and other covariates, long-term weight gain (since age 25 years) of more than 2.7% was associated with elevated CHD risk, and any long-term weight gain was associated with increased stroke risk. Among middle-aged adults, short-term (3-year) weight loss of more than 3% was associated with elevated immediate CHD risk (hazard ratio = 1.46, 95% CI: 1.18, 1.81) and stroke risk (hazard ratio = 1.45, 95% CI: 1.10, 1.92). Risk tended to be larger in adults whose weight loss did not occur through dieting. Avoidance of weight gain between early and middle adulthood can reduce risks of CHD and stroke, but short-term, unintentional weight loss in middle adulthood may be an indicator of immediate elevated risk that has not previously been well recognized.

Sources of food affect dietary adequacy of Inuit women of childbearing age in Arctic Canada.

Dietary transition in the Arctic is associated with decreased quality of diet, which is of particular concern for women of childbearing age due to the potential impact of maternal nutrition status on the next generation. The study assessed dietary intake and adequacy among Inuit women of childbearing age living in three communities in Nunavut, Canada. A culturally-appropriate quantitative food-frequency questionnaire was administered to 106 Inuit women aged 19-44 years. Sources of key foods, energy and nutrient intakes were determined; dietary adequacy was determined by comparing nutrient intakes with recommendations. The prevalence of overweight/obesity was >70%, and many consumed inadequate dietary fibre, folate, calcium, potassium, magnesium, and vitamin A, D, E, and K. Non-nutrient-dense foods were primary sources of fat, carbohydrate and sugar intakes and contributed >30% of energy. Traditional foods accounted for 21% of energy and >50% of protein and iron intakes. Strategies to improve weight status and nutrient intake are needed among Inuit women in this important life stage.

Dietary fiber, magnesium, and glycemic load alter risk of type 2 diabetes in a multiethnic cohort in Hawaii.

The influence of dietary fiber, magnesium (Mg), and glycemic load (GL) on diabetes was examined in the Hawaii component of the Multiethnic Cohort. The 75,512 Caucasian, Japanese American, and Native Hawaiian participants aged 45-75 y at baseline completed a FFQ. After 14 y of follow-up, 8587 incident diabetes cases were identified through self-reports and health plans. We applied Cox regression stratified for age at cohort entry and adjusted for ethnicity, BMI, physical activity, education, and total energy with further stratifications by sex and ethnicity. When comparing extreme quintiles, total fiber intake was associated with reduced diabetes risk among all men [hazard ratio (HR): 0.75; 95% CI: 0.67, 0.84; P-trend < 0.001) and women (HR: 0.95; 95% CI: 0.85, 1.06; P-trend = 0.05). High intake of grain fiber reduced diabetes risk significantly by 10% in men and women. High vegetable fiber intake lowered risk by 22% in all men but not women. Mg intake reduced risk (HR = 0.77 and 0.84 for men and women, respectively) and, due to its strong correlation with fiber (r = 0.83; P < 0.001), may explain the protective effect of fiber. The top GL quintile was associated with a significantly elevated diabetes incidence in Caucasian men and in all women except Japanese Americans. Overall, several associations were more pronounced in Caucasians than in the other groups. These findings suggest that protection against diabetes can be achieved through food choices after taking into account body weight, but, due to differences in commonly consumed foods, risk estimates may differ by ethnic group.

Dietary vitamin D and risk of non-Hodgkin lymphoma: the multiethnic cohort.

The present study explored the association between dietary vitamin D and non-Hodgkin's lymphoma (NHL) risk. The multiethnic cohort (MEC) includes more than 215 000 Caucasians, African Americans, Native Hawaiians, Japanese Americans and Latinos, aged 45-75. After 10 years of follow-up, 939 incident NHL cases were identified. Risk was estimated using proportional hazards' models adjusted for possible confounders. Vitamin D intake was not associated with NHL risk in the entire cohort (P(trend) = 0.72 for men and P(trend) = 0.83 for women), but significantly lowered disease risk in African American women (hazard ratio (HR) = 0.50, 95 % CI: 0.28, 0.90, P(trend) = 0.03) and was borderline protective in African American men (HR = 0.68; 95 % CI: 0.39, 1.19; P(trend) = 0.31) when the highest to the lowest tertile was compared. In NHL subtype analyses, a 19, 36 and 32 % lowered risk, although not significant, was observed for diffuse large B-cell lymphoma, follicular lymphoma and small lymphocytic lymphoma/chronic lymphocytic leukemia in women, respectively. High dietary intake of vitamin D did not show a protective effect against NHL within the MEC except among African Americans, possibly because vitamin D production due to sun exposure is limited in this population.

Common immune-related risk factors and incident non-Hodgkin lymphoma: the multiethnic cohort.

Severe immune dysfunction is an established risk factor of lymphoma, but the role of moderate alterations of immunity is not clear and prospective investigations are needed. We examined several immune-related disorders and medications in relation to non-Hodgkin lymphoma (NHL) in the Multiethnic Cohort. Over 215,000 subjects of African American, Caucasian, Japanese American, Latino and Native Hawaiian ancestry aged 45-75 years completed a questionnaire, including information on medical history, in 1993-1996. After exclusions, we performed Cox regression among 193,050 cohort members including 939 incident NHL cases while adjusting for sex, age, ethnicity, education, body mass index and alcohol intake. Self-reported diabetes was not associated with NHL overall, but was positively associated with risk among Japanese Americans [hazard ratio (HR) = 1.55; 95% confidence interval (CI): 1.10-2.17]. Participants with a history of blood transfusion were at increased risk with HR = 1.39 (95% CI: 1.06-1.84) in men and HR = 1.22 (95% CI: 0.94-1.58) in women, especially for the diffuse large B-cell lymphoma subtype. History of asthma or other allergies was associated with elevated risk only among Latinos (HR = 1.46; 95% CI: 1.07-2.00) who also showed a significant relation between current use of antihistamines and NHL (HR = 1.80; 95% CI: 1.09-2.97). Use of nonsteroidal anti-inflammatory drugs was not associated with NHL. Our findings from this large prospective study support a moderate risk for NHL related to blood transfusions, current long-term antihistamine use and diabetes, but the associations were limited to certain ethnic groups and require further replications.

Mammographic density and epithelial histopathologic markers.

BACKGROUND: We explored the association of mammographic density, a breast cancer risk factor, with hormonal and proliferation markers in benign tissue from tumor blocks of pre-and postmenopausal breast cancer cases. METHODS: Breast cancer cases were recruited from a case-control study on breast density. Mammographic density was assessed on digitized prediagnostic mammograms using a computer-assisted method. For 279 participants of the original study, we obtained tumor blocks and prepared tissue microarrays (TMA), but benign tissue cores were only available for 159 women. The TMAs were immunostained for estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor (PR), HER2/neu, Ki-67, and Proliferating Cell Nuclear Antigen (PCNA). We applied general linear models to compute breast density according to marker expression. RESULTS: A substantial proportion of the samples were in the low or no staining categories. None of the results was statistically significant, but women with PR and ERbeta staining had 3.4% and 2.4% higher percent density. The respective values for Caucasians were 5.7% and 11.6% but less in Japanese women (3.5% and -1.1%). Percent density was 3.4% higher in women with any Ki-67 staining and 2.2% in those with positive PCNA staining. CONCLUSION: This study detected little evidence for an association between mammographic density and expression of steroid receptors and proliferation markers in breast tissue, but it illustrated the problems of locating tumor blocks and benign breast tissue samples for epidemiologic research. Given the suggestive findings, future studies examining estrogen effects in tissue, cell proliferation, and density in the breast may be informative.

Soy consumption and histopathologic markers in breast tissue using tissue microarrays.

This study examined the relation of soy intake with hormonal and proliferation markers in benign and malignant breast tissue using tissue microarrays (TMAs). TMAs with up to 4 malignant and 4 benign tissue samples for 268 breast cancer cases were constructed. Soy intake in early life and in adulthood was assessed by questionnaire. The TMAs were stained for estrogen receptor (ER) alpha, ERbeta, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), proliferating cell nuclear antigen (PCNA), and Ki-67 using standard immunohistochemical methods. Logistic regression was applied for statistical analysis. A higher percentage of women showed positive marker expression in malignant than in benign tissue. With one exception, HER2/neu, no significant associations between soy intake and pathologic markers were observed. Early life soy intake was associated with lower HER2/neu and PCNA staining of malignant tissue. In benign tissue, early life soy intake showed higher ER and PR expression, but no difference in proliferation markers. The results of this investigation provide some assurance that soy intake does not adversely affect markers of proliferation. TMAs were shown to be a useful tool for epidemiologic research.

Overweight and obesity at different times in life as risk factors for non-Hodgkin's lymphoma: the multiethnic cohort.

Obesity may increase the risk for non-Hodgkin's lymphoma (NHL) through an inflammatory pathway. We explored the relation of NHL with body size at different times in life within the Multiethnic Cohort that includes African Americans, Caucasians, Japanese, Latinos, and Native Hawaiians. Participants were 45 to 75 years old at recruitment in 1993 to 1996. This analysis included 87,079 men and 105,972 women with 461 male and 378 female NHL cases. We used Cox regression to model NHL risk with age as the time metric while adjusting for age at baseline, ethnicity, education, alcohol intake, and age at first live birth. Body weight and body mass index at age 21 were stronger predictors of NHL risk than anthropometric characteristics at baseline. For men, being in the highest quartile of body mass index and body weight at age 21 conferred a nonsignificant 86% and 41% higher NHL risk, respectively, whereas there was no association at baseline. For women, the risk associated with the highest quartile of weight at age 21 was 1.6 (P(trend) = 0.04), whereas women in the highest quartile at baseline had a nonsignificant risk of 27%. Height was positively related to NHL in men and women. Despite the small numbers, there was some consistency for risk estimates across ethnic groups and weak evidence for an association with NHL subtypes. These findings indicate that weight at age 21 may represent lifetime adiposity better than body weight at cohort entry. Alternatively, weight at age 21 may be more relevant for the etiology of NHL.

Body mass index at age 25 and all-cause mortality in whites and African Americans: the Atherosclerosis Risk in Communities study.

PURPOSE: Approximately 20% of young adults in the United States are obese, and most of them gain weight between young and middle adulthood. Few studies have examined the association between elevated body mass index (BMI) in early adulthood and mortality or have examined that such effects are independent of changes in weight. To our knowledge, no such study has been conducted in African-American samples. METHODS: We used data from 13,941 African-American and white adults who self-reported their weight at the age of 25, and had weight and height measured when they were 45-64 years of age (1987-1989). Date of death was ascertained between 1987 and 2005. Hazard ratios and hazard differences for the effects of BMI at age 25 on all-cause mortality were determined using Cox proportional hazard and additive hazard models, respectively. RESULTS: In the combined ethnic-gender groups, the hazard ratio associated with a 5 kg/m(2) increase in BMI at age 25 was 1.28 (95% confidence interval [CI]: 1.22-1.35), and the hazard difference was 2.75 (2.01-3.50) deaths/1,000 person-years. Associations were observed in all four ethnic-gender groups. Models including weight change from age 25 to age in 1987-1989 resulted in null estimates for BMI in African-American men, whereas associations were maintained or only mildly attenuated in other ethnic-gender groups. CONCLUSIONS: Excess weight during young adulthood should be avoided because it contributes to increases in death rates that may be independent of changes in weight experienced in later life. Further study is needed to better understand these associations in African-American men.

Physical activity and risk of type 2 diabetes among Native Hawaiians, Japanese Americans, and Caucasians: the Multiethnic Cohort.

BACKGROUND: Physical inactivity is an established risk factor for diabetes; however, little is known about this association across ethnic groups with different diabetes risk. Therefore, we evaluated the association between physical activity and diabetes and potential effect modification by ethnicity in the Hawaii component of the Multiethnic Cohort. METHODS: Participants, aged 45 to 75 years, were enrolled by completing a questionnaire on demographics, diet, and self-reported weekly hours of strenuous sports, vigorous work, and moderate activity. Among the 74,913 participants (39% Caucasian, 14% Native Hawaiian, 47% Japanese American), 8561 incident diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Cox regression was applied to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) while adjusting for known confounders. RESULTS: Engaging in strenuous sports was inversely related to diabetes risk with HRs (4+ hours/week vs. never) of 0.67 (95%CI: 0.57-0.79) in women and 0.80 (95%CI: 0.72-0.88) in men. In stratified analyses, the inverse association was consistent across ethnic groups. The inverse association of vigorous work with diabetes was limited to men, while beneficial effects of moderate activity were observed only in Caucasians. CONCLUSIONS: These findings support a role of high-intensity physical activity and ethnic-specific guidelines in diabetes prevention.