The frequency and influence of dementia risk factors in prodromal Alzheimer's disease

We investigated whether dementia risk factors were associated with prodromal Alzheimer's disease (AD) according to the International Working Group-2 and National Institute of Aging-Alzheimer's Association criteria, and with cognitive decline. A total of 1394 subjects with mild cognitive impairment from 14 different studies were classified according to these research criteria, based on cognitive performance and biomarkers. We compared the frequency of 10 risk factors between the subgroups, and used Coxregression to examine the effect of risk factors on cognitive decline. Depression, obesity, and hyper-cholesterolemia occurred more often in individuals with low-AD-likelihood, compared with those with a high-AD-likelihood. Only alcohol use increased the risk of cognitive decline, regardless of AD pathology. These results suggest that traditional risk factors for AD are not associated with prodromal AD or with progression to dementia, among subjects with mild cognitive impairment. Future studies should validate these findings and determine whether risk factors might be of influence at an earlier stage (i.e., preclinical) of AD. (C) 2017 Elsevier Inc. All rights reserved

Prospective study on physical activity and risk of in situ breast cancer

Abstract Background: Physical activity has been identified as protective factor for invasive breast cancer risk, whereas comparable studies on in situ carcinoma are rare. Methods: The study included data from 283,827 women of the multinational European Prospective Investigation into C7ancer and Nutrition (EPIC)-cohort study. Detailed information on different types of physical activity conducted during the prior year, such as occupational, recreational, and household activity, as well as on important cofactors, was assessed at baseline. Adjusted HRs for in situ breast cancer were estimated by Cox proportional hazards models. Results: During a median follow-up period of 11.7 years, 1,059 incidents of breast carcinoma in situ were identified. In crude and adjusted multivariable models, no associations were found for occupational, household, and recreational physical activity. Furthermore, total physical activity was not associated with risk of in situ breast cancer. Comparing moderately inactive, moderately active, and active participants with inactive study participants resulted in adjusted HRs of 0.99 [95% confidence interval (CI), 0.83–1.19], 0.99 (95% CI, 0.82–1.20), and 1.07 (95% CI, 0.81–1.40), respectively (P value of trend test: 0.788). No inverse associations were found in any substrata defined by age at diagnosis or body mass index (BMI) status. Conclusions: In this large prospective study, we did not find any evidence of an association between physical activity and in situ breast cancer risk. If not by chance, the contrast between our results for carcinoma in situ and the recognized inverse association for invasive breast cancer suggests that physical activity may have stronger effects on proliferation and late stage carcinogenesis. Cancer Epidemiol Biomarkers Prev; 21(12); 2209–19. ©2012 AACR.</jats:p

Physical activity and risk of breast cancer overall and by hormone receptor status: The European prospective investigation into cancer and nutrition

Physical activity is associated with reduced risks of invasive breast cancer. However, whether this holds true for breast cancer subtypes defined by the estrogen receptor (ER) and the progesterone receptor (PR) status is controversial. The study included 257,805 women from the multinational EPIC-cohort study with detailed information on occupational, recreational and household physical activity and important cofactors assessed at baseline. During 11.6 years of median follow-up, 8,034 incident invasive breast cancer cases were identified. Data on ER, PR and combined ER/PR expression were available for 6,007 (67.6%), 4,814 (54.2%) and 4,798 (53.9%) cases, respectively. Adjusted hazard ratios (HR) were estimated by proportional hazards models. Breast cancer risk was inversely associated with moderate and high levels of total physical activity (HR = 0.92, 95% confidence interval (CI): 0.86-0.99, HR = 0.87, 95%-CI: 0.79-0.97, respectively; p-trend = 0.002), compared to the lowest quartile. Among women diagnosed with breast cancer after age 50, the largest risk reduction was found with highest activity (HR = 0.86, 95%-CI: 0.77-0.97), whereas for cancers diagnosed before age 50 strongest associations were found for moderate total physical activity (HR = 0.78, 95%-CI: 0.64-0.94). Analyses by hormone receptor status suggested differential associations for total physical activity (p-heterogeneity = 0.04), with a somewhat stronger inverse relationship for ER+/PR+ breast tumors, primarily driven by PR+ tumors (p-heterogeneity < 0.01). Household physical activity was inversely associated with ER-/PR- tumors. The results of this largest prospective study on the protective effects of physical activity indicate that moderate and high physical activity are associated with modest decreased breast cancer risk. Heterogeneities by receptor status indicate hormone-related mechanisms