@article {7554, title = {Trends in the incidence of dementia: design and methods in the Alzheimer Cohorts Consortium.}, journal = {Eur J Epidemiol}, volume = {32}, year = {2017}, month = {2017 Oct}, pages = {931-938}, abstract = {

Several studies have reported a decline in incidence of dementia which may have large implications for the projected burden of disease, and provide important guidance to preventive efforts. However, reports are conflicting or inconclusive with regard to the impact of gender and education with underlying causes of a presumed declining trend remaining largely unidentified. The Alzheimer Cohorts Consortium aggregates data from nine international population-based cohorts to determine changes in the incidence of dementia since 1990. We will employ Poisson regression models to calculate incidence rates in each cohort and Cox proportional hazard regression to compare 5-year cumulative hazards across study-specific epochs. Finally, we will meta-analyse changes per decade across cohorts, and repeat all analysis stratified by sex, education and APOE genotype. In all cohorts combined, there are data on almost 69,000 people at risk of dementia with the range of follow-up years between 2 and 27. The average age at baseline is similar across cohorts ranging between 72 and 77. Uniting a wide range of disease-specific and methodological expertise in research teams, the first analyses within the Alzheimer Cohorts Consortium are underway to tackle outstanding challenges in the assessment of time-trends in dementia occurrence.

}, issn = {1573-7284}, doi = {10.1007/s10654-017-0320-5}, author = {Chibnik, Lori B and Wolters, Frank J and B{\"a}ckman, Kristoffer and Beiser, Alexa and Berr, Claudine and Bis, Joshua C and Boerwinkle, Eric and Bos, Daniel and Brayne, Carol and Dartigues, Jean-Fran{\c c}ois and Darweesh, Sirwan K L and Debette, Stephanie and Davis-Plourde, Kendra L and Dufouil, Carole and Fornage, Myriam and Grasset, Leslie and Gudnason, Vilmundur and Hadjichrysanthou, Christoforos and Helmer, Catherine and Ikram, M Arfan and Ikram, M Kamran and Kern, Silke and Kuller, Lewis H and Launer, Lenore and Lopez, Oscar L and Matthews, Fiona and Meirelles, Osorio and Mosley, Thomas and Ower, Alison and Psaty, Bruce M and Satizabal, Claudia L and Seshadri, Sudha and Skoog, Ingmar and Stephan, Blossom C M and Tzourio, Christophe and Waziry, Reem and Wong, Mei Mei and Zettergren, Anna and Hofman, Albert} } @article {8793, title = {Body mass index in early adulthood and dementia in late life: Findings from a pooled cohort.}, journal = {Alzheimers Dement}, year = {2021}, month = {2021 May 13}, abstract = {

INTRODUCTION: To examine the independent association of body mass index (BMI) in early adulthood with dementia incidence among men and women.

METHODS: We studied 5104 older adults from the Cardiovascular Health Study (CHS) and the Health, Aging, and Body Composition (Health ABC) study. We imputed early adulthood and midlife BMI using a pooled parent cohort with complete adult lifespan coverage and previously established methods. Dementia was ascertained using criteria such as neuropsychological test battery, medical records, and dementia-related drug use. Pooled logistic regression (PLR) models were used.

RESULTS: Compared to women with normal BMI in early adulthood, the odds of dementia were higher among both overweight (odds ratio [OR]~=~1.8; 95\% confidence interval [CI]~=~1.31 to 2.54) and obese (OR~=~2.45; 95\% CI~=~1.47 to 4.06) women, independent of mid- and late-life BMI. Similar relationship was observed in men.

CONCLUSIONS: With the growing obesity epidemic among US adults, efforts aimed at reducing dementia may need to begin obesity prevention and treatment early in the life course.

}, issn = {1552-5279}, doi = {10.1002/alz.12367}, author = {Zeki Al Hazzouri, Adina and Vittinghoff, Eric and Hoang, Tina and Golden, Sherita H and Fitzpatrick, Annette L and Zhang, Adina and Grasset, Leslie and Yaffe, Kristine} } @article {8840, title = {Statins and cognitive decline in the Cardiovascular Health Study: A comparison of different analytical approaches.}, journal = {J Gerontol A Biol Sci Med Sci}, year = {2021}, month = {2021 Jul 31}, abstract = {

BACKGROUND: Despite their well-established benefits for the prevention of cardiovascular disease, robust evidence on the effects of statins on cognition is largely inconclusive. We apply various study designs and analytical approaches to mimic randomized controlled trial (RCT) effects from observational data.

METHODS: We used observational data from 5,580 participants enrolled in the Cardiovascular Health Study from 1989/90 to 1999/2000. We conceptualized the cohort as an overlapping sequence of non-randomized trials. We compared multiple selection (eligible population, prevalent users, new-users) and analytic approaches (multivariable adjustment, inverse probability treatment weights, propensity score matching) to evaluate the association between statin use and 5-year change in global cognitive function, assessed using the Modified Mini-Mental State (3MS) examination.

RESULTS: When comparing prevalent users to non-users (N=2,772), statin use was associated with slower cognitive decline over 5 years (adjusted annual change in 3MSE = 0.34 points/year; 95\% CI:0.05;0.63). Compared to prevalent user design, estimates from new user designs (e.g. comparing eligible statin initiators to non-initiators) were attenuated showing either null or negative association, though not significant. For example, in a propensity score-matched sample of statin-eligible individuals (N=454), annual 3MS change comparing statin initiators to non-initiators was -0.21 points/year (95\% CI:-0.81;0.39).

CONCLUSIONS: The association of statin use and cognitive decline is attenuated towards the null when using rigorous analytical approaches that more closely mimic RCTs. Point estimates, even within the same study, may vary depending on the analytical methods used. Further studies that leverage natural or quasi experiments around statin use are needed to replicate our findings.

}, issn = {1758-535X}, doi = {10.1093/gerona/glab220}, author = {Zeki Al Hazzouri, Adina and Jawadekar, Neal and Grasset, Leslie and Kaiser, Paulina and Kezios, Katrina and Calonico, Sebastian and Glymour, M Maria and Hirsch, Calvin and Arnold, Alice M and Varadhan, Ravi and Opoodden, Michelle C} } @article {9940, title = {Selected social and lifestyle correlates of brain health markers: the Cross-Cohort Collaboration Consortium.}, journal = {Alzheimers Dement}, volume = {21}, year = {2025}, month = {2025 Apr}, pages = {e70148}, abstract = {

INTRODUCTION: To investigate the associations of education level, marital status, and physical activity with dementia risk and brain MRI markers.

METHODS: Data from six community-based samples from the Cross-Cohort Collaboration Consortium were analyzed. Self-reported education level, marital status, and physical activity at age 60 to 75 years were harmonized. Subsamples of participants with brain MRI markers at time of exposure were selected. Associations with dementia risk and cross-sectional MRI markers were meta-analyzed.

RESULTS: Higher education level was associated with lower dementia risk (hazard ratio [HR]~=~0.65, 95\% confidence interval [CI]~=~0.59; 0.72~vs low level) but not significantly with brain MRI markers. Compared with being unmarried, being married was only associated with higher total brain and hippocampal volumes. Being physically active was associated with lower dementia risk (HR~=~0.73, 95\% CI~=~0.52; 1.04), as well as larger total brain volume and smaller white matter hyperintensity volume.

DISCUSSION: This study provides further evidence regarding the contribution of education level and physical activity to dementia resilience.

HIGHLIGHTS: Education level, marital status, and physical activity are thought to contribute to resilience against ADRD. We used random-effects meta-analysis to summarize results from six community-based samples from the CCC. In this cross-cohort meta-analysis, higher education level and being physically active were associated with lower risk of dementia. In cross-sectional analyses, being married was associated with larger TBV and HV, while being physically active was associated with larger TBV and lower WMHV.

}, keywords = {Aged, Brain, Cohort Studies, Cross-Sectional Studies, Dementia, Educational Status, Exercise, Female, Humans, Life Style, Magnetic Resonance Imaging, Male, Marital Status, Middle Aged, Risk Factors}, issn = {1552-5279}, doi = {10.1002/alz.70148}, author = {Grasset, Leslie and Bis, Joshua C and Frenzel, Stefan and Kojis, Daniel and Simino, Jeannette and Yaqub, Amber and Beiser, Alexa and Berr, Claudine and Bressler, Jan and B{\"u}low, Robin and DeCarli, Charles S and Fohner, Alison E and Harrington, Laura B and Helmer, Catherine and Ikram, M Arfan and Lemaitre, Rozenn N and Lopez, Oscar L and Longstreth, W T and Neitzel, Julia and Odden, Michelle C and Palta, Priya and Schmidt, Carsten O and Talluri, Rajesh and Vernooij, Meike W and V{\"o}lzke, Henry and Voortman, Trudy and Whalen, Quest and Wittfeld, Katharina and Grabe, Hans J and Mosley, Thomas H and Psaty, Bruce M and Wolters, Frank J and Seshadri, Sudha and Dufouil, Carole} }