Individualized clinical management of patients at risk for Alzheimer's dementia.

INTRODUCTION: Multidomain intervention for Alzheimer's disease (AD) risk reduction is an emerging therapeutic paradigm. METHODS: Patients were prescribed individually tailored interventions (education/pharmacologic/nonpharmacologic) and rated on compliance. Normal cognition/subjective cognitive decline/preclinical AD was classified as Prevention. Mild cognitive impairment due to AD/mild-AD was classified as Early Treatment. Change from baseline to 18 months on the modified Alzheimer's Prevention Cognitive Composite (primary outcome) was compared against matched historical control cohorts. Cognitive aging composite (CogAging), AD/cardiovascular risk scales, and serum biomarkers were secondary outcomes. RESULTS: One hundred seventy-four were assigned interventions (age 25-86). Higher-compliance Prevention improved more than both historical cohorts (P = .0012, P < .0001). Lower-compliance Prevention also improved more than both historical cohorts (P = .0088, P < .0055). Higher-compliance Early Treatment improved more than lower compliance (P = .0007). Higher-compliance Early Treatment improved more than historical cohorts (P < .0001, P = .0428). Lower-compliance Early Treatment did not differ (P = .9820, P = .1115). Similar effects occurred for CogAging. AD/cardiovascular risk scales and serum biomarkers improved. DISCUSSION: Individualized multidomain interventions may improve cognition and reduce AD/cardiovascular risk scores in patients at-risk for AD dementia.

The clinical practice of risk reduction for Alzheimer's disease: A precision medicine approach.

Like virtually all age-related chronic diseases, late-onset Alzheimer's disease (AD) develops over an extended preclinical period and is associated with modifiable lifestyle and environmental factors. We hypothesize that multimodal interventions that address many risk factors simultaneously and are individually tailored to patients may help reduce AD risk. We describe a novel clinical methodology used to evaluate and treat patients at two Alzheimer's Prevention Clinics. The framework applies evidence-based principles of clinical precision medicine to tailor individualized recommendations, follow patients longitudinally to continually refine the interventions, and evaluate N-of-1 effectiveness (trial registered at ClinicalTrials.gov NCT03687710). Prior preliminary results suggest that the clinical practice of AD risk reduction is feasible, with measurable improvements in cognition and biomarkers of AD risk. We propose using these early findings as a foundation to evaluate the comparative effectiveness of personalized risk management within an international network of clinician researchers in a cohort study possibly leading to a randomized controlled trial.

Endogenous and Exogenous Estrogen Exposures: How Women's Reproductive Health Can Drive Brain Aging and Inform Alzheimer's Prevention.

After advanced age, female sex is the major risk factor for late-onset Alzheimer's disease (AD), the most common cause of dementia affecting over 24 million people worldwide. The prevalence of AD is higher in women than in men, with postmenopausal women accounting for over 60% of all those affected. While most research has focused on gender-combined risk, emerging data indicate sex and gender differences in AD pathophysiology, onset, and progression, which may help account for the higher prevalence in women. Notably, AD-related brain changes develop during a 10-20 year prodromal phase originating in midlife, thus proximate with the hormonal transitions of endocrine aging characteristic of the menopause transition in women. Preclinical evidence for neuroprotective effects of gonadal sex steroid hormones, especially 17ß-estradiol, strongly argue for associations between female fertility, reproductive history, and AD risk. The level of gonadal hormones to which the female brain is exposed changes considerably across the lifespan, with relevance to AD risk. However, the neurobiological consequences of hormonal fluctuations, as well as that of hormone therapies, are yet to be fully understood. Epidemiological studies have yielded contrasting results of protective, deleterious and null effects of estrogen exposure on dementia risk. In contrast, brain imaging studies provide encouraging evidence for positive associations between greater cumulative lifetime estrogen exposure and lower AD risk in women, whereas estrogen deprivation is associated with negative consequences on brain structure, function, and biochemistry. Herein, we review the existing literature and evaluate the strength of observed associations between female-specific reproductive health factors and AD risk in women, with a focus on the role of endogenous and exogenous estrogen exposures as a key underlying mechanism. Chief among these variables are reproductive lifespan, menopause status, type of menopause (spontaneous vs. induced), number of pregnancies, and exposure to hormonal therapy, including hormonal contraceptives, hormonal therapy for menopause, and anti-estrogen treatment. As aging is the greatest risk factor for AD followed by female sex, understanding sex-specific biological pathways through which reproductive history modulates brain aging is crucial to inform preventative and therapeutic strategies for AD.

Association of Reproductive History With Brain MRI Biomarkers of Dementia Risk in Midlife.

BACKGROUND AND OBJECTIVES: To examine associations between indicators of estrogen exposure from women's reproductive history and brain MRI biomarkers of Alzheimer disease (AD) in midlife. METHODS: We evaluated 99 cognitively normal women 52 ± 6 years of age and 29 men 52 ± 7 years of age with reproductive history data, neuropsychological testing, and volumetric MRI scans. We used multiple regressions to examine associations among reproductive history indicators, voxel-wise gray matter volume (GMV), and memory and global cognition scores, adjusting for demographics and midlife health indicators. Exposure variables were menopause status, age at menarche, age at menopause, reproductive span, hysterectomy status, number of children and pregnancies, and use of menopause hormonal therapy (HT) and hormonal contraceptives (HC). RESULTS: All menopausal groups exhibited lower GMV in AD-vulnerable regions compared to men, with perimenopausal and postmenopausal groups also exhibiting lower GMV in temporal cortex compared to the premenopausal group. Reproductive span, number of children and pregnancies, and use of HT and HC were positively associated with GMV, chiefly in temporal cortex, frontal cortex, and precuneus, independent of age, APOE ε4 status, and midlife health indicators. Although reproductive history indicators were not directly associated with cognitive measures, GMV in temporal regions was positively associated with memory and global cognition scores. DISCUSSION: Reproductive history events signaling more estrogen exposure such as premenopausal status, longer reproductive span, higher number of children, and use of HT and HC were associated with larger GMV in women in midlife. Further studies are needed to elucidate sex-specific biological pathways through which reproductive history influences cognitive aging and AD risk.

Menopause impacts human brain structure, connectivity, energy metabolism, and amyloid-beta deposition.

All women undergo the menopause transition (MT), a neuro-endocrinological process that impacts aging trajectories of multiple organ systems including brain. The MT occurs over time and is characterized by clinically defined stages with specific neurological symptoms. Yet, little is known of how this process impacts the human brain. This multi-modality neuroimaging study indicates substantial differences in brain structure, connectivity, and energy metabolism across MT stages (pre-menopause, peri-menopause, and post-menopause). These effects involved brain regions subserving higher-order cognitive processes and were specific to menopausal endocrine aging rather than chronological aging, as determined by comparison to age-matched males. Brain biomarkers largely stabilized post-menopause, and gray matter volume (GMV) recovered in key brain regions for cognitive aging. Notably, GMV recovery and in vivo brain mitochondria ATP production correlated with preservation of cognitive performance post-menopause, suggesting adaptive compensatory processes. In parallel to the adaptive process, amyloid-ß deposition was more pronounced in peri-menopausal and post-menopausal women carrying apolipoprotein E-4 (APOE-4) genotype, the major genetic risk factor for late-onset Alzheimer's disease, relative to genotype-matched males. These data show that human menopause is a dynamic neurological transition that significantly impacts brain structure, connectivity, and metabolic profile during midlife endocrine aging of the female brain.

The Role of Nutrition in Individualized Alzheimer's Risk Reduction.

PURPOSE OF REVIEW: Decades of research suggests nutritional interventions can be an effective tool for reducing risk of Alzheimer's disease (AD), especially as part of an individualized clinical management plan. This review aims to emphasize new findings examining how specific dietary changes may delay or possibly prevent AD onset, and highlight how interventions can be adopted in clinical practice based on emerging principles of precision medicine. RECENT FINDINGS: Specific dietary patterns and varied nutrient combinations can have a protective effect on brain health, promote cognitive function, and mediate the comorbidity of chronic conditions associated with increased AD risk. Individuals at risk for AD may see a greater impact of evidence-based dietary changes when initiated earlier in the AD spectrum. Depending on individual clinical profiles, incorporation of nutrition strategies is an essential component of an AD risk reduction plan in clinical practice.

Education Research: Online Alzheimer education for high school and college students: A randomized controlled trial.

OBJECTIVE: Alzheimer disease (AD) risk factors are present throughout the lifespan. This randomized controlled trial evaluated the effectiveness of various online education strategies concerning AD risk reduction and brain health in younger populations. METHOD: High school and college students were recruited via social media (Facebook and Instagram) to join AlzU.org, an evidence-based education portal, and were randomized to 1 of 4 courses: highly interactive webinar lessons narrated by actor Seth Rogen (celebrity webinar) or a physician (doctor webinar), minimally interactive video lessons with Seth Rogen (celebrity video), or minimally interactive video lessons (control). Surveys were administered at baseline and postcourse. The primary outcome was change in knowledge of AD risk reduction assessed by pre vs post lesson quiz scores. Secondary outcomes included change in awareness of AD research, hopefulness about AD, interest in pursuing health care, willingness to volunteer, and likelihood of recommending AlzU.org. RESULT: A total of 721 participants joined. A total of 281 (38.9%) completed the course. Among college students, quiz score improvements were greater in celebrity webinar and celebrity video vs doctor webinar and control. Among high school students, no differences were found in quiz scores. In both groups, celebrity webinar, celebrity video, and doctor webinar resulted in greater improvements in awareness that nutrition and exercise may reduce AD risk vs controls. Among college students, celebrity webinar and celebrity video group participants felt more hopeful about the future of AD and more likely to recommend AlzU.org vs doctor webinar and control participants. Among college students, celebrity webinar, celebrity video, and doctor webinar participants were more willing to volunteer for AD causes and pursue health care careers vs controls. CONCLUSION: Online education involving a celebrity may be an effective strategy for educating college students about AD risk reduction strategies. Further studies are warranted in high school students.

Effectiveness of online education for recruitment to an Alzheimer's disease prevention clinical trial.

INTRODUCTION: Low awareness of Alzheimer's disease (AD) clinical trials is a recruitment barrier. To assess whether online education may affect screening rates for AD prevention clinical trials, we conducted an initial prospective cohort study (n = 10,450) and subsequent randomized study (n = 351) using an online digital tool: AlzU.org. METHODS: A total of 10,450 participants were enrolled in an initial cohort study and asked to complete a six-lesson course on AlzU.org, as well as a baseline and 6-month follow-up questionnaire. Participants were stratified into three groups based on lesson completion at 6 months: group 1 (zero to one lesson completed), group 2 (two to four lessons), and group 3 (five or more lessons). For the subsequent randomized-controlled trial (RCT), 351 new participants were enrolled in a six-lesson course (n = 180) versus a time-neutral control (n = 171). Screening and enrollment in the Anti-Amyloid Treatment in Asymptomatic AD (A4) clinical trial were reported via the 6-month questionnaire and are the primary outcomes. RESULTS: Cohort: 3.9% of group 1, 5% of group 2, and 8.4% of group 3 screened for the A4 trial. Significant differences were found among the groups (P < 0.001). Post hoc analyses showed differences in A4 screening rates between groups 1 and 3 (P < 0.001) and groups 2 and 3 (P = 0.0194). There were no differences in enrollment among the three groups. RCT: 2.78% of the intervention group screened for A4 compared to 0% of controls (P = 0.0611). DISCUSSION: Online education via the AlzU.org digital tool may serve as an effective strategy to supplement clinical trial recruitment.

Sex-driven modifiers of Alzheimer risk: A multimodality brain imaging study.

OBJECTIVE: To investigate sex differences in late-onset Alzheimer disease (AD) risks by means of multimodality brain biomarkers (ß-amyloid load via 11C-Pittsburgh compound B [PiB] PET, neurodegeneration via 18F-fluorodeoxyglucose [FDG] PET and structural MRI). METHODS: We examined 121 cognitively normal participants (85 women and 36 men) 40 to 65 years of age with clinical, laboratory, neuropsychological, lifestyle, MRI, FDG- and PiB-PET examinations. Several clinical (e.g., age, education, APOE status, family history), medical (e.g., depression, diabetes mellitus, hyperlipidemia), hormonal (e.g., thyroid disease, menopause), and lifestyle AD risk factors (e.g., smoking, diet, exercise, intellectual activity) were assessed. Statistical parametric mapping and least absolute shrinkage and selection operator regressions were used to compare AD biomarkers between men and women and to identify the risk factors associated with sex-related differences. RESULTS: Groups were comparable on clinical and cognitive measures. After adjustment for each modality-specific confounders, the female group showed higher PiB ß-amyloid deposition, lower FDG glucose metabolism, and lower MRI gray and white matter volumes compared to the male group (p < 0.05, family-wise error corrected for multiple comparisons). The male group did not show biomarker abnormalities compared to the female group. Results were independent of age and remained significant with the use of age-matched groups. Second to female sex, menopausal status was the predictor most consistently and strongly associated with the observed brain biomarker differences, followed by hormone therapy, hysterectomy status, and thyroid disease. CONCLUSION: Hormonal risk factors, in particular menopause, predict AD endophenotype in middle-aged women. These findings suggest that the window of opportunity for AD preventive interventions in women is early in the endocrine aging process.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks.

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer's disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the "estrogen hypothesis." This posits that sex hormones, 17ß-estradiol in particular, exert a neuroprotective effect by shielding females' brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17ß-estradiol during the menopause transition (MT) as key underlying mechanisms.

Precision Medicine for Alzheimer's Disease Prevention.

Precision medicine is an approach to medical treatment and prevention that takes into account individual variability in genes, environment, and lifestyle and allows for personalization that is based on factors that may affect the response to treatment. Several genetic and epigenetic risk factors have been shown to increase susceptibility to late-onset Alzheimer's disease (AD). As such, it may be beneficial to integrate genetic risk factors into the AD prevention approach, which in the past has primarily been focused on universal risk-reduction strategies for the general population rather than individualized interventions in a targeted fashion. This review discusses examples of a "one-size-fits-all" versus clinical precision medicine AD prevention strategy, in which the precision medicine approach considers two genes that can be commercially sequenced for polymorphisms associated with AD, apolipoprotein E (APOE), and methylenetetrahydrofolate reductase (MTHFR). Comparing these two distinct approaches provides support for a clinical precision medicine prevention strategy, which may ultimately lead to more favorable patient outcomes as the interventions are targeted to address individualized risks.

Utility of the NIH Toolbox for assessment of prodromal Alzheimer's disease and dementia.

INTRODUCTION: The NIH Toolbox Cognition Battery (NIHTB-CB) is a computer-based protocol not yet validated for clinical assessment. METHODS: We administered the NIHTB-CB and traditional neuropsychological tests to 247 Memory Disorders and Alzheimer's Prevention Clinic patients with subjective cognitive decline, mild cognitive impairment, mild dementia due to Alzheimer's disease, and normal cognition. Principal component analysis, partial correlations, and univariate general linear model tests were performed to assess construct validity. Discriminant function analyses compared classification accuracy. RESULTS: Principal component analysis identified three conceptually coherent factors: memory (MEMNIH), executive function (EFNIH), and crystallized intelligence (CINIH). These factors were strongly associated with corresponding traditional tests and differed across diagnostic groups as expected. Both NIHTB and traditional batteries yielded strong overall discriminative ability (>80%). DISCUSSION: The NIHTB-CB is a valid method to assess neurocognitive domains pertinent to aging and dementia and has utility for applications in a memory clinic setting.

Increased Alzheimer's risk during the menopause transition: A 3-year longitudinal brain imaging study.

Two thirds of all persons with late-onset Alzheimer's disease (AD) are women. Identification of sex-based molecular mechanisms underpinning the female-based prevalence of AD would advance development of therapeutic targets during the prodromal AD phase when prevention or delay in progression is most likely to be effective. This 3-year brain imaging study examines the impact of the menopausal transition on Alzheimer's disease (AD) biomarker changes [brain ß-amyloid load via 11C-PiB PET, and neurodegeneration via 18F-FDG PET and structural MRI] and cognitive performance in midlife. Fifty-nine 40-60 year-old cognitively normal participants with clinical, neuropsychological, and brain imaging exams at least 2 years apart were examined. These included 41 women [15 premenopausal controls (PRE), 14 perimenopausal (PERI), and 12 postmenopausal women (MENO)] and 18 men. We used targeted minimum loss-based estimation to evaluate AD biomarker and cognitive changes. Older age was associated with baseline Aß and neurodegeneration markers, but not with rates of change in these biomarkers. APOE4 status influenced change in Aß load, but not neurodegenerative changes. Longitudinally, MENO and PERI groups showed declines in estrogen-dependent memory tests as compared to men (p < .04). Adjusting for age, APOE4 status, and vascular risk confounds, the MENO and PERI groups exhibited higher rates of CMRglc decline as compared to males (p ≤ .015). The MENO group exhibited the highest rate of hippocampal volume loss (p's ≤ .001), and higher rates of Aß deposition than males (p < .01). CMRglc decline exceeded Aß and atrophy changes in all female groups vs. men. These findings indicate emergence and progression of a female-specific hypometabolic AD-endophenotype during the menopausal transition. These findings suggest that the optimal window of opportunity for therapeutic intervention to prevent or delay progression of AD endophenotype in women is early in the endocrine aging process.

Alzheimer's "Prevention" vs. "Risk Reduction": Transcending Semantics for Clinical Practice.

The terms "prevention" and "risk reduction" are often used interchangeably in medicine. There is considerable debate, however, over the use of these terms in describing interventions that aim to preserve cognitive health and/or delay disease progression of Alzheimer's disease (AD) for patients seeking clinical care. Furthermore, it is important to distinguish between Alzheimer's disease prevention and Alzheimer's dementia prevention when using these terms. While prior studies have codified research-based criteria for the progressive stages of AD, there are no clear clinical consensus criteria to guide the use of these terms for physicians in practice. A clear understanding of the implications of each term will help guide clinical practice and clinical research. The authors explore the semantics and appropriate use of the terms "prevention" and "risk reduction" as they relate to AD in clinical practice.