Contribution of Alzheimer disease to mortality in the United States

Epigenomics of Alzheimer's disease

Alzheimer's disease (AD) is a large and growing public health problem. It is characterized by the accumulation of amyloid β peptides and abnormally phosphorylated tau proteins that are associated with cognitive decline and dementia. Much has been learned about the genomics of AD from linkage analyses and, more recently, genome-wide association studies. Several but not all aspects of the genomic landscape are involved in amyloid β metabolism. The moderate concordance of disease among twins suggests other factors, potentially epigenomic factors, are related to AD. We are at the earliest stages of examining the relation of the epigenome to the clinical and pathologic phenotypes that characterize AD. Our literature review suggests that there is some evidence of age-related changes in human brain methylation. Unfortunately, studies of AD have been relatively small with limited coverage of methylation sites and microRNA, let alone other epigenomic marks. We are in the midst of 2 large studies of human brains including coverage of more than 420,000 autosomal cytosine-guanine dinucleotides with the Illumina Infinium HumanMethylation450 BeadArray, and histone acetylation with chromatin immunoprecipitation sequencing. We present descriptive data to help inform other researchers what to expect from these approaches to better design and power their studies. We then discuss future directions to inform on the epigenomic architecture of AD.

Seizures in Alzheimer's disease

Alzheimer's disease (AD) increases the risk for late-onset seizures and neuronal network abnormalities. An elevated co-occurrence of AD and seizures has been established in the more prevalent sporadic form of AD. Recent evidence suggests that nonconvulsive network abnormalities, including seizures and other electroencephalographic abnormalities, may be more commonly found in patients than previously thought. Patients with familial AD are at an even greater risk for seizures, which have been found in patients with mutations in PSEN1, PSEN2, or APP, as well as with APP duplication. This review also provides an overview of seizure and electroencephalography studies in AD mouse models. The amyloid-β (Aβ) peptide has been identified as a possible link between AD and seizures, and while Aβ is known to affect neuronal activity, the full-length amyloid precursor protein (APP) and other APP cleavage products may be important for the development and maintenance of cortical network hyperexcitability. Nonconvulsive epileptiform activity, such as seizures or network abnormalities that are shorter in duration but may occur with higher frequency, may contribute to cognitive impairments characteristic of AD, such as amnestic wandering. Finally, the review discusses recent studies using antiepileptic drugs to rescue cognitive deficits in AD mouse models and human patients. Understanding the mechanistic link between epileptiform activity and AD is a research area of growing interest. Further understanding of the connection between neuronal hyperexcitability and Alzheimer's as well as the potential role of epileptiform activity in the progression of AD will be beneficial for improving treatment strategies.

The NLM evaluation lecture series: introduction to the special section on evaluating health communication programs

This article introduces the Journal of Health Communication's special section, Evaluating Health Communication Programs. This special section is based on a public lecture series supported by the National Library of Medicine titled "Better Health: Evaluating Health Communication Programs" designed to share best practices for using evaluation research to develop, implement, refine, and institutionalize the best health communication programs for promoting public health. This introduction provides an overview to the series, summarizes the major presentations in the series, and describe implications from the series for translational health communication research, interventions, and programs that can enhance health outcomes.

Underrecognition and Undertreatment of Pain and Behavioral Symptoms in End-Stage Dementia

End-stage dementia, a terminal condition, is associated with a high prevalence of physical pain and behavioral symptoms. As these patients often have a decreased ability to express their symptoms, they are often underrecognized and undertreated. This article proposes opportunities to improve patient care. The article underscores the role of assessment scales to optimize behavioral management for patients with dementia and discusses the value of pain management to improve behavioral symptoms. Additionally, a collaborative interdisciplinary team, including palliative medicine, pharmacy services, and spiritual support can optimize patient care and develop a plan of care.

2014 Alzheimer's disease facts and figures

This report discusses the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality rates, costs of care, and overall effect on caregivers and society. It also examines the impact of AD on women compared with men. An estimated 5.2 million Americans have AD. Approximately 200,000 people younger than 65 years with AD comprise the younger onset AD population; 5 million are age 65 years or older. By mid-century, fueled in large part by the baby boom generation, the number of people living with AD in the United States is projected to grow by about 9 million. Today, someone in the country develops AD every 67 seconds. By 2050, one new case of AD is expected to develop every 33 seconds, or nearly a million new cases per year, and the total estimated prevalence is expected to be 13.8 million. In 2010, official death certificates recorded 83,494 deaths from AD, making AD the sixth leading cause of death in the United States and the fifth leading cause of death in Americans aged 65 years or older. Between 2000 and 2010, the proportion of deaths resulting from heart disease, stroke, and prostate cancer decreased 16%, 23%, and 8%, respectively, whereas the proportion resulting from AD increased 68%. The actual number of deaths to which AD contributes (or deaths with AD) is likely much larger than the number of deaths from AD recorded on death certificates. In 2014, an estimated 700,000 older Americans will die with AD, and many of them will die from complications caused by AD. In 2013, more than 15 million family members and other unpaid caregivers provided an estimated 17.7 billion hours of care to people with AD and other dementias, a contribution valued at more than $220 billion. Average per-person Medicare payments for services to beneficiaries aged 65 years and older with AD and other dementias are more than two and a half times as great as payments for all beneficiaries without these conditions, and Medicaid payments are 19 times as great. Total payments in 2014 for health care, long-term care, and hospice services for people aged 65 years and older with dementia are expected to be $214 billion. AD takes a stronger toll on women than men. More women than men develop the disease, and women are more likely than men to be informal caregivers for someone with AD or another dementia. As caregiving responsibilities become more time consuming and burdensome or extend for prolonged durations, women assume an even greater share of the caregiving burden. For every man who spends 21 to more than 60 hours per week as a caregiver, there are 2.1 women. For every man who lives with the care recipient and provides around-the-clock care, there are 2.5 women. In addition, for every man who has provided caregiving assistance for more than 5 years, there are 2.3 women.

The key role of transient receptor potential melastatin-2 channels in amyloid-β-induced neurovascular dysfunction

Alzheimer's dementia is a devastating and incurable disease afflicting over 35 million people worldwide. Amyloid-β (Aβ), a key pathogenic factor in this disease, has potent cerebrovascular effects that contribute to brain dysfunction underlying dementia by limiting the delivery of oxygen and glucose to the working brain. However, the downstream pathways responsible for the vascular alterations remain unclear. Here we report that the cerebrovascular dysfunction induced by Aβ is mediated by DNA damage caused by vascular oxidative-nitrosative stress in cerebral endothelial cells, which, in turn, activates the DNA repair enzyme poly(ADP)-ribose polymerase. The resulting increase in ADP ribose opens transient receptor potential melastatin-2 (TRPM2) channels in endothelial cells leading to intracellular Ca(2+) overload and endothelial dysfunction. The findings provide evidence for a previously unrecognized mechanism by which Aβ impairs neurovascular regulation and suggest that TRPM2 channels are a potential therapeutic target to counteract cerebrovascular dysfunction in Alzheimer's dementia and related pathologies.

Acceptability of an Advance Directive That Limits Food and Liquids in Advanced Dementia

Some individuals fear living with advanced dementia and may even commit suicide if they receive dementia diagnosis. Living with advanced dementia could be prevented if a person who cannot feed himself or herself would not be fed by others. The purpose of the study was to find out how acceptable would be an advance directive that includes discontinuation of feeding at certain stage of dementia for relatives of persons who died with dementia. All participants of 2 focus groups would be willing to indicate at least 1 condition in which they would not want to be fed. Some of them would be willing to make a proxy decision to stop feeding in the absence of advance directives.

Reversal of cognitive decline: a novel therapeutic program

This report describes a novel, comprehensive, and personalized therapeutic program that is based on the underlying pathogenesis of Alzheimer's disease, and which involves multiple modalities designed to achieve metabolic enhancement for neurodegeneration (MEND). The first 10 patients who have utilized this program include patients with memory loss associated with Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), or subjective cognitive impairment (SCI). Nine of the 10 displayed subjective or objective improvement in cognition beginning within 3-6 months, with the one failure being a patient with very late stage AD. Six of the patients had had to discontinue working or were struggling with their jobs at the time of presentation, and all were able to return to work or continue working with improved performance. Improvements have been sustained, and at this time the longest patient follow-up is two and one-half years from initial treatment, with sustained and marked improvement. These results suggest that a larger, more extensive trial of this therapeutic program is warranted. The results also suggest that, at least early in the course, cognitive decline may be driven in large part by metabolic processes. Furthermore, given the failure of monotherapeutics in AD to date, the results raise the possibility that such a therapeutic system may be useful as a platform on which drugs that would fail as monotherapeutics may succeed as key components of a therapeutic system.

Neural correlates of cognitive intervention in persons at risk of developing Alzheimer's disease

Cognitive training is an emergent approach that has begun to receive increased attention in recent years as a non-pharmacological, cost-effective intervention for Alzheimer’s disease (AD). There has been increasing behavioral evidence regarding training-related improvement in cognitive performance in early stages of AD. Although these studies provide important insight about the efficacy of cognitive training, neuroimaging studies are crucial to pinpoint changes in brain structure and function associated with training and to examine their overlap with pathology in AD. In this study, we reviewed the existing neuroimaging studies on cognitive training in persons at risk of developing AD to provide an overview of the overlap between neural networks rehabilitated by the current training methods and those affected in AD. The data suggest a consistent training-related increase in brain activity in medial temporal, prefrontal, and posterior default mode networks, as well as increase in gray matter structure in frontoparietal and entorhinal regions. This pattern differs from the observed pattern in healthy older adults that shows a combination of increased and decreased activity in response to training. Detailed investigation of the data suggests that training in persons at risk of developing AD mainly improves compensatory mechanisms and partly restores the affected functions. While current neuroimaging studies are quite helpful in identifying the mechanisms underlying cognitive training, the data calls for future multi-modal neuroimaging studies with focus on multi-domain cognitive training, network level connectivity, and individual differences in response to training.

Association Between Serum Amyloid-Beta and Renal Functions: Implications for Roles of Kidney in Amyloid-Beta Clearance

Amyloid-beta (Aβ) plays a central role in the pathogenesis of Alzheimer's disease (AD), and it is a major therapeutic target for AD. It is proposed that removal of Aβ in blood can facilitate Aβ clearance from the brain, representing a promising therapeutic approach for AD. However, the efficacy and mechanisms for Aβ clearance by peripheral organs and tissues remain largely unknown. In the present study, 47 chronic kidney disease (CKD) patients (16 newly diagnosed patients who had never been dialyzed and 31 patients who were receiving dialysis) and 43 normal controls (NC) were enrolled. We found that serum Aβ levels were significantly higher in CKD patients than NC. CKD patients who were receiving dialysis had lower serum Aβ levels than patients without receiving dialysis, being comparable to NC. Furthermore, serum Aβ levels were correlated with renal functions reflected by estimated glomerular filtration rate (eGFR) and residual GFR (rGFR). Our study suggests that kidney is involved in peripheral clearance of Aβ, and dialysis might be a potential therapeutic approach of Aβ removal.

CSF Biomarkers of Alzheimer’s Disease: Impact on Disease Concept, Diagnosis, and Clinical Trial Design

Data from clinicopathologic and biomarker studies have converged to support the view of Alzheimer’s disease (AD) as a continuum, with pathology developing decades prior to the onset of cognitive symptoms which culminate as dementia at the end stage of the disease. This concept is impacting disease nomenclature, diagnostic criteria, prognostic potential, and clinical trial design. Revisions to diagnostic criteria to incorporate biomarker results have recently been proposed in order to increase the confidence of AD as the underlying etiology of a clinical impairment and to permit a diagnosis of AD across the disease continuum, eventually perhaps in the asymptomatic period. Individuals in this preclinical stage are receiving intense focus as a targeted population for secondary prevention trials aimed at identifying disease-modifying therapies that have the best chance of preserving normal cognitive function. The goal is to bring validated biomarkers to clinical practice for the purpose of disease diagnosis, prognosis, and evaluation of therapeutic efficacy once disease-modifying treatments become available. Realization of this goal requires worldwide biomarker standardization efforts, consensus among researchers and clinicians regarding the clinical utility of assessing biomarkers in patient care settings, and eventually the endorsement and adoption of such procedures and practices into global health care systems.