National Institutes of Health State-of-the-Science Conference statement: preventing alzheimer disease and cognitive decline.

The National Institute on Aging and the Office of Medical Applications of Research of the National Institutes of Health convened a State-of-the-Science Conference on 26-28 April 2010 to assess the available scientific evidence on prevention of cognitive decline and Alzheimer disease. This article provides the panel's assessment of the available evidence.

NIH state-of-the-science conference statement: Preventing Alzheimer's disease and cognitive decline.

OBJECTIVE: To provide health care providers, patients, and the general public with a responsible assessment of currently available data on prevention of Alzheimer's disease and cognitive decline. PARTICIPANTS: A non-Department of Health and Human Services, nonadvocate 15-member panel representing the fields of preventive medicine, geriatrics, internal medicine, neurology, neurological surgery, psychiatry, mental health, human nutrition, pharmacology, genetic medicine, nursing, health economics, health services research, family caregiving, and a public representative. In addition, 20 experts from pertinent fields presented data to the panel and conference audience. EVIDENCE: Presentations by experts and a systematic review of the literature prepared by the Duke University Evidence-based Practice Center, through the Agency for Healthcare Research and Quality. Scientific evidence was given precedence over anecdotal experience. CONFERENCE PROCESS: The panel drafted its statement based on scientific evidence presented in open forum and on published scientific literature. The draft statement was presented on the final day of the conference and circulated to the audience for comment. The panel released a revised statement later that day at http://consensus.nih.gov. This statement is an independent report of the panel and is not a policy statement of the NIH or the Federal Government. CONCLUSIONS: Cognitive decline and Alzheimer's disease are major causes of morbidity and mortality worldwide and are substantially burdensome to the affected persons, their caregivers, and society in general. Extensive research over the past 20 years has provided important insights on the nature of Alzheimer's disease and cognitive decline and the magnitude of the problem. Nevertheless, there remain important and formidable challenges in conducting research on these diseases, particularly in the area of prevention. Currently, firm conclusions cannot be drawn about the association of any modifiable risk factor with cognitive decline or Alzheimer's disease. Highly reliable consensus-based diagnostic criteria for cognitive decline, mild cognitive impairment, and Alzheimer's disease are lacking, and available criteria have not been uniformly applied. Evidence is insufficient to support the use of pharmaceutical agents or dietary supplements to prevent cognitive decline or Alzheimer's disease. We recognize that a large amount of promising research is under way; these efforts need to be increased and added to by new understandings and innovations (as noted in our recommendations for future research). For example, ongoing studies including (but not limited to) studies on antihypertensive medications, omega-3 fatty acids, physical activity, and cognitive engagement may provide new insights into the prevention or delay of cognitive decline or Alzheimer's disease. This important research needs to be supplemented by further studies. Large-scale population-based studies and randomized controlled trials (RCTs) are critically needed to investigate strategies to maintain cognitive function in individuals at risk for decline, to identify factors that may delay the onset of Alzheimer's disease among persons at risk, and to identify factors that may slow the progression of Alzheimer's disease among persons in whom the condition is already diagnosed.

FstSNP-HapMap3: a database of SNPs with high population differentiation for HapMap3.

UNLABELLED: The International HapMap Project has recently made available genotypes and frequency data for phase 3 (NCBI build 36, dbSNPb129) of the HapMap providing an enriched genotype dataset for approximately 1.6 million single nucleotide polymorphisms (SNPs) from 1,115 individuals with ancestry from parts of Africa, Asia, Europe, North America and Mexico. In the present study, we aim to facilitate pharmacogenetics studies by providing a database of SNPs with high population differentiation through a genomewide test on allele frequency variation among 11 HapMap3 samples. Common SNPs with minor allele frequency greater than 5 cent from each of 11 HapMap3 samples were included in the present analysis. The population differentiation is measured in terms of fixation index (Fst), and the SNPs with Fst values over 0.5 were defined as highly differentiated SNPs. Our tests were carried out between all pairs of the 11 HapMap3 samples or among subgroups with the same continental ancestries. Altogether we carried out 64 genomewide Fst tests and identified 28,215 highly differentiated SNPs for 49 different combinations of HapMap3 samples in the current database. AVAILABILITY: http://FstSNP-hapmap3.googlecode.com/

SNPinProbe_1.0: a database for filtering out probes in the Affymetrix GeneChip human exon 1.0 ST array potentially affected by SNPs.

UNLABELLED: The Affymetrix GeneChip(R) Human Exon 1.0 ST array (exon array) is designed to measure both gene-level and exon-level expression in human samples. This exon array contains approximately 1.4 million probesets consisting of approximately 5.4 million probes and profiles over 17,000 well-annotated gene transcripts in the human genome. As with all expression arrays, the exon array is vulnerable to SNPs within probes, because these SNPs can affect the hybridization of the probes and thus produce misleading expression values. In some cases, this could result in dramatic fluctuations of the exon-level expression. For this reason, we performed a genome-wide search for SNPs within regions that hybridize to probes by evaluating approximately 18 million SNPs in dbSNP (Build 129) and about 5.4 million probes in the exon array. We identified 597,068 probes within 350,382 probe sets that hybridized to regions containing SNPs. These affected probes and/or probesets can be filtered in the data processing procedure thus controlling for potential false expression phenotypes when using this exon array. AVAILABILITY: http://cid-fb2a64e541add2be.skydrive.live.com/browse.aspx/Affy%7C_HuEx%7C_1.0ST?uc=2.