ABSTRACT
Alzheimer’s disease (AD) is a complex multifactorial neurodegenerative disease and a leading cause of dementia among elderly people. About 5% of the people aged 65 or above are affected with AD, and the prevalence rises steeply to 19% after age 75 and to 47% after age 85 [1]. Currently there are approximately > 4 million AD cases in the United States and 12-14 million worldwide. Owing to its long clinical course, AD is a major public health problem. The average life expectancy after diagnosis is 8-10 years, though the disease can last for up to 20 years. The estimated annual cost for caring of one AD patient in the United States ranges from about $18,000 for a patient with mild AD, to $30,000 for a patient with moderate AD, up to $36,000 for a patient with severe AD; this translates into a hefty total annual cost of >$50 billion [2]. Approximately 360,000 incidence cases occur each year [3], and this number is increasing as the population ages and life expectancy increases. Currently 35 million Americans are age 65 and older, and the Bureau of the Census estimates that this number will double by the year 2030 and exceeds 80 million in 2050. Furthermore, the 85 and older group, in which almost 50% of the people are affected with some form of dementia, is one of the fastest-growing segments of the U.S. population [4]. Currently 4
million Americans are in this group, which is expected to double by the year 2030 and quadruple by the year 2050. Because of this alarming increase in the elderly population and with the possibility that the bulk of this elderly population will suffer from AD, it is essential to devise effective preventive measures soon to curb the disease. Up until a decade ago the understanding of the causes of AD were either lacking or limited. Although we still do not understand the exact underlying cause of AD, the combined research findings from genetic, molecular, and functional studies over the past few years have been illuminating, and now we are closer than ever in establishing the molecular and biochemical basis of the disease.
