الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
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Abstract
The world elderly population was estimated to be 291 million in 1970, and is expected to be 600 million in 2000. This led to the growing importance of studying the different aspects of the elderly.
Ageing of individuals is defined as a decline in the functional status based upon irreversible changes. Within each individual, each organ grows old in its own biological clock. The heart and lungs, however have to function till the very end of life. Their diseases form the leading causes of morbidity and mortality among the elderly in most countries.
The phenomena of differential ageing of individuals within a population led to the dissatisfaction with the use of the chronological age as the sole criterion for measuring the extent of the ageing process. The concept of biological age assessment was hence introduced to add more information to the chronological age about the health status and/or the longevity potential of an individual.