TECHNIQUES OF ASSESSING MUSCLE MASS AND FUNCTION (SARCOPENIA) FOR EPIDEMIOLOGIC STUDIES OF THE ELDERLY

For epidemiological studies, reliable and valid measurements or indice s of muscle mass are needed to screen for those elderly persons at ris k for sarcopenia, and to determine the prevalence of these conditions on a national level. The methods more suitable for field or epidemiolo gical settings are anthropometry, bioelectrical impedance, and grip st rength. These field methods, while reliable, have limited demonstrated validity in their application to the elderly and are restricted by th e limited functional capabilities of the elderly, which decrease with age. Epidemiological studies of the elderly need to include sufficient numbers of persons of different ethnic backgrounds, and at the older ages. For an epidemiological study of tire elderly today, one also nee ds to select the categories of elderly persons to be included in such studies: healthy, sick, very old, handicapped, level of functional sta tus, etc., because relationships among variables can have different st atistical and biological associations. Future work should be directed at improving the design and methodology of epidemiological and serial studies so as to maximize the numbers and categories of elderly person s who can be studied.