Author
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Lukaski, Henry |
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HEYMSFIELD, STEVEN - COLUMBIA UNIVERSITY |
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Submitted to: Journal of Nutrition
Publication Type: Review Article Publication Acceptance Date: 1/29/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Although skeletal muscle represents the largest component of the human body, it remains a difficult quantity to measure. The importance of skeletal muscle is emphasized by its role in regulating physical function in all age groups and its importance in determining energy requirements. Many methods are available for estimation of whole body and regional muscle emass. These methods range from relatively simple and inexpensive approaches such as measurement of circumferences and skinfold thicknesses at selected sites of the body to more detailed methods as determination of specific compounds eliminated in the urine during a 24-hour period after consumption of meat-free diets for specified periods of time. Recently, more sophisticated techniques involving medical instrumentation have provided the most accurate and precise determinations of skeletal muscle despite their high cost and availability only in medical centers. Because of the increasing demand by researchers and medical professionals for a routine determination of skeletal muscle mass, reliance on these sophisticated methods for nutritional assessment and evaluation of the effects of various therapies will stimulate the development and implementation of less costly and more practical methods and instrumentation such as bioelectrical impedance analysis. It is anticipated that instrumentation will be available in the near future to facilitate the safe, inexpensive and practical measurement of skeletal muscle mass in humans. Technical Abstract: Skeletal muscle mass is the largest organ in the human body. Although many methods for the assessment of muscle mass are available, each has its limitations which prohibit their routine use. Measurement of upper arm circumference in conjunction with skinfold thickness at the triceps is a practical approach which is used in assessment of nutritional status but is sinsensitive as an index of total body skeletal muscle mass. Alternatively muscle circumferences determined at several sites and corrected for skinfold thickness apparently is a more precise predictor of whole-body skeletal muscle. The use of endogenous muscle metabolites is another approach which is limited by the need for use of a meat-free diet and timed urine collections. The application of radiological techniques, computed tomography and magnetic resonance imaging, provides the best methods for accurate and precise measurements of appendicular and whole- body musculature, but are restricted to medical centers. A more practical alternative is the use of dual x-ray absorptiometry which is less expensive than the radiologic approaches, has minimal exposure to ionizing radiation and provides precise determinations of appendicular skeletal muscle. An adaptation of the bioelectrical impendance method for the estimation of regional muscle mass overcomes the technical and practical limitations of other methods of skeletal muscle mass assessment. However, additional evaluation and validation of this impedance approach is needed. At present, an acceptable method for estimation of regional or whole-body skeletal muscle remains a need for routine human nutritional assessment. |
