ESTIMATION OF BODY-COMPOSITION IN CHINESE AND BRITISH MEN BY ULTRASONOGRAPHIC ASSESSMENT OF SEGMENTAL ADIPOSE-TISSUE VOLUME

It has been shown that ultrasonographic measurements can be used to pr edict body composition in adults. The purpose of this study was to ass ess the relationship between ultrasonograph and caliper (SKF) measurem ents of subcutaneous adipose tissue thickness in athletic Caucasian (E nglish, E) and Asian (Chinese, C) men against estimates of body compos ition determined from hydrodensitometry (HYD). The usefulness of a pro posed ultrasonographic method of estimating lean and fat proportions i n the upper and lower limbs was also evaluated as a potential method o f predicting body composition. Ultrasonography (US) was used to measur e adipose and skin thickness at the following sites: biceps, triceps, subscapular, suprailiac, abdominal, pectoral, thigh and calf. Caliper measurements were also made at the above sites. Subcutaneous fat thick ness and segmental radius were measured directly from the display scre en of the ultrasonic scanner (Aloka 500 SD). By applying the geometry of a cone, the proximal and distal radii of the upper arm and upper le g were used to calculate the proportionate volumes of adipose tissue. The best correlations for US and SKF were obtained at the quadriceps; subscapular and pectoral sites for E (r = 0.96, 0.93 and 0.90, respect ively) and at the quadriceps, calf and abdominal sites for C (r = 0.90 , 0.81 and 0.75, respectively). The best ultrasonographic predictor of the percentage fat in both groups was the percentage adipose tissue v olume in the upper leg (r = 0.83 and 0.79 for C and E, respectively). The proportion of adipose tissue in the upper arm segment was not a go od predictor in either group (r = 0.48 and 0.55 for C and E, respectiv ely). Stepwise multiple regression analysis indicated that the predict ion of percentage fat was improved by the addition of the ultrasonogra phic abdomen measurement in both groups: Chinese sample: %fat = %fat(l eg) (0.491) + US abdomen (0.337) + 0.95 (R = 0.89, s.e.e. = 1.9%); Eng lish sample: %fat = %fat(leg) (0.435) + US abdomen (0.230) - 0.765 (R = 0.80, s.e.e. = 3.6%). It is concluded that ultrasonographic measurem ents of subcutaneous adipose tissue and volumetric assessment of perce ntage adipose tissue in the thigh are useful estimates of body composi tion in athletic English and Chinese males.