REGIONAL VARIATION IN RELATIVE ADIPOSE TISSUE DISTRIBUTION DURING ADOLESCENCE1380

Abstract

Studies of relative adipose tissue distribution presently place considerable emphasis on the abdominal region. The present study examines changes in three skinfolds during adolescence, two trunk (subscapular [SUB] and abdominal [ABD]) and one extremity (triceps [TRI]), in 105 youth (53 males, 52 females) followed longitudinally from 11-16 years of age. The three skinfold thicknesses were taken quarterly from 11-14 years, and then semiannually to 16 years of age. Two trunk/extremity skinfold ratios (SUB/TRI, ABD/TRI) and one upper trunk/ lower trunk ratio (SUB/ABD) ratio were calculated to provide an indication of relative subcutaneous adipose tissue(SAT) distribution and are reported as age- and sex-specific medians. There is no sex difference in the SUB/TRI ratio from 11-13 years; subsequently, the ratio increases in males indicating proportionally greater accumulation of SAT on the upper trunk than on the upper extremity. The ABD/TRI ratio is greater in females from 11-13 years, then the ABD/TRI ratio increases around the time of peak height velocity in males so that there is no sex difference through 15 years of age. Males gain proportionally more lower trunk SAT compared to that on the upper extremity, which declines in thickness during the growth spurt. The SUB/ABD ratio is higher in males throughout adolescence, indicating more upper than lower trunk SAT. The SUB/ABD ratio is stable in males from 11-16 years, while it is stable from 11-14 years in females and then declines in later adolescence. These trends suggest that, during adolescence, both upper and lower trunk SAT accumulate at about the same rate in males, but that lower trunk SAT accumulates more rapidly than upper trunk SAT later in females. The results emphasize the differential behavior of individual skinfolds during adolescence in both sexes.