Three protocols for measuring subcutaneous fat thickness on the upper extremities

Three protocols for measuring subcutaneous fat thickness were compared and their level of association determined in young adults. Subjects included 21 men and 21 women, 18-24 years of age. Skinfold calipers, A- and B-mode ultrasound were used to measure the thickness of the subcutaneous fat layer overlying the anterior and posterior aspects of the upper arm. Each protocol was independently administered within a 30-min block of time in a randomly rotated sequence. Significant differences (p less than 0.05) between protocols were observed depending upon site of measurement and gender of the subject. At both the anterior and posterior sites for men, B-mode and halved skinfold were similar but significantly less than A-mode measurements. At the anterior site for women, A-mode and skinfold were similar but significantly greater than B-mode measurements. At the posterior site for women, all three measurements were similar. Correlations between the protocols were positive with men's levels ranging from 0.59 to 0.74, while women's levels were from 0.39 to 0.89. It was concluded that although skinfold calipers, A-mode ultrasound, and B-mode ultrasound may be used to obtain moderately associated measurements of upper-arm subcutaneous fat thickness in young adults, the three protocols yield inconsistently similar data.