Measuring subcutaneous fat thickness using skinfold calipers vs. high-resolution B-scan ultrasonography in healthy volunteers: A pilot study

Abstract

Background & AimsMeasuring the thickness of skinfolds using calipers is a frequently used method for determining body fat in clinical practice. It is inexpensive and time saving compared to other methods and can be learned quickly. The aim of this study is to compare skinfold measurements made using calipers against measurements obtained using high-resolution ultrasonography (USG).MethodsA monocentric cross-sectional observational pilot study with 69 normal-weight volunteer participants aged between 18 and 80 years (women: n = 36, men: n = 33). Subcutaneous fat thickness was measured at five different sites (chest, abdomen, thighs, triceps, and back) using calipers and via USG.The mean values from the calipers and the USG measurements were examined for statistical significance using the paired t-test, and the Bland–Altman plot was used to compare the two methods. We then performed an agreement analysis by calculating the percentage of the differences less than or equal to 1 mm between the measurements made using calipers and those obtained via USG.ResultsFrom the Bland–Altman analysis, the best matches among measurements for the female subjects were the skinfolds on the triceps (ULoA: 4.6 mm, mean: −0.1 mm, LLoA: −4.8 mm), the back (ULoA: 3.9 mm, mean: −0.2 mm, LLoA: −4.4 mm), and on the chest (ULoA: 5.9 mm, mean: 0.6 mm, LLoA: −4.6 mm). In contrast, for the male subjects, the best matches were the skinfolds on the triceps (ULoA: 3.3 mm, mean: −0.3 mm, LLoA −4.0 mm), the back (ULoA 3.5 mm, mean −0.3 mm, LLoA −4.0 mm), and the thigh (ULoA 2.2 mm, mean −0.5 mm, LLoA −3.2 mm).The best agreement for women was obtained with the measurements of the chest fold (47.2%), followed by the measurements of the back fold (38.9%). For men, it was the measurements of the thigh fold (63.6%), followed by the measurements of the triceps (51.5%) and back fold (51.5%).ConclusionThe agreement between skinfold measurements made using calipers and ultrasonography depends on the skinfold thickness and the localization of the measurement, with gender-based differences. Measuring the thickness of skinfolds using calipers is a frequently used method for determining body fat in clinical practice. It is inexpensive and time saving compared to other methods and can be learned quickly. The aim of this study is to compare skinfold measurements made using calipers against measurements obtained using high-resolution ultrasonography (USG). A monocentric cross-sectional observational pilot study with 69 normal-weight volunteer participants aged between 18 and 80 years (women: n = 36, men: n = 33). Subcutaneous fat thickness was measured at five different sites (chest, abdomen, thighs, triceps, and back) using calipers and via USG. The mean values from the calipers and the USG measurements were examined for statistical significance using the paired t-test, and the Bland–Altman plot was used to compare the two methods. We then performed an agreement analysis by calculating the percentage of the differences less than or equal to 1 mm between the measurements made using calipers and those obtained via USG. From the Bland–Altman analysis, the best matches among measurements for the female subjects were the skinfolds on the triceps (ULoA: 4.6 mm, mean: −0.1 mm, LLoA: −4.8 mm), the back (ULoA: 3.9 mm, mean: −0.2 mm, LLoA: −4.4 mm), and on the chest (ULoA: 5.9 mm, mean: 0.6 mm, LLoA: −4.6 mm). In contrast, for the male subjects, the best matches were the skinfolds on the triceps (ULoA: 3.3 mm, mean: −0.3 mm, LLoA −4.0 mm), the back (ULoA 3.5 mm, mean −0.3 mm, LLoA −4.0 mm), and the thigh (ULoA 2.2 mm, mean −0.5 mm, LLoA −3.2 mm). The best agreement for women was obtained with the measurements of the chest fold (47.2%), followed by the measurements of the back fold (38.9%). For men, it was the measurements of the thigh fold (63.6%), followed by the measurements of the triceps (51.5%) and back fold (51.5%). The agreement between skinfold measurements made using calipers and ultrasonography depends on the skinfold thickness and the localization of the measurement, with gender-based differences.