Simple skinfold-thickness measurements complement conventional anthropometric assessments in predicting glucose tolerance

Abstract

Background: Skinfold-thickness measurements are considered to have limited clinical utility. Objective: To assess whether skinfold-thickness measurements may be a useful adjunct to conventional anthropometric assessments in predicting glucose and insulin regulation, we studied responses to replicate 75-g oral-glucose-tolerance tests (OGTTs) and performed simple anthropometry in a cross section of subjects. Design: Thirty-five subjects completed the study: 11 lean [mean (±SEM) age: 33 ± 3.2 y; body mass index (BMI; in kg/m2): 24.1 ± 0.8; and percentage body fat (%BF): 11.5 ± 1.5%], 12 normal-weight (age: 33 ± 2.9 y; BMI: 23.9 ± 0.7; and %BF: 24.3.5 ± 1.3%), and 12 obese (age: 41 ± 4.5 y; BMI: 34.5 ± 1.7; and %BF: 34.2 ± 1.5%) individuals. The lean and normal-weight groups were selected to have similar BMIs but different %BFs. We measured the participants' heights, weights, %BFs, waist circumferences, hip circumferences, and truncal and peripheral skinfold thicknesses. Subjects received nine 75-g OGTTs and blood samples were collected at 0, 15, 30, 45, 60, 90, and 120 min. Mean plasma glucose and insulin values were used to calculate the insulin sensitivity index. Results: The obese group had higher plasma glucose concentrations and areas under the curve (AUCs) than did the normal-weight or lean group and higher plasma insulin concentrations and AUCs than did the lean group (P < 0.05). Stepwise multiple regression, with adjustment for demographic and anthropometric measurements, identified the following predictors: waist circumference, peripheral skinfold thickness, and BMI for fasting plasma glucose (partial R2 = 0.20, 0.13, and 0.13, P < 0.05); waist circumference and truncal skinfold thickness for plasma glucose AUC (partial R2 = 0.20 and 0.13, P < 0.05); age, waist-to-hip ratio, and peripheral skinfold thickness for fasting plasma insulin (partial R2 = 0.26, 0.22, and 0.15, P < 0.05); truncal skinfold thickness for plasma insulin AUC (partial R2 = 0.41, P < 0.001); and peripheral skinfold thickness for both 2-h plasma glucose (partial R2 = 0.59, P < 0.001) and the insulin sensitivity index (partial R2 = 0.49, P < 0.001). Conclusion: Skinfold-thickness measurements may complement other established measurements for predicting abnormal glucose and insulin regulation.