Age-related changes in subcutaneous adipose tissue of adolescent distance runners and association with blood lipoproteins

Abstract

Primary objective : The purpose of this study was to examine age- and sex-associated variation in subcutaneous adipose tissue (SAT) and its association with blood lipoproteins among adolescent distance runners. Methods : Serial data included 99 annual measurements for 27 males and 84 annual measurements for 27 females, aged 9-18 years. SAT was expressed as the sum of six skinfolds (SUM6; subscapular, supra-iliac, abdominal, triceps, biceps and medial calf). The ratio of the sum of three trunk skinfolds to the sum of three extremity skinfolds (TER) was used an index of relative subcutaneous fat distribution. Total blood cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were determined by standard procedures. Results : Age- and sex-associated variation in SAT of adolescents engaged in regular endurance training is similar to trends observed in the general population of youths, although SUM6 is less. An increase in SUM6, rather than the TER, is significantly associated with an increase in LDL-C, TG and TC:HDL in adolescent males, and a decline in HDL-C and an increase in TG in females. Conclusions : This study demonstrates the differential effects of gender on the pubertal development of SAT and blood lipoproteins in young distance runners and highlights the need to explore the interactions among sexual maturation, fatness, fat distribution, exercise training, and blood lipoproteins during adolescence.