Background: The large HDL subclass is considered to possess cardioprotective properties. The purpose of this study is to determine the relationship among abdominal adiposity, insulin resistance and HDL subclass profiles of Japanese schoolchildren. Methods: The study subjects included 164 children (79 boys and 85 girls). We obtained waist to height ratio (WHtR), lipid profile, and HOMA-IR. The HDL subclass profile was analyzed by HPLC. Results: Children of either sex with abdominal obesity (WHtR. ≧. 0.5) had reduced concentrations of very large, large, and medium HDLC in conjunction with elevated triglyceride (TG) concentrations and HOMA-IR. WHtR was inversely related to the concentrations of very large (boys: r=0.5306, p. &lt
. 0.0001
girls: r=0.3483, p=0.0011), large (r=0.6168, p. &lt
. 0.0001
r=0.4387, p. &lt
. 0.0001), and medium (r=0.4170, p=0.0001
r=0.4116, p&lt
0.0001) HDLC. The multiple regression analyses revealed that WHtR was an independent factor of the concentrations of very large, large, small, and very small HDLC in boys and the concentrations of large and medium HDLC in girls. Conclusions: In Japanese schoolchildren, abdominal obesity is associated with atherogenic HDL subclass profile. Abdominal obesity may be an important target for the prevention and management of HDL subclass alteration, even in children who do not suffer from insulin resistance or hypertriglyceridemia. © 2013 Elsevier B.V.