Adipose tissue metabolism in young and middle-aged men after control for total body fatness.

The aim of this study was to compare the sc adipose tissue metabolism of young (29 ± 4 yr) vs. middle-aged men (57 ± 5 yr), once the concomitant variation in total adiposity was taken into account. For this purpose, sc abdominal and femoral adipose tissue lipoprotein lipase activities, as well as fat cell lipolytic responses, were investigated in 2 groups of 16 men, differing in age but displaying similar adipose tissue mass (within 2 kg) and sc abdominal adipose tissue area, measured by computed tomography (within 15 cm2). No difference was observed in adipose tissue lipoprotein lipase activity of young vs. middle-aged subjects, regardless of the adipose region considered. Epinephrine induced antilipolysis at low concentrations (10−9 to 10−7 mol/L) and a net lipolytic response at higher doses (10−6 to 10−5 mol/L), regardless of the subjects’ age and the anatomic location of fat. In addition, the selective α2-adrenergic agonist, UK-14304, promoted a similar antilipolytic response in sc abdominal and femor...