Adrenomedullary response to caffeine in prepubertal and pubertal obese subjects

OBJECTIVE: To investigate whether blunted adrenomedullary responsiveness to stimuli is a primary feature of human obesity in childhood and adolescence DESIGN: Comparison of plasma catecholamine response to caffeine in obese an d lean subjects before and after puberty onset. SUBJECTS: Twelve lean prepubertal subjects (six males and six females), 15 prepubertal obese subjects (seven males and eight females), 12 pubertal lea n subjects (six males and six females) and 24 pubertal obese subjects (12 m ales and 12 females). MEASUREMENTS: Plasma levels of Luteinizing hormone (LH), follicle-stimulati ng hormone (FSH), 17 beta-estradiol and testosterone were used to validate Tanner score. Systolic and diastolic blood pressure, pulse rate and plasma catecholamines before and after caffeine administration (4 mg/kg of ideal b ody weight). RESULTS: Caffeine administration significantly stimulated adrenaline releas e in all subjects studied. The incremental area of adrenaline response to c affeine, analysed by multiple comparison test, was lower in pubertal obese subjects with respect to other groups. CONCLUSIONS: At variance with what is observed in adulthood obesity, prepub ertal obese subjects show an intact adrenomedullary response to caffeine.