The excretion of noradrenergic metabolites, particularly MHPG, in obese children and adolescents.

Eighty obese children and adolescents (41 males) aged 4-18 were screened for urinary adrenergic derivatives (NA, A, AVM, MN, MHPG) and the results compared with age- and sex-matched controls. Significantly higher amounts of A (8.1 +/- 0.38 micrograms/24 h), MN (0.327 +/- 0.032 mg/24 h) and MHPG (2.74 +/- 0.192 mg/24 h) were found and significantly linear regression curves of MHPG were plotted against urinary creatinine and NA but not against age, weight and Quettelet index. A subgroup of 26 obese having urinary MHPG over 3 mg/24 h ("high MHPG excretors") revealed significantly greater means of weight Quettelet index, A and NA than the remaining 54--member subgroup ("low MHPG excretors"). It was concluded that in randomly selected obese children and adolescents there are obvious humoral signs of sympathetic nervous system overactivity and, possibly, of adrenomedullary increased tonus and that these manifestations may be due, at least in part, to increased central (encephalic) noradrenergic activity, especially in more overweight patients.