Evidence for differing dopaminergic activity in childhood- or adult-onset obesity

In order to investigate dopaminergic activity in two types of human obesity, childhood- and adult-onset, we have studied the responses of plasma TSH and prolactin to domperidone, a dopamine receptor antagonist, in 12 patients obese since early childhood, 12 patients with adult-onset obesity, and in 12 lean controls. All subjects were females. In childhood-onset obese patients the responses of plasma prolactin and TSH to antidopaminergic stimulation were lower than those of adult-onset obese patients and lean controls. Conversely, the stimulus elicited a normal response of plasma prolactin and an exaggerated response of plasma TSH in adult-onset obese patients. These data indicate the presence of differing dopaminergic tone in the two types of human obesity.