Different plasma neuropeptide Y concentrations in women athletes with and without menstrual cyclicity.

The circulating levels of leptin and neuropeptide Y, which are both involved in the control of feeding and reproduction, were measured in amenorrheic and normal cycling highly trained women athletes, and in normal cycling sedentary controls. Leptin showed similar low values in all athletes, whereas neuropeptide Y levels were significantly higher in normal cycling athletes than in the other groups, suggesting the possibility of a protective role of neuropeptide Y in the maintenance of the menstrual cycle in highly trained athletes.