D-G. Spiroergometry results from PEO patients and control subjects on normal diet (ND), as well as one month and six months after mAD initiation. PEO patients had higher serumlactate levels, and attenuated respiratory response to exercise. These effects were further enhanced after mAD and remained after 6 months of the study. mAD increased patients' serumammonium (NH4+) levels. Data presented as mean and SD. 