Unique Exercise Lactate Profile in Muscle Phosphofructokinase Deficiency (Tarui Disease); Difference Compared with McArdle Disease.
BACKGROUND
Glycogen storage disease V (GSDV, McArdle disease) and GSDVII (Tarui disease) are the most common of the rare disorders of glycogen metabolism. Both are associated with low lactate levels on exercise. Our aim was to find out whether lactate response associated with exercise testing could distinguish between these disorders.


METHODS
Two siblings with Tarui disease, two patients with McArdle disease and eight healthy controls were tested on spiroergometric exercise tests with follow-up of venous lactate and ammonia.


RESULTS
A late increase of lactate about three times the basal level was seen 10-30 min after exercise in patients with Tarui disease being higher than in McArdle disease and lower than in the controls. Ammonia was increased in Tarui disease.


CONCLUSIONS
Our results suggest that follow-up of lactate associated with exercise testing can be utilized in diagnostics to distinguish between different GSD diseases.
Unit of Clinical Physiology, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki , Helsinki , Finland.
Päivi
P
Piirilä
Department of Clinical Nutrition Therapy, Helsinki University Central Hospital , Helsinki , Finland.
Minna E
ME
Similä
Neuromuscular Research Center, Tampere University Hospital, University of Tampere , Tampere , Finland.
Johanna
J
Palmio
Unit of Clinical Physiology, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki , Helsinki , Finland.
Tomi
T
Wuorimaa
Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki , Helsinki , Finland.
Emil
E
Ylikallio
Neuromuscular Research Center, Tampere University Hospital, University of Tampere, Tampere, Finland; Department of Neurology, Seinäjoki Central Hospital, Seinäjoki, Finland; Department of Neurology, Tampere University Hospital, Tampere University, Tampere, Finland.
Satu
S
Sandell
Unit of Clinical Physiology, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki , Helsinki , Finland.
Petri
P
Haapalahti
Laboratory of Clinical Chemistry, HUSLAB, Helsinki University Hospital , Helsinki , Finland.
Lasse
L
Uotila
Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
Henna
H
Tyynismaa
Neuromuscular Research Center, Tampere University Hospital, University of Tampere , Tampere , Finland.
Bjarne
B
Udd
Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences, Neurology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
Mari
M
Auranen
McArdle disease; Tarui disease; ammonia; lactate; muscle metabolism; muscle phosphofructokinase; pentose phosphate pathway; spiroergometry