[Forearm ischemic exercise test. Standardization and diagnostic value in the identification of McArdle disease].
OBJECTIVE
The forearm ischemic exercise test (FIET) with serial lactate determinations is used worldwide for the screening of McArdle's disease and other glucogenosis. Yet there is no uniformity with regard to the intensity of the work and the ischemia time. The aim of this study was to standardize the test conditions in normal people and to check its efficacy in our population.


METHODS
In a first stage, we included 9 healthy persons in whom four different conditions were applied regarding the cuff pressure and ischemia time. In a second stage, 5 previously known McArdle disease patients, 30 normal individuals and 25 patients with a diagnosis of myopathy other than glucogenosis underwent FIET with the conditions standardized in the first stage.


RESULTS
The best curve profile was obtained with a cuff pressure 20 mm Hg above systolic blood pressure and with exercise until fatigue o cramps without time limitation. With a cut-point at 200% of the basal values of ammonium and lactate, the sensitivity and specificity of FIET were 100% and 96%, respectively, for McArdle's disease. No major side effects were recorded in any case.


CONCLUSIONS
Conditions of FIET have been standardized. Taking into account the high sensitivity and specificity of the test, its use should be considered in the screening of anaerobic metabolic myopathies.
Sanjurjo
Eduard
E
Unidad de Investigación de Muscular, Servicio de Medicina Interna, Institut de Recerca Biomèdica August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universidad de Barcelona, Spain.
Laguno
Montserrat
M
Bedini
Josep Lluís
JL
Miró
Oscar
O
Grau
Josep Maria
JM
D000328:Adult; D005080:Exercise Test / Q000592:standards*; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006012:Glycogen Storage Disease Type V / Q000175:diagnosis*; D006801:Humans; D007511:Ischemia / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity