Diagnosis value of minimum exercise test of lactic acid and pyruvic acid for mitochondrial myopathy

Objective: To investigate the diagnosis value of minimum exercise test of lactic acid and pyruvic acid (METLP) for mitochondrial myopathy. Methods: METLP were applied in 21 patients with mitochondrial myopathy, 6 patients with other myopathy and 14 patients without myopathy. All of them were diagnosed by muscle biopsy. The results of METLP were analyzed. Results: The abnormal results of METLP were found in 18 (85. 7%) patients with mitochondrial myopathy, including 12 cases had 2 or more abnormal indexes. The mainly abnormal index was the value of lactic acid post-exercise/ pyruvic acid pre-exercise (L2/P1) > 17. The abnormal results of METLP were found in 6 (100%) patients with other myopathy. Most of them showed a high concentration of lactic acid post-aerobic exercise(L2), and sustainable to after rest, or even more higher(L3). 3(21.4%) patients without myopathy showed abnormal results of METLP. Conclusions: In all the indexes of METLP, the value of L2/P1 is the reliable index for diagnosis mitochondrial myopathy or no-myopathy; the value of L2/L3 is the most important index in differential diagnosis of mitochondrial myopathy and other myopathy. METLP plays a certain role in the diagnosis of the mitochondrial myopathy, but the clinical and pathological data ought to be combined.