Figure 2. Ten mitochondrial metabolites are diagnostic for sarcopenia. (A) Three short-chain carnitines and their derivatives (acetyl-carnitine, isovaleryl-carnitine, and butyro-betaine) decreased significantly in sarcopenia. Isovaleryl-carnitine was significantly decreased in the low-SMI group. (B) Four TCA-related metabolites (2-oxoglutarate, cis-aconitate, succinate, and pantothenate) decreased significantly in sarcopenia. 2-oxoglutarate and cis-aconitate were significantly reduced in the low-SMI group. (C) N-acetyl-glutamate, which is related to the urea cycle, was significantly diminished in sarcopenia. (D) Hippurate, which is related to ammonia synthesis, was significantly decreased in the low-SMI group. (E) Aspartate, which is involved in the mitochondrial malate-aspartate shuttle, was significantly increased in sarcopenia. *p < 0.05 Error bars represent means ± SD. **p < 0.01. Error bars represent means ± SD.