Table 7.
Skeletal muscle metabolic intermediate concentrations
| Rheumatoid arthririts (n = 51) | Controls (n = 50) | |||
|---|---|---|---|---|
| Mean | SD | Mean | SD | |
| Amino acids | ||||
| Glycine | 1012.669 | 304.568 | 1042.875 | 360.089 |
| Alanine | 2781.241 | 876.247 | 2735.464 | 820.802 |
| Serine | 773.987 | 190.246 | 777.726 | 286.455 |
| Proline | 502.861 | 179.5 | 528.023 | 222.984 |
| Valine | 291.82 | 75.004 | 300.739 | 99.003 |
| Leucine/isoleucine | 659.544 | 197.996 | 663.116 | 233.404 |
| Methionine | 54.167 | 14.36 | 55.372 | 17.48 |
| Histidine | 488.821 | 164.605 | 548.187 | 276.048 |
| Phenylalanine | 77.739 | 22.414 | 80.155 | 27.759 |
| Tyrosine | 80.962 | 23.249 | 88.815 | 32.052 |
| Aspartate/asparagine | 100.518 | 62.088 | 144.672 | 198.704 |
| Glutamate/glutamine | 2096.524 | 658.272 | 2359.04 | 878.482 |
| Ornithine | 212.338 | 85.775 | 184.849 | 69.873 |
| Citrulline | 69.446 | 39.718 | 75.05 | 50.441 |
| Arginine | 431.024 | 182.215 | 394.565 | 149.594 |
| Organic acids | ||||
| Lactate | 22862.683 | 9246.29 | 20956.576 | 8926.553 |
| Pyruvate | 1168.544* | 604.675 | 803.474 | 539.098 |
| Succinate | 48.143 | 35.538 | 41.793 | 29.968 |
| Fumarate | 70.313 | 26.403 | 62.708 | 25.253 |
| Malate | 521.019 | 205.905 | 476.648 | 198.079 |
| alphaKetoglutarate | 144.24 | 143.952 | 113.438 | 118.669 |
| Citrate | 41.677 | 33.591 | 36.853 | 24.096 |
| Acylcarnitines | ||||
| Free carnitine: C0 | 3369.034 | 1006.646 | 3631.978 | 1243.598 |
| C2 | 455.175 | 288.39 | 485.702 | 312.966 |
| C3 | 5.206 | 2.024 | 5.019 | 2.018 |
| C4/Ci4 | 3.541 | 4.994 | 3.008 | 2.594 |
| C5:1 | 1.033 | 0.397 | 1.03 | 0.41 |
| C5 | 1.667 | 1.15 | 2.246 | 5.666 |
| C4OH | 2.789 | 2.231 | 2.378 | 1.778 |
| C6 | 3.58 | 3.882 | 2.956 | 2.855 |
| C5OH | 0.676 | 0.363 | 0.65 | 0.343 |
| C3DC | 0.793 | 0.356 | 0.809 | 0.292 |
| C4DC/Ci4DC | 2.439 | 1.424 | 2.547 | 1.192 |
| C8:1 | 0.531 | 0.328 | 0.532 | 0.252 |
| C8 | 0.942 | 0.904 | 0.826 | 0.694 |
| C5DC | 1.528 | 1.043 | 1.43 | 0.727 |
| C8:1OH/C6:1 DC | 0.216 | 0.129 | 0.204 | 0.123 |
| C6DC/C8OH | 0.353 | 0.239 | 0.388 | 0.226 |
| C10:3 | 0.067 | 0.047 | 0.067 | 0.034 |
| C10:2 | 0.05 | 0.03 | 0.063 | 0.041 |
| C10:1 | 0.261 | 0.253 | 0.239 | 0.164 |
| C10 | 0.655 | 0.6 | 0.58 | 0.48 |
| C7DC | 0.108 | 0.079 | 0.088 | 0.049 |
| C8:1 DC | 0.087 | 0.073 | 0.093 | 0.051 |
| C10OH:C8DC | 0.305 | 0.253 | 0.31 | 0.21 |
| C12:2 | 0.052 | 0.034 | 0.052 | 0.035 |
| C12:1 | 0.364 | 0.281 | 0.366 | 0.287 |
| C12 | 1.359 | 1.073 | 1.31 | 1.125 |
| C12:2OH/C10:2 DC | 0.075 | 0.045 | 0.064 | 0.04 |
| C12:1OH/C10:1 DC | 0.224 | 0.178 | 0.202 | 0.114 |
| C12OH/C10DC | 0.441 | 0.472 | 0.417 | 0.382 |
| C14:3 | 0.078 | 0.052 | 0.073 | 0.054 |
| C14:2 | 1.126 | 1.025 | 0.902 | 0.83 |
| C14:1 | 2.726 | 2.354 | 2.449 | 2.232 |
| C14 | 4.156 | 3.277 | 3.781 | 3.373 |
| C14:3OH/C12:3 DC | 0.032 | 0.025 | 0.028 | 0.022 |
| C14:2OH/C12:2 DC | 0.174 | 0.121 | 0.143 | 0.081 |
| C14:1OH/C12:1 DC | 0.704 | 0.538 | 0.701 | 0.431 |
| C14OH/C12DC | 0.502 | 0.525 | 0.487 | 0.381 |
| C16:3 | 0.198 | 0.164 | 0.157 | 0.103 |
| C16:2 | 1.533 | 1.201 | 1.199 | 0.948 |
| C16:1 | 6.736 | 5.227 | 5.751 | 3.973 |
| C16 | 20.041 | 15.253 | 17.878 | 12.497 |
| C16:3OH/C14:3-DC | 0.053 | 0.038 | 0.045 | 0.024 |
| C16:2OH/C14:2 DC | 0.477 | 0.336 | 0.412 | 0.248 |
| C16:1OH/C14:1 DC | 1.306 | 1.077 | 1.256 | 0.834 |
| C16OH/C14DC | 1.18 | 1.265 | 1.229 | 1.059 |
| C18:3 | 1.463 | 0.982 | 1.354 | 0.925 |
| C18:2 | 20.561 | 15.909 | 17.722 | 13.495 |
| C18:1 | 46.521 | 37.117 | 40.451 | 28.311 |
| C18 | 11.278 | 8.401 | 10.817 | 8.203 |
| C18:3OH/C16:3 DC | 0.186 | 0.158 | 0.168 | 0.101 |
| C18:2OH/C16:2 DC | 1.357 | 1.235 | 1.323 | 1.177 |
| C18:1OH/C16:1 DC | 2.683 | 2.889 | 2.844 | 2.749 |
| C18OH/C16DC | 0.695 | 0.68 | 0.732 | 0.523 |
| C20:4 | 2.023 | 1.801 | 1.778 | 1.872 |
| C20:3 | 0.63 | 0.597 | 0.57 | 0.431 |
| C20:2 | 0.308 | 0.271 | 0.261 | 0.164 |
| C20:1 | 0.554 | 0.484 | 0.485 | 0.409 |
| C20 | 0.369 | 0.4 | 0.329 | 0.308 |
| C20:3OH/C18:3 DC | 0.075 | 0.059 | 0.074 | 0.056 |
| C20:2OH/C18:2 DC | 0.053 | 0.034 | 0.05 | 0.03 |
| C20:1OH/C18:1 DC | 0.071 | 0.062 | 0.062 | 0.046 |
| C20OHC18DC/C22:6 | 0.212 | 0.248 | 0.198 | 0.206 |
| C22:5 | 0.264 | 0.299 | 0.247 | 0.277 |
| C22:4 | 0.241 | 0.279 | 0.193 | 0.158 |
| C22:3 | 0.064 | 0.057 | 0.056 | 0.044 |
| C22:2 | 0.051 | 0.035 | 0.044 | 0.025 |
| C22:1 | 0.069 | 0.05 | 0.065 | 0.038 |
| C22 | 0.059 | 0.049 | 0.062 | 0.046 |
Data are shown as means and standard deviations (pmol/mg tissue). Metabolic intermediates were measured in muscle homogenates. Group comparisons between muscle from patients with rheumatoid arthritis and from controls were performed using logarithmically transformed metabolic intermediates and mixed models. Prefix C denotes acylcarnitines followed by carbon number and degree of unsaturation. Suffixes OH and DC denote hydroxyl and dicarboxyl groups, respectively. *P < 0.05 for comparison with matched controls