Table 3.
Basis for the sample size calculation.
| Power for detecting metabolite | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Metabolite | FM | Control | Sample | Method | Effect size | P-value | n = 25 | n = 50 | n = 100 |
| 2-hydroxybutyrate | 19 | 19 | Urine | NMR | 0.72 | 0.0001 | 0.704 | 0.946 | 0.999 |
| Succinate | 0.61 | 0.0001 | 0.558 | 0.852 | 0.990 | ||||
| Taurine | 0.52 | 0.0007 | 0.567 | 0.726 | 0.954 | ||||
| Tyrosine | 0.45 | 0.0029 | 0.468 | 0.603 | 0.884 | ||||
| Lactate | 0.42 | 0.0044 | 0.428 | 0.670 | 0.837 | ||||
| Hypoxanthine | 22(F) | 22(F) | serum | HPLC-UV | 9.78 | <0.00001 | 1.000 | 1.000 | 1.000 |
| Xanthine | 8.64 | <0.00001 | 1.000 | 1.000 | 1.000 | ||||
| Inosine | 8.46 | <0.00001 | 1.000 | 1.000 | 1.000 | ||||
| lysoPC(14:0) | 22 | 21 | plasma | LC-MS | 1.10 | 0.000036 | 0.968 | 1.000 | 1.000 |
| PC(18:1(9Z)/0:0) | 0.74 | 0.00013 | 0.727 | 9.956 | 0.999 | ||||
| lysoPC(22:6) | 0.72 | 0.0024 | 0.704 | 0.946 | 0.999 | ||||
| lysoPC(18:2) | 0.64 | 0.0049 | 0.602 | 0.887 | 0.994 | ||||
| glutamate | 105 | 54 | serum | LC-MS | 0.50* | 0.034 | 0.410 | 0.700 | 0.940 |
| glutamine | 0.76* | 0.00035 | 0.766 | 0.970 | 1.000 | ||||
*
Estimated. FM: Fibromyalgia
The metabolites are derived by our review on metabolomics in chronic pain: Teckchandani, S., Nagana Gowda, G.A., Raftery, D., & Curatolo, M. (2021). Metabolomics in chronic pain research. European Journal of Pain, 25, 313–326. 10.1002/ejp.1677