TABLE 1.
Summary of metabolomic platforms used in analysis, including predictive performance in single platform analysis
| Platform | Abbreviation | Details | N data points a | r b | MAE b |
|---|---|---|---|---|---|
| MS HPOS in serum | sHPOS | Hydrophilic interaction chromatography (HILIC), provides enhanced separation of small, highly polar molecules ionized in positive mode | 1,505 | .62 (.56, .67) | 5.69 (5.34, 6.07) |
| MS LNEG in serum | sLNEG | Lipid‐targeted reversed‐phase chromatography provides maximal resolution of fatty acids, triglycerides, and phospholipids, ionized in negative mode | 5,833 | .71 (.67, .75) | 5.07 (4.76, 5.37) |
| MS LPOS in serum | sLPOS | Lipid‐targeted reversed‐phase chromatography, ionized in positive mode | 7,211 | .80 (.77, .83) | 4.29 (4.06, 4.55) |
| NMR BiLISA in serum | sBiLISA | Quantifies cholesterol, free cholesterol, phospholipids, triglycerides, apolipoprotein A1, A2, B and particle numbers for the primary lipoproteins and their subclasses | 105 | .45 (.39, .51) | 6.49 (6.19, 6.79) |
| NMR CPMG in serum | sNMR | Highly robust, repeatable and precise platform | 23,571 | .65 (.62, .69) | 5.53 (5.21, 5.82) |
| MS HPOS in urine | uHPOS | Hydrophilic interaction chromatography (HILIC), provides enhanced separation of small, highly polar molecules ionized in positive mode | 7,325 | .77 (.74, .80) | 4.62 (4.27, 4.95) |
| MS RNEG in urine | uRNEG | Reversed‐phase chromatography targets small moderately polar molecules, ionized in negative mode | 14,481 | .79 (.75, .82) | 4.42 (4.14, 4.70) |
| MS RPOS in urine | uRPOS | Reversed‐phase chromatography, ionized in positive mode | 14,300 | .83 (.80, .85) | 4.17 (3.92, 4.38) |
| NMR NOESY in urine | uNMR | Highly robust, repeatable and precise platform | 24,493 | .58 (.52, .62) | 5.88 (5.62, 6.20) |
a
Refers to spectral data points in uNMR and sNMR, to lipoprotein and subclass measures in sBiLISA and retention time‐m/z pairs in MS analysis.
b
r and MAE refer to the mean Pearson's correlation and mean absolute error, respectively, with chronological age across the independent test sets, with brackets showing bootstrapped 95% confidence internals.