Table 2.
Average annual decay (+/−95%CI level) 2013–2017.
| Amino Acid | Model of Decay | Mean Annual Decay | |
|---|---|---|---|
| Absolute decay (µM) | Percentile decay (%) | ||
| Alanine | Stable between 2017–2016. Linear decay from 2016–2013 | 22 (14–30) | 7 (5–10) |
| Arginine | Cannot be interpreted | - | - |
| Asparagine | Linear decay | 4 (2–6) | 13 (7–20) |
| Aspartate | Stable between 2017–2014. Linear decay from 2014–2013 | 1 (0–2) | 3 (0–6) |
| Citrulline | Linear decay | 1 (0.3–1.4) | 8 (3–14) |
| Glutamine | Exponential decay | 2017–2016: 63% 2017–2015: 82% 2017–2014: 91% 2017–2013 92% |
|
| Glutamate | Non-significant increase 2017–2016 (5%). Linear decay from 2016–2013 |
30 (20–40) | 9 (6–12) |
| Glycine | Linear decay | 36 (31–41) | 12 (10–13) |
| Histidine | Cannot be interpreted | - | - |
| Isoleucine | Stable between 2017–2016. Linear decay from 2016–2013 | 2 (1.2–2.5) | 4 (2–5) |
| Leucine | Linear decay | 6 (5–7) | 6 (5–7) |
| Lysine | Linear decay | 5 (4–6) | 15 (12–19) |
| Methionine | Cannot be interpreted | - | - |
| Ornithine | Linear decay | 3 (2–3) | 10 (8–13) |
| Phenylalanine | Linear decay | 4 (3–4) | 7 (6–8) |
| Proline | Stable between 2017–2016. Linear decay from 2016–2013 | 7 (3–10) | 4 (2–6) |
| Serine | Linear decay | 18 (15–21) | 10 (8–12) |
| Taurine | Linear decay | 23 (18–27) | 15 (12–19) |
| Threonine | Linear decay | 9 (8–10) | 8 (7–9) |
| Tryptophan | Linear decay | 4 (3–5) | 25 (18–32) |
| Tyrosine | Stable between 2017–2016. Linear decay from 2016–2013 | 4 (2–6) | 6 (3–9) |
| Valine | Linear decay | 7 (5–10) | 5 (3–6) |
The model of decay (linear or other) for each AA and both the mean absolute (µM) and percentual annual decay (%), including their 95% confidence intervals are presented. Trends for Arg, His and Met could not be interpreted because many measurements were below the detection limit. Assessment of Asp, Arg, Orn, Gln and Lys was possibly less reliable due to high CVs (indicated in light grey).