Table 4.
Relationship between untargeted PL FA chains and the % of geometric and positional FA isomers in plasma PL.
| Common namea | Palmiticb C16:0 | Stearicb C18:0 | Oleicb C18:1 | Elaidicb C18:1 | Eicosenoicb C20:1 | Linoleicb C18:2 | Linoelaidicb C18:2 | ALAb C18:3 | Eicosadienoicb C20:2 | DGLAb C20:3 | ARAb C20:4 | EPAb C20:5 | DPA ω-3b C22:5 | DPAω-6b C22:5 | DHAb C22:6 | Nervonicb C24:1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LPC(20:5) | — | — | — | — | — | — | — | — | — | — | — | 1.02 | — | — | — | — |
| LPC(18:3) | — | — | — | — | — | — | — | 0.24 | — | — | — | — | — | — | — | — |
| LPC(22:6) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 0.96 | — |
| LPC(18:2) | — | — | — | — | — | 0.90 | 0.01 | — | — | — | — | — | — | — | — | — |
| LPE(18:2) | — | — | — | — | — | 1.33 | 0.03 | — | — | — | — | — | — | — | — | — |
| LPS(20:4) | — | — | — | — | — | — | — | — | — | — | −0.85 | — | — | — | — | — |
| LPC(18:1) | — | — | 0.36 | 0.02 | — | — | — | — | — | — | — | — | — | — | — | — |
| LPE(18:1) | — | — | 0.48 | 0.09 | — | — | — | — | — | — | — | — | — | — | — | — |
| LPC(20:2) | — | — | — | — | — | — | — | — | 0.28 | — | — | — | — | — | — | — |
| LPC(17:0) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| LPC(20:1) | — | — | — | — | 0.11 | — | — | — | — | — | — | — | — | — | — | — |
| Palmitic acid | 1.24 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| PI(16:0_22:6) | 0.09 | — | — | — | — | — | — | — | — | — | — | — | — | — | 0.97 | — |
| PC(18:2_18:2) | — | — | — | — | — | 2.61 | —0.29 | — | — | — | — | — | — | — | — | — |
| PC(O—16:0_20:5) | — | — | — | — | — | — | — | — | — | — | — | 0.99 | — | — | — | — |
| PC(18:1_18:2) | — | — | 0.15 | −0.17 | — | 1.05 | −0.14 | — | — | — | — | — | — | — | — | — |
| PC(O-16:1_18:2) | — | — | — | — | — | 0.93 | −0.12 | — | — | — | — | — | — | — | — | — |
| PC(O-18:1_22:5) | — | — | — | — | — | — | — | — | — | — | — | — | 0.70 | 0.21 | — | — |
| PC(O-16:0_18:2) | — | — | — | — | — | 1.14 | −0.13 | — | — | — | — | — | — | — | — | — |
| PC(18:0_18:2) | — | 0.54 | — | — | — | 1.04 | −0.33 | — | — | — | — | — | — | — | — | — |
| PC(20:1_20:4) | — | — | — | — | 0.31 | — | — | — | — | — | −0.11 | — | — | — | — | — |
| PE(16:0_18:1) | 2.53 | — | 0.33 | −0.21 | — | — | — | — | — | — | — | — | — | — | — | — |
| PE(18:0_20:4) | — | 0.77 | — | — | — | — | — | — | — | — | 0.12 | — | — | — | — | — |
| PC(O-18:0_22:6) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 0.74 | — |
| PC(18:0_22:5) | — | 1.86 | — | — | — | — | — | — | — | — | — | — | −0.28 | 0.63 | — | — |
| PC(18:0_20:3) | — | 0.76 | — | — | — | — | — | — | — | 0.68 | — | — | — | — | — | — |
| PC(O-18:1_18:2) | — | — | — | — | — | 0.65 | −0.11 | — | — | — | — | — | — | — | — | — |
| PE(18:0_20:3) | — | 1.62 | — | — | — | — | — | — | — | 0.82 | — | — | — | — | — | — |
| SM(d19:1/24:1) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 0.81 |
Each plasma PL was regressed on the % of each FA isomer in the plasma PL, and models were adjusted for BMI. This was performed to determine the relationship between the abundance of each plasma PL significantly associated with the responses in our study and the % of FA isomers in plasma PL from our previous study. For instance, LPC(18:2) and LPE(18:2) were significantly associated with the % of linoleic acid (LA, ω-6, C18:2Δ9Z,12Z) in plasma PL, whereas LPC(18:2) and LPE(18:2) were not correlated with the % of trans-isomer linoelaidic acid (ω-6, C18:2Δ9E,12E) in plasma PL. Numeric values represent the estimated effects (beta coefficients) and are bolded if p < 0.05. The plasma analyzed from both data sets were collected at the same time point from the same patients. Models were defined as: log(plasma PL) = log(% FA isomer in plasma PL) + BMI.
aThe significant PL associated with the responses that were structurally characterized in our study. The experimental methodology employed was the UPLC-ESI-MSE analysis of crude lipid extracts outlined in this manuscript.
bThe geometric and positional FA isomers that were targeted in our previous study (Pickens et al. PLEFA. 2015). The experimental methodology employed was the FAME analysis of isolated plasma PL by GC-FID. The specific isomers investigated were: oleic acid (ω-9C18:1Δ9Z), elaidic acid (ω-9C18:1Δ9E), eicosaenoic acid (ω-9, C20:1Δ11Z), linoleic acid (LA, ω-6, C18:2Δ9Z,12Z), linoelaidic acid (ω-6, C18:2Δ9E,12E), dihomo-gamma-linolenic acid (DGLA, ω-6, C20:3Δ8Z,11Z,14Z), arachidonic acid (ARA, ω-6, C20:4Δ5Z,8Z,11Z,14Z), docosapentaenoic acid ω-6 (DPA ω-6, C22:5Δ4Z,7Z,10Z,13Z,16Z), alpha-linolenic acid (ALA, ω-3, C18:3Δ9Z,12Z,15Z), eicosapentaenoic acid (EPA, ω-3, C20:5Δ5Z,8Z,11Z,14Z,17Z), docosapentaenoic acid ω-3 (DPA ω-3, C22:5Δ7Z,10Z,13Z,16Z,19Z), docosahexaenoic acid (DHA, ω-3,C20:5Δ4Z,7Z,10Z,13Z,16Z,19Z), and nervonic acid (ω-9, C24:1Δ15Z).