Table 2.
Erythrocyte fatty acid concentrations in low and high NAL.
| Low NAL (mean ± SD) | High NAL (mean ± SD) | p | pa | pb | |
|---|---|---|---|---|---|
| SFA | |||||
| C14:0 (Myristic acid) | 0.40 ± 0.07 | 0.38 ± 0.06 | 0.184 | 0.335 | 0.364 |
| C16:0 (Palmitic acid) | 21.94 ± 1.40 | 21.67 ± 0.85 | †0.374 | †0.576 | †0.610 |
| C18:0 (Stearic acid) | 15.70 ± 1.03 | 16.05 ± 0.80 | 0.088 | 0.062 | 0.080 |
| C20:0 (Arachidic acid) | 0.40 ± 0.07 | 0.42 ± 0.06 | 0.196 | 0.128 | 0.157 |
| C24:0 (Lignoceric acid) | 5.03 ± 2.29 | 4.77 ± 0.84 | 0.520 | 0.217 | 0.236 |
| Total SFA | 43.49 ± 0.87 | 43.31 ± 1.21 | 0.392 | 0.157 | 0.157 |
| MUFA | |||||
| C14:1 (Myristoleic acid) | 0.01 ± 0.00 | 0.01 ± 0.01 | 0.171 | 0.306 | 0.313 |
| C16:1 (Palmitoleic acid) | 0.34 ± 0.13 | 0.30 ± 0.08 | †0.345 | †0.265 | †0.239 |
| C18:1n-9 (Oleic acid) | 8.74 ± 0.71 | 8.77 ± 0.64 | 0.824 | 0.946 | 0.887 |
| C18:1n-7 (Vaccenic acid) | 1.91 ± 0.43 | 2.02 ± 0.61 | †0.385 | †0.865 | †0.787 |
| C20:1n-9 (Eicosenoic acid) | 0.25 ± 0.05 | 0.26 ± 0.07 | †0.578 | †0.231 | †0.246 |
| C24:1 (Nervonic acid) | 4.92 ± 0.92 | 5.06 ± 0.89 | 0.478 | 0.841 | 0.831 |
| Total MUFA | 16.19 ± 1.25 | 16.45 ± 1.38 | 0.334 | 0.939 | 0.921 |
| n-6 PUFA | |||||
| C18:2n-6 (Linoleic acid) | 8.82 ± 1.41 | 8.23 ± 1.48 | 0.052 | 0.878 | 0.924 |
| C18:3n-6 (γ-Linolenic acid) | 0.77 ± 0.73 | 1.08 ± 1.64 | †0.928 | †0.244 | †0.281 |
| C20:2n-6 (Eicosadienoic acid) | 0.14 ± 0.04 | 0.13 ± 0.04 | 0.300 | 0.717 | 0.668 |
| C20:3n-6 (Dihomo-γ-linolenic acid) | 1.60 ± 0.46 | 1.66 ± 0.41 | 0.586 | 0.237 | 0.301 |
| C20:4n-6 (Arachidonic acid) | 15.70 ± 2.12 | 16.72 ± 1.91 | 0.020 | 0.035 | 0.043 |
| Total omega-6 | 27.07 ± 2.62 | 27.84 ± 2.29 | 0.145 | 0.023 | 0.027 |
| n-3 PUFA | |||||
| C18:3n-3 (Linolenic acid) | 0.16 ± 0.10 | 0.12 ± 0.07 | 0.033 | 0.076 | 0.084 |
| C20:5n-3 (Eicosapentaenoic acid) | 1.72 ± 0.96 | 1.42 ± 0.69 | 0.106 | 0.063 | 0.068 |
| C22:5n-3 (Docosapentaenoic acid) | 3.33 ± 0.64 | 3.15 ± 0.50 | 0.143 | 0.027 | 0.025 |
| C22:6n-3 (Docosahexaenoic acid) | 8.01 ± 1.59 | 7.68 ± 1.40 | 0.308 | 0.458 | 0.512 |
| Total omega-3 | 13.24 ± 2.72 | 12.38 ± 2.20 | 0.111 | 0.100 | 0.116 |
| Omega-3 Index | 9.73 ± 2.32 | 9.10 ± 1.96 | 0.176 | 0.337 | 0.233 |
Using linear models, fatty acid concentrations were compared between study participants with low (N = 65) and high (N = 35) neocortical amyloid load (NAL) represented by the standard uptake value ratio (SUVR) of the ligand 18F-Florbetaben in the neocortical region normalised with that in the cerebellum. Low NAL was defined as SUVR < 1.35 while high NAL was defined as SUVR ≥ 1.35. pa indicates p values adjusted for age, gender, years of education and APOE ε4 status; pb indicates p values adjusted age, gender, years of education, APOE ε4 status, body mass index, fatty acid supplement intake (cod liver oil, flaxseed oil), hormone replacement therapy. ‘†’ indicates p-values obtained from variables transformed to the logarithmic scale for analyses. SFA: saturated fatty acids; MUFA: monounsaturated fatty acids; PUFA: polyunsaturated fatty acids; omega-3 index: sum of eicosapentaenoic acid and docosahexaenoic acid, expressed as a percentage of total erythrocyte fatty acid measured.