Characteristics in the different P-tau181 tertiles
| First tertile | Second tertile | Third tertile | P value | P value$ | |
| N=158 | N=157 | N=161 | |||
| Plasma P-tau181 | |||||
| Age (years) | 76.9 (5.4) | 77.9 (5.1) | 78.3 (5.9) | 0.06 | 0.0009 |
| Women (%) | 101 (63.9) | 96 (61.1) | 95 (59.0) | 0.66 | 0.32 |
| BMI (kg/m2) | 25.8 (3.7) | 24.9 (3.9) | 24.4 (3.7) | 0.004 | 0.01 |
| MMSE (/30) | 26.7 (2.4) | 26.4 (2.5) | 26.1 (2.7) | 0.16 | 0.19 |
| 1 or 2 APOE4 alleles (%) | 38 (17.7) | 63 (40.1) | 84 (52.2) | <0.0001 | <0.0001 |
| Hippocampal volume (R+L) (cm3) | 4.75 (1.13) | 4.38 (1.16) | 4.5 (1.04) | 0.02 | 0.28 |
| Aβ+ status (%) | 13 (19.1) | 40 (62.5) | 64 (78.0) | <0.0001 | <0.0001 |
| Conversion MCI (%) | 26 (16.4) | 41 (26.1) | 77 (47.8) | <0.0001 | <0.0001 |
| Blood biomarkers | |||||
| Fasting glycaemia (mmol/L) | 5.46 (1.28) | 5.4 (1.1) | 5.26 (1.18) | 0.32 | 0.12 |
| Triglycerides (mmol/L) | 1.2 (0.6) | 1.3 (0.7) | 1.2 (0.5) | 0.26 | 0.23 |
| Cholesterol (mmol/L) | 5.52 (1.19) | 5.48 (1.23) | 5.5 (1.06) | 0.94 | 0.82 |
| Cholesterol HDL (mmol/L) | 1.72 (0.47) | 1.76 (0.56) | 1.75 (0.52) | 0.85 | 0.29 |
| Cholesterol LDL (mmol/L) | 3.25 (1.03) | 3.15 (1.07) | 3.21 (0.9) | 0.69 | 0.59 |
| Prealbumin (mg/dL) | 27.5 (6.2) | 28 (6.7) | 28.4 (5.4) | 0.47 | 0.17 |
| Albumin (g/L) | 40.4 (3.7) | 40.2 (4.8) | 40.3 (3.1) | 0.87 | 0.90 |
| Creatinine (μmol/L) | 73.5 (16.5) | 78.6 (19) | 82.1 (26.1) | 0.002 | 0.0005 |
| eGFR (mL/min/1.73 m2) | 80.3 (13.5) | 76 (14.1) | 74.4 (15.9) | 0.02 | 0.01 |
| Plasma P-tau181(pg/mL) | 1.75 (0.38) | 2.93 (0.36) | 4.86 (1.19) | NA | NA |
P: Comparison between the three groups, by ANOVA or χ2); P$: comparison between the three groups with linear regression adjusted for age, sex and the presence of the APOE ε4 allele; % (number) were used to describe categorical variables, mean±SD for continuous variables.
ANOVA, analysis of variance; APOE, apolipoprotein E; BMI, body mass index; eGFR, estimated glomerular filtration rate; MCI, mild cognitive impairment; MMSE, Mini Mental State Examination; NA, not available; R+L, right+left.