Table 2. Unadjusted Mean and Covariate-Adjusted LSM Concentrations of 3 CSF Biomarkers and 2 Ratios by Race in B-SHARP Cohort.
| Biomarker by Study Population | Unadjusted Analysis | Adjusted Analysis | Difference (95% CI)c | ||||
|---|---|---|---|---|---|---|---|
| Racial Group, Mean (SE) | P Value | Racial Group, LSM (SE)a | P Valueb | ||||
| African American | White | African American | White | ||||
| Aβ1-42 level, pg/mL | |||||||
| Full | 247.76 (77.79) | 235.33 (74.50) | .16 | 249.35 (8.27) | 239.09 (6.34) | .35 | 10.26 (−11.18 to 31.71) |
| MCI | 246.68 (81.50) | 206.40 (73.52) | .001 | 246.01 (11.64) | 224.77 (9.90) | .19 | 21.24 (−10.64 to 53.12) |
| Normal cognition | 249.18 (73.39) | 261.42 (65.47) | .30 | 254.18 (11.38) | 256.54 (7.73) | .87 | −2.36 (−30.53 to 25.82) |
| Tau level, pg/mL | |||||||
| Full | 48.00 (29.51) | 69.80 (45.52) | <.001 | 48.15 (3.89) | 65.16 (2.98) | .001 | −17.01 (−27.10 to −6.92) |
| MCI | 50.59 (29.26) | 86.55 (56.39) | <.001 | 52.40 (5.90) | 78.98 (5.02) | .001 | −26.58 (−42.75 to −10.41) |
| Normal cognition | 44.58 (29.79) | 54.70 (24.68) | .03 | 48.03 (4.49) | 50.93 (3.05) | .61 | −2.9 (−14.02 to 8.22) |
| pTau181 level, pg/mL | |||||||
| Full | 13.25 (6.37) | 20.31 (14.82) | <.001 | 13.60 (1.28) | 19.81 (0.98) | <.001 | −6.21 (−9.54 to −2.88) |
| MCI | 13.83 (6.72) | 25.92 (18.19) | <.001 | 15.42 (2.06) | 25.24 (1.75) | .001 | −9.82 (−15.47 to −4.17) |
| Normal cognition | 12.49 (5.86) | 15.24 (8.17) | .04 | 13.08 (1.33) | 14.23 (0.90) | .49 | −1.15 (−4.44 to 2.15) |
| Tau to Aβ1-42 ratio | |||||||
| Full | 0.23 (0.27) | 0.36 (0.38) | .001 | 0.22 (0.03) | 0.33 (0.03) | .009 | −0.12 (−0.20 to −0.03) |
| MCI | 0.25 (0.34) | 0.51 (0.48) | <.001 | 0.25 (0.06) | 0.44 (0.05) | .01 | −0.19 (−0.34 to −0.04) |
| Normal cognition | 0.19 (0.11) | 0.23 (0.16) | .09 | 0.21 (0.03) | 0.22 (0.02) | .75 | −0.01 (−0.07 to 0.05) |
| pTau181 to Aβ1-42 ratio | |||||||
| Full | 0.06 (0.06) | 0.11 (0.11) | <.001 | 0.06 (0.01) | 0.10 (0.01) | .001 | −0.04 (−0.06 to −0.02) |
| MCI | 0.07 (0.08) | 0.15 (0.13) | <.001 | 0.07 (0.02) | 0.14 (0.01) | .003 | −0.06 (−0.11 to −0.02) |
| Normal cognition | 0.05 (0.03) | 0.06 (0.04) | .12 | 0.06 (0.01) | 0.06 (0.01) | .60 | 0.00 (−0.02 to 0.01) |
Abbreviations: Aβ1-42, β-amyloid 1-42; B-SHARP, Brain Stress Hypertension and Aging Research Program; LSM, least square means; MCI, mild cognitive impairment; pTau181, phosphorylated tau 181.
a
Derived from the general linear models after adjustment for age, sex, educational level, family history of Alzheimer disease, body mass index, Montreal Cognitive Assessment score, hypertension, diabetes, and income level.
b
Bonferroni correction (P < .017) did not alter the results for the adjusted P values.
c
Derived from the general linear model using the SAS code statement for the difference between least square means with associated 95% CI.