Table 2.
Characteristics of study subjects by tertiles of INP.
| INP Tertile | |||||
|---|---|---|---|---|---|
| Total | Lowest | Middle | Highest | P | |
| 330 | 110 | 110 | 110 | ||
| INP score, mean (SD) | 0 (0.24) | -0.25 (0.19) | 0.02 (0.05) | 0.23 (0.12) | <0.0001 |
| INP score, range | -1.0~ -0.76 | -1.0~ -0.09 | -0.08 ~0.10 | 0.10 ~ 0.76 | |
| Age | 79.0 (5.76) | 78.5 (5.4) | 78.4 (5.5) | 80.1 (6.2) | 0.040 |
| Education | 11.04 (4.66) | 12.17 (4.38) | 10.96 (4.61) | 9.99 (4.76) | 0.002 |
| Female, N(%) | 212 (64) | 72 (66) | 67 (61) | 73 (66) | 0.660 |
| APOE 1 or 2 ε4, N(%) | 81 (25) | 26 (24) | 26 (24) | 29 (26) | 0.860 |
| Race/Ethnicity, N(%) | 0.008 | ||||
| Whites | 108 (33) | 49 (45) | 35(32) | 24 (22) | |
| Blacks | 104 (32) | 29 (26) | 31 (28) | 44 (40) | |
| Hispanics | 109 (33) | 29 (26) | 39 (35) | 41 (37) | |
| Others | 9 (3) | 3 (3) | 5 (5) | 1 (1) | |
| BMI | 27.65 (5.07) | 27.02 (5.19) | 27.96 (4.48) | 27.96 (5.49) | 0.292 |
| Vascular Score | 1.14 (0.85) | 1.2 (0.93) | 1.09 (0.74) | 1.13 (0.86) | 0.621 |
| Language z-score | 0.34 (0.65) | 0.46 (0.59) | 0.35 (0.74) | 0.22 (0.59) | 0.024 |
| Memory z-score | 0.14 (0.78) | 0.20 (0.84) | 0.13 (0.75) | 0.09 (0.75) | 0.570 |
| Speed z-score | 0.21 (1.01) | 0.33 (0.86) | 0.29 (1.02) | -0.01 (1.11) | 0.039 |
| Visuospatial z-score | 0.34 (0.55) | 0.48 (0.50) | 0.32 (0.57) | 0.20 (0.56) | 0.001 |
| Global z-score | 0.25 (0.6) | 0.37 (0.55) | 0.26 (0.65) | 0.13 (0.57) | 0.009 |
| ICV, cm3 | 1317 (160) | 1328 (167) | 1322 (156) | 1305 (157) | 0.583 |
| TBV, cm3 | 880.2 (105) | 895.7 (114) | 881.3 (111) | 863.6 (88) | 0.076 |
| TGMV, cm3 | 522.2 (53.2) | 531.2 (54.8) | 522 (56.5) | 513.4 (46.9) | 0.047 |
| TWMV, cm3 | 379.3 (57.3) | 387.8 (60.1) | 381.6 (59.9) | 368.6 (50.3) | 0.039 |
| TBV residual, cm3 | 2.68 (67.18) | 13.9 (60.44) | 1.61 (71.72) | -7.46 (67.76) | 0.060 |
| TGMV residual, cm3 | 0.05 (35.5) | 7 (33.74) | -1.21 (38.03) | -5.65 (33.7) | 0.027 |
| TWMV residual, cm3 | 2.44 (45.02) | 9.08 (42.18) | 3.81 (47.92) | -5.55 (43.95) | 0.050 |
| Mean cortical thickness, mm | 2.46 (0.11) | 2.47 (0.09) | 2.45 (0.13) | 2.45 (0.10) | 0.170 |
| WMHV, cm3 | 3.6 (5.8) | 2.99 (4.98) | 3.43 (5.81) | 4.37 (6.46) | 0.201 |
| Log10 (WMHV/ICV) | -6 .0(0.69) | -6.07 (0.67) | -6.09 (0.74) | -5.85 (0.65) | 0.022 |
Abbreviations: apolipoprotein (APOE); intracranial volume (ICV); total brain volume (TBV); total gray matter volume (TGMV); total white matter volume (TWMV); white matter hyperintensity volume (WMHV). Values in the table show mean (SD) for all variables except for categorical variables, which are N(%). P values were from chi-squared test for categorical variables and ANOVA for continuous variables.