Table 1.
Clinical characteristics and MRI findings of the studied population and by cystatin C groups.
| All Participants | Cystatin C ≤ 1.21 mg/l | Cystatin C > 1.21 mg/l | Test statistic and effect size a | |
|---|---|---|---|---|
| Participants | 735 | 534 | 201 | – |
| Age, years † | 73.1±3.8 | 72.7 ± 3.6 | 74.4 ± 4.1 | −5.58, 0.20* |
| Race, % white (n) | 91.3 (671) | 89.7 (479) | 95.5 (192) | 6.22, −0.09 * |
| Sex, % women (n) | 58.5 (430) | 60.7 (324) | 52.7 (106) | 3.79, 0.07 |
| Education level >12 years, % (n) | 48.7 (358) | 48.5 (259) | 49.3 (99) | 0.03, 0.007 |
| ApoE4 allele, % (n) | 23.8 (165) | 23.8 (121) | 23.7 (44) | 0.002, −0.002 |
| Cystatin C, mg/l † | 1.05±0.23 | - | - | - |
| CRP, mg/dl † | 4.77±9.39 | 4.4 ± 8.9 | 5.7 ±10.5 | −3.51, 0.13* |
| SBP, mmHg † | 130.0±18.5 | 129.3 ± 17.7 | 131.9 ± 20.4 | −1.69, 0.06 |
| DBP, mmHg † | 69.3±10.9 | 69.5 ± 10.4 | 68.6 ± 12.1 | 0.98, 0.03 |
| HTN, % (n) † | 32.7 (240) | 29.4 (157) | 41.3 (83) | 9.58, 0.11 * |
| Diabetes mellitus, % (n) † | 9.8 (72) | 10.1 (54) | 8.9 (18) | 0.22, −0.02 |
| Smoking, % (n) † | 50.3 (370) | 50.3 (269) | 50.2 (101) | 0.01, −0.005 |
| Total cholesterol, mg/dl † | 208.3±33.8 | 207.9 ± 33.0 | 209.4 ± 36.0 | −0.52, 0.02 |
| Lipid lowering medication, % (n) † | 8.3 (61) | 7.7 (41) | 10.0 (20) | 0.99, 0.03 |
| Aspirin intake, % (n) † | 43.5 (320) | 45.7 (244) | 37.8 (76) | 3.69, −0.07 |
| Blocks walked per week † | 38.6±54.6 | 41.8 ± 56.2 | 30.18 ± 48.9 | 3.27, 0.12 * |
| Body mass index, kg/m2 † | 26.8±4.2 | 26.6 ± 4.1 | 27.3 ± 4.5 | −1.85, 0.06 |
| Waist circumference, cm † | 97.1±12.9 | 94.5 ± 12.4 | 99.7 ± 13.4 | −4.86, 0.17 * |
| CHD, % (n) † | 15.4 (113) | 15.0 (80) | 16.4 (33) | 0.23, 0.02 |
| % GM/TIV ∫ | 45.5 ± 2.1 | 45.8 ± 2.1 | 45.2 ± 2.1 | 3.79, 0.13 * |
| WMG > 3, % (n) ∫ | 21.8 (160) | 19.1 (102) | 28.9 (58) | 8.16, 0.10 * |
| Infarcts on MRI, % (n) ∫ | 28.2 (207) | 25.8 (138) | 34.3 (69) | 5.19, 0.08 * |
| 3MSE § | 95.4±4.5 | 95.6 ± 4.3 | 94.8 ±5.0 | 2.13, 0.07 * |
| DSST § | 43.9±12.1 | 44.5 ± 12.2 | 42.3 ± 11.4 | 2.26, 0.08 * |
| BVRT § | 4.7±2.1 | 4.7 ± 2.1 | 4.4 ± 2.1 | 2.55, 0.09 * |
Continuous variables are represented as mean ± standard deviation.
Variables defined at the time of the blood sample (1993–94).
Variables defined at the time of the brain MRI scan (1997–98).
Variables defined at the last clinic evaluation (1998–99).
t and point biserial correlation for means, χ2 and φ for cross-tabulations.
indicates a p-value < 0.05.
3MSE: Modified Mini-Mental State Examination; ApoE4: Apolipoprotein Eε4; CHD: coronary heart disease; DBP: diastolic blood pressure; BVRT: Benton Visual Retention Test; CRP: C-reactive protein; DSST: Digit Symbol Substitution Test; GM: gray matter; MRI: magnetic resonance imaging; SBP: systolic blood pressure; TIV: total intracranial volume; WMG: white matter grade.