Table 4.
Hazard ratios of dementia according to coronary artery calcium (CAC) score at baseline (N=6293, from 2000 through 2013)
| CAC category | Continuous CAC | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||||||
| 0 | 1 to 400 | 401 to 1000 | ≥ 1001 | per 1SD5) higher CAC [log2(CAC+1)] | |||||||||
|
| |||||||||||||
| HR | (95% CI) | P | HR | (95% CI) | P | HR | (95% CI) | P | HR | (95% CI) | P | ||
|
|
|||||||||||||
| Model | |||||||||||||
| Minimal adjustment1) | 1.0 (ref) | 1.27 | (0.93, 1.74) | 0.127 | 1.37 | (0.89, 2.13) | 0.157 | 1.65 | (1.04, 2.63) | 0.033 | 1.23 | (1.08, 1.40) | 0.002 |
| Full adjustment1) | 1.0 (ref) | 1.23 | (0.90, 1.69) | 0.189 | 1.35 | (0.86, 2.11) | 0.187 | 1.71 | (1.07, 2.73) | 0.026 | 1.24 | (1.08, 1.41) | 0.002 |
| Full adjustment + interim stroke2) adjusted | 1.0 (ref) | 1.13 | (0.82, 1.56) | 0.445 | 1.21 | (0.77, 1.90) | 0.412 | 1.51 | (0.94, 2.42) | 0.087 | 1.19 | (1.04, 1.36) | 0.013 |
| Full adjustment + interim CVD2) adjusted | 1.0 (ref) | 1.07 | (0.78, 1.48) | 0.664 | 1.06 | (0.67, 1.67) | 0.799 | 1.26 | (0.78, 2.04) | 0.341 | 1.13 | (0.98, 1.29) | 0.084 |
| Competing risk model (full adjustment) 3) | 1.0 (ref) | 1.18 | (0.86, 1.62) | 0.310 | 1.23 | (0.78, 1.95) | 0.364 | 1.40 | (0.85, 2.29) | 0.183 | 1.17 | (1.02, 1.35) | 0.023 |
| Age as time-scale, stratified by birth cohort 4) | 1.0 (ref) | 1.22 | (0.89, 1.67) | 0.226 | 1.33 | (0.85, 2.08) | 0.220 | 1.65 | (1.03, 2.63) | 0.037 | 1.22 | (1.07, 1.40) | 0.003 |
| Full adjustment with exclusion | |||||||||||||
| interim stroke excluded (n=6120, case=241) | 1.0 (ref) | 1.11 | (0.81, 1.54) | 0.513 | 1.16 | (0.72, 1.87) | 0.553 | 1.50 | (0.92, 2.46) | 0.106 | 1.18 | (1.03, 1.36) | 0.018 |
| interim CVD excluded (n=5908, case=220) | 1.0 (ref) | 1.10 | (0.79, 1.53) | 0.569 | 0.96 | (0.57, 1.63) | 0.883 | 1.60 | (0.95, 2.68) | 0.075 | 1.17 | (1.01, 1.35) | 0.039 |
Adjusting covariates in “Minimal adjustment”: age (years), sex, and race (White/Black/Chinese/Hispanic). “Full adjustment” further included education level (to high school/to associate degree/bachelor’s degree or higher), having health insurance (yes/no), physical activity (MET-minutes/week, log-transformed), smoking (current/former/never), obesity (yes/no), hypertension (yes/no), medication(s) for hypertension or dyslipidemia (yes/no), systolic blood pressure (mmHg), non high-density lipoprotein cholesterol (mg/dL), diabetes mellitus (yes/no), APOE ε4 genotype (homo/hetero/none).
Interim stroke and interim CVD were treated as time-dependent variables.
In the competing risk model, death without dementia diagnosis was treated as the competing risk to dementia.
The results were based on cox regression model stratified with 3-birth cohorts (1917 to <1925, 1925 to <1935, and thereafter).
1SD (standard deviation) of log2[CAC+1] =3.634, equivalent to multiplying CAC score by 12.4.
The corresponding HRs (95%CIs) per doubling [CAC+1] in models from the top to the bottom rows were 1.06 (1.02, 1.10), 1.06 (1.02, 1.10), 1.05 (1.01, 1.09), 1.03 (1.00, 1.07), 1.05 (1.01, 1.09), 1.06 (1.02, 1.10), 1.05 (1.01, 1.09), and 1.04 (1.00, 1.09).