Table 1.
Association between blood pressure levels and vascular dementia in age 60–65 and 70–75 cohorts
| Blood pressure levels | N | Death, % | VaD, % | Hazard ratioa (95% CI) | P value | Hazard ratiob (95% CI) | P value | Hazard ratioc (95% CI) | P value |
|---|---|---|---|---|---|---|---|---|---|
| Age 60–65 cohort – untreated with antihypertensive drug | |||||||||
| Normal | 10,335 | 13.49 | 0.39 | 1.00 (reference) | 1.00 (reference) | ||||
| Prehypertension | 56,231 | 13.24 | 0.55 | 1.50 (1.02, 2.20) | 0.04 | 1.25 (0.88, 1.77) | 0.21 | 1.53 (1.04, 2.25) | 0.03 |
| Stage 1 hypertension | 71,191 | 15.73 | 0.66 | 1.84 (1.26, 2.68) | 0.002 | 1.46 (1.03, 2.05) | 0.032 | 1.90 (1.30, 2.78) | 0.001 |
| Stage 2 hypertension | 29,197 | 20.86 | 0.83 | 2.09 (1.41, 3.10) | <0.001 | 1.49 (1.04, 2.13) | 0.03 | 2.19 (1.48, 3.26) | < 0.001 |
| Age 60–65 cohort – treated with antihypertensive drug | |||||||||
| Normal | 3344 | 25.60 | 0.84 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | |||
| Prehypertension | 22,707 | 18.64 | 0.66 | 0.92 (0.56, 1.52) | 0.75 | 0.90 (0.58, 1.40) | 0.64 | 0.91 (0.55, 1.50) | 0.71 |
| Stage 1 hypertension | 47,227 | 17.50 | 0.75 | 1.05 (0.65, 1.69) | 0.84 | 0.97 (0.63, 1.48) | 0.88 | 1.04 (0.65, 1.68) | 0.86 |
| Stage 2 hypertension | 25,665 | 22.70 | 0.86 | 1.07 (0.65, 1.75) | 0.79 | 0.92 (0.59, 1.42) | 0.70 | 1.08 (0.66, 1.77) | 0.76 |
| Age 70–75 cohort – untreated with antihypertensive drug | |||||||||
| Normal | 3269 | 32.82 | 1.50 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | |||
| Prehypertension | 24,080 | 30.32 | 1.65 | 1.18 (0.82, 1.72) | 0.37 | 1.07 (0.76, 1.52) | 0.69 | 1.19 (0.82, 1.72) | 0.37 |
| Stage 1 hypertension | 46,194 | 31.58 | 1.72 | 1.18 (0.82, 1.69) | 0.38 | 1.13 (0.81, 1.59) | 0.47 | 1.18 (0.82, 1.70) | 0.37 |
| Stage 2 hypertension | 30,874 | 36.97 | 1.72 | 1.12 (0.77, 1.62) | 0.55 | 1.09 (0.77, 1.53) | 0.64 | 1.14 (0.79, 1.65) | 0.49 |
| Age 70–75 cohort – treated with antihypertensive drug | |||||||||
| Normal | 2854 | 46.74 | 1.51 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | |||
| Prehypertension | 20,032 | 36.74 | 1.81 | 1.49 (0.94, 2.35) | 0.09 | 1.10 (0.78, 1.54) | 0.60 | 1.50 (0.95, 2.37) | 0.085 |
| Stage 1 hypertension | 48,593 | 33.30 | 1.91 | 1.76 (1.12, 2.74) | 0.013 | 1.17 (0.84, 1.63) | 0.37 | 1.78 (1.14, 2.79) | 0.011 |
| Stage 2 hypertension | 36,220 | 38.65 | 1.89 | 1.56 (1.00, 2.45) | 0.052 | 1.11 (0.79, 1.54) | 0.56 | 1.60 (1.02, 2.51) | 0.041 |
VaD Vascular dementia, CI Confidence interval
aAdjusted for sex (female = 1) and age
bAdjusted for sex (female = 1), age, body mass index, smoking status, history of diabetes, stroke, transient ischemic attack, head injury and Parkinson’ disease while excluding any individuals with missing values
cAdjusted for sex (female = 1), age, body mass index, smoking status, history of diabetes, stroke, transient ischemic attack, head injury and Parkinson’ disease with missing values imputed by multiple imputation method