Table 4.
Adjusted Predictors of Poorer Cognitive Performance by Groupa
| Predictor | Risk Group, OR (95% CI) | |
|---|---|---|
| VASC+ (n = 2018) |
VASC− (n = 555) |
|
| Age, y | 1.12 (1.08–1.17) | 1.02 (0.87–1.17) |
| Female sex, yes/no | 0.37 (0.18–0.72) | 0.85 (0.36–2.05) |
| Non-Hispanic white, yes/no | 0.16 (0.09–0.26) | 0.22 (0.06–0.86) |
| Educational attainment, No. of school years | 0.23 (0.14–0.38) | 0.19 (0.10–0.38) |
| Ratio of poverty to income, yes/no | 0.56 (0.07–0.76) | 0.85 (0.50–1.44) |
| Sedentary lifestyle, yes/no | 2.99 (1.62–5.55) | 0.52 (0.12–2.22) |
| Obesity, yes/no | 1.33 (0.72–2.44) | 0.56 (0.10–3.10) |
| C-reactive protein level, mg/dL | 1.13 (0.80–1.59) | 0.99 (0.52–1.89) |
| Current smoking, yes/no | 0.50 (0.19–1.35) | 0.35 (0.05–2.54) |
| Increased blood pressure variability, yes/no | 1.46 (0.74–2.80) | 3.49 (1.07–11.35) |
| Ankle-brachial index >1.30, yes/no | 0.65 (0.12–3.44) | 18.56 (2.94–117.05) |
| Tibial systolic blood pressure | 0.99 (0.99–1.01) | 0.99 (0.96–1.01) |
| Total cholesterol level, per every 10 mg/dL | 0.99 (0.94–1.05) | 1.09 (0.93–1.01) |
| Hemoglobin A1c level | 1.14 (0.85–1.54) | 7.78 (0.95–63.71) |
| Stroke, yes/no | 1.63 (0.60–4.44) | NA |
| Cardiac disease, yes/nob | 1.15 (0.70–3.01) | NA |
| PAD, yes/no | 1.56 (0.66–3.72) | NA |
| Use of renin-angiotensin system blockers, yes/no | 0.24 (0.07–0.79) | NA |
| Use of dihydropyridine calcium channel blockers, yes/no | 9.24 (1.35–63.23) | NA |
Abbreviations: DSST, Digit Symbol Substitution Test; NA, not applicable; OR, odds ratio; PAD, peripheral arterial disease; VASC−, absence of vascular variables negatively associated with cognition; VASC+, presence of vascular variables negatively associated with cognition.
SI conversion factors: To convert cholesterol to millimoles per liter, multiply by 0.0259; C-reactive protein to nanomoles per liter, multiply by 9.524; hemoglobin A1c to proportion of total hemoglobin, multiply by 0.01.
In the VASC+ regression, we adjusted for the degree of blood pressure control. Optimally controlled hypertension was defined as evidence of a systolic blood pressure of less than 140 mm Hg and a diastolic blood pressure of less than 90 mm Hg (or <130 mm Hg and <80 mm Hg, respectively, in participants with diabetes mellitus).
Given that more than 50% of participants with congestive heart failure had cardiac ischemic disease, we merged both categories into cardiac disease to solve the collinearity.