Table 2.
Participant Characteristics (n = 440) with Separate Characteristics for the African Americans within the Sample (n = 70)
| Total sample (n = 440) |
African Americans (n = 70) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Variable | Mean | Min | Max | SD | Mean | Min | Max | SD |
| Age (years) | 43.0 | 30.0 | 54.0 | 7.3 | 44.5 | 30.0 | 54.0 | 7.0 |
| Body mass index (kg/m2) | 26.9 | 17.5 | 49.6 | 5.2 | 29.2 | 18.8 | 45.1 | 5.8 |
| Systolic blood pressure (mmHg) | 114.9 | 89.0 | 151.0 | 11.2 | 119.3 | 91.0 | 147.0 | 10.4 |
| Diastolic blood pressure (mmHg) | 72.3 | 45.0 | 99.0 | 8.2 | 74.8 | 58.0 | 97.0 | 7.4 |
| Years of school | 16.9 | 9.0 | 24.0 | 2.8 | 15.3 | 9.0 | 24.0 | 2.6 |
| Verbal intelligence estimate (IQ)a | 111.1 | 65.0 | 142.0 | 12.3 | 99.3 | 65.0 | 130.0 | 12.8 |
| Performance intelligence estimate (IQ)a | 111.7 | 67.0 | 139.0 | 12.9 | 98.9 | 67.0 | 129.0 | 13.3 |
| Ln HF-HRV | 6.1 | 1.8 | 9.4 | 1.4 | 6.3 | 1.8 | 9.4 | 1.5 |
| Respiratory frequency (Hz) | 0.22 | 0.18 | 0.37 | 0.05 | 0.23 | 0.18 | 0.34 | 0.04 |
| Global cerebral blood flow (ml/100 ml/min) | 57.9 | 33.0 | 100.8 | 10.4 | 58.8 | 35.2 | 94.1 | 10.8 |
N = 430 for all sample participants with both HF-HRV and neuropsychological data.
N = 70 for participants of African American ethnicity with both HF-HRV and neuropsychological data.
N = 432 for cerebral blood flow in the entire sample.
N = 63 for cerebral blood flow in the African American sample.
Note. Caucasian and African American groups differed significantly by t test on all variables except LnHF-HRV, respiratory frequency, and global cerebral blood flow. IQ = derived intelligence quotient.
a
Intelligence estimate was derived from overall testing with the Wechsler Adult Intelligence Scale.