Table 1. Comparisons of Key Characteristics in the Normal Cognitive and MCI Groups of White and African American Study Participantsa.
| Characteristic | Diagnostic Group | P Value | |||
|---|---|---|---|---|---|
| Normal Cognition | MCI | ||||
| White (n = 106) | African American (n = 67) | White (n = 104) | African American (n = 85) | ||
| Age, mean (SD), y | 64.7 (7.5) | 62.8 (6.1) | 70.1 (8.1) | 63.4 (7.4) | <.001 |
| Sex | |||||
| Female | 70 (66.0) | 47 (70.1) | 61 (58.7) | 52 (61.2) | .42 |
| Male | 36 (34.0) | 20 (29.9) | 43 (41.3) | 33 (38.8) | |
| Education | |||||
| Some high school | 1 (0.9) | 0 | 2 (1.9) | 3 (3.5) | <.001 |
| High school diploma or GED | 4 (3.8) | 6 (9.0) | 13 (12.5) | 19 (22.4) | |
| Associate degree, some college, or vocational school | 20 (18.9) | 26 (38.8) | 18 (17.3) | 31 (36.5) | |
| Bachelor or college degree | 34 (32.1) | 16 (23.9) | 33 (31.7) | 16 (18.8) | |
| Postgraduate study | 47 (44.3) | 19 (28.4) | 38 (36.5) | 16 (18.8) | |
| BMIb | |||||
| Underweight | 1 (0.9) | 2 (3.2) | 5 (4.9) | 0 | <.001 |
| Normal or healthy weight | 48 (45.3) | 10 (15.9) | 44 (43.1) | 18 (21.2) | |
| Overweight | 32 (30.2) | 23 (36.5) | 28 (27.5) | 29 (34.1) | |
| Obese | 20 (18.9) | 21 (33.3) | 22 (21.6) | 31 (36.5) | |
| Morbid obesity | 5 (4.7) | 7 (11.1) | 3 (2.9) | 7 (8.2) | |
| CDR Memory Sum of Boxes scorec | |||||
| 0 | 103 (98.1) | 65 (97.0) | 9 (9.0) | 12 (14.1) | <.001 |
| 0.5 | 2 (1.9) | 2 (3.0) | 91 (91.0) | 73 (85.9) | |
| MoCA scored | |||||
| ≥26 | 86 (81.1) | 34 (50.7) | 7 (6.8) | 5 (5.9) | <.001 |
| <26 | 20 (18.9) | 33 (49.3) | 96 (93.2) | 80 (94.1) | |
| Family history of AD | 62 (60.2) | 31 (47.0) | 63 (61.8) | 32 (37.6) | .002 |
| Hypertension | 51 (48.6) | 48 (75.0) | 25 (25.3) | 53 (64.6) | <.001 |
| Diabetes | 8 (7.6) | 16 (25.0) | 7 (7.0) | 18 (22.0) | <.001 |
| Heart disease | 16 (15.1) | 18 (26.9) | 26 (25.0) | 19 (22.4) | .22 |
| High cholesterol level | 51 (49.0) | 31 (48.4) | 38 (38.8) | 39 (47.6) | .45 |
| Stroke | 3 (2.9) | 2 (3.1) | 2 (2.0) | 2 (2.4) | .97 |
| Hippocampal volume, mean (SD), mm3 | 7615 (902) | 7344 (814) | 6738 (1218) | 7258 (826) | <.001 |
Abbreviations: AD, Alzheimer disease; BMI, body mass index; CDR, Clinical Dementia Rating; GED, General Educational Development; MCI, mild cognitive impairment; MoCA, Montreal Cognitive Assessment.
a
Data are missing for some participants for BMI, CRD, family history of AD, hypertension, diabetes, high cholesterol level, and stroke.
b
Normal or healthy weight indicates BMI (calculated as weight in kilograms divided by height in meters squared) of 18.5 to 24.9; overweight, 25.0 to 29.9; and obesity, greater than or equal to 30.0.
c
Higher scores indicate worse cognition.
d
Higher scores indicate better cognition.