Table 1.
Characteristics of participants with normal and low cognitive scores.
| Characteristics | Total | CERAD-IR | CERAD-DR | DSST | AF | ||||
|---|---|---|---|---|---|---|---|---|---|
| ≥17 (n = 2016) | <17 (n = 863) | ≥5 (n = 2102) | <5 (n = 769) | ≥34 (n = 2074) | <34 (n = 710) | ≥14 (n = 1975) | <14 (n = 885) | ||
| Age, years | 69.42 ± 6.74 | 68.33 ± 6.06 * | 72.95 ± 7.74 | 68.30 ± 6.19 # | 73.11 ± 7.22 | 68.59 ± 6.05 ǂ | 73.13 ± 8.64 | 68.58 ± 6.13 § | 72.23 ± 7.97 |
| Gender, % | |||||||||
| Male | 45.4 | 73.0 * | 27.0 | 73.2 # | 26.8 | 85.0 | 15.0 | 78.8 | 21.2 |
| Female | 54.6 | 80.1 | 19.9 | 81.0 | 19.0 | 85.3 | 14.7 | 76.8 | 23.2 |
| Race, % | |||||||||
| White | 79.5 | 79.0 | 21.0 | 78.4 | 21.6 | 89.5 | 10.5 | 81.7 | 18.3 |
| Black | 8.2 | 71.5 | 28.5 | 72.8 | 27.2 | 64.2 | 35.8 | 57.4 | 42.6 |
| Asian | 3.4 | 73.1 | 26.9 | 83.0 | 17.0 | 84.3 | 15.7 | 54.3 | 45.7 |
| Hispanic | 7.3 | 62.7 | 37.3 | 69.6 | 30.4 | 57.3 | 42.7 | 67.2 | 32.8 |
| Education, % | |||||||||
| <9th grade | 6.2 | 43.5 | 56.5 | 56.7 | 43.3 | 33.5 | 66.5 | 49.6 | 50.4 |
| 9–11th grade | 10.5 | 60.9 | 39.1 | 68.7 | 31.3 | 67.2 | 32.8 | 62.6 | 37.4 |
| High school | 21.8 | 74.0 | 26.0 | 74.3 | 25.7 | 83.4 | 16.6 | 71.2 | 28.8 |
| Some college | 31.3 | 82.0 | 18.0 | 82.5 | 17.5 | 91.0 | 9.0 | 82.3 | 17.7 |
| ≥ College | 30.2 | 86.0 | 14.0 | 81.7 | 18.3 | 95.7 | 4.3 | 88.4 | 11.6 |
| Oral hypoglycemic agents/insulin, % | |||||||||
| Yes | 14.7 | 71.9 | 28.1 | 73.6 | 26.4 | 77.5 | 22.5 | 79.0 § | 21.0 |
| No | 85.3 | 77.7 | 22.3 | 78.1 | 21.9 | 86.5 ǂ | 13.6 | 70.1 | 29.9 |
| Sleep disorder, % | |||||||||
| Yes | 11.6 | 77.0 | 23.0 | 78.0 | 22.0 | 86.0ǂ | 14.0 | 78.9§ | 21.1 |
| No | 88.4 | 77.0 | 23.0 | 77.5 | 22.5 | 85.2 | 14.9 | 77.6 | 22.4 |
| History of stroke, % | |||||||||
| Yes | 6.7 | 62.7* | 37.3 | 66.2# | 33.8 | 66.1ǂ | 33.9 | 61.0 § | 39.0 |
| No | 93.3 | 77.9 | 22.1 | 78.2 | 21.8 | 86.4 | 13.6 | 79.0 | 21.0 |
| History of hyperlipidemia, % | |||||||||
| Yes | 57.5 | 77.4* | 22.6 | 77.6# | 22.5 | 85.7ǂ | 14.3 | 78.0 | 22.0 |
| No | 42.5 | 76.7 | 23.3 | 77.8 | 22.2 | 85.2 | 14.8 | 77.7 | 22.3 |
| Smoking | |||||||||
| Yes | 50.3 | 77.5 | 22.5 | 78.7 | 21.3 | 84.8 | 15.2 | 78.0 | 22.0 |
| No | 49.7 | 76.2 | 23.8 | 76.2 | 23.8 | 85.5 | 14.5 | 77.4 | 22.6 |
| Consuming alcohol, % | |||||||||
| Yes | 72.4 | 79.9* | 20.1 | 79.5# | 20.5 | 88.4ǂ | 11.6 | 81.1 § | 18.9 |
| No | 27.6 | 70.2 | 29.8 | 72.9 | 27.1 | 77.7 | 22.4 | 70.0 | 30.0 |
| BMI, kg/m2 | 28.90 ± 6.24 | 29.18 ± 6.12 * | 28.02 ± 6.44 | 29.07 ± 6.15 # | 28.37 ± 6.60 | 28.89 ± 5.78 | 28.81 ± 8.62 | 28.97 ± 5.82 | 28.70 ± 7.78 |
| SBP, mmHg | 131.68 ± 18.85 | 130.63 ± 17.34 * | 134.63 ± 23.30 | 130.76 ± 17.88 # | 134.53 ± 22.04 | 130.57 ± 16.73 ǂ | 137.28 ± 29.01 | 130.64 ± 17.49 § | 135.23 ± 23.09 |
| PHQ-9 score | 2.93 | 2.83 ± 3.84 * | 3.43 ± 5.37 | 2.83 ± 3.90 # | 3.42 ± 5.22 | 2.66 ± 3.60 ǂ | 4.46 ± 7.22 | 2.74 ± 3.68 § | 3.75 ± 5.98 |
| HOMA-IR | 2.41 (1.47–4.11) | 2.43 (1.43–4.05) | 2.39 (1.52–4.36) | 2.39 (1.42–4.05) | 2.48 (1.55–4.34) | 2.43 (1.47–4.04) | 2.50 (1.48–4.5) | 2.42 (1.48–4.11) | 2.36 (1.36–4.11) |
| FPG, mmol/L | 5.99 ± 1.71 | 5.97 ± 1.59 | 6.05 ± 2.11 | 5.96 ± 1.62 | 6.09 ± 2.02 | 5.96 ± 1.58 | 6.13 ± 2.22 | 5.96 ± 1.49 | 6.06 ± 2.29 |
| Insulin, μIU/ml | 9.41 (6.06–15.13) | 9.40 (6.01–15.04) | 9.59 (6.28–15.27) | 9.32 (6.04–14.97) | 9.89 (6.41–15.56) | 9.41 (6.06–15.07) | 9.87 (6.03–15.54) | 9.42 (6.13–15.07) | 9.16 (5.88–15.07) |
| HbA1c, %1 | 5.90 ± 0.91 | 5.88 ± 0.85 | 5.97 ± 1.06 | 5.88 ± 0.88 # | 5.98 ± 0.99 | 5.85 ± 0.78 ǂ | 6.15 ± 1.60 | 5.87 ± 0.81 § | 6.03 ± 1.23 |
| 2h-PG, mmol/L | 7.47 ± 2.98 | 7.36 ± 2.85 * | 8.01 ± 3.38 | 7.31 ± 2.90 # | 8.21 ± 3.17 | 7.25 ± 2.65 ǂ | 8.74 ± 4.71 | 7.36 ± 2.82 § | 7.95 ± 3.59 |
*CERAD-IR ≥ 17 vs. CERAD-IR < 17, p < 0.05; #CERAD-DR ≥ 5 vs. CERAD-DR < 5, p < 0.05; ǂDSST ≥ 34 vs. DSST < 34, p < 0.05; §AF ≥ 14 vs. AF < 14, p < 0.05. Constituent ratios of race and education differed significantly between participants with normal and low scores in all cognitive tests according to design-based χ2 tests.
Data were presented as mean ± standard deviations for normal distribution variables, median (25th–75th percentile) for skewed distribution variables, and weighted percentages for categorical variables.
Design-based t tests for continuous data and design-based χ2 tests for categorical data were performed to determine statistical difference between characteristics of participants with normal and low cognitive scores. Skewed distribution variables (HOMA-IR, Insulin) were log-transformed before statistical comparisons.
AF, Animal Fluency Test; BMI, body mass index; CERAD-IR, Consortium to Establish a Registry for Alzheimer’s Disease Immediate Recall; CERAD-DR, Consortium to Establish a Registry for Alzheimer’s Disease Delayed Recall; DSST, Digit Symbol Substitution Test; HOMA-IR, homoeostasis model assessment of insulin resistance; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; 2h-PG, 2-h postload glucose; PHQ-9, Patient Health Questionnaire (a nine-item screening instrument that asked questions about the frequency of symptoms of depression over the past 2 weeks); SBP, systolic blood pressure.