Table 1.
Demographic and clinical characteristics and sleep-related
| Memory impairment |
P | ||
|---|---|---|---|
| No (n = 24,966) | Yes (n = 3,704) | ||
| Age, years | 61.5 ± 7.0 | 65.3 ± 7.2 | < 0.001 |
| Sex, % men | 27.2 | 29.6 | 0.003 |
| Education, % primary or below | 39.1 | 65.9 | < 0.001 |
| Employment, % current | 4.5 | 2.3 | < 0.001 |
| Longest occupation, % manual | 47.0 | 62.2 | < 0.001 |
| Smoking, % current | 9.8 | 11.7 | < 0.001 |
| Drinking, % current | 31.4 | 22.1 | < 0.001 |
| Physical activity, % active | 51.7 | 47.8 | < 0.001 |
| Tea consumption, % regular | 40.5 | 40.8 | 0.73 |
| Poor self-rated health | 17.0 | 21.1 | < 0.001 |
| Waist circumference, cm | 78.7 ± 9.0 | 79.7 ± 9.2 | < 0.001 |
| High-density lipoprotein cholesterol, mmol/L | 1.66 ± 0.41 | 1.64 ± 0.40 | 0.007 |
| Low-density lipoprotein cholesterol, mmol/L | 3.27 ± 0.70 | 3.21 ± 0.73 | < 0.001 |
| Triglycerides, mmol/L | 1.68 ± 1.26 | 1.70 ± 1.30 | 0.33 |
| Systolic blood pressure, mm Hg | 130 ± 22 | 134 ± 23 | < 0.001 |
| Diastolic blood pressure, mm Hg | 73.6 ± 11.2 | 73.7 ± 11.4 | 0.48 |
| Fasting plasma glucose, mmol/L | 5.73 ± 1.63 | 5.89 ± 1.84 | < 0.001 |
| Sleep duration, hours per day | 6.94 ± 1.32 | 6.82 ± 1.48 | < 0.001 |
| Daytime napping, % daily | 39.0 | 42.1 | < 0.001 |
| Morning tiredness, % daily | 3.3 | 4.6 | < 0.001 |
| Insomnia, % yes | 17.0 | 17.9 | 0.21 |
Data were expressed as percentage (%) or mean ± standard deviation. P for one-way analysis of variance or chi-square test.