Table 1. Study sample characteristics by race/ethnicity: The UK Biobank 2006–2021a.
| Study sample characteristics | All participants | Both sexes combined, n = 323,483 | P | |
| White | Non-white | |||
| Socio-demographic | ||||
| Baseline age, y | 60.4 ± 5.4 | 60.5 ± 5.4 | 58.6 ± 5.6 | <0.001 |
| Sex, % female | 53.6 | 53.6 | 53.8 | 0.81 |
| Race/ethnicity | — | |||
| White | 96.4 | 100.0 | 0.0 | — |
| Black | 0.9 | 0.0 | 25.2 | — |
| South Asian | 1.2 | 0.0 | 33.6 | — |
| Other | 1.5 | 0.0 | 41.1 | — |
| Household size | 2.2 ± 1.2 | 2.2 ± 1.1 | 2.7 ± 1.6 | <0.001 |
| Socio-economic status | ||||
| Education | ||||
| Low | 21.8 | 21.7 | 23.4 | — |
| Intermediate | 39.6 | 40.0 | 29.8 | <0.001 |
| High | 38.6 | 38.3 | 46.8 | <0.001 |
| Income | <0.001 | |||
| Less than £18,000 | 25.3 | 25.2 | 30.3 | — |
| £18,000–£29,999 | 28.0 | 28.0 | 27.8 | — |
| £30,000–£51,999 | 24.9 | 24.9 | 22.5 | — |
| £52,000–£100,000 | 17.4 | 17.5 | 15.1 | — |
| greater than £100,000 | 4.4 | 4.4 | 4.3 | — |
| TDI | −1.56 ± 2.95 | −1.63 ± 2.90 | 0.47 ± 3.48 | <0.001 |
| SES z-score | −0.03 ± 0.70 | −0.02 ± 0.70 | −0.28 ± 0.79 | <0.001 |
| Lifestyle factors | ||||
| Smoking | ||||
| Smoking status | ||||
| Never | 81.3 | 81.2 | 86.0 | — |
| Former | 9.5 | 9.7 | 4.2 | <0.001 |
| Current | 9.2 | 9.2 | 9.9 | 0.61 |
| Environmental tobacco smoke | 0.88 ± 5.2 | 0.88 ± 5.26 | 1.03 ± 4.72 | 0.002 |
| Pack-years of tobacco smoke | 0.08 ± 0.26 | 0.08 ± 0.26 | 0.05 ± 0.19 | <0.001 |
| SMOKING z-score | −0.005 ± 0.442 | −0.004 ± 0.442 | −0.025 ± 0.418 | <0.001 |
| Alcohol consumption | ||||
| Alcohol consumption frequency | ||||
| 0 "never" | 7.3 | 6.6 | 24.5 | — |
| 1 "special occasions only" | 11.1 | 10.6 | 23.7 | <0.001 |
| 2 "1–3 times per month" | 10.4 | 10.4 | 10.9 | <0.001 |
| 3 "1–3 times per week" | 24.7 | 25.0 | 18.2 | <0.001 |
| 4 "3–4 times per week" | 23.7 | 24.2 | 12.0 | <0.001 |
| 5 "daily or almost daily" | 22.8 | 23.2 | 10.7 | <0.001 |
| ALCOHOL z-score | 0.00 ± 1.00 | +0.03 ± 0.98 | −0.743 ± 1.11 | <0.001 |
| Physical activity, PA | ||||
| PA, Met.min.wk-1 | 1,963 ± 2,812 | 1,971 ± 2,817 | 1,772 ± 2,796 | <0.001 |
| PA z-score | 0.00 ± 1.00 | +0.00 ± 1.00 | −0.068 ± 0.992 | <0.001 |
| Diet quality | ||||
| HDI total score | 5.11 ± 1.50 | 5.10 ± 1.50 | 5.36 ± 1.43 | <0.001 |
| DIET z-score | 0.00 ± 1.00 | −0.01 ± 1.00 | 0.17 ± 0.96 | <0.001 |
| Nutritional Biomarkers | ||||
| 25-hydroxyvitamin D | 49.6 ± 20.9 | 50.2 ± 20.8 | 35.4 ± 18.1 | <0.001 |
| Red cell distribution width | 13.5 ± 0.9 | 13.5 ± 0.9 | 13.8 ± 1.2 | <0.001 |
| NUTR z-score | −0.001 ± 0.757 | +0.017 ± 0.746 | −0.496 ± 0.871 | <0.001 |
| Social Support | ||||
| “How often do you visit friends or family or have them visit you?” | 5.27 ± 1.13 | 5.28 ± 1.13 | 4.84 ± 1.21 | <0.001 |
| “How often are you able to confide in someone close to you?” | 1.04 ± 0.87 | 1.04 ± 0.87 | 0.95 ± 0.83 | <0.001 |
| “Which of the following do you attend once a week or more often?” | 3.55 ± 1.89 | 3.56 ± 1.88 | 3.03 ± 1.98 | <0.001 |
| SS z-score | −0.001 ± 0.630 | +0.008 ± 0.631 | −0.254 ± 0.669 | <0.001 |
| Cardio-metabolic and general health-related factors | ||||
| Body mass index, kg.m-1 | 27.5 ± 4.7 | 27.5 ± 4.7 | 27.8 ± 5.0 | <0.001 |
| Allostatic load | 2.10 ± 1.39 | 2.10 ± 1.38 | 2.23 ± 1.41 | <0.001 |
| Co-morbidity index | 2.11 ± 1.94 | 2.11 ± 1.94 | 2.12 ± 1.92 | <0.001 |
| Self-rated health | <0.001 | |||
| Excellent | 16.5 | 16.7 | 11.2 | |
| Good | 59.0 | 59.2 | 53.2 | |
| Fair | 20.4 | 20.1 | 28.8 | |
| Poor | 4.1 | 4.0 | 6.7 | |
| HEALTH z-score | 0.0004 ± 0.687 | −0.004 ± 0.687 | 0.110 ± 0.701 | <0.001 |
| Cognitive performance | ||||
| Reaction Time | 6.33 ± 0.19 | 6.32 ± 0.18 | 6.41 ± 0.22 | <0.001 |
| Pairs matching, errors | 0.72 ± 0.70 | 0.70 ± 0.70 | 0.99 ± 0.73 | <0.001 |
| Pairs matching, time to complete | 5.35 ± 0.37 | 5.34 ± 0.4 | 5.57 ± 0.46 | <0.001 |
| COGN z-score | 0.000 ± 0.756 | −0.018 ± 0.743 | 0.481 ± 0.917 | <0.001 |
| LE8 | ||||
| Total score | 502.3 ± 95.6 | 502.8 ± 95.6 | 488.8 ± 95.2 | <0.001 |
| Biological score | 246.4 ± 65.9 | 246.8 ± 65.7 | 236.0 ± 63.1 | <0.001 |
| Lifestyle score | 255.9 ± 63.3 | 256.0 ± 63.3 | 251.9 ± 63.1 | <0.001 |
| Incidence proportion | ||||
| All-cause dementia | 1.70 (n = 5,491) | 1.71 (n = 5,321) | 1.45 (n = 170) | 0.035 |
| AD dementia | 0.72 (n = 2,314) | 0.72 (n = 2,245) | 0.59 (n = 69) | 0.098 |
Abbreviations: AD: Alzheimer’s Disease; ALCOHOL: Alcohol consumption z-score; COGN: Poor cognitive performance z-score; DIET: diet quality z-score; HDI: Healthy Diet Index; HEALTH: Poor cardio-metabolic and general health z-score; LE8: Life’s Essential 8; PA: Physical Activity z-score; NUTR: Nutritional biomarker z-score; SES: Socio-economic status z-score; SMOKING: Smoking z-score; SS: Social Support z-score; TDI: Townsend Deprivation Index. aValues are percentages or means +/− standard deviations. P for null hypothesis of no difference by race.