Table 2 Impact of viral infection on the risk of dementia via multivariate time-varying cox regression analyses
Variables | Cohort (N = 752,205) | All dementia | Alzheimer’s disease | Vascular dementia | ||||
|---|---|---|---|---|---|---|---|---|
Hazard ratio (95% CI) | p-value†| Hazard ratio (95% CI) | p-value†| Hazard ratio (95% CI) | p-value†| |||
HSV or VZV infection | No | 475,884 (63.3%) | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 0.0001 0.0001 |
HSV only VZV only Co-infection | 91,990 (12.2%) 113,645 (15.1%) 70,686 (9.4%) | 1.38 (1.33–1.43) 1.41 (1.37–1.46) 1.57 (1.50–1.63) | 1.49 (1.42–1.56) 1.52 (1.46–1.57) 1.75 (1.66–1.85) | 1.46 (1.24–1.72) 1.34 (1.16–1.54) 1.52 (1.24–1.87) | ||||
Age (years) | < 65 | 537,743 (71.5%) | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 |
≥ 65 | 214,462 (28.5%) | 14.03 (13.64–14.44) | 14.70 (14.18–15.24) | 8.26 (7.37–9.26) | ||||
Sex | Male Female | 348,125 (46.3%) 404,080 (53.7%) | 1 (ref) 1.49 (1.46–1.53) | < 0.0001 | 1 (ref) 1.61 (1.57–1.66) | < 0.0001 | 1 (ref) 1.21 (1.10–1.34) | 0.0002 |
Depression |  | 58,961 (7.8%) | 1.40 (1.36–1.44) | < 0.0001 | 1.41 (1.36–1.46) | < 0.0001 | 1.30 (1.12–1.51) | 0.0005 |
Dyslipidaemia |  | 137,800 (18.3%) | 0.94 (0.91–0.96) | < 0.0001 | 0.93 (0.90–0.96) | < 0.0001 | 0.89 (0.79–1.01) | 0.07 |
Ischaemic stroke |  | 30,950 (4.1%) | 1.54 (1.49–1.59) | < 0.0001 | 1.44 (1.38–1.51) | < 0.0001 | 2.16 (1.86–2.52) | < 0.0001 |
Coronary heart disease |  | 86,082 (11.4%) | 1.10 (1.07–1.13) | < 0.0001 | 1.11 (1.07–1.15) | < 0.0001 | 1.02 (0.89–1.17) | 0.77 |
Hypertension |  | 239,976 (31.9%) | 1.39 (1.35–1.42) | < 0.0001 | 1.37 (1.33–1.41) | < 0.0001 | 1.76 (1.57–1.97) | < 0.0001 |
Diabetes mellitus |  | 157,642 (21%) | 1.31 (1.28–1.34) | < 0.0001 | 1.30 (1.26–1.34) | < 0.0001 | 1.34 (1.20–1.49) | < 0.0001 |
Chronic kidney disease |  | 3,287 (0.4%) | 1.10 (0.96–1.25) | 0.16 | 1.05 (0.89–1.25) | 0.55 | 0.92 (0.48–1.78) | 0.80 |
Body mass index | Underweight | 15,993 (2.1%) | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 | 1 (ref) | < 0.0001 |
Normal | 220,444 (29.3%) | 0.66 (0.63–0.69) | 0.62 (0.58–0.66) | 0.59 (0.47–0.74) | ||||
Overweight | 169,660 (22.6%) | 0.54 (0.51–0.56) | 0.50 (0.47–0.53) | 0.45 (0.36–0.57) | ||||
Obese | 226,268 (30.1%) | 0.46 (0.44–0.49) | 0.42 (0.40–0.45) | 0.45 (0.36–0.57) | ||||
Household income level | Low | 138,623 (18.4%) | 1 (ref) | < 0.0001 | 1 (ref) |  | 1 (ref) |  |
Lower middle | 136,824 (18.2%) | 0.96 (0.93–0.99) | 0.97 (0.93–1.01) | 0.13 | 0.95 (0.81–1.11) | 0.52 | ||
Higher middle | 181,648 (24.1%) | 0.88 (0.86–0.91) | 0.89 (0.85–0.92) | < 0.0001 | 0.83 (0.72–0.96) | 0.01 | ||
High | 255,307 (33.9%) | 0.88 (0.86–0.91) | 0.90 (0.86–0.93) | < 0.0001 | 0.77 (0.68–0.89) | 0.0002 | ||