Abstract
Background: There is limited primary-care based evidence for an association
between chronic inflammation and related therapy with all-cause dementia.
Objective: To estimate the association between several chronic inflammatory
disorders and related drug therapy and all-cause dementia.
Methods: The study population included a cohort of patients diagnosed with
inflammatory conditions and matching controls (ratio 1:2) from the Clinical Practice
Research Datalink, a database or primary care records in the UK. Inflammation patients and
controls were matched on age, gender, and family practice. The study outcome measure was
all-cause dementia. Chronic inflammation diagnosis and anti-inflammatory drugs represented
the exposure variables of interest. Competing risks analyses were used to estimate the
risk of dementia associated with exposure variables.
Results: There were 1,378 (1% ) and 2,805 (1% ) dementia events recorded for
chronic inflammation patients and their matched controls, respectively. Systemic
vasculitis was associated with increased hazard ratios of dementia (1.75, 95% confidence
interval (CI) 1.35–2.27, p < 0.001). The analyses revealed increased
risk of dementia for systemic vasculitis (1.64, 95% CI 1.24–2.18), Crohn’s diseases (2.08,
95% CI 1.16–3.74), bullous skin diseases (1.55, 95% CI 1.11–2.18), and inflammatory
arthritis (1.33, 95% CI1.06–1.63) among treated patients. Combined glucocorticoids and
NSAID therapy suggested reduced risk of dementia across most conditions, particularly
systemic autoimmune disorders (0.41, 95% CI 0.18–0.95).
Conclusion: The association between chronic inflammation and dementia varied
across inflammatory disorders, being stronger for systemic vasculitis. There was evidence
that combined therapy was associated with lower risk of dementia across most disorders.
These data highlight potential avenues for future mechanistic and intervention
investigations.
