Peptic ulcer does not increase the risk of dementia A nested case control study using a national sample cohort

Studies have shown that peptic ulcer disease (PUD) increases the risk of dementia via the mechanism of systemic inflammation. We examined the association between PUD and the risk of dementia using a population-based national sample cohort from South Korea. Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with dementia (n = 11,434) and for 1:4 matched control participants (n = 45,736) and then analyzed the previous histories of PUD from 2002 to 2013 using conditional logistic regression analyses. The controls were matched to the patients according to age, sex, income, region of residence, and past medical history. Subgroup analyses were performed based on age and sex. There was no statistically significant difference in the incidence of PUD between the dementia and control groups (18.0% vs 17.4%,P = .107). The adjusted odds ratio (OR) for PUD was 0.92 (95% confidence interval [CI] = 0.88-0.97,P = .002). In the subgroup analysis based on age, the adjusted ORs for PUD were 0.93 (95% CI = 0.88-0.99) in the <80-year-old group and 0.90 (95% CI = 0.82-1.00) in the >= 80-year-old group (eachP < .05). In the subgroup analysis based on sex, the adjusted ORs for PUD were 0.89 (95% CI = 0.81-0.97;P < .05) in men and 0.94 (95% CI = 0.89-1.00;P = .06) in women. PUD does not increase the risk of dementia at any age or in either sex after adjusting for age and the history of hypertension, diabetes mellitus, dyslipidemia, ischemic heart disease, stroke, and depression.