Introduction: There is little evidence to describe risk factors for dementia in a Thai general population.
Hypothesis: This study was aimed to examine factors associated with the risk of developing dementia in a Thai general population in Ubon Ratchathani.
Methods: Data on 761,935 men and women participating in the Health Check Ubon Ratchathani (HCUR) Project in 2006-7 were merged with diagnostic information from hospital’s electronic medical records in the following 5 years (2006-2012). Using a retrospective cohort study design, we examined the incidence of physician-diagnosed dementia over 5 years. Factors independently associated with the risk of developing dementia were examined using multivariate cox proportional hazard regression.
Results: Over a total time at risk of 4,407,201 person-years, 519 individuals developed dementia, the incidence rate of dementia was 0.12 (95%CI 0.11-0.13) per 1,000 person-years. Factors independently associated with the risk of developing dementia in multivariate cox regression included increasing age, diabetes and lack of physical exercise. The risk of dementia rose by 9% for every one year of age older (Hazard ratio (HR) of 1.09 (1.08-1.09), p<0.001). Diabetes increased the risk of dementia by almost 2 times (HR 1.67 (1.26-2.23), p<0.05). Compared to no physical exercise, regular physical exercise of 3-5 days/week and >5 days/week reduced the risk of dementia by 36% and 57% (HR 0.64 (0.52-0.78) and 0.43 (0.28-0.67) respectively). These associations remained significant after controlling for sex, hypertension, systolic blood pressure, smoking, body mass index, waist circumference, high salt diet and alcohol drinking.
Discussion: In this Thai general population, the incidence of dementia was modest and its independent risk factors included increasing age, diabetes and lack of physical exercise. Regular physical exercise may counter balance aging process, the main drive of dementia. The more physical exercise you do, the lower risk of dementia.