Association between timed up and go test and future dementia onset

Background: This study evaluated whether baseline results of the Timed Up and Go (TUG) test is associated with future dementia occurrence. Methods: Using the Korean National Health Insurance Service-National Health Screening Cohort database, we identified 49,283 subjects without a dementia diagnosis who participated in the National Screening Program for Transitional Ages at 66 years of age during 2007-2012. Gait impairment was defined as taking longer than 10 seconds to perform the TUG test. Dementia occurrence was defined by the first prescription for acetylcholinesterase inhibitors or N-Methyl-D-Aspartate receptor antagonist with an International Classification of Diseases 10th Revision (ICD-10) code for dementia (F00, F01, F02, F03, G30, F051, or G311) during 2007-2013. Cox proportional hazard regression models were used to assess the hazard ratios for dementia occurrence according to baseline TUG test results. Results: Mean follow-up period was 3.8 years. Incidence rates of dementia were 4.6 and 6.8 cases per 1,000 person-years in the normal and impaired TUG groups, respectively. The impaired TUG group showed a higher risk of total dementia incidence (adjusted hazard ratio [aHR], 1.34; 95% confidence interval [95% CI], 1.14-1.57). Subtype analysis showed that the impaired TUG group had a higher risk of Alzheimer's disease (aHR, 1.26; 95% CI, 1.06-1.51) and vascular dementia (aHR, 1.65; 95% CI, 1.19-2.30). Conclusions: The TUG test result was associated with future dementia occurrence. More vigilant follow-up and early intervention to prevent dementia would benefit elderly people with impaired TUG test result.