Traumatic Spinal Cord Injury and Risk of Early and Late Onset Alzheimer's Disease and Related Dementia: Large Longitudinal Study

Objective: Traumatic spinal cord injury (TSCI) is a life altering event most often causing permanent physical disability. Little is known about the risk of developing Alzheimer disease and related dementia (ADRD) among middle-aged and older adults living with TSCI. Time to diagnosis of and adjusted hazard for ADRD was assessed.

Design: Cohort study.

Setting: Using 2007-2017 claims data from the Optum Clinformatics Data Mart, we identified adults (45+) with diagnosis of TSCI (n=7019). Adults without TSCI diagnosis were included as comparators (n=916,516). Using age, sex, race/ethnicity, cardiometabolic, psychological, and musculoskeletal chronic conditions, US Census division, and socioeconomic variables, we propensity score matched persons with and without TSCI (n=6083). Incidence estimates of ADRD were compared at 4 years of enrollment. Survival models were used to quantify unadjusted, fully adjusted, and propensity-matched unadjusted and adjusted hazard ratios (HRs) for incident ADRD.

Participants: Adults with and without TSCI (N=6083).

Intervention: Not applicable.

Main outcomes measures: Diagnosis of ADRD.

Results: Both middle-aged and older adults with TSCI had higher incident ADRD compared to those without TSCI (0.5% vs 0.2% and 11.7% vs 3.3% among 45-64 and 65+ y old unmatched cohorts, respectively) (0.5% vs 0.3% and 10.6% vs 6.2% among 45-64 and 65+ y old matched cohorts, respectively). Fully adjusted survival models indicated that adults with TSCI had a greater hazard for ADRD (among 45-64y old: unmatched HR: 3.19 [95% confidence interval, 95% CI, 2.30-4.44], matched HR: 1.93 [95% CI, 1.06-3.51]; among 65+ years old: unmatched HR: 1.90 [95% CI, 1.77-2.04], matched HR: 1.77 [1.55-2.02]).

Conclusions: Adults with TSCI are at a heightened risk for ADRD. Improved clinical screening and early interventions aiming to preserve cognitive function are of paramount importance for this patient cohort.