Depression and Diabetes Mellitus Multimorbidity Is Associated With Loss of Independence and Dementia Poststroke

Background and purpose: Many patients with ischemic stroke present with multiple comorbidities that threaten survival and recovery. This study sought to determine the risks of adverse long-term stroke outcomes associated with multimorbid diabetes mellitus and depression.

Methods: Retrospective analysis of prospectively collected data on consecutive patients without premorbid dementia admitted from the community for a first-ever acute ischemic stroke to comprehensive stroke centers across Ontario, Canada (2003-2013). Premorbid histories of diabetes mellitus and depression were ascertained within 5 years before stroke admission. Adjusted hazard ratios (aHR [95% CI]) of admission to long-term care, incident dementia, readmission for stroke or transient ischemic attack and all-cause mortality, over time among those discharged back into the community poststroke.

Results: Among 23 579 stroke admissions, n=20 201 were discharged back into the community. Diabetes mellitus and depression were associated with synergistic hazards of admission to long-term care (X²=5.4; P=0.02) over a median follow-up of 5.6 years. This interaction was observed among women specifically; depression multimorbidity showed particularly high hazards of admission to long-term care (aHR_Depression=1.57 [1.24-1.98]) and incident dementia (aHR_Depression=1.85 [1.40-2.44]) among women with diabetes mellitus. In the whole cohort, diabetes mellitus and depression were associated individually with long-term care admission (aHR_Diabetes=1.20 [1.12-1.29]; aHR_Depression=1.19 [1.04-1.37]), incident dementia (aHR_Diabetes=1.14 [1.06-1.23]; aHR_Depression=1.27 [1.08-1.49]), stroke/transient ischemic attack readmission (aHR_Diabetes=1.18 [1.10-1.26]; aHR_Depression=1.24 [1.07-1.42]), and all-cause mortality (aHR_Diabetes=1.29 [1.23-1.36]; aHR_Depression=1.16 [1.05-1.29]).

Conclusions: The risks of dementia and needing long-term care in the years after surviving a stroke were particularly elevated among women when premorbid diabetes mellitus and depression occurred together. Long-term stroke recovery strategies might target high-risk patients with mood and metabolic multimorbidity.