Confirmation that MS more than doubles your risk of being admitted to hospital with dementia. #ResearchSpeak #MSBlog
A HES record-linkage study shows that having MS more than doubles your risk of being admitted to hospital in the future with a dementia. Is this surprising? Medical coding in the HES database seems to treat MS and dementia as separate diagnoses. I think this is wrong. MS is the dementing disease and most people who have dementia and MS are likely to have their dementia as a result of having MS. I agree that some of these pwMS may have additional factors contributing to dementia, for example vascular disease with multiple strokes or possibly Alzheimer's disease. Unfortunately, we don't have an answer to this because I have not yet found a convincing study that looks the incidence/prevalence of co-morbid dementing diseases in people with MS. However, as MS shreds brain reserve it is likely to increase the risk of pwMS getting other dementias. The latter supports our treatment paradigm of treat early and effectively to maximise lifelong brain health.
I have recently written about my campaign on 'rebranding MS a dementia'. I have been heavily criticised about this campaign, but I stand by it and my motivations for doing it. What do you think?
Wotton & Goldacre. Associations between specific autoimmune diseases and subsequent dementia: retrospective record-linkage cohort study, UK. J Epidemiol Community Health, 2017
Objective: To determine whether hospital admission for autoimmune disease is associated with an elevated risk of future admission for dementia.
Methods: Retrospective, record-linkage cohort study using national hospital care and mortality administrative data, 1999–2012. Cohorts of people admitted to hospital with a range of autoimmune diseases were constructed, along with a control cohort, and followed forward in time to see if they developed dementia. 1 833 827 people were admitted to hospital with an autoimmune disease; the number of people in cohorts for each autoimmune disease ranged from 1019 people in the Goodpasture's syndrome cohort, to 316 043 people in the rheumatoid arthritis cohort.
Results: The rate ratio for dementia after admission for an autoimmune disease, compared with the control cohort, was 1.20 (95% CI 1.19 to 1.21). Where dementia type was specified, the rate ratio was 1.06 (1.04 to 1.08) for Alzheimer's disease and 1.28 (1.26 to 1.31) for vascular dementia. Of 25 autoimmune diseases studied, 18 showed significant positive associations with dementia at p<0.05 (with 14 significant at p<0.001) including Addison's disease (1.48, 1.34 to 1.64), multiple sclerosis (1.97, 1.88 to 2.07), psoriasis (1.29, 1.25 to 1.34) and systemic lupus erythematosus (1.46, 1.32 to 1.61).
Conclusions: The associations with vascular dementia may be one component of a broader association between autoimmune diseases and vascular damage. Though findings were significant, effect sizes were small. Clinicians should be aware of the possible coexistence of autoimmune disease and dementia in individuals. Further studies are needed to confirm or refute our findings and to explore possible mechanisms mediating any elevation of risk.