Autoimmune disease may be linked to heightened dementia risk

March 1, 2017

Autoimmune disease may be linked to a heightened risk of dementia, indicates a large long term study, published in the Journal of Epidemiology & Community Health.

Although significant, the extent of the association found was small, caution the researchers. But the findings are consistent with the theory that Alzheimer's disease may have an autoimmune component, they point out.

It has been suggested that autoimmune and inflammatory activity may have a role in the development of . In a bid to try and quantify this further, the researchers drew on admissions data, including day cases, from 1998 to 2012 for England.

They wanted to know if admission to hospital with one of 25 , including coeliac disease, multiple sclerosis (MS), , and ulcerative colitis, was associated with a heightened of subsequent admission to hospital with dementia.

During the monitoring period, more than 1.8 million were admitted with an autoimmune disease, ranging from just over 1000 people with the rare condition, Goodpasture's syndrome, in which antibodies attack the lungs and kidneys, to more than 300,000 with rheumatoid arthritis.

Compared with people admitted to hospital for other causes, those admitted with an autoimmune disorder were 20 per cent more likely to be admitted subsequently with dementia, the data showed.

Of the 25 autoimmune diseases included in the analysis, 18 were significantly associated with dementia.

These included conditions as diverse as Addison's disease (48 per cent heightened risk); MS (an almost doubling in risk); psoriasis (29 per cent heightened risk); and (46 per cent increased risk).

Most of these associations remained significant for five or more years after admission to hospital for autoimmune disease.

The type of dementia was not always documented, but the risk was 6 per cent higher for Alzheimer's disease, and 28 per cent higher for .

The higher risk for vascular dementia might reflect associations between autoimmune disease and risk factors for cardiovascular and cerebrovascular diseases more generally, suggest the researchers.

People with autoimmune disease were 53 per cent more likely to be admitted subsequently for and 46 per cent more likely to be admitted with a stroke.

A previous hospital admission for rheumatoid arthritis seemed to be protective for Alzheimer's disease, the data showed.

This might be because people with rheumatoid arthritis are more likely to take non-steroidal anti-inflammatory drugs, such as aspirin and paracetamol which have been associated with a reduced risk of Alzheimer's disease, suggest the researchers.

The excess risk of dementia was significantly higher for men than for women with MS, but for most of the other conditions the relative risks were broadly similar for both sexes.

This is an observational study so no firm conclusions can be drawn about cause and effect, added to which the research was limited only to people admitted to hospital and so unable to account for potentially influential factors.

And the researchers emphasise that the size of the associations they found was small, so the results should be taken as indicative rather than definitive: further research would be needed to confirm or refute the findings, they say.

But they speculate that autoimmune diseases or their treatment might boost the risk of circulatory disease generally, of which vascular disease is a component, in some people.

Explore further: Increased risk of blood clots on the lung for patients with autoimmune diseases

More information: Associations between specific autoimmune diseases and subsequent dementia: retrospective record-linkage cohort study, jech.bmj.com/lookup/doi/10.1136/jech-2016-207809

Related Stories

Increased risk of blood clots on the lung for patients with autoimmune diseases

November 28, 2011
Autoimmune diseases, in which the immune system attacks the body, are fairly common. Thyroid diseases, type 1 diabetes, rheumatoid arthritis, psoriasis and inflammatory bowel disease are some examples. Autoimmune diseases ...

Early to mid-life obesity linked to heightened risk of dementia in later life

August 20, 2014
Obesity is linked to a heightened risk of dementia in later life, reveals an observational study published online in Postgraduate Medical Journal.

Heart risks in middle age boost dementia risk later in life

February 22, 2017
People who have heart disease risks in middle age - such as diabetes, high blood pressure or smoking - are at higher risk for dementia later in life, according to research presented at the American Stroke Association's International ...

Targeted preventive measures for hip fracture are needed for persons with Alzheimer's disease

December 7, 2016
The hip fracture risk factors are generally similar among those with and without Alzheimer's disease, according to a recent study from the University of Eastern Finland. However, the incidence of hip fracture is higher among ...

High blood pressure linked to vascular dementia

May 18, 2016
High blood pressure could significantly raise the risk of developing the second most common form of dementia, according to a new study from The George Institute for Global Health.

Study links mothers with rheumatoid arthritis and kids with epilepsy

November 16, 2016
A new study shows a link between mothers with rheumatoid arthritis and children with epilepsy. The study is published in the November 16, 2016, online issue of Neurology, a medical journal of the American Academy of Neurology. ...

Recommended for you

Lifestyle changes to stave off Alzheimer's? Hints, no proof

July 20, 2017
There are no proven ways to stave off Alzheimer's, but a new report raises the prospect that avoiding nine key risks starting in childhood just might delay or even prevent about a third of dementia cases around the world.

Steering an enzyme's 'scissors' shows potential for stopping Alzheimer's disease

July 19, 2017
The old real estate adage about "location, location, location" might also apply to the biochemical genesis of Alzheimer's disease, according to new research from the University of British Columbia.

Brain scans may change care for some people with memory loss

July 19, 2017
Does it really take an expensive brain scan to diagnose Alzheimer's? Not everybody needs one but new research suggests that for a surprising number of patients whose memory problems are hard to pin down, PET scans may lead ...

Can poor sleep boost odds for Alzheimer's?

July 18, 2017
(HealthDay)— Breathing problems during sleep may signal an increased risk for Alzheimer's disease, a trio of studies suggests.

Hearing is believing: Speech may be a clue to mental decline

July 17, 2017
Your speech may, um, help reveal if you're uh ... developing thinking problems. More pauses, filler words and other verbal changes might be an early sign of mental decline, which can lead to Alzheimer's disease, a study suggests.

Bacteria found in Alzheimer's brains

July 17, 2017
Researchers in the UK have used DNA sequencing to examine bacteria in post-mortem brains from patients with Alzheimer's disease. Their findings suggest increased bacterial populations and different proportions of specific ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.