Young healthcare worker speaking with elderly person in wheelchair
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Having more than one chronic health condition or disease is associated with a 63% increased risk of developing dementia over a 15-year period, according to a study published in JAMA Network Open. Identifying high-risk disease clusters may help clinicians to better target at-risk patients for dementia care, the researchers say.

Investigators used data from the UK Biobank cohort to study health outcomes in more than 200,000 participants who did not have dementia and were aged at least 60 years. Baseline data was collected between 2006 and 2010. Multimorbidity was defined as having at least two of 42 predetermined conditions, and high genetic risk for dementia was based on the presence of one or two known, specific gene markers.

More conditions, higher risk

The more conditions, the higher a patient’s dementia risk 15 years later, according to Catherine M. Calvin, PhD, of the University of Oxford in the United Kingdom. About 3% of the study participants developed dementia, with an incidence rate of 1.87 per 1000 person-years for those without multimorbidity and 3.41 per 1000 person-years for those with multimorbidity, she and her colleagues reported. 

When compared with their peers who had no multimorbidity, women were at the highest risk for dementia when they had a hypertension, diabetes and coronary heart disease health cluster, or a cluster of pain, osteoporosis, and dyspepsia. Men were most at risk when they had a diabetes and hypertension cluster or a coronary heart disease, hypertension and stroke cluster.

Links between multimorbidity and dementia were greater for participants who had a lower genetic risk of dementia as defined in the study than in those with a higher genetic risk of dementia. But ​​”the risk differences between absence and presence of multimorbidity were larger in those with a higher genetic risk for dementia,” the researchers noted.

Identifying patients

The overall findings could help clinicians better identify patients at high risk of dementia “and highlight the necessity of targeting clusters of diseases for dementia prevention rather than individual risk factors,” the authors concluded. 

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