Adults with multiple chronic conditions are more likely to develop dementia later in life, and each additional condition is related to 15% higher odds of cognitive decline, a new study has found.

The findings could apply to a large percentage of the US population. In 2018, 52% of US adults reported having at least one chronic condition, and 27% of US adults said that they live with multiple chronic conditions, according to the Centers for Disease Control and Prevention.

The investigation included healthcare data from more than 5,000 Health and Retirement Study participants from 1994 to 2008. Reported conditions included hypertension, diabetes, cancer, lung diseases, heart disease, stroke, psychological disorders and arthritis. The researchers then examined reports of dementia diagnoses in the same group from 2008 to 2018.

Rapid accumulation raises risk

Among participants who were aged 80 or fewer years at baseline, a larger number of chronic conditions was associated with higher odds of developing dementia. The more rapidly these conditions accumulated, the higher the person’s risk rose, investigators discovered.

The results also linked specific conditions with dementia risk, including heart disease, stroke and psychological disorders, whether those conditions ​​were new or ongoing during the 16-year study period.

Monitor and manage

The findings were observational and do not imply a cause, yet they highlight the importance of monitoring and managing multimorbidity to help prevent dementia in an aging society, concluded study lead Changzheng Yuan, PhD, of Harvard and Zhejiang University in China. 

In 2020, at least one fifth of older adults reported that their health was fair or poor. In addition to chronic disease, 18% reported having difficulties in one of six functional domains such as sight or hearing, according to the Centers for Disease Control and Prevention. Cognitive decline was reported by 28%, the highest percentage after ambulatory difficulties (39%) and hearing difficulties (29%).

The study was published in the journal Alzheimer’s & Dementia

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