Coronary heart disease before age 45 may increase risk of dementia later in life

 Adults diagnosed with coronary heart disease, especially before the age of 45, may be at increased risk of developing dementia, Alzheimer's disease and vascular dementia later in life, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

"Coronary heart disease has previously been associated with dementia risk in older adults, however, this is believed to be the first large-scale study examining whether the age of coronary heart disease onset may impact the risk of developing dementia later in life," said Fanfan Zheng, Ph.D., senior study author and researcher in the School of Nursing at the Chinese Academy of Medical Sciences & Peking Union Medical College in Beijing, China.

"In previous research, we found that adults experienced accelerated cognitive decline after new diagnoses of coronary heart disease," she said.

The researchers assessed the potential relationship between age at coronary heart disease onset and the development of dementia by analyzing health data from the UK Biobank.

The analysis found:

• Among the 432,667 participants in the study, there were 5,876 cases of dementia, 2,540 cases of Alzheimer's disease and 1,220 cases of vascular dementia that occurred over an average of 13 years of follow-up.
• Compared with participants who did not have coronary heart disease, participants with coronary heart disease had higher risks of developing dementia from any cause, Alzheimer's disease and vascular dementia.
• After adjusting the analysis for demographic and lifestyle factors, participants with coronary heart disease had a 36% increased risk of developing dementia, a 13% increased risk of developing Alzheimer's and a 78% greater risk of developing vascular dementia.
• Earlier coronary heart disease-onset was associated with a 25% increased risk of dementia, a 29% increased risk of Alzheimer's disease and a 22% increased risk of vascular dementia.
• The risk of dementia rose in direct proportion to the younger age of coronary heart disease onset (per 10-year decrease in age).
• Participants diagnosed with coronary heart disease before age 45 had a significantly increased risk of developing dementia compared to their counterparts who did not have coronary heart disease.

"What surprised us most was the linear relationship between age of coronary heart disease onset and dementia. This shows the huge detrimental influence of premature coronary heart disease on brain health," Zheng said. "As more people live longer and are diagnosed with coronary heart disease at a younger age, it's likely there will be a large increase in the number of people living with dementia in years to come. Health care professionals should be aware of individuals diagnosed with coronary heart disease at a young age. The next step is to determine whether modifying cardiovascular risk early in life will promote better brain health later in life."