乌鸦传媒

Younger onset age of coronary heart disease was tied to higher risks of incident all-cause dementia, Alzheimer's disease, and vascular dementia, a large prospective cohort study in Great Britain showed.

Each 10-year decrease in coronary heart disease onset age was associated with a 25% increased risk of all-cause dementia, a 29% increased risk of Alzheimer's disease, and a 22% increased risk of vascular dementia (all P<0.001), reported Fanfan Zheng, PhD, of the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, and co-authors in the .

Across all age groups, coronary heart disease diagnosed before age 45 had the highest hazard ratio (HR) for incident dementia compared with people who didn't have coronary heart disease (HR 2.40, P<0.001).

"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," Zheng said in a statement.

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

The researchers assessed data from 432,667 participants in the ongoing . Participants had a mean age of 57 at baseline and about 55% were women. Overall, 11.7% (50,685 people) had coronary heart disease at the time of enrollment and through the follow-up period.

Over a median follow-up of 12.8 years, 5,876 cases of all-cause dementia, 2,540 cases of Alzheimer's disease, and 1,220 cases of vascular dementia emerged.

After adjusting for multiple covariates ranging from age and sex to BMI and statin use, people with coronary heart disease had a 36% increased risk of all-cause dementia (P<0.001), 13% greater risk of Alzheimer's (P=0.019), and 78% higher risk of vascular dementia (P<0.001) compared with all other participants who didn't have coronary heart disease.

In a propensity score-matched analysis, people with coronary heart disease had significantly higher risks of dementia than matched controls in all onset age groups. Hazard ratios rose with decreasing onset age.

Compared with people who had coronary heart disease onset at age 60 or older, those with onset at age 45 or younger had a 71% higher risk of all-cause dementia (P<0.001), 75% higher risk of Alzheimer's disease (P=0.003), and 65% higher risk of vascular dementia (P=0.015).

"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," she observed.

"Healthcare professionals should be aware of individuals diagnosed with coronary heart disease at a young age," Zheng added. "The next step is to determine whether modifying cardiovascular risk early in life will promote better brain health later in life."

The study was observational, so cause and effect cannot be determined, the researchers noted. More than 94% of the study population were white, and the findings may not apply to people of other races or ethnicities, they acknowledged.

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