Midlife Chronic Conditions Increase Risk for Later Dementia

Having two or more chronic conditions in middle age is associated with an increased risk for dementia later in life, according to a study published online Feb. 2 in The BMJ.

Céline Ben Hassen, Ph.D., from Université de Paris, and colleagues examined the association of mid- and late-life multimorbidity with incident dementia. The analysis included 10,095 participants (aged 35 to 55 years at baseline) followed for a median of 31.7 years.

The researchers found that after adjusting for sociodemographic factors and health behaviors, multimorbidity at age 55 years was associated with the subsequent risk for dementia (difference in incidence rate per 1,000 person-years, 1.56; hazard ratio [HR], 2.44). With older age at onset of multimorbidity, the association weakened progressively. At age 65 years, having onset of multimorbidity before age 55 years was associated with a 3.86 per 1,000 person years higher incidence of dementia (HR, 2.46) versus onset between 60 and 65 years (1.85 per 1,000 person years higher incidence; HR, 1.51). There was also an association for severity of multimorbidity (three or more chronic diseases) at age 55 years with a higher incidence of dementia (HR, 4.96) versus at age 70 years (HR, 1.65).

"These findings highlight the role of prevention and management of chronic diseases over the course of adulthood to mitigate adverse outcomes in old age," the authors write.