People having two or more chronic conditions, or multimorbidity, in midlife were shown to have a higher risk of subsequent dementia in a prospective cohort study.

Midlife multimorbidity increased the risk of dementia later in life more than two-fold, reported researchers in the BMJ. Every 5-year younger age at the onset of multimorbidity increased dementia risk by 18%. The study included data from 10,095 British civil servants in the Whitehall II cohort aged between 35 and 55 years, who were dementia-free in 1985-1988. The prevalence of multimorbidity was 6.6% at 55 years of age and 31.7% at age 70 years. Overall, 639 cases of incident dementia were noted over a median follow-up of 31.7 years. The strongest associations were evident among those with multimorbidity at 55 years of age, while weaker associations were noted for onset of multimorbidity at older ages. Multimorbidity at age 55 was associated with 2.4-fold higher risk of dementia vs. having no or one chronic condition… (Medpage Today)