(HealthDay News) – Nine risk factors have been identified for young-onset dementia (YOD; dementia diagnosed before the age of 65 years), which together account for 68% of the population-attributable risk for YOD, according to a study published online Aug. 12 in JAMA Internal Medicine.
Peter Nordström, PhD, from Umeå University in Sweden, and colleagues assessed risk factors in late adolescence for the development of YOD later in life in a cohort of 488,484 Swedish men (mean age, 18 years) conscripted for mandatory military service.
During a median follow-up of 37 years, the researchers identified 487 men who were diagnosed as having YOD (median age, 54 years). Significant risk factors for YOD included alcohol intoxication (hazard ratio [HR], 4.82), stroke (HR, 2.96), use of antipsychotics (HR, 2.75), depression (HR, 1.89), father’s dementia (HR, 1.65), drug intoxication other than alcohol (HR, 1.54), low cognitive function at conscription (HR, 1.26 per one-standard deviation decrease), low height at conscription (HR, 1.16 per one-standard deviation decrease), and high systolic blood pressure at conscription (HR, 0.9 per one-standard deviation decrease), in multivariate analysis. For all nine risk factors, the population-attributable risk was 68%. During follow-up, the risk of YOD was increased 20-fold for men with at least two of these risk factors and in the lowest third of overall cognitive function.
“In this nationwide cohort, nine independent risk factors were identified that accounted for most cases of YOD in men,” the authors write. “These risk factors were multiplicative, most were potentially modifiable, and most could be traced to adolescence, suggesting excellent opportunities for early prevention.”