Hypertension, obesity, physical inactivity among highest risk factors for dementia

Dementia cases in the United States were largely associated with modifiable risk factors, such as hypertension, obesity and physical inactivity — especially among Black and Hispanic people, researchers reported in JAMA Network Open.

Mark Lee, MA, a PhD candidate at the University of Minnesota, and colleagues aimed to calculate the population attributable fraction of dementia associated with 12 established modifiable risk factors for all U.S. adults while separating for race and ethnicity.

Lee and colleagues conducted a cross-sectional study using survey data from representative samples of U.S. adults. Population attributable factors were calculated using relative risks and prevalence estimates for the 12 risk factors — less education, obesity, hypertension, diabetes, hearing loss, smoking, physical inactivity, excessive alcohol consumption, social isolation, traumatic brain injury, depression and air pollution.

Among all U.S. adults, 41% (95% CI, 22.7%-55.9%) of all cases were attributable to the 12 risk factors. A 15% proportional decrease in each risk factor would reduce dementia prevalence in the overall population by 7.3% (95% CI, 3.7%-10.9%), the researchers reported.

All reported population attributable factors were greater for Black and Hispanic individuals compared with white and Asian people.

The greatest attributable fraction of dementia cases was reported for hypertension (population attributable factors [PAF], 20.2%; 95% CI, 6.3%-34.4%), obesity (PAF, 20.9%; 95% CI, 13%-28.8%) and physical inactivity (PAF, 20.1%; 95% CI, 9.1%-29.6%).

“Until an effective treatment for dementia is developed, delaying dementia onset in the population by targeting modifiable risk factors is the best tool to curb the projected increase in dementia cases,” Lee and colleagues wrote. “Policymakers should prioritize efforts to reduce the prevalence of midlife obesity, midlife hypertension and late-life physical inactivity, which are currently associated with the largest fraction of dementia cases in the U.S.”