Sex and Race/Ethnic Differences in Risk Factors for Alzheimer’s Disease and Related Dementias: Implications for Prevention

Abstract

AbstractBackgroundWe previously estimated that 1 in 3 cases of Alzheimer’s disease and related dementias (ADRD) in the U.S. may be attributable to modifiable risk factors, the most important being physical inactivity, depression, and smoking. However, these estimates do not account for changes in risk factor prevalence over the past decade and do not consider potential differences based on sex or race/ethnicity. The objective of this study was to update and estimate the proportion of ADRD in the U.S. that are potentially attributable to modifiable risk factors and to assess for differences by sex and race/ethnicity.MethodWe estimated individual and combined population attributable risks (PARs) for ADRD for the following risk factors: physical inactivity, current smoking, depression, low education, diabetes, midlife obesity, midlife hypertension, and hearing loss. To account for non‐independence of the risk factors, we estimated their communality and uniqueness via principal component analysis. Risk factor prevalence and communality were determined using data from the nationally‐representative Behavioral Risk Factor Surveillance Survey (BRFSS) and relative risks for each risk factor were extracted from recent meta‐analyses. Respondents included 378,615 noninstitutionalized adults in the U.S., older than 18 years.ResultApproximately 1 in 3 (37%) cases of ADRD in the U.S. are potentially attributable to 8 modifiable risk factors, the most important of which are midlife obesity (17.7%, 95% CI: 17.5,18.0) physical inactivity (11.8%, 95% CI: 11.7, 11.9), and low educational attainment (11.7%, 95% CI: 11.5, 12.0). Combined PARs were higher for men (36%) than women (30%) and differed by race/ethnicity: Black (40%), Native Americans/Alaska Natives (39%), Hispanic (any race, 34%), White (29%), and Asian (16%). The most important modifiable risk factors, regardless of sex, were midlife obesity for Whites, Native Americans/Alaska Natives and Blacks; low education for Hispanics; and physical inactivity for Asians.ConclusionOur findings suggested that the major contributors to ADRD have changed over the past decade and differ based on sex and race/ethnicity. Therefore, Alzheimer’s disease risk reduction strategies may be more effective if they target higher‐risk groups and consider current risk factor profiles.