UC San Diego

Rationale: Ethnic/racial minorities have increased prevalence of Alzheimer’s disease (AD) and other dementias and may differ from the non-Hispanic White population in terms of risk factors and disease manifestation. The metabolic syndrome (MetS) is a modifiable risk factor for vascular-related cognitive decline and AD, and prevalence varies across ethnic/racial groups. Neuropsychological process scores used in conjunction with total scores have been shown to help detect subtle cognitive changes predictive of Mild Cognitive Impairment and dementia; however, this has not been well-studied in minorities or MetS. The present study examined relationships between MetS, process scores, and future cognitive function in a racially/ethnically diverse sample from the Framingham Heart Study.

Design: Participants included 258 middle-aged and 155 older Black/African American, Hispanic, and Asian American adults. 32% met criteria for MetS (n = 130), with similar rates across ethnicity/race groups. Repeated measures and univariate analyses of covariance were used to examine group differences in total and process error scores on neuropsychological tests of memory and executive function. Relationships between baseline process errors, exam 2 total scores, MCI status were explored using regression. It was predicted that MetS would be associated with increased process errors, and process errors would be predictive of future cognitive declines.

Results: MetS interacted with ethnicity/race to predict Logical Memory immediate recall. Among the Black/African American group, those with MetS scored higher than controls. The trend was in the opposite direction among the Hispanic and Asian American groups; however, the effect was not significant. MetS did not predict any other cognitive outcome. Across groups, multiple baseline Trails B sequencing errors were associated with a 10x higher likelihood of progression to MCI at exam 2, controlling for inter-exam interval, age, Trails B total scores, WRAT reading scores, sex, and MetS. No other process errors predicted future cognitive status.

Conclusions: Present results suggest Trails B process errors may be useful indicators of risk for cognitive decline among minority groups. Future research investigating potential mediating effects of genetic risk for AD in clinical and more socioeconomically diverse samples is warranted in order to determine whether these results are generalizable to larger populations.