Socioeconomic position, modifiable dementia risk and cognitive decline: results of 12‐year Maastricht Aging Study

Abstract

AbstractBackgroundEvidence of modifiable risk factors for cognitive decline and dementia is accumulating, showing the potential of dementia risk reduction via lifestyle modification and cardiovascular risk management. People with low socioeconomic status (SES) have increased dementia risk and on average worse health. This study investigated whether the association between a modifiable dementia risk score and rate of cognitive decline differs across SES strata.MethodData were used from Maastricht Aging Study (MAAS), a prospective cohort study with a 12‐year follow‐up. Participants aged ≥40 years with complete dementia risk profiles were included (n = 1223). The validated ’LIfestyle for BRAin health’ (LIBRA) index was used to assess the modifiable dementia risk fraction. Cognitive performance was serially assessed at baseline, 6 and 12 years and measured in the domains of information processing speed, executive functioning and verbal memory function. A SES compound score was calculated from equivalent income and educational level and divided into tertiles (low, middle, high). Linear mixed models were used to study the association between LIBRA, SES and their interaction on the rate of cognitive decline.ResultParticipants in the lowest SES tertile displayed more decline in information processing speed (vs. middle SES: X2 = 7.08, p = 0.029; vs. high SES: X2 = 9.49, p = 0.009) and verbal memory (vs. middle SES: X2 = 9.28, p<0.001; vs. high SES: X2 = 16.68, p<0.001) compared to their middle‐ and high‐SES counterparts. Higher (unhealthier) LIBRA scores were also associated with more decline in information processing speed (X2 = 12.66, p = 0.002) and verbal memory (X2 = 4.63, p = 0.032). No consistent effect modification by SES on the association between LIBRA and cognition was found.ConclusionThis study shows that lower SES and higher modifiable dementia risk predict faster decline in information processing speed and verbal memory function over 12 years. Results suggest that lifestyle is an important determinant of cognitive decline across SES groups. Yet, people with low SES had a more unfavourable modifiable risk score suggesting more potential for lifestyle‐based interventions. LIBRA could be useful as a participant selection tool or as a surrogate outcome measure in lifestyle intervention trials, and can inform people about individual risk behaviours as part of public health initiatives.