In a cohort study, researchers found that individuals who experienced upward socioeconomic status transitions throughout their lives had the lowest risk of developing dementia in older age. The study also revealed that those with downward socioeconomic status transitions had the largest reduction in dementia-free years later in life.

The study, published in JAMA Network Open, analyzed data from 9,186 participants aged 65 years or older from the Japan Gerontological Evaluation Study (JAGES) cohort. The researchers identified six distinct socioeconomic status (SES) transition patterns: upward, stable-high, upper-middle, lower-middle, downward, and stable-low.

During the 6.4-year follow-up period, 800 cases of dementia were identified. Compared to the lower-middle SES transition group, the lowest risk of dementia was observed in the upward transition group (hazard ratio [HR], 0.66; 95% CI, 0.57-0.74), followed by stable-high (HR, 0.77; 95% CI, 0.69-0.86), downward (HR, 1.15; 95% CI, 1.09-1.23), and stable-low (HR, 1.45; 95% CI, 1.31-1.61) transitions.

The study also found that the upward SES transition group experienced the greatest increase in dementia-free years across all age categories. For example, at age 65, the upward transition group gained 1.8 dementia-free years (95% CI, 1.4-2.2) compared to the lower-middle SES transition group. In contrast, the downward transition group had the largest loss of dementia-free years at age 75 and older, with a loss of 1.4 years (95% CI, −2.4 to −0.4) at age 85.

The researchers noted that various dementia risk factors, including lifestyle behaviors, comorbidities, and social factors, were associated with SES transition patterns. They also found that the association between SES transitions and dementia risk was more prominent in men, those born later, and urban residents.
"To our knowledge, this is the first report highlighting changes in SES classes from childhood and their specific associations with a dementia diagnosis at an older age," said Dr. Hiroyasu Iso, the corresponding author of the study.

The study found an association between upward socioeconomic mobility throughout life and a reduced risk of dementia in older age. However, the authors noted that the observational nature of the study and the possibility of unmeasured bias should be considered when interpreting the results.

Full disclosures can be found in the study.