What type of study is this?

October 16, 2025

Higher interleukin-6 (IL-6) is associated with decline in psychomotor processing speed but not executive functioning in older adults: Gender-specific effects

EGElana M. GlogerNorthwestern University PSPatrick J. SmithUniversity College Dublin SSSuzanne C. SegerstromOregon State University

Key Points

Higher mean levels of interleukin-6 were associated with slower psychomotor processing speed in older women, not in men.
Multilevel models indicated significant associations between IL-6 and cognitive measures, especially for female participants.
The study utilized neuropsychological assessments every six months over a period of up to 12 years for older adults.
Findings highlight the importance of gender-specific influences on cognitive aging and inflammation-related decline.

Abstract

Elevated peripheral inflammatory markers among older adults are associated with cognitive decline, particularly for women, for whom cognitive decline is more prevalent and rapid. Few prospective studies have examined gender-specific associations between inflammation and cognitive decline or examined stable, mean differences (i.e., between-person effects) versus fluctuations (i.e., within-person effects) in inflammation. Participants (N = 235) were older adults (Mage= 75.1, range = 60-92) from a longitudinal study that included neuropsychological assessments and blood draws every six months for up to 12 years. Systemic inflammation was operationalized as serum interleukin-6 (IL-6). The Trail Making Test measured psychomotor processing speed (TMT-A), task-switching (TMT-B), and executive functioning (TMT-B-TMT-A). Multilevel models tested associations between cognition and inflammation and moderation by gender. Models controlled for relevant covariates (e.g., age, gender, education, body mass index, cardiovascular medication count). Higher mean IL-6 was associated with slower TMT-A performance for women (γ = .036, p = .04) but not men (γ = -.01, p = .45). Higher mean IL-6 was associated with slower TMT-B performance (γ = .036, p = .02), but not after covariate adjustment (γ = .016, p = .28) and there was no significant moderation by gender. There were no significant associations between within-person IL-6 and any outcome, between- or within--person IL-6 and TMT B-A performance, or any 3-way interactions between gender, IL-6, and study wave on any outcome. Psychomotor speed, but not executive function, was sensitive to changes in systemic inflammation in a gender-specific way. -Gender-specific differences in neurological aging remain a fruitful direction and critical target for future intervention research aimed at addressing preclinical Alzheimer's disease and accelerated aging.

Ask AI

Helpful

Bookmark

View Full Paper