Interleukin 6 plasma concentration associates with cognitive decline: the northern Manhattan study.

Abstract

BACKGROUND:

Interleukin 6 (IL-6) is an inflammatory cytokine that has been associated with vascular disease and cognitive impairment, but few studies have examined these relationships in population-based studies that include Hispanic and Black people who often have a greater prevalence of vascular risk factors and are at an elevated risk of dementia than Whites. We examined relative elevations of plasma IL-6 concentrations in relation to cognitive decline in a stroke-free racially/ethnically diverse community-based sample from Northern Manhattan.

METHODS:

We used mixed effects models to measure the effect of IL-6 on change in performance on the modified Telephone Interview for Cognitive Status (TICS-m) measured annually in our cohort, adjusting for sociodemographic and vascular risk factors.

RESULTS:

There were 1,224 participants with IL-6 levels (median 1.5 pg/ml, interquartile range 0.83-2.57 pg/ml) and TICS-m data available (mean = 31.6 points, SD 6.5). The mean age was 71 (SD 9.3; 64% women, 59% Hispanic, 19% Black, 19% White) with 3,406 person-years and a median 3.0 years of follow-up (interquartile range 1.1-4.0 years). Participants with IL-6 levels above the median showed greater cognitive decline on the TICS-m compared to those with levels below the median, adjusting for sociodemographic and vascular factors (β = -0.17 points/year, p = 0.02). Decline on the TICS-m among participants with IL-6 above the median differed by age (p for interaction <0.001). There was no interaction by race/ethnicity, vascular risk factors, C-reactive protein, apolipoprotein ε4 allele status, or the metabolic syndrome among nondiabetics.

CONCLUSIONS:

IL-6 associated with cognitive decline among older participants in this racially/ethnically diverse sample independent of other vascular risk factors and C-reactive protein.

• Authors: Alexis Economos, Clinton B Wright, Yeseon Park Moon, Tatjana Rundek, Leroy Rabbani, Myunghee C Paik, Ralph L Sacco, Mitchell S V Elkind
• Journal: Neuroepidemiology (Neuroepidemiology) Vol. 40 Issue 4 Pg. 253-9 ( 2013) ISSN: 1423-0208 [Electronic] Switzerland
• PMID: 23364322 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 S. Karger AG, Basel.

Chemical References

• Interleukin-6
• C-Reactive Protein

Topics

• Aged
• Aged, 80 and over
• C-Reactive Protein
• Cognition (physiology)
• Cognition Disorders (blood, diagnosis)
• Female
• Humans
• Interleukin-6 (blood)
• Male
• Middle Aged
• Neuropsychological Tests
• Risk Factors