TY - JOUR
T1 - Interleukin-6 and C-reactive protein levels and 9-year cognitive decline in community-dwelling older women
T2 - The women's health and aging study II
AU - Palta, Priya
AU - Xue, Qian Li
AU - Deal, Jennifer A.
AU - Fried, Linda P.
AU - Walston, Jeremy D.
AU - Carlson, Michelle C.
N1 - Publisher Copyright:
© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America.
PY - 2015/7
Y1 - 2015/7
N2 - Background. Elevated inflammation is a proposed mechanism relating chronic diseases to cognitive dysfunction. The objective of this study was to test the hypothesis that greater levels of inflammation, as measured by the proinflammatory cytokine interleukin-6 (IL-6) and C-reactive protein, are associated with faster rates of cognitive decline among cognitively intact community-dwelling older women. Methods. We analyzed 336 women from the Women's Health and Aging Study II. Cognitive assessments were performed at baseline and every 18-36 months, and included the following domains: immediate and delayed memory (Hopkins Verbal Learning Test), psychomotor speed (Trail Making Test, Part A), and executive function (Trail Making Test, Part B). Aggregate measures of IL-6 and C-reactive protein, based on the average from visits one and two, were analyzed categorically. Random effects models were employed to test the relationship between tertiles of each inflammatory marker and changes in cognitive domain scores over 9 years. Results. Moderate and high levels of IL-6 predicted early declines in psychomotor speed by 1.0 connection/min per year. There were no differences in baseline scores or rates of change across tertiles of IL-6 in memory or executive function. No differences were observed across tertiles of C-reactive protein for all cognitive domains. Conclusions. Higher levels of serum IL-6 were associated with greater declines in psychomotor speed over 9 years. This finding could suggest that elevated IL-6 may result in microvascular changes that may lead to damage of myelin sheaths that line neuronal axons, leading to decreased neuron propagation and impaired processing speed; however, mechanistic studies are needed to evaluate these hypotheses.
AB - Background. Elevated inflammation is a proposed mechanism relating chronic diseases to cognitive dysfunction. The objective of this study was to test the hypothesis that greater levels of inflammation, as measured by the proinflammatory cytokine interleukin-6 (IL-6) and C-reactive protein, are associated with faster rates of cognitive decline among cognitively intact community-dwelling older women. Methods. We analyzed 336 women from the Women's Health and Aging Study II. Cognitive assessments were performed at baseline and every 18-36 months, and included the following domains: immediate and delayed memory (Hopkins Verbal Learning Test), psychomotor speed (Trail Making Test, Part A), and executive function (Trail Making Test, Part B). Aggregate measures of IL-6 and C-reactive protein, based on the average from visits one and two, were analyzed categorically. Random effects models were employed to test the relationship between tertiles of each inflammatory marker and changes in cognitive domain scores over 9 years. Results. Moderate and high levels of IL-6 predicted early declines in psychomotor speed by 1.0 connection/min per year. There were no differences in baseline scores or rates of change across tertiles of IL-6 in memory or executive function. No differences were observed across tertiles of C-reactive protein for all cognitive domains. Conclusions. Higher levels of serum IL-6 were associated with greater declines in psychomotor speed over 9 years. This finding could suggest that elevated IL-6 may result in microvascular changes that may lead to damage of myelin sheaths that line neuronal axons, leading to decreased neuron propagation and impaired processing speed; however, mechanistic studies are needed to evaluate these hypotheses.
KW - C-reactive protein
KW - Cognitive decline
KW - Interleukin-6
KW - Psychomotor speed
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U2 - 10.1093/gerona/glu132
DO - 10.1093/gerona/glu132
M3 - Article
C2 - 25161214
AN - SCOPUS:84936759291
SN - 1079-5006
VL - 70
SP - 873
EP - 878
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 7
ER -