Trajectories of peripheral interleukin-6, structure of the hippocampus, and cognitive impairment over 14 years in older adults.
We aimed to investigate if trajectory components (baseline level, slope, and variability) of peripheral interleukin-6 (IL-6) over time were related to cognitive impairment and smaller hippocampal volume and if hippocampal volume explained the associations between IL-6 and cognitive impairment. Multivariable regression models were used to test the association between IL-6 trajectory components with change in neuroimaging measures of the hippocampus and with cognitive impairment among 135 older adults (70-79 years at baseline) from the Healthy Brain Project over 14 years. IL-6 variability was positively associated with cognitive impairment (odds ratio [OR] = 5.86, 95% confidence interval [CI]: 1.24, 27.61) and with greater decrease per year of gray matter volume of the hippocampus (β = -0.008, standard error = 0.004, p = 0.03). After adjustment for hippocampal volume, the OR of cognitive impairment decreased for each unit of IL-6 variability and CIs widened (OR = 4.36, 95% CI: 0.67, 28.29). Neither baseline levels nor slopes of IL-6 were related to cognitive impairment or hippocampal volume. We believe this has potential clinical and public health implications by suggesting adults with stable levels of peripheral IL-6 may be better targets for intervention studies for slowing or preventing cognitive decline.
Metti Consulting Company, Pittsburgh, PA, USA. Electronic address: andrealmetti@gmail.com.
Andrea L
AL
Metti
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
Howard
H
Aizenstein
Department of Psychiatry, University of California San Francisco, San Francisco, CA, USA; Department of Neurology, University of California San Francisco, San Francisco, CA, USA; Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.
Kristine
K
Yaffe
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Robert M
RM
Boudreau
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Anne
A
Newman
Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, MD, USA.
Lenore
L
Launer
Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
Peter J
PJ
Gianaros
Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
Oscar L
OL
Lopez
Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
Judith
J
Saxton
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Diane G
DG
Ives
Department of Internal Medicine, Wake Forest University, Medical Center Boulevard, Winston-Salem, NC, USA.
Stephen
S
Kritchevsky
Division of Pediatric Rheumatology, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; Department of Pediatrics and Immunology, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
Abbe N
AN
Vallejo
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Caterina
C
Rosano
D000368:Aged; D000375:Aging / Q000378:metabolism* / Q000473:pathology*; D003072:Cognition Disorders / Q000378:metabolism* / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D066128:Gray Matter / Q000473:pathology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D059906:Neuroimaging; D011446:Prospective Studies; D012044:Regression Analysis; D013997:Time Factors
C508600:IL6 protein, human; D015850:Interleukin-6
Aging; Cognitive impairment; Epidemiology; Hippocampal morphology; Interleukin-6