title: Cortisol, cytokines, and hippocampal volume interactions in the elderly.
abstract: Separate bodies of literature report that elevated pro-inflammatory cytokines and cortisol negatively affect hippocampal structure and cognitive functioning, particularly in older adults. Although interactions between cytokines and cortisol occur through a variety of known mechanisms, few studies consider how their interactions affect brain structure. In this preliminary study, we assess the impact of interactions between circulating levels of IL-1Beta, IL-6, IL-8, IL-10, IL-12, TNF-alpha, and waking cortisol on hippocampal volume. Twenty-eight community-dwelling older adults underwent blood draws for quantification of circulating cytokines and saliva collections to quantify the cortisol awakening response. Hippocampal volume measurements were made using structural magnetic resonance imaging. Elevated levels of waking cortisol in conjunction with higher concentrations of IL-6 and TNF-alpha were associated with smaller hippocampal volumes. In addition, independent of cortisol, higher levels of IL-1beta and TNF-alpha were also associated with smaller hippocampal volumes. These data provide preliminary evidence that higher cortisol, in conjunction with higher IL-6 and TNF-alpha, are associated with smaller hippocampal volume in older adults. We suggest that the dynamic balance between the hypothalamic-pituitary adrenal axis and inflammation processes may explain hippocampal volume reductions in older adults better than either set of measures do in isolation.
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Keith D
authors: KD
authors: Sudheimer
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Ruth
authors: R
authors: O'Hara
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: David
authors: D
authors: Spiegel
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Bevin
authors: B
authors: Powers
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Helena C
authors: HC
authors: Kraemer
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Eric
authors: E
authors: Neri
authors: Department of Radiology, University of California San Francisco, CA, USA ; Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases San Francisco, CA, USA.
authors: Michael
authors: M
authors: Weiner
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Antonio
authors: A
authors: Hardan
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA.
authors: Joachim
authors: J
authors: Hallmayer
authors: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University Stanford, CA, USA ; Institute for Immunity, Transplantation, and Infection, Stanford University Stanford, CA, USA.
authors: Firdaus S
authors: FS
authors: Dhabhar
keywords: aging; cognition; cortisol; cytokines; hippocampus