Keenan A Walker1, Alden L Gross2, Abhay R Moghekar3, Anja Soldan4, Corinne Pettigrew5, Xirui Hou6, Hanzhang Lu7, Alfonso J Alfini8, Murat Bilgel9, Michael I Miller10, Marilyn S Albert11, Jeremy Walston12. 1. Department of Neurology, Johns Hopkins University, Baltimore, United States. Electronic address: Kwalke26@jhmi.edu. 2. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States. Electronic address: agross14@jhu.edu. 3. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: amogheka@jhmi.edu. 4. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: asoldan1@jhmi.edu. 5. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: cpettigrew@jhmi.edu. 6. Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: xhou4@jhu.edu. 7. Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: hlu3@jhmi.edu. 8. Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States. Electronic address: aalfini1@jhu.edu. 9. Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, United States. Electronic address: bilgelm@mail.nih.gov. 10. Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States. Electronic address: mim@cis.jhu.edu. 11. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: malbert9@jhmi.edu. 12. Division of Geriatric Medicine and Gerontology, Center on Aging and Health, Johns Hopkins University School of Medicine, Baltimore, United States. Electronic address: jwalston@jhmi.edu.
Abstract
BACKGROUND: Systemic inflammation has emerged as a risk factor for cognitive decline and Alzheimer's disease, but inflammation's effect on distributed brain networks is unclear. We examined the relationship between peripheral inflammatory markers and subsequent functional connectivity within five large-scale cognitive networks and evaluated the modifying role of cortical amyloid and APOE ε4 status. METHODS: Blood levels of soluble tumor necrosis factor-alpha receptor-1 and interleukin 6 were assessed in 176 participants (at baseline mean age: 65 (SD 9) years; 63% women; 85% cognitively normal, 15% mild cognitive impairment (MCI)) and were combined to derive an Inflammatory Index. Approximately six years later, participants underwent resting-state functional magnetic resonance imaging to quantify functional connectivity; a subset of 137 participants also underwent 11C Pittsburgh compound-B (PiB) PET imaging to assess cortical amyloid burden. RESULTS: Using linear regression models adjusted for demographic characteristics and cardiovascular risk factors, a higher Inflammatory Index was associated with lower connectivity within the Default Mode (β = -0.013; 95% CI: -0.023, -0.003) and the Dorsal Attention Networks (β = -0.017; 95% CI: -0.028, -0.006). The strength of these associations did not vary by amyloid status (positive/negative). However, there was a significant interaction between Inflammatory Index and APOE ε4 status, whereby ε4-positive participants with a higher Inflammatory Index demonstrated lower connectivity. Inflammatory Index was unrelated to connectivity within other large-scale cognitive networks (Control, Limbic, and Salience/Ventral Attention networks). CONCLUSION: Peripheral pro-inflammatory signaling in older adults without dementia, especially among APOE ε4-positive individuals, is associated with altered connectivity within two large-scale cognitive networks.
BACKGROUND: Systemic inflammation has emerged as a risk factor for cognitive decline and Alzheimer's disease, but inflammation's effect on distributed brain networks is unclear. We examined the relationship between peripheral inflammatory markers and subsequent functional connectivity within five large-scale cognitive networks and evaluated the modifying role of cortical amyloid and APOE ε4 status. METHODS: Blood levels of soluble tumor necrosis factor-alpha receptor-1 and interleukin 6 were assessed in 176 participants (at baseline mean age: 65 (SD 9) years; 63% women; 85% cognitively normal, 15% mild cognitive impairment (MCI)) and were combined to derive an Inflammatory Index. Approximately six years later, participants underwent resting-state functional magnetic resonance imaging to quantify functional connectivity; a subset of 137 participants also underwent 11C Pittsburgh compound-B (PiB) PET imaging to assess cortical amyloid burden. RESULTS: Using linear regression models adjusted for demographic characteristics and cardiovascular risk factors, a higher Inflammatory Index was associated with lower connectivity within the Default Mode (β = -0.013; 95% CI: -0.023, -0.003) and the Dorsal Attention Networks (β = -0.017; 95% CI: -0.028, -0.006). The strength of these associations did not vary by amyloid status (positive/negative). However, there was a significant interaction between Inflammatory Index and APOE ε4 status, whereby ε4-positive participants with a higher Inflammatory Index demonstrated lower connectivity. Inflammatory Index was unrelated to connectivity within other large-scale cognitive networks (Control, Limbic, and Salience/Ventral Attention networks). CONCLUSION: Peripheral pro-inflammatory signaling in older adults without dementia, especially among APOE ε4-positive individuals, is associated with altered connectivity within two large-scale cognitive networks.
Authors: Elizabeth K Belcher; Eva Culakova; Nikesha J Gilmore; Sara J Hardy; Amber S Kleckner; Ian R Kleckner; Lianlian Lei; Charles Heckler; Michael B Sohn; Bryan D Thompson; Louis T Lotta; Zachary A Werner; Jodi Geer; Judith O Hopkins; Steven W Corso; David Q Rich; Edwin van Wijngaarden; Michelle C Janelsins Journal: J Natl Cancer Inst Date: 2022-05-09 Impact factor: 11.816
Authors: Lauren E Oberlin; Kirk I Erickson; Rachel Mackey; William E Klunk; Howard Aizenstein; Brian J Lopresti; Lewis H Kuller; Oscar L Lopez; Beth E Snitz Journal: Brain Behav Immun Date: 2021-03-15 Impact factor: 19.227