1. Elevated C-Reactive Protein in Older Men With Chronic Pain: Association With Plasma Amyloid Levels and Hippocampal Volume
- Author
-
Bell, Tyler R, Franz, Carol E, Thomas, Kelsey R, Williams, McKenna E, Eyler, Lisa T, Lerman, Imanuel, Fennema-Notestine, Christine, Puckett, Olivia K, Dorros, Stephen M, Panizzon, Matthew S, Pearce, Rahul C, Hagler, Donald J, Lyons, Michael J, Elman, Jeremy A, and Kremen, William S
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Aging ,Chronic Pain ,Neurosciences ,Brain Disorders ,Neurodegenerative ,Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD) ,Alzheimer's Disease ,Pain Research ,Dementia ,Acquired Cognitive Impairment ,2.1 Biological and endogenous factors ,Neurological ,Humans ,Male ,Hippocampus ,C-Reactive Protein ,Aged ,Amyloid beta-Peptides ,Biomarkers ,Middle Aged ,Magnetic Resonance Imaging ,tau Proteins ,Alzheimer Disease ,Neurofilament Proteins ,Organ Size ,Peptide Fragments ,Inflammation ,Amyloid-beta ,Chronic pain ,Plasma biomarkers ,Gerontology ,Biomedical and clinical sciences ,Health sciences - Abstract
BackgroundChronic pain leads to tau accumulation and hippocampal atrophy, which may be moderated through inflammation. In older men, we examined associations of chronic pain with Alzheimer's disease (AD)-related plasma biomarkers and hippocampal volume as moderated by systemic inflammation.MethodsParticipants were men without dementia. Chronic pain was defined as moderate-to-severe pain in 2+ study waves at average ages 56, 62, and 68. At age 68, we measured plasma amyloid-beta (Aβ42, n = 871), Aβ40 (n = 887), total tau (t-tau, n = 841), and neurofilament light chain (NfL, n = 915), and serum high-sensitivity C-reactive protein (hs-CRP, n = 968), a marker of systemic inflammation. A subgroup underwent structural MRI to measure hippocampal volume (n = 385). Analyses adjusted for medical morbidities, depressive symptoms, and opioid use.ResultsChronic pain was related to higher Aβ40 (β = 0.25, p = .009), but hs-CRP was unrelated to AD-related biomarkers (ps > .05). There was a significant interaction such that older men with both chronic pain and higher levels of hs-CRP had higher levels of Aβ42 (β = 0.36, p = .001) and Aβ40 (β = 0.29, p = .003). Chronic pain and hs-CRP did not interact to predict levels of Aβ42/Aβ40, t-tau, or NfL. Furthermore, there were significant interactions such that Aβ42 and Aβ40 were associated with lower hippocampal volume, particularly when levels of hs-CRP were elevated (hs-CRP × Aβ42: β = -0.19, p = .002; hs-CRP × Aβ40: β = -0.21, p = .001), regardless of chronic pain status.ConclusionsChronic pain was associated with higher plasma Aβ, especially when hs-CRP was also elevated. Higher hs-CRP and Aβ levels were both related to smaller hippocampal volumes. Chronic pain, when accompanied by systemic inflammation, may elevate the risk of neurodegeneration in AD-vulnerable regions.
- Published
- 2024