The association of mid-to late-life systemic inflammation with white matter structure in older adults: The Atherosclerosis Risk in Communities Study.

We examined whether the pattern of middle- to late-life systemic inflammation was associated with white matter (WM) structural abnormalities in older adults. A total of 1532 participants (age = 76.5; standard deviations = 5.4) underwent 3T brain magnetic resonance imaging to quantify white matter hyperintensity volume and whole-brain WM microstructural integrity (fractional anisotropy, mean diffusivity). High-sensitivity C-reactive protein (CRP), a marker of systemic inflammation, was measured at 3 visits (21 and 14 years before, and concurrent with, neuroimaging). Participants were categorized into 1 of 6 groups based on their 21-year pattern of low (<3 mg/L) versus elevated (≥3 mg/L) CRP. Compared to the group with low CRP at all 3 visits, the group that transitioned from low to elevated CRP during midlife demonstrated greatest white matter hyperintensity volume and poorest WM microstructural integrity, after adjusting for demographic variables and cardiovascular risk factors. Participants with high CRP at all visits also demonstrated greater WM structural abnormalities, but only after accounting for differential attrition. These results suggest that increasing and persistent inflammation in the decades spanning middle-to late-life may promote WM disease in older adults.