Midlife systemic inflammation may promote the development of white matter dysfunction
Midlife Systemic Inflammation, Late-Life White Matter Integrity, and Cerebral Small Vessel Disease: The Atherosclerosis Risk in Communities StudyLiterature - Walker KA, Power MC, Hoogeveen RC, et al. - Stroke 2017;48: 3196-3202
- Mean time between hsCRP measurement and MRI was 21 years (SD 0.9). Individuals with high midlife hsCRP levels were more likely women, black, with a lower level of education, with fewer copies of the APOE ε4 allele, with higher levels of vascular risk factors, diagnosed with hypertension, HF and arthritis.
- In the primary analysis, higher hsCRP levels were only marginally associated with greater WMH volume. However, there was a significant association between each SD increase in hsCRP level and greater WMH volume in participants with ≥1 copy of the APOE ε4 allele (SD: 0.14; 95%CI: 0.01–0.26; P=0.032), but not in APOE ε4-negative participants (SD: 0.03; 95%CI: −0.06 to 0.11; P=0.522).
- Weighting analyses that account for differential attrition, strengthened the association between higher hsCRP levels and larger WMH volume.
- Higher midlife hsCRP levels were associated with lower fractional anisotropy and greater MD within deep WM, as well as with lower fractional anisotropy within periventricular WM.
- There was a significant interaction of race by hsCRP level on MD within the periventricular WM (P interaction=0.011). The association between higher midlife hsCRP and reduced periventricular WM microstructural integrity was significantly stronger among black, compared with white, participants.
- The associations between hsCRP levels and deep WM microstructural integrity did not differ by race, and there was no evidence for effect modification by APOE ε4 status.
- After accounting for differential attrition, associations between higher hsCRP levels and reduced periventricular microstructural integrity were strengthened, particularly among white participants.
- Cortical and lacunar infarcts and CMBs were present on MRI in 10% (n=148), 17% (n=257) and 25% (n=362), respectively. No association of midlife hsCRP levels with cortical or lacunar infarct presence, CMB presence, or SVD composite score was found.
In a sub-analysis of the ARIC study, midlife systemic inflammation was associated with the development of chronic microangiopathic structural WM abnormalities in the elderly. These results provide insight into the temporal relationship between systemic inflammation and brain health and support the hypothesis that systemic inflammation plays a role in the pathogenesis of late-life WM dysfunction.