Cystatin C as an index of cerebral small vessel disease: results of a cross-sectional study in community-based Japanese elderly

Background and purpose: Recent studies have shown that kidney dysfunction is associated with cerebral small vessel disease (SVD). Although creatinine-based estimating equations have been used as the standard measure for the evaluation of kidney function, the accuracy of these is limited in the elderly because of muscle mass decrease with aging. Cystatin C is a more useful measurement than creatinine-based estimating equations for evaluating kidney function, however, the relationship amongst cystatin C, cognitive dysfunction, and cerebral SVD has not been fully examined in community-based elderly. Methods: We performed a cross-sectional study using MRI to determine the relationship amongst cystatin C, cognitive function, and cerebral SVD in a total of 604 community-based Japanese elderly. Results: In this study, subjects with higher cystatin C levels tended to have more lacunas and higher grades of white matter lesions. Although a decline of the Mini-Mental State Examination (MMSE) scores was associated with SVD-related lesions, the relationship between the tertiles of cystatin C and mean MMSE scores was not statistically significant. In the logistic regression analysis, the association between cystatin C and SVD-related lesions was statistically significant, even after adjustment for conventional risk factors and high-sensitivity C-reactive protein. Furthermore, subjects with higher cystatin C levels accompanied with albuminuria had a greater risk for the presence of subclinical cerebral SVD than those with lower cystatin C levels without albuminuria. Conclusions: The present study suggests that there is a close relationship between cystatin C and subclinical cerebral SVD, independently of conventional risk factors, in community-based elderly.