Renal function affects hippocampal volume and cognition: The role of vascular burden and amyloid deposition

AimWe determined if differences in renal function, even within normal levels, influenced hippocampal volume (HCV) and cognition. MethodsCognitively normal (CN) and mild cognitive impairment (MCI) subjects with eGFR 60 ml/min/1.73m(2) were selected from the ADNI database (N = 1,269) and divided into three groups (eGFR 60-75, 75-90 and 90). Associations between eGFR, HCV and cognition scores were examined using regression methods, and random-coefficient models. The relationship between various factors, such as vascular burden and brain amyloid deposition, were investigated using path analysis. ResultsHigher eGFR was associated with larger HCVs and better cognition in all subjects at baseline. In MCI subjects, hippocampal atrophy in the eGFR 90 group progressed at just half the rate of the eGFR 75-90 group (P = .006), and was also somewhat slower than the eGFR 60-75 group (P = .08). A comprehensive path model linking eGFR, HCV and cognition, and integrating vascular burden and amyloid deposition, is proposed. ConclusionsHigher renal function was associated with slower hippocampal atrophy and cognitive decline even within normal levels of renal function. This relationship was mediated mainly through cardiovascular risk burden and amyloid deposition. Further studies examining neuroinflammation are needed. Geriatr Gerontol Int 2017; 17: 1899-1906.