Renal disease is a risk factor for vascular diseases and for dementia, and renal insufficiency can be a feature of
Alzheimer’s disease (AD). Evidence has suggested that vascular mechanisms mediate the link between renal disease and
dementia. Our study sought to test this hypothesis by examining renal and vascular functioning in AD by investigating estimated
glomerular filtration rates (eGFR), calculated from serum creatinine concentrations, and established biomarkers of
vascular functioning, asymmetrical dimethylarginine (ADMA) and plasma homocysteine (Hcy), in individuals with mild
to moderate AD (n = 34) and a group of older adult controls (n = 34). We found significantly reduced eGFR, indicative of
impaired renal functioning, in individuals with AD (M = 62.9, SD = 15.2) compared with controls (M = 73.6, SD = 11.8).
However, concentrations of ADMA and Hcy did not differ between patient and control groups (ADMA: M = 0.47; M =
0.50; Hcy: M = 17.2; M = 14.9; patients and controls). The criteria for a mediation analysis were not met, as concentrations
of ADMA and Hcy did not predict AD, indicating that these biomarkers of vascular functioning did not mediate a relationship
between renal functioning and AD. This study indicated that renal insufficiency may independently contribute
to AD pathology, and other vascular mechanisms may influence a relationship between renal impairment and AD.
Alzheimer’s disease, asymmetrical dimethylarginine, biomarkers of vascular disease, glomerular filtration rate,
homocysteine, renal disease.
Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9RR, UK.