Albuminuria and cognitive functioning in an older population: The Hoorn study

Background/Aims: Markers of vascular disease elsewhere in the body may reflect vascular abnormalities in the brain relevant to age-related cognitive decline and dementia. We examined the association between albuminuria, as a marker of microvascular damage, and cognition in older individuals. Methods: 380 individuals (age 73 +/- 6 years), participating in the population-based Hoorn Study, underwent extensive neuropsychological examination in 2005-2008, and urinary albumin-to-creatinine ratios measurements in 2000-2001 (n = 378) and/or 2005-2008 (n = 346). Cognition was expressed in z-scores on 6 domains. Results: In 2000-2001, 42 participants were with and 336 without albuminuria, and in 2005-2008 51 were with and 295 were without. In age-, sex- and premorbid IQ-adjusted analyses, participants with albuminuria 5-7 years earlier had slightly lower z-scores for the domains attention and executive functioning [mean difference: -0.21 (95% CI -0.40 to -0.02)] and language [-0.36 (95% CI -0.63 to -0.09)]. No statistically significant differences in cognition were found between participants with and without albuminuria at the time of neuropsychological testing. Conclusion: Albuminuria predicts future modest cognitive decrements, but concurrent albuminuria is unrelated to cognitive functioning. The link between albuminuria and cognitive dysfunction may convey an etiological message, but because effect sizes were modest its value in prognostic models for cognitive decline may be limited.