Protein in urine linked to increased risk of memory problems
Chronic kidney disease and dementia share many risk factors, researchers point out
Thursday, 15 December 2016
People who have protein in their urine (albuminuria or proteinuria), which is a sign of kidney problems, may also be more likely to later develop problems with thinking and memory skills or even dementia, according to a meta-analysis* published in the online issue of Neurology.
Researchers identified 22 studies looking at kidney problems and the development of cognitive impairment or dementia for the systematic review. Five of the studies, including 27,805 people, were evaluated in the meta-analysis on protein in the urine. The analysis showed that people with protein in the urine were 35% more likely to develop cognitive impairment or dementia than people who did not have protein in their urine.
For another marker of kidney function, estimated glomerular filtration rate, the results were mixed and did not show an association. For three other markers of kidney function, cystatin C, serum creatinine and creatinine clearance, no meta-analysis could be completed because the few studies available did not use the same methods and could not be compared.
Lead author Kay Deckers, from Maastricht University in the Netherlands, said: "Kidney dysfunction has been considered a possible risk factor for cognitive impairment or dementia. Chronic kidney disease and dementia share many risk factors, such as high blood pressure, diabetes and high cholesterol, and both show similar effects on the brain, so they may have shared vascular factors or there may even be a direct effect on the brain from kidney problems."
As protein in the urine was associated with a modestly increased risk of cognitive impairment or dementia, Deckers said: "More research is needed to determine whether the kidney problems are a cause of the cognitive problems or if they are both caused by the same mechanisms."
* Deckers K, Camerino I, van Boxtel MPJ, et al. Dementia risk in renal dysfunction. A systematic review and meta-analysis of prospective studies. Neurology, published online before print 14 December 2016. DOI: 10.1212/WNL.0000000000003482