Potential beneficial effects of low molecular weight heparin on cognitive impairment in elderly patients on haemodialysis.

Vascular cognitive impairment or mixed vascular cognitive impairment and Alzheimer's disease (AD) appear to be much more common in elderly patients than AD alone. Furthermore, vascular dementia (VaD) and AD are more prevalent in elderly patients receiving haemodialysis (HD), leading to a loss of independence and a poor quality of life. Hypotensive episodes in patients receiving HD contribute to vascular changes in the brain, with consequent progression of VaD and AD. The use of the lowest individually optimized bolus dose of low molecular weight heparin (LMWH) during HD, with fewer hypotensive episodes during and between HD procedures, may exert a sparing effect on changes in microvascular circulation and decrease the incidence of VaD and AD. We believe that long-term use of LMWH, with its direct effect on amyloid β protein (Aβ) in the blood and on Aβ accumulation in the brain and indirect effects on prevention of complement activation, may delay the progression of cognitive impairment in patients receiving HD. There is a need for a robustly designed, prospective trial to evaluate the effects of long-term treatment with LMWH on mild cognitive impairment, VaD and AD in elderly patients receiving maintenance HD.