in particular smaller than 0 01 more preferably the membrane is a permselective membrane of the type disclosed in wo 2004 056460 such membranes preferably allow passage of molecules having a molecular weight of up to 45 kda in the presence of whole blood and have a molecular weight exclusion limit in water of about 200 kda in one embodiment of the invention the membrane takes the form of a permselective asymmetric hollow fiber membrane it preferably comprises at least one hydrophobic polymer and at least one hydrophilic polymer preferably the polymers are present as domains on the surface in one embodiment the membrane is free light chain flc leaking that is the u03ba or u03bb free light chains pass through the membrane high flux membranes with smaller pore sizes have been observed to remove some free light chains however this appears to be primarily due to binding of the flc onto the dialysis membranes flc may be used as markers of middle molecular weight proteins although clearing of free light chains is not a primary target of the invention their reduction can be used as an indicator of membrane functionality according to one aspect of the invention a dialysis membrane that allows the passage of molecules having a molecular weight of up to 45 kda in the presence of whole blood and with a molecular weight exclusion limit in water of about 200 kda is provided for reducing the risk of cardiovascular disease or retard the progression of cardiovascular disease in a esrd patient preferably the cardiovascular disease risk is reduced or the development or progression of cardiovascular disease is slowed irrespective of the patient 39 s inflammatory status according to a.