Effects of haemodialysis on taste and thirst

Fifteen patients undergoing haemodialysis tasted soup varying in salt concentration and apple puree varying in sucrose concentration, immediately before and after dialysis. Matched controls tasted the same foods with a similar interval between tastings. The samples were rated for intensity, and on a relative-to-ideal scale. For the salt, the slopes of the functions plotted against log (concentration) were higher after dialysis than before, whilst the most preferred concentration was lower. There were no effects found for the sweetness ratings or for the controls. Likewise there were no overall differences in the ratings between the patients and controls. Thirst was found to increase on dialysis, and there was a trend of this being higher for the patients than for the controls. The reduction in preferences for salt by dialysis would make compliance with a reduced salt diet easier, but the increase in thirst would make compliance with reduced fluid intake more difficult.