For people on dialysis, keeping your mind sharp may depend on more than just your kidneys. A new study of 86 patients undergoing maintenance hemodialysis found that those with protein-energy wasting, a condition marked by muscle loss and poor nutrition, were more likely to have cognitive impairment.
Researchers measured muscle mass using mid-arm muscle circumference (MAMC) and inflammation using the malnutrition-inflammation score (MIS). They found that lower MAMC and higher MIS were independently linked to cognitive problems. In fact, each unit decrease in MAMC raised the odds of cognitive impairment by about 43%, while each unit increase in MIS raised the odds by about 25%.
The study included 50 patients with cognitive impairment and 36 without. The combination of MAMC and MIS was very good at predicting who had cognitive issues, with an accuracy score of 0.942.
However, this was a cross-sectional study, meaning it looked at a single point in time. So we can't say whether muscle loss and inflammation cause cognitive decline or the other way around. More research is needed to understand the direction of this relationship.