Malnutrition and inflammation are associated with severity of depressive and cognitive symptoms of old patients affected by chronic kidney disease

Objective: Chronic kidney disease (CKD) is a disabling condition associated with different medical comorbidities including depression and cognitive impairment. We investigated the association between malnutrition, inflammation and depressive/cognitive symptoms in elderly subjects with advanced CKD. Methods: We evaluated cross-sectionally 132 elderly subjects (age >= 65 years) with advanced CKD (stage 4-5, non-dialytic-ND) in regular follow up at the outpatient clinic of nephrology. Blood and urinary samples were collected after an overnight fast. All patients were evaluated by Geriatric Depression Scale (GDS)-30 items for severity of depressive symptoms, Mini Mental State Examination (MMSE) and the Clock Drawing Test (CDT) for cognition. Nutritional status was assessed by Malnutrition Inflammation Score (MIS). Different linear regression models were performed to study the association between clinical variables, diet and inflammatory parameters with the above mentioned rating scale scores. A final linear regression model with only previous statistically significant variables was performed for GDS scores. Results: Our cohort consisted of 95 males and 37 females with a mean age of 78 +/- 7. Female gender (B = 3.20, p < .01), higher MIS (B = 0.29, p = .02) and higher IL-12p70 serum levels (pg/mL) (B = 0.37, p = .03) were associated with severity of depressive symptoms. MIS was associated with the severity of cognitive impairment as assessed by MMSE (B = -0.19, p < .01) and CDT (B = 0.10, p = .03). Conclusion: In elderly subjects affected by CKD the severity of depressive symptoms and cognitive impairment is associated with specific inflammatory and nutritional parameters. These results have to be considered as preliminary and need replication by further studies.