Prevalence of mild cognitive impairment in automated peritoneal dialysis patients

BACKGROUND: Cognitive deterioration decreases quality of life, self-care and adherence to treatment, increasing mortality risk. There is scarce information of cognitive impairment in peritoneal dialysis (PD) and data are controversial. Our aim was to determine the frequency and associated factors of cognitive impairment in patients on automated PD (APD). METHODS: In this cross-sectional study, 71 patients on APD underwent clinical, biochemical and cognitive function evaluation by means of the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Cognitive function was also evaluated in healthy controls. RESULTS: Participants mean age was 42 ± 16 years, 79% were men and dialysis vintage was 17 months ( interquartile range 7-32). In APD patients, cognitive impairment was present in 7% (mild deterioration) and 68% according to the MMSE and MoCA, respectively, and 4 and 37% in the healthy controls. Patients with cognitive impairment (according to MoCA) were older, with less education, had diabetes more frequently and higher serum glucose as well as lower serum creatinine, phosphorus and sodium concentrations than patients with normal cognitive function. In multiple linear regression analysis, predictors for the MoCA score (R2 = 0.63, P = 0.002) were education {B = 0.54 [95% confidence interval (CI) 0.20-0.89]; P = 0.003}, age [B = -0.11 (95% CI -0.21 to -0.01); P = 0.04], serum sodium [B = 0.58 (95% CI 0.05-1.11); P = 0.03] and creatinine concentration [B = 3.9 (95% CI 0.03-0.83); P = 0.03]. CONCLUSIONS: In this sample of APD patients, the prevalence of cognitive impairment by the MoCA was 65% and was associated with older age, lower education level and lower serum concentrations of sodium and creatinine.