Cognitive impairment in peritoneal dialysis patients.

BACKGROUND

The prevalence of moderate to severe cognitive impairment in hemodialysis patients is more than double the prevalence in the general population. This study describes cognitive impairment occurrence in a peritoneal dialysis cohort compared with a cohort without chronic kidney disease (CKD).

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS: 51 English-speaking peritoneal dialysis patients from 2 urban dialysis units compared with 338 hemodialysis patients from 16 urban dialysis units and 101 voluntary controls without CKD from urban general medicine clinics.

PREDICTOR

45-minute battery of 9 validated neuropsychological tests (cognitive domains memory, executive function, and language).

OUTCOMES

Mild, moderate, or severe cognitive impairment, classified according to a previously designed algorithm.

RESULTS

Of the peritoneal dialysis cohort, 33.3% had no or mild, 35.3% had moderate, and 31.4% had severe cognitive impairment; corresponding values were 60.4%, 26.7%, and 12.9% of the non-CKD cohort and 26.6%, 36.4%, and 37.0% of the hemodialysis cohort. A logistic regression model including age, sex, race, education, hemoglobin level, diabetes, and stroke showed that only nonwhite race (P = 0.002) and low education (P = 0.002) were associated with moderate to severe cognitive impairment in the peritoneal dialysis cohort. Compared with hemodialysis patients, more peritoneal dialysis patients had moderate to severe memory impairment (58% vs 51%), but fewer had impaired executive function (one-third vs one-half). Peritoneal dialysis was associated with a more than 2.5-fold increased risk of moderate to severe global cognitive impairment compared with no CKD (OR, 2.58; 95% CI, 1.02-6.53), as was hemodialysis (OR, 3.16; 95% CI, 1.91-5.24), in an adjusted logistic regression model.

LIMITATIONS

Small sample size, participation rate somewhat low.

CONCLUSIONS

Similar to hemodialysis patients, two-thirds of peritoneal dialysis patients had moderate to severe cognitive impairment, enough to interfere with safely self-administering dialysis and adhering to complex medication regimens. These patients could benefit from cognitive assessment before and periodically after dialysis therapy initiation.