Risk of dementia in peritoneal dialysis patients compared with hemodialysis patients.
BACKGROUND
Compared with similarly aged controls, patients with end-stage renal disease (ESRD) have a higher prevalence of cognitive impairment and more rapid cognitive decline, which is not explained by traditional risk factors alone. Since previous small studies suggest an association of cognitive impairment with dialysis modality, we compared incident dementia among patients initiating hemodialysis (HD) vs peritoneal dialysis (PD) in a large national cohort.


METHODS
This is a retrospective cohort study of incident dialysis patients in the United States from 2006 to 2008 with no diagnosis of dementia prior to beginning dialysis. We evaluated the effect of initial dialysis modality on incidence of dementia, diagnosed by Medicare claims data, adjusted for baseline demographic and clinical data from the USRDS registry.


RESULTS
Our analysis included 121,623 patients, of whom 8,663 initiated dialysis on PD. The mean age of our cohort was 69.2 years. Patients who initiated PD had a lower cumulative incidence of dementia than those who initiated HD (1.0% vs 2.7%, 2.5% vs 5.3%, and 3.9% vs 7.3% at 1, 2, and 3 years, respectively). The risk of dementia for patients who started on PD was lower compared with those who started on HD, with a hazard ratio (HR) = 0.46 [0.41, 0.53], in an unadjusted model and HR 0.74 [0.64, 0.86] in a matched model.


CONCLUSIONS
Dialysis modality is associated with incident dementia in a cohort of older ESRD patients. This finding warrants further investigation of the effect of dialysis modality on cognitive function and evaluation for possible mechanisms.
Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI Section of Nephrology, Department of Medicine, Zablocki VA Medical Center, Milwaukee, WI.
Dawn F
DF
Wolfgram
Division of Biostatistics, Institute for Health and Society, Medical College of Wisconsin, Milwaukee, WI.
Aniko
A
Szabo
Division of Geriatrics, Department of Medicine, Hennepin County Medical Center and University of Minnesota, Minneapolis, MN.
Anne M
AM
Murray
Division of General Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI Primary Care, Department of Medicine, Zablocki VA Medical Center, Milwaukee, WI.
Jeff
J
Whittle
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007676:Kidney Failure, Chronic / Q000523:psychology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States; D055815:Young Adult
Dementia; cognitive impairment; end-stage renal disease; hemodialysis; peritoneal dialysis