MO691: Risk Factors Associated with Cognitive Dysfunction in Peritoneal Dialysis
Authors: Catarina Brás Ana , Marques Joana , Alves Patrícia , Fernandes Vasco , Carina Ferreira Ana 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Cognitive dysfunction (CD) in peritoneal dialysis (PD) patients has been increasingly described as a risk factor for worse outcomes such as peritonitis, technique failure and mortality. Identification of these patients and associated risk factors is of most importance to mitigate these consequences. In this study our aims were: (i) to determine the presence of CD in a population of PD patients and (ii) to identify possible risk factors associated with CD.

METHOD
We performed an observational, cross-sectional study to evaluate cognitive function using the Montreal cognitive assessment (MOCA) test and mini mental state (MMS) test in 56 PD patients at our program whenever they were present in a schedule PD appointment. Patients with diagnosis of dementia or severe neurological impairment, active cancer or active infection were excluded. Demographic variables, comorbidities, peritonitis and exit-site infections episodes, laboratory data and dialysis adequacy were retrospectively collected in a 3-month period.

RESULTS
We evaluated 56 patients with a median age of 65 years (IQR 25.5); 53.6% were male. About 73.2% of our patients had a lower level of education; 64.3% were not professionally active; 16.1% lived alone and 25.0% needed help to perform PD treatment. Charlson comorbidity index (CCI) median score was 5 (IQR 2). Most prevalent comorbidities were hypertension (85.7%), cardiovascular disease (37.5%), diabetes (37.5%) and peripheral arterial disease (PAD) (21.4%). PD therapy median duration was 20 months (IQR 24). Automated PD was the most common modality (60.7%). Episodes of peritonitis and exit-site infection were detected in 10.7% and 3.6% of patients, respectively.
CD assessed by MOCA test was present in 64.3% of patients, with a median score of 21.5 (IQR 5.5). Visuospatial/executive, naming, attention, language, abstraction and delayed recall areas were impaired in this population (P &lt; 0.05).
Possible predictors of CD with MOCA test (Mann–Whitney or Qui square) were: higher age (P = 0.0001); lower level of education (P = 0.003); not professionally active (P = 0.004); need of a helper (P = 0.014); continuous ambulatory PD modality (P = 0.004). Higher CCI score (P = 0.0003), cardiovascular disease (P = 0.061) and PAD (P = 0.024) were also associated with CD. Lower levels of urea (P = 0.022) and Kt/V (P = 0.031) and higher levels of bicarbonate (P = 0.040), all related to CD. Multivariable analysis showed that lower Kt/V was the most relevant factor related to CD (P = 0.006).
CD assessed by MMS test was present in 33.9% of patients, with a median score of 23 (IQR 5). Impairment of all areas evaluated were observed namely orientation, immediate and delayed recall, attention and calculation, language and visuospatial (P &lt; 0.05). Again, predictors of CD were higher age (P = 0.044); very low level of education (P = 0.024); need of a helper (P = 0.004). Higher CCI score (P = 0.001), diabetes (P = 0.018) and PAD (P = 0.012) were also associated with CD. Multivariate analysis showed that higher CCI score was the most relevant factor related to CD (P = 0.02).

CONCLUSION
CD in our PD population was present in 64.3% of patients with MOCA test and 33.9% of patients with MMS test, with similar results to those described in the current literature. Patients with CD had impairment of multiple areas of cognition, such as visuospatial, memory, attention and language. Higher age, lower level of education, and need of a helper were risk factors identified for CD. Patients with CD also have a higher load of vascular diseases. Patients with lower Kt/V levels presented more CD detected by MOCA test, which can be associated with a lower clearance of possible toxins that contribute to CD; however, larger studies have to be done to confirm this hypothesis.