COGNITIVE IMPAIRMENT IN DIALYSIS PATIENTS IN NORTHEN GAUTENG PROVINCE, SOUTH AFRICA

Chronic kidney disease results in cognitive impairment.[1] Cognitive impairment is a major cause of morbidity in people with chronic kidney disease (CKD) and is associated with poor survival. The pattern of cognitive impairment in CKD is still not clear. With dialysis, CKD-related cognitive impairment is at least partially reversible (with the domains of orientation, attention and memory showing significant improvement). All domains show improvement with renal transplantation.[2] Previous studies indicated that haemodialysis patients are at increased risk of cognitive impairment because of their older age, low level of education, and a high prevalence of cardiovascular risk factors.[3]

We have previously shown a low 30% adherence rate in our chronic dialysis program at Steve Biko Academic Hospital, Pretoria, Gauteng, South Africa.[4]   We postulated that cognitive impairment might be a significant contributory factor to sub-optimal patient centered decision-making and self-management of CKD.

The study took place at the Dialysis Unit at Steve Biko Academic Hospital. One hundred and fifty one participants (males and females) were purposively sampled utilising a descriptive research design. For optimal patient time utilisation, an intradialytic Mini-Mental State Examination was conducted to establish the prevalence of cognitive impairment. 

 Participants were aged between 19 and 61 years with a mean age of 37.69 years (SD±10.56). Ninety nine percent of the recruited population showed no cognitive impairment, irrespective of dialysis modality, demographic characteristics and socio-economic status.

Utilizing the summary statistic for numeric data, the reported mean MMSE score for the entire group was 27.1 (±1.65) with minimum score of 22 and maximum score of 30. No valid associations could be drawn on the influence of the age, gender, dialysis vintage, education background, socio-economic factors and aetiology of kidney disease.

Table 1. MMSE frequencies and scores.

Although the prevalence of cognitive impairment was low (0.66%), increased awareness of cognitive impairment effects on daily activity functions, quality of life, medication, fluid and dietary adherence is important. However, this study found no valid association between cognitive impairment and dialysis treatment adherence.

Mild cognitive impairment may be missed which might be attributed to low sensitivity of the measuring MMSE instrument. Because of state rationing practices, our dialysis population has a median dialysis vintage under 3 years, is younger and physiologically fitter than patients in other countries. We aim to explore other ways to conduct routine monitoring in this population. A combination of the MMSE instrument and a reproducible robotic device in future may be beneficial for early detection of cognitive impairment among patients with CKD.

References:

1. Viggiano D, Wagner CA, Martino G et al. Mechanisms of cognitive dysfunction in CKD. Nat Rev Nephrol 2020;16:418-452

1. O’Lone E, Connors M, Masson P, Wu S, Kelly PJ, Gillespie G, Parker D, Whiteley W, Strippoli GFM, Palmer S, Craig JC, Webster AC. Cognition in people with end-stage kidney disease treated with hemodialysis: a systematic review and meta-analysis. Am J Kidney Dis. 2016; 67(6):925–35.

2. Kurella Tamura M, Xie D, Yaffe K, Cohen DL, Teal V, Kasner SE, et al. Vascular risk factors and cognitive impairment in chronic kidney disease: the chronic renal insufficiency cohort (CRIC) study. Clin J Am Soc Nephrol. 2011; 6(2):248–56.

4.T. Ndlovu, L. Repsold, AZ Muranda Factors influencing fluid restriction non adherence amongst patients undergoing chronic dialysis at Steve Biko Academic Hospital, Pretoria, South Africa. KI reports, vol 6, issue 4, S296