Risk factors for cognitive dysfunction in CKD and hypertensive subjects.

Purpose: Cognitive dysfunction (CO/DY) in chronic kidney disease (CKD) patients has long been recognized. Hypertension is also associated with CO/DY. The study describes associated factors with CO/DY in CKD patients compared to hypertensive subjects.

Methods: Ninety-six hypertensive subjects without CKD, 19 patients with CKD stages I-II, 33 with CKD III, 42 with CKD stage IV, 33 on hemodialysis (HD) and 33 on peritoneal dialysis (PD) were included in our study. Cognitive impairment measured by MMSE, clock-drawing test and IADL was considered as primary outcome.

Results: In all groups tested, age was significantly associated with CO/DY by almost all cognitive function tests. Among CKD patients, CKD stage and DM were significantly associated with CO/DY by all three cognitive function tests. PTH levels were also associated with CO/DY by MMSE and clock-drawing tests. In hypertensives, pulse pressure (PP) was associated with CO/DY by clock-drawing and IADL tests, while those receiving CCBs as monotherapy were less likely to have CO/DY by IADL test. For dialysis patients, DM was significantly related to CO/DY by MMSE and clock-drawing tests. In the same group of patients Hb <11 g/dl was significantly correlated with CO/DY by MMSE, dialysis modality and Kt/V >1.2 by IADL test. PD patients were less likely to present with CO/DY by clock-drawing test.

Conclusions: In every CKD stage, the risk of CO/DY increased significantly. Low Hb levels (Hb <11 g/dl) and increased serum PTH levels were associated with CO/DY while DM plays also a significant role in cognitive function deterioration. Among hypertensive subjects, those with PP ≤60 mmHg or receiving CCBs showed a better executive function.