Renal function and cognitive dysfunction: cross-sectional study of users enrolled at Ponte Family Health Unit.

INTRODUCTION Recent studies show increased prevalence of Cognitive Dysfunction in patients with Chronic Kidney Disease. OBJECTIVE To evaluate this association in users enrolled in the Family Health Unit Ponte. METHODS We studied a sample of 246 elderly. We assessed cognitive function using the Mini Mental State Examination and the Glomerular Filtration Rate using the equation Modification of Diet in Renal Disease. The Glomerular Filtration Rate values obtained (ml/min/1,73 m2) were divided into three categories: < 60.00, 60 to 89.99 and ≥ 90. We collected additional variables from the Medical Support Service and studied the data using bivariate analyzes and logistic regression models. RESULTS The groups with Glomerular Filtration Rate < 60 and ≥ 90 had a higher prevalence of Cognitive Dysfunction, irrespective of other factors. The odds ratios were, respectively, of 4.534 (95%CI: 1.257 to 16.356) and 3.302 (95% CI: 1.434 to 7.607). DISCUSSION According to the literature, we found higher prevalence of Cognitive Dysfunction in the group with Glomerular Filtration Rate < 60. The high prevalence of Cognitive Dysfunction in users with GFR ≥ 90 is described in some studies and may be caused by situations that lead to overestimation of that rate, as the states of cachexia, or situations of glomerular hyperfiltration. CONCLUSION The relationship between renal function and the prevalence of Cognitive Dysfunction was not linear, but rather in a parabolic shape. Further studies are needed to explain this relationship and to determine the need for monitoring Cognitive Dysfunction in patients with impaired renal function.