Associations Of Cognition With Physical And Vascular Function In Patients With Chronic Kidney Disease.

Abstract

Cognitive impairment is prevalent in patients with chronic kidney disease (CKD), but little is known about its relationship with physical and vascular function. PURPOSE: To investigate the relationship between cognitive function, and physical and vascular function in older adults with stage 3-4 CKD and preclinical cognitive impairment. We hypothesized that physical and vascular function would be related to cognitive function. METHODS: Participants (n=28) with CKD and preclinical cognitive impairment (57% female, 68% black, eGFR 43.7, age 68) completed the Trail Making Test (TMT-A: psychomotor speed, and TMT-B executive control), and digit symbol coding (DSC) (visuomotor speed/complex attention). These are standard measures that are sensitive to cognitive decline. Physical function was determined via the short physical performance battery test (SPPB) and the 6-minute walk test (6MWT). Vascular function was determined via brachial artery flow mediated vasodilation (FMD) following 5-minutes of forearm occlusion. Correlations were assessed via Pearson’s bivariate correlation. RESULTS: All participants scored below the fiftieth percentile of age and sex specific normative values on the TMT; 32% scored below the tenth percentile on the TMT-A and 50% scored below the tenth percentile for TMT-B. Age, years of education, sex, or race did not correlate with TMT-A, TMT-B, or DSC. TMT-A were inversely correlated with 6MWD (r=-.5, p=.007), SPPB score (r=-.65, p<.001), and FMD (r=-.4, p=.04). TMT-B was inversely correlated with 6MWD (r=-.39, p=.04), but not with SPPB, or FMD. DSC was correlated with 6MWD (r=.47, p=.01), but not with SPBB, or FMD. CONCLUSION: In patients with CKD, psychomotor speed is associated with indicators of physical function and fitness levels, and with vascular function. Executive control, visuomotor speed, and complex attention was associated with physical fitness levels. These results indicate a concomitance between higher levels of fitness, physical, and vascular function, and higher scores in psychomotor speed and executive control in patients with CKD. The clinical implications of our work remains to be further explored, but interventions to improve fitness levels, and physical and vascular function may contribute to lessening the impact of CKD-associated cognitive alterations.