Effect Of Intradialytic Hypotension On Cognitive Function

Objective To study the effect of intradialytic hypotension on cognitive function and the possible mechanism of cognitive impairment induced by hypotension,so as to provide theoretical basis for improving cognitive function,quality of life and prognosis of patients with hypotension during hemodialysis.Methods This study included 38 patients who had regular dialysis and had intradialytic hypotension(IDH)in the blood purification center of our hospital from November 2018 to November 2019.Then,according to the results of the Montreal Cognitive Assessment(MOCA),the patients were divided into two groups:no-mild cognitive impairment group and moderate-severe cognitive impairment group.At the same time,the basic clinical data of patients in the same period,biomarkers related to cognitive impairment,and all blood pressure measurements during 48 times of dialysis were collected.The differences of basic clinical data,biochemical indexes and blood pressure fluctuation between non-mild cognitive impairment group and moderate-severe cognitive impairment group were compared.Before the beginning of each dialysis,38patients were scanned by GE discovery MR 750 3.0T magnetic resonance imaging system with diffusion tensor imaging(DTI).The routine imaging changes of the two groups were compared.And 18 regions of interest(ROI)of bilateral cerebral hemispheres were delineated by GE post-processing system.The fractional anisotropy(FA)and mean diffusivity(MD)were measured and compared.The differences of FA and MD values were obtained.The differences of basic clinical data,biochemical indexes and blood pressure fluctuations between the two groups were compared by univariate analysis,and the indexes with statistical differences were analyzed by logistic regression.According to the results,pearson correlation analysis was made between clinical index,biochemical index,blood pressure variable,FA value significantly decreased in brain white matter region,significantly increased MD value and MOCA score in patients with IDH.Result(1)24 of the 38 patients had moderate-severe cognitive impairment.There was statistically significant in the frequency of hypotension between the two groups(0.48±0.31 vs 0.41±0.26,P<0.05).(2)DTI imaging analysis showed that there were statistically significant in left frontal lobe FA,right frontal lobe FA,left hippocampal FA and right hippocampal FA between moderate-severe cognitive impairment group and non-mild cognitive impairment group(0.45±0.12 vs 0.55±0.07;0.47±0.11 vs 0.59±0.09;0.33±0.18 vs0.47±0.10;0.28±0.09 vs 0.45±0.20,respectively,P<0.05).The left frontal lobe MD,right frontal lobe MD,left hippocampal MD and right hippocampal MD in moderate-severe cognitive impairment group were statistically significant from those in non-mild cognitive impairment group(0.79±0.10μm~2/ms vs 0.67±0.11μm~2/ms;0.75±0.07μm~2/ms vs 0.68±0.10μm~2/ms;0.91±0.13μm~2/ms vs 0.79±0.10μm~2/ms;1.23±0.58μm~2/ms vs 0.77±0.20μm~2/ms,respectively,P<0.05).(3)There were statistically significant in age,years of education,albumin,albumin/globulin ratio,hemoglobin and C-reactive protein between the two groups(P<0.05).There was no statistically significant in sex,duration of dialysis,hypertension,diabetes,heart failure,cerebrovascular disease,coronary heart disease,globulin,uric acid,urea reduction ratio(URR))and urea clearance index(Kt/V)(P>0.05).(4)The results of logistic regression analysis showed that age,years of education,frequency of hypotension and C-reactive protein were the risk factors of cognitive impairment,(OR=1.187,95%CI 1.013-1.391,P=0.034;OR=6.071,95%CI 1.416-26.033,P=0.015;OR=3.118,95%CI 1.418-6.857,P=0.005;OR=4.334,95%CI1.467-12.804,P=0.008).(5)The results of Pearson correlation analysis showed that MOCA score was positively correlated with years of education,albumin,albumin/globulin ratio,hemoglobin,left frontal lobe FA,right frontal lobe FA.The corresponding r values were0.428,0.575,0.391,0.442,0.534,0.530 respectively,and p values were 0.007,0.000,0.015,0.005,0.001,0.001 respectively.The MOCA score was negatively correlated with age,frequency of hypotension,C-reactive protein,left frontal lobe MD and right frontal lobe MD.The corresponding r values were-0.510,-0.147,-0.448,-0.445,-0.423,and p values were 0.001,0.005,0.005,0.005,0.008,respectively.Conclusion(1)There is a high incidence of cognitive impairment in patients with IDH,and the changes of white matter in frontal lobe and hippocampus may be involved in the process of cognitive impairment in patients with IDH.(2)The age,education years,frequency of hypotension and C-reactive protein of IDH patients are the risk factors of cognitive impairment.Nutritional status and chronic inflammation may affect cognitive function.