Risk Factors Of Cognitive Impairment In Elderly Patients Of Hypertension With Atrial Fibrillation

Background: Both hypertension and atrial fibrillation(AF)are associated with an increasing risk of cognitive impairment,and witch may contribute to development of dementia.But it is still unclear that whether ventricular rate,aortic stiffness,and the size of left atrial and left ventricle would increase risk of cognitive impairment in patients of hypertension with AF.Methods: A total of 263 patients aged 60 and above were recruited,of which 112 patients of hypertension with AF,79 patients of hypertension without AF,and 72 patients without neither hypertension nor AF were included.We compared the difference of general clinical characteristics,biochemical parameters,auxiliary examination,and MMSE scores among these three different groups.Risk factors of cognitive impairment in patients of hypertension with AF were also studied.Results: There was no significant difference in the baseline data among three groups(P>0.05).The MMSE scores varied significantly among different groups(22.09±5.18 vs.23.96±3.68 vs.24.94±4.11,P<0.01).Furthermore,patients of hypertension with AF got lower MMSE scores than that of patients of hypertension without AF(P<0.01),or that of patients without neither hypertension nor AF(P<0.01).Compared with patients without neither hypertension nor AF,patients of hypertension without AF seemed to have lower MMSE scores,but the difference between two groups was not statistically significant(P>0.05).When compared five different cognitive domains in different groups,the scores of orientation(7.79±2.05 vs.8.03±1.44 vs.8.72±1.58,P<0.01),attention(3.09±1.66 vs.3.94±0.97 vs.3.96±1.34,P<0.01),and recall(2.19±0.96 vs.2.43±0.69 vs.2.57±0.69,P<0.01)were significantly different,while memory(2.83±0.52 vs.2.91±0.29 vs.2.92±0.33,P>0.05),and language skills(6.23±1.80 vs.6.67±1.96 vs.6.72±1.99,P>0.05)had no significant difference.In the pairwise comparison in patients of hypertension with AF and patients of hypertension without AF,the former had lower attention scores(P<0.05)and recall scores(P<0.05),but the orientation scores had no difference between these two groups(P<0.05).Also,patients of hypertension with AF had lower orientation scores(P<0.01),attention scores(P<0.01),and recall scores(P<0.01)compared to patients without neither hypertension nor AF.There were remarkable difference in the scores of orientation(P<0.05)between patients of hypertension without AF and patients without neither hypertension nor AF,but no difference in the scores of attention(P>0.05)and recall(P>0.05).In patients of hypertension with AF,multiple factors analysis showed that advanced age was risk factor for cognitive impairment(OR=2.564,95%CI 1.361~4.830),while serum bilirubin(OR=0.948,95%CI 0.904~0.993)and left ventricular ejection fraction(OR=0.963,95%CI 0.927~0.999)might have protective effect against cognitive impairment.We also found no association of ventricular heart rate,systolic blood pressure,diastolic blood pressure,pulse pressure,carotid arterial intima-media thickness,or the size of left atrial and left ventricle with cognitive impairment in patients of hypertension with AF.Conclusion: Cognitive function of patients of hypertension with AF declines,particularly in orientation,attention,and recall.In patients of hypertension with AF,advanced age is risk factor for cognitive impairment,while left ventricular ejection fraction have protective effect against cognitive impairment.Moderately high levels serum bilirubin may also be protective against cognitive impairment,which may be due to that persistent mild hyperbilirubinemia would reduce oxidative stress and decrease the risk of cognitive decline.And further studies are needed to clarify this problem.