Prediction Of The Risk Of Cognitive Decline In Elderly Hypertensive Patients Based On Blood Pressure Variability

Objective Explore the effects of long-term blood pressure variability and pulse pressure variability reflected by home self-measured blood pressure on cognitive decline;establish a risk prediction model suitable for assessing the risk of cognitive decline in elderly patients with hypertension.Methods In the light of the inclusion and exclusion criteria,elderly patients with hypertension aged ≥60 years old in the community were selected as the subjects,and continuous blood pressure monitoring was performed.The Montreal Cognitive Assessment(MoCA)was used for evaluating the cognitive function status of the participants,and relevant information such as patient’s demographics,behavior and diet were collected for model analysis.Blood pressure variability and pulse pressure variability were expressed via the average real variability(ARV),and patients were divided into four groups according to their quartiles(Q1～Q4).Among them,blood pressure variability includes systolic blood pressure variability and diastolic blood pressure variability.Using blood pressure variability and pulse pressure variability as the main indicators,logistic regression model was established,and the key predictive indicators were screened.Finally,the nomogram was used to visualize the model results.The bootstrap re-sampling method was used for internal verification of the model.The discrimination of the model was evaluated by the consistency index(C-index).The calibration of the model was evaluated by calibration curve method and Hosmer-Lemeshow goodness of fit test.The clinical effectiveness of the model was evaluated by decision curve analysis.Results A total of 232 elderly patients with hypertension were finally enrolled in this study,of which 151 patients developed cognitive decline.The differences in systolic blood pressure variability,diastolic blood pressure variability and pulse pressure variability in cognitive decline among the groups were statistically significant(P<0.05).The systolic blood pressure variability has a statistically significant difference in the language scores between the groups(P<0.05),diastolic blood pressure variability has statistically significant differences in delayed memory scores between groups(P<0.05).Logistic regression analysis results showed that when the systolic blood pressure variability was at the highest variability(Q4)level,the risk of cognitive decline was greater(OR=4.33,95%CI: 1.67～11.22);When the diastolic blood pressure variability was at the Q3 and Q4 level,the risk of cognitive decline gradually increases(OR=2.76,95%CI: 1.19～6.38;OR=2.84,95%CI: 1.22～6.62);Compared with the Q1 level of pulse pressure variability,the Q4 level has a higher risk of cognitive decline(OR=3.50,95%CI: 1.50～8.19).The cognitive decline risk prediction model established with systolic blood pressure variability,diastolic blood pressure variability and pulse pressure variability as the main predictors,C-index were 0.740,0.748,and 0.740,indicating that the constructed prediction model has better discrimination.The calibration curve showed that the predicted risk of cognitive decline was highly consistent with the actual risk.The Hosmer-Lemeshow test result also showed that the predicted probability of the model was highly consistent with the actual probability(P>0.05),indicating that the prediction model has a high degree of calibration.The decision curve analysis showed that when the probability threshold was in the range of 0.1～0.8,the prediction results of the patients had high net income.Conclusion In elderly patients with hypertension,blood pressure variability and pulse pressure variability were independent risk factors for cognitive decline.The constructed cognitive decline risk prediction model has good predictive ability.It not only facilitates public health practitioners or doctors to quickly assess the risk of cognitive decline in the elderly hypertensive patients,but also provides valuable reference for the establishment of early preventive intervention measures,and have high clinical applications.