Study on the Relationship between Inter-arm Blood Pressure Difference and Mild Cognitive Impairment in Rural Elderly People

Abstract

Background Previous studies have found that inter-arm blood pressure difference (IAD) and mild cognitive impairment (MCI) are both associated with cardiovascular risk factors, but it is unclear whether there is an association between IAD and MCI. Objective To explore the relationship between IAD and MCI in rural elderly persons and to provide a scientific basis for clarifying the mechanisms of cognitive decline in elderly persons. Methods From July to August 2019, the rural elderly residents aged 60 years and older were selected using the multi-stage cluster sampling method from 5 townships in 2 counties (districts) of Guizhou Province, and questionnaire surveys, general physical examinations, cognitive function assessments, and bilateral arm blood pressure measurements were carried out among them. Cognitive function was evaluated using the Mini-mental State Examination (MMSE) scale, and activities of daily living were assessed using the Activities of Daily Living Scale (ADL). Spearman rank correlation analysis and binary Logistic regression model were used to investigate the association between IAD and MCI in the elderly persons. Results A total of 1 795 questionnaires were distributed, and data from 1 088 participants were finally included in the study after excluding subjects with incomplete information on the questionnaires, those who did not undergo blood pressure measurements, and those who did not undergo blood tests. Among the 1 088 rural elderly residents, 138 patients (12.68%) with MCI, 99 patients (9.10%) with systolic inter-arm blood pressure difference (sIAD) ≥10 mmHg, and 80 patients (7.35%) with diastolic inter-arm blood pressure difference (dIAD) ≥10 mmHg were detected. Individuals with IAD ≥10 mmHg had a higher prevalence of MCI and lower MMSE scores, orientation scores, language scores, and delayed recall scores compared to those with IAD <10 mmHg (P<0.05). The results of correlation analysis showed that the sIAD was significantly negatively associated with the total MMSE score (rs=-0.094), orientation score (rs= -0.082), verbal ability score (rs=-0.065) and delayed recall score (rs=-0.104) ; and the dIAD was significantly negatively associated with the total MMSE score (rs=-0.080), orientation score (rs=-0.094), and attentional calculation score (rs= -0.063) (all P<0.05). Multivariate Logistic regression analysis showed that the risk of MCI increased by 8.80% for each 1 mmHg increase in sIAD (OR=1.088, 95%CI=1.046-1.131, P<0.001) ; sIAD≥10 mmHg (OR=2.169, 95%CI=1.262-3.728, P<0.05) and dIAD ≥10 mmHg (OR=1.926, 95%CI=1.047-3.542, P<0.05) were the influencing factors for the occurrence of MCI in the elderly. Conclusion The prevalence of MCI in rural elderly is 12.68%, and their elevated IAD is associated with an increased risk of MCI. And the risk of MCI is higher in elderly with IAD ≥10 mmHg than in those with IAD <10 mmHg.

Keywords

• mild cognitive impairment|inter-arm blood pressure difference|rural|aged|cross-sectional study