Hemodynamic parameters and cognitive impairment in middle-aged and elderly people in rural China: a community-based transcranial Doppler ultrasound study

Lili HUANG; Zhihong KE; Yun XU

ABSTRACT

Objective:

To investigate the differences in transcranial Doppler (TCD) hemodynamic parameters and their correlation with cognitive impairment in middle-aged and elderly populations with different cognitive states in rural communities.

Methods:

From January to February 2022, participants were recruited from rural communities in Yandu District, Yancheng for cognitive assessment and TCD examination. TCD parameters were recorded, including mean flow velocity (MFV), peak systolic velocity (PSV), pulsatile index, and resistance index of bilateral anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA), vertebral artery and basilar artery. According to the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores, the participants were divided into a normal cognitive function group, a mild cognitive impairment (MCI) group, and a dementia group. Spearman correlation analysis was used to investigate the correlation between hemodynamic parameters and blood pressure. Multivariate logistic regression analysis was used to identify the independent influencing factors of MCI and dementia, and multiple linear regression analysis was used to identify the correlation between hemodynamic parameters and cognitive assessment scale scores.

Results:

A total of 270 participants were enrolled, including 82 in the normal cognitive function group, 100 in the MCI group, and 88 in the dementia group. The comparison between groups showed that advanced age, female and low education years might be the risk factors for dementia in rural areas. The proportion of smoking and drinking in the dementia group was lower than that in the normal cognitive function group and the MCI group. The right ACA MFV and PSV in the dementia group were significantly lower than those in the normal cognitive function group and the MCI group, while the left PCA PSV was significantly lower than that in the MCI group (all P<0.05). Multivariate logistic regression analysis showed that compared with the normal cognitive function group, the right ACA PSV (odds ratio [ OR] 0.964, 95% confidence interval [ CI] 0.935-0.993; P=0.016) was an independent related factor associated with dementia; compared with the MCI group, right ACA PSV ( OR 0.967, 95% CI 0.936-0.999; P=0.043) and left PCA PSV ( OR 0.953, 95% CI 0.911-0.998; P=0.039) were the independent related factors for dementia. Multiple linear regression analysis showed that the right ACA PSV ( β=0.431, P=0.036) and left PCA PSV ( β=0.133, P=0.021) were the independent related factors for MMSE score. Spearman correlation analysis showed that there was a significant correlation between blood pressure and several hemodynamic parameters (all P<0.05).

Conclusion:

The right ACA and left PCA PSV are significantly associated with dementia in rural middle-aged and elderly people, and are expected to serve as non-invasive early screening biomarkers for cognitive impairment in rural population.