Increase in Right Temporal Cortex Thickness Is Related to Decline of Overall Cognitive Function in Patients With Hypertension

Abstract Background Hypertension is associated with poorer cognitive function, but the mechanisms are unclear. Objective The current research is to explore the cognitive status of elderly patients with hypertension and explore the possible mechanisms of hypertension affecting cognitive function. Methods: The current data was obtained from the China Longitudinal Aging Study (CLAS), and a total of 128 residents aged 60 years and above were recruited in this study. Based on whether they had hypertension, these 128 people were divided into hypertension (n=64) and non hypertension groups (n=64). The Beijing version of the Mini-mental State Examination(MMSE) and Montreal Cognitive Assessment (MoCA) were used to assess the subjects' overall cognitive function, while digit span, language fluency, Wechsler mapping and Wechsler wood block were used to assess their domain-specific cognitive function (both at baseline and follow-up stages). At the same time, we also examined baseline blood biochemical indicators (such as the total protein, fasting plasma glucose(FPG), high-density lipoprotein (HDL), low-density lipoprotein(LDL), cholesterol, and triglyceride) and baseline MRI data of hippocampus and amygdala volume and temporal polar cortex thickness Results The total protein and thickness of temporal polar cortex in patients with hypertension were significantly higher than those in normal controls, but the scores of MMSE, MoCA, digit span, Wechsler mapping and Wechsler wood block at baseline were significantly lower than those in normal controls (p<0.05). By using linear regression analysis and correlation analysis, we found that baseline Wechsler mapping scores were negatively correlated with total protein(B=-0.234, t=-2.968, p=0.004, 95%CL: -0.390~-0.078); and both the follow-up MMSE score (B=2.657, t=2.002, p=0.049, 95%CL: 0.009~5.306) and the change score of MMSE (r=-0.025, p=0,047) were related to the right temporal pole cortex thickness. Then by using the linear regression analysis(mediating model), we found that hypertension may influence follow-up MMSE scores by influencing cortical thickness of the right temporal pole (B=1.727, p=0.022). Conclusions Elderly patients with hypertension exhibit poorer overall cognitive function and executive function, and the mechanism may be related to the effect of hypertension on the cortical thickness of the right temporal pole. Keywords Hypertension, cognition, elderly, longitudinal study, temporal pole, cortical thickness