| Objective: Previous studies have identified effects of age and vascular risk factors on brain injury in elderly individuals. We aimed to establish whether the early latent effects of high blood pressure and age in the brain on N-acetylaspartate(NAA) and choline(Cho) ratios are evident in a middle-aged population.Methods: All participants were recruited from the cardiology clinic and Medical Center of The second hospital of Hebei Medical University since October 2015 to January 2016. Proton magnetic resonance spectroscopy(MRS) were performed in 42 middle aged(45-59 years old) subjects from the Study. Twenty-four participants had hypertension. Eighteen were healthy individuals. The NAA/Cr and Cho/Cr ratios were obtained in the left anterior corpus callosum, the left thalami and the left hippocampal body. The linear correlation and the multiple linear regressions relate NAA/Cr and Cho/Cr ratios to age, systolic blood pressure(SBP), duration of hypertension, sex and body mass index(BMI). We then carried out the multiple linear regression analysis, including the parameters with a significance level ≤0.20 of linear correlation analysis. These statistical results were confirmed by the multiple linear regression analysis.Results: In the left anterior corpus callosum and the left thalami of the hypertensive group, NAA/Cr ratios were significantly lower(1.62±0.493 and 1.33±0.270) than those in the normotensive control goup(2.11±0.562 and1. 68±0.530), whereas no significant differences was observed between middleaged hypertensive brains and normotensive control goup on the Cho/Cr ratios.In the left thalami, the multiple linear regression analysis of NAA/Cr, SBP, age and duration of hypertension suggested that NAA/Cr had a significantly negative linear regression correlation(R2=0.364) with SBP(P=0.024) and age(P=0.007). No statistically significant regression association was seen between NAA/Cr and duration of hypertension.In the left anterior corpus callosum, the multiple linear regression analysis of NAA/Cr, SBP, age, duration of hypertension and BMI suggested that NAA/Cr had a significantly negative linear regression correlation(R2=0.512) with duration of hypertension(P=0.002). No statistically significant regression association was seen between NAA/Cr and SBP, age and BMI.In the left hippocampal body, NAA/Cr ratios of the hypertension and non-hypertension group were 1.24±0.350 and 1.48±0.400(P=0.048). Cho/Cr ratios were 1.07±0.693 and 1.31±0.757(P=0.283). As the coefficients of determination of the multiple linear regression analysis of NAA/Cr and Cho/Cr ratios were R2=0.17 and R2=0.11, the goodness of fit was lower, so the results were not discussed here.Conclusion:1)In the left thalamus, increased blood pressure and age can lead to reduction in NAA/Cr; and the extension of duration of hypertension can not cause the decrease of NAA/Cr.2) In the left anterior corpus callosum, the extension of duration of hypertension can cause the decrease of NAA/Cr; on the contrary, increased blood pressure and age can not cause the decrease of NAA/Cr.3)In the left thalamus and the left anterior corpus callosum, the increase of blood pressure, age and duration of hypertension can not cause the change of Cho/Cr. |
PDF Full Text Request