Oulu Functional NeuroImaging (OFNI), Diagnostic Imaging, Medical Research Center (MRC), Finland Oulu University Hospital, 90029, Oulu, Finland.
Research Unit of Health Sciences and Technology (HST), Faculty of Medicine, University of Oulu, 90220, Oulu, Finland.
Int J Obes (Lond). 2024 Jul;48(7):1011-1018. doi: 10.1038/s41366-024-01515-5. Epub 2024 Mar 29.
BACKGROUND/OBJECTIVE: Obesity is a risk factor for several brain-related health issues, and high body-mass index (BMI) is associated with an increased risk for several neurological conditions, including cognitive decline and dementia. Cardiovascular, respiratory, and vasomotor brain pulsations have each been shown to drive intracranial cerebrovascular fluid (CSF) flow, which is linked to the brain metabolite efflux that sustains homeostasis. While these three physiological pulsations are demonstrably altered in numerous brain diseases, there is no previous investigation of the association between physiological brain pulsations and BMI.
SUBJECTS/METHODS: We measured the amplitudes of the physiological brain pulsations using amplitude of low frequency fluctation (ALFF) based method with resting-state functional magnetic resonance imaging via high temporal resolution whole-brain magnetic resonance encephalography (MREG) in 115 healthy subjects. We next undertook multiple linear regression to model the BMI effect voxel-wise whole-brain on very low frequency (VLF), respiration, cardiovascular, and respiratory induced modulation of cardiovascular pulsation amplitudes with age, pulse pressure, and gender as nuisance variables.
In our study population, BMI was positively associated with the amplitudes of vasomotor, respiratory, and respiratory induced modulations of cardiovascular pulsations (p < 0.05), while negatively associated with the amplitudes of cardiovascular pulsations (p < 0.05).
The findings suggest that BMI is a significant factor in alterations of cardiovascular pulsation of neurofluids. As physiological pulsations are the drivers of CSF flow and subsequent metabolite clearance, these results emphasize the need for further research into the mechanisms through which obesity affects brain clearance.
背景/目的：肥胖是多种与大脑相关健康问题的一个风险因素，而高身体质量指数（BMI）与多种神经疾病的风险增加相关，包括认知能力下降和痴呆。心血管、呼吸和血管搏动性脑脉动都已被证明可以驱动颅内脑脊液（CSF）流动，而颅内 CSF 流动与维持脑内环境稳定的脑代谢物外排有关。虽然这三种生理脉动在许多脑部疾病中都明显改变，但目前尚未有研究探讨生理脉动与 BMI 之间的关系。
受试者/方法：我们使用基于低频波动幅度（ALFF）的方法，通过高时间分辨率全脑磁共振脑电描记术（MREG），对 115 名健康受试者的静息状态功能磁共振成像进行了生理脉动幅度的测量。接下来，我们进行了多元线性回归，以模型化 BMI 对 VLF、呼吸、心血管和呼吸诱导的心血管脉动幅度调制的影响，将年龄、脉搏压和性别作为混杂变量。
在我们的研究人群中，BMI 与血管搏动性、呼吸性和呼吸诱导的心血管脉动幅度调制呈正相关（p<0.05），而与心血管脉动幅度呈负相关（p<0.05）。
这些发现表明 BMI 是神经液心血管脉动改变的一个重要因素。由于生理脉动是 CSF 流动和随后代谢物清除的驱动力，这些结果强调了需要进一步研究肥胖影响脑清除的机制。
