Mood Disorders Centre, University of British Columbia, Vancouver, BC, Canada; Department of Psychiatry and Behavioral Sciences, University of Minnesota Medical School, Minneapolis, MN, USA.
Departments of Psychiatry and Pharmacology, University of Toronto and Centre for Addiction and Mental Health, Toronto, ON, Canada.
J Affect Disord. 2022 Dec 15;319:229-234. doi: 10.1016/j.jad.2022.09.044. Epub 2022 Sep 22.
We previously reported that in early-stage bipolar disorder (BD), frontal and temporal lobe volume reductions were more pronounced in patients with elevated BMI and more rapidly progressive in patients with additional weight gain. Elevated BMI is a pro-inflammatory state, and inflammation may contribute to brain volume reductions in BD. However, few studies have investigated the relationship between inflammation and brain volumes.
We conducted a proof-of-concept analysis to investigate whether a composite measure of total peripheral inflammation derived from 9 cytokines predicted lower frontal and temporal lobe volumes, measured with 3 T MRI, in early-stage BD.
In 25 early-stage patients, linear regression models showed that greater total inflammation predicted lower white matter (WM) volumes in the left frontal lobe (β = -0.691, p = 0.001) and bilateral temporal lobes (left: β = -0.617, p = 0.003; right: β = -0.636, p = 0.001). Greater inflammation also predicted lower right frontal WM, although this did not survive correction for multiple comparisons (β = -0.557, p = 0.020). It did not predict frontal or temporal GM. Total inflammation was a stronger predictor of lower WM volumes than were individual cytokines.
Although the magnitude of the association between total inflammation and lower WM volumes was large, our sample was small. Our findings require confirmation in further studies, with samples large enough to determine whether inflammation mediates the relationship between elevated BMI and brain volumes.
This study supports the hypothesis that inflammation contributes to brain volume reductions in BD and suggests that total inflammatory burden best captures the impact of inflammation on the brain.
我们之前报道过，在早期双相情感障碍（BD）中，BMI 升高的患者额叶和颞叶体积减少更明显，且体重增加的患者体积减少进展更快。BMI 升高是一种促炎状态，炎症可能导致 BD 患者脑容量减少。然而，很少有研究调查炎症与脑容量之间的关系。
我们进行了概念验证分析，以调查来自 9 种细胞因子的总外周炎症综合指标是否可预测早期 BD 患者使用 3T MRI 测量的额叶和颞叶体积较低。
在 25 名早期患者中，线性回归模型显示，总炎症程度越高，左侧额叶（β=-0.691，p=0.001）和双侧颞叶（左侧：β=-0.617，p=0.003；右侧：β=-0.636，p=0.001）的白质（WM）体积越低。炎症程度越高也预测右侧额叶 WM 体积较低，尽管这并未通过多重比较校正而具有统计学意义（β=-0.557，p=0.020）。炎症程度与 GM 体积无关。总炎症对 WM 体积降低的预测作用强于单个细胞因子。
尽管总炎症与 WM 体积降低之间的关联程度较大，但我们的样本量较小。我们的发现需要在进一步的研究中得到证实，样本量要足够大，以确定炎症是否介导了 BMI 升高与脑容量之间的关系。
本研究支持炎症导致 BD 患者脑容量减少的假设，并表明总炎症负担能更好地反映炎症对大脑的影响。
