Objectives: Studies have demonstrated that sex differences may play a crucial role in the alternations of brain structures in individuals with bipolar disorder, but findings are not consistent. The current study identified sex differences in brain structure and function among a large sample of individuals with bipolar I disorder (BD-I). Methods: Structural and functional magnetic resonance imaging datasets were acquired from 105 individuals with BD-I (36 men and 69 women) and 210 healthy adults (72 men and 138 women). A general linear regression model was used for voxel-wise analysis of grey matter (GM) and functional connectivity. Age, sex, diagnosis, and sex-by-diagnosis interaction were defined as predictors. Results: In GM, the left caudate (p < .001), left thalamus (p < .001), right caudate (p = .003), right thalamus (p < .001), left anterior cingulate gyrus (p = .015), and left middle/posterior cingulate gyrus (p = .022) exhibited sex-by-diagnosis interaction. Furthermore, by using these six brain regions as seeds, we observed sex-by-diagnosis interaction in the alteration of functional connectivity between the left thalamus and right angular gyrus (p = .019). Conclusions: Our data revealed a sex-by-diagnosis interaction associated with structure and function of the limbic system in individuals with BD-I. These findings may serve as reference for future studies on the pathophysiology of bipolar disorder.

中文翻译：

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躁郁症I型患者脑结构和功能连接性的性别差异

目的：研究表明，性别差异可能在躁郁症患者的脑结构改变中起关键作用，但发现并不一致。当前的研究确定了患有双相性I障碍（BD-I）的大量样本中大脑结构和功能的性别差异。方法：从105名BD-I患者（36名男性和69名女性）和210名健康成年人（72名男性和138名女性）中获取了结构和功能磁共振成像数据集。通用线性回归模型用于灰质（GM）和功能连通性的体素分析。年龄，性别，诊断和按诊断性别的相互作用被定义为预测因素。结果：在GM中，左尾状肌（p <.001），左丘脑（p <.001），右尾状肌（p = .003），右丘脑（p <.001），左前扣带回（p = .015）和左中/后扣带回（p = .022）表现出按诊断的性别相互作用。此外，通过将这六个大脑区域用作种子，我们观察到左丘脑和右角回之间的功能连通性改变对性别的诊断相互作用（p = .019）。结论：我们的数据显示，BD-I患者的按性别诊断与边缘系统的结构和功能有关。这些发现可为将来关于躁郁症的病理生理学研究提供参考。我们观察到了在左丘脑和右角回之间的功能连通性改变中，按性别进行的诊断交互作用（p = .019）。结论：我们的数据显示，BD-I患者的按性别诊断与边缘系统的结构和功能有关。这些发现可为将来关于躁郁症的病理生理学研究提供参考。我们观察到了在左丘脑和右角回之间的功能连通性改变中，按性别进行的诊断交互作用（p = .019）。结论：我们的数据显示，BD-I患者的按性别诊断与边缘系统的结构和功能有关。这些发现可为将来关于躁郁症的病理生理学研究提供参考。