Larger hypothalamic subfield volumes in patients with chronic insomnia disorder and relationships to levels of corticotropin-releasing hormone

• Published in: Journal of affective disorders 2024-04, Vol.351, p.870-877
• Main Authors: Luo, Yucai, Yu, Liyong, Zhang, Pan, Lin, Wenting, Xu, Hao, Dou, Zeyang, Zhao, Guangli, Peng, Wei, Zeng, Fang, Yu, Siyi
• Format: Article
• Language: English
• Subjects: Causal mediation analysis; Chronic insomnia disorder; Corticotropin-releasing hormone; Corticotropin-Releasing Hormone - metabolism; Humans; Hypothalamo-Hypophyseal System - metabolism; Hypothalamus; Hypothalamus - diagnostic imaging; Pituitary-Adrenal System - metabolism; Sleep Initiation and Maintenance Disorders - diagnostic imaging; Volumes
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2024.02.023

The hypothalamus is a well-established core structure in the sleep-wake cycle. While previous studies have not consistently found whole hypothalamus volume changes in chronic insomnia disorder (CID), differences may exist at the smaller substructural level of the hypothalamic nuclei. The study aimed to investigate the differences in total and subfield hypothalamic volumes, between CID patients and healthy controls (HCs) in vivo, through an advanced deep learning-based automated segmentation tool. A total of 150 patients with CID and 155 demographically matched HCs underwent T1-weighted structural magnetic resonance scanning. We utilized FreeSurfer v7.2 for automated segmentation of the hypothalamus and its five nuclei. Additionally, correlation and causal mediation analyses were performed to investigate the association between hypothalamic volume changes, insomnia symptom severity, and hypothalamus-pituitary-adrenal (HPA) axis-related blood biomarkers. CID patients exhibited larger volumes in the right anterior inferior, left anterior superior, and left posterior subunits of the hypothalamus compared to HCs. Moreover, we observed a positive association between blood corticotropin-releasing hormone (CRH) levels and insomnia severity, with anterior inferior hypothalamus (a-iHyp) hypertrophy mediating this relationship. In conclusion, we found significant volume increases in several hypothalamic subfield regions in CID patients, highlighting the central role of the HPA axis in the pathophysiology of insomnia. •Patients with CID exhibited enlarged volumes in several hypothalamic subfield regions.•Insomnia severity positively correlated with both elevated blood CRH levels and a-iHyp volume hypertrophy.•Causal mediation analysis revealed that a-iHyp hypertrophy mediated the relationship between CRH level and insomnia severity.