Altered local functional synchronization in night-shift nurses: Associations with peripheral metabolic variation and...

Night-shift work in nurses is associated with circadian disruption, sleep disturbance, and increased vulnerability to affective symptoms. However, the neural and metabolic correlates of these alterations remain insufficiently understood.

A total of 121 female nurses, including 59 day-shift nurses (DSN) and 62 night-shift nurses (NSN), underwent resting-state functional MRI. Regional homogeneity (ReHo) was calculated to assess local functional synchronization. Between-group ReHo differences were examined, followed by transcriptomic and neurotransmitter decoding analyses. Untargeted serum metabolomics was performed to assess peripheral metabolic differences and their associations with ReHo.

Compared with DSN, NSN showed decreased ReHo in the left superior temporal cortex and left anterior hippocampus, and increased ReHo in the right medial amygdala and right superior parietal lobule. The cortical ReHo pattern was associated with gene expression profiles enriched for cellular responses to stress, protein phosphorylation, and mitochondrion organization, and showed spatial correspondence with dopamine D1 receptor distribution. Serum metabolomics revealed widespread between-group metabolic differences. In NSN, metabolite PC1 was positively associated with right medial amygdala ReHo, and an exploratory indirect association between metabolite PC1 and Beck Depression Inventory scores through right medial amygdala ReHo was observed.

Night-shift work in nurses is associated with alterations in peripheral metabolism, local functional synchronization, and depressive symptoms. Right medial amygdala ReHo may represent a neural correlate associated with peripheral metabolic variation and affective symptom burden.