Regional homogeneity and degree of centrality in social jetlag and sleep deprivation and their correlations with appetite: a resting-state fMRI study

This research aimed to explore in free-living condition, in healthy normal weight subjects, the effect of social jetlag (SJL) and sleep deprivation on resting-state brain connectivity and synchronization, as assessed by resting-state fMRI, and their association with appetite. We found abnormal local functional synchronization in resting-state, as depicted by altered regional homogeneity (ReHo), in posterior cerebellar regions in subjects with SJL and/or sleep deprivation. We also found altered intrinsic global connectivity patterns, as depicted by altered degree of centrality (DC), in cerebellar regions in these subjects. In our sample, ReHo was correlated with appetite in fasting state in subjects with SJL and in those with sleep deprivation, while DC was correlated with appetite only in subjects with SJL. The effect size evaluation showed that 21.1% to 35.7% of the variance in appetite of subjects with SJL was explained by altered ReHo and DC; in subjects with sleep deprivation 21.2% to 61.3% of the variance in appetite was explained by altered ReHo. This analysis provides the first evidence of abnormal resting-state local functional synchronization and intrinsic global connectivity patterns in healthy subjects with SJL in real-life settings. These changes were independent of sleep deprivation and correlated with appetite.