Purpose: Our previous study using (123)I-iodo-benzamide single photon emission computed tomography (SPECT) showed a positive relationship in healthy adults between striatal postsynaptic D(2)/D(3) receptor availability and sleep duration in good sleepers. To further investigate the role of dopamine (DA) in the sleep-wake cycle, we explored the correlation between presynaptic dopamine transporter (DAT) availability and sleep quality in healthy volunteers.
Methods: A total of 83 healthy volunteers (33 males, 50 females; mean age, 34.62 years), including 39 good sleepers and 44 poor sleepers, were recruited. The sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Striatal DAT availability was determined by (99m)Tc-TRODAT-1 SPECT, and the DAT availability in the good and poor sleepers was compared. Furthermore, the correlation between PSQI and DAT availability was analyzed.
Results: There was no significant difference in DAT availability between the good and poor sleepers. No significant relationship was found between the global score or individual-component PSQI scores and DAT availability in the good sleepers. However, the sleep duration component score in the poor sleepers negatively correlated with DAT availability in the caudate (ρ = -0.31, P = 0.049).
Conclusions: The study demonstrates that healthy poor sleepers, with a lower DAT availability in the caudate, sleep for a shorter length of time. This suggests that a decrease in DA reuptake due to reduced DAT availability causes a shorter sleep duration in poor sleepers.