highly significantp < 0.001
This is supported by a highly significant correlation ( r = 0.405, p < 0.001) between Melatonin and NREM sleep (Figure 2 ). 3.8 ICP Mean ICP values remained near zero or slightly negative in the afternoon and morning but peaked around the time of maximal NREM sleep (Figures S2 and S4 ). 3.9 Electrolytes The normalised levels of all electrolytes showed minimal variation, which remained within ±1% throughout the study period (Figure S3 ). 3.10 Cosinor Analysis Finally, we conducted a cosinor analysis to investigate the circadian rhythms of Aβ42, hypocretin and ICP.