While it is difficult to speculate about a causal link between orexin and Alzheimer’s, Dr Claudio Liguori told Medscape Medical News that “taking into account disturbed sleep causes a more rapid cognitive decline, higher orexin levels determining a more compromised sleep may have a secondary effect on the Alzheimer’s pathology.”

For the case-control study, 49 drug-naive patients with AD had CSF levels of orexin, tau proteins, and amyloid ? (A ?) measured. The quality of sleep was assessed by 2 polysomnographic studies. Results were compared with findings in 21 age- and sex-matched controls who did not have dementia.