While awake, adults with SDB have high baseline sympathetic nervous system activity (SNSA), which further increases during sleep, especially in association with apneas and arousals from apneas.12 Release of leptin, a hormone with multiple functions, including regulating food intake, has been shown to be inhibited by SNSA.13 It would, therefore, be expected that, in individuals with SDB, leptin levels would be low. Here, LEP is linked to sleep apnea syndrome.