<p><b>INTRODUCTION: </b>We aimed to determine whether obesity or metabolic syndrome (MetS) modify associations between sleep-disordered breathing (SDB), self-reported sleep duration (SD), and phenotypes of combined SDB/SD with 7-year neurocognitive decline (ND) in a community based-cohort of U.S. Hispanic/Latinos (N = 5500) in different age and sex groups.</p><p><b>METHODS: </b>The exposures were baseline SDB (respiratory event index ≥ 15), sleepiness (Epworth Sleepiness Scale ≥ 10), SD (< 6 hours, 6-9 hours, ≥ 9 hours). The outcome was 7-year ND.</p><p><b>RESULTS: </b>Mean age was 56.0 years, 54.8% were females. Obesity modified the association between SDB/SD and ND in memory (F = 21.49, P < 0.001) and global cognition (F = 9.14, P < 0.001) in the oldest age group. Women without MetS with combined long sleep/SDB exhibited most pronounced decline in global cognition (F = 3.07, P = 0.010).</p><p><b>DISCUSSION: </b>The association between combined SDB/long sleep and declines in memory and global cognition was most pronounced in obese older adults. Among women, MetS status modified the association between long sleep/SDB and decline in global cognition.</p>