In adjusted analyses, responders from the South and the Northeast were more likely to report insufficient sleep. This finding is consistent with our previous study (40), which showed that those in the South are often most likely to report sleep disturbance and daytime fatigue, and those in the West are often least likely. It is plausible that environmental factors including noise, green space, and air pollution, which have been shown to contribute to obesity (41, 42), diabetes risk (43), and other chronic diseases (44), may contribute to sleep disturbance. However, studies are needed to examine these determinants in relation to insufficient sleep.