Extreme chronotype and circadian disrupting work hours may increase nurse disease risks. This national, cross-sectional study of nurses (N = 527) had three hypotheses. When chronotype and shift times are incongruent, nurses will experience increased likelihood of (1) obesity, (2) cardiovascular disease/risk factors, and (3) obesity or cardiovascular disease/risk factors when theoretically linked variables exist. Chronotype mismatched nurses' (n = 206) average sleep (6.1 hours, SD = 1.2) fell below 7-9 hours/24-hours sleep recommendations. Proportion of male nurses was significantly higher chronotype mismatched (12.3%) than matched (6.3%). Analyses found no direct relationship between chronotype match/mismatch with outcome variables. Exploratory interaction analysis demonstrated nurses with mismatched chronotype and above average sleep quality had an estimated 3.51 times the adjusted odds (95% CI 1.52,8.17; p = .003) of being obese. Although mechanism is unclear, this suggests sleep quality may be intricately associated with obesity. Further research is needed to inform nurses on health risks from disrupted sleep, chronotypes, and shift work.
Keywords: cardiovascular disease; chronotype; healthcare workers; obesity; shift work; sleep.