Sleep Phenotype, Shift-Related Occupation, and Coronary Plaque Complexity in Young Adults: Association with CT-Derived Functional Ischemia.

Background: Sleep disruption and irregular work schedules are increasingly recognized as behavioral risk factors for premature cardiovascular disease. Their associations with coronary plaque complexity and CT-derived functional ischemia in young adults remain underexplored. Objective: To investigate the association of multidimensional sleep phenotype, shift-related occupation, and coronary plaque complexity as well as CT-derived functional ischemia in adults aged ≤40 years, adjusting for clinical confounders. Methods: This retrospective study included 3,983 young adults who underwent coronary CT angiography (CCTA). Sleep phenotype was assessed using a multidimensional score incorporating sleep duration, timing, regularity, quality, and sleep-related symptoms. Occupations were classified as shift-related or non-shift. Coronary plaque characteristics, including stenosis severity, minimum lumen area, lesion length, diffuse disease, occlusion, coronary artery calcium score, and CT-derived fractional flow reserve (CT-FFR), were analyzed. Multivariable logistic regression, adjusted for age, sex, BMI, smoking, hypertension, diabetes, dyslipidemia, and shift-related occupation, assessed associations with CT-FFR ≤ 0.80. Results: Poor sleep phenotype was associated with more severe stenosis, smaller lumen area, longer lesions, and higher prevalences of diffuse disease, occlusion, and CT-FFR ≤ 0.80. In multivariable analysis, sleep phenotype remained independently associated with CT-FFR ≤ 0.80 after adjusting for clinical covariates and shift-related occupation. Shift-related occupation further modified this association, with a stronger relationship observed among shift workers. Conclusions: In young adults, poorer sleep phenotype was accompanied by more complex coronary plaque features and was independently associated with a higher likelihood of CT-FFR-defined functional ischemia after adjustment for clinical covariates. Lay Summary: Poor sleep and irregular working hours may affect heart health, but their relationship with early coronary artery disease in young adults is not well understood. We studied 3,983 adults aged 40 years or younger who underwent coronary CT scans. Participants with poorer sleep patterns were more likely to have longer and more severe coronary artery narrowing, more widespread plaque, and reduced blood flow to the heart. These associations remained after accounting for established cardiovascular risk factors. The relationship between poor sleep and impaired coronary blood flow was particularly strong among people working night shifts or other irregular schedules. Although this observational study cannot prove that poor sleep directly causes coronary disease, the findings suggest that sleep habits and work schedules may help identify young adults who could benefit from earlier cardiovascular risk assessment and preventive support.