Trajectories of blood pressure measures and the incidence of electrocardiographic abnormalities: a worker-based cohort study.

Background: Evidence on the association between longitudinal blood pressure trajectories and incident electrocardiographic abnormalities among factory workers is limited, and whether occupational exposure modifies this association remains unclear. Methods: Using health examination data collected between 2016 and 2024, we applied Group-based trajectory modeling (GBTM) to identify trajectories of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), mid-blood pressure (Mid-BP), pulse pressure (PP), and pulse pressure index (PPI). Cox proportional hazards regression models were used to evaluate the associations between blood pressure trajectories and incident electrocardiographic (ECG) abnormalities. Stratified analyses and interaction tests were further performed to assess the modifying effects of occupational exposure. Results: Among 2,561 workers (mean age 34.65 years), 1,183 (46.2%) developed at least one ECG abnormality during the 4-year follow-up. Two trajectory patterns were identified for each blood pressure indicator. After controlling for age, gender, years of service, job type, work location, smoking status, ownership type, occupational exposure and company size, Cox regression showed HRs of 1.17 (95% CI: 1.04-1.31) for the persisting high SBP trajectory and 1.17 (95% CI: 1.04-1.32) for the increasing Mid-BP trajectory. Stratified analyses showed significant interactions of high temperature exposure with SBP and Mid-BP trajectories on ECG abnormalities (all Conclusion: The increasing Mid-BP and the persisting high SBP trajectories are prospectively associated with an increased risk of ECG abnormalities among factory workers, with high temperature exposure significantly modifying these associations. Regular monitoring of these trajectories constitutes a viable approach for workplace risk assessment and targeted cardiovascular prevention.