To evaluate changes in heart rate variability (HRV) after the six-minute walk test (6MWT) in nurses following a night shift and explore the impact of night shift work on the regulation of the autonomic nervous system in the heart.

Thirty-five female nurses, with a mean age of 28.7 years (range 21.0-37.0 years), participated in this study. On the first and second mornings after a night shift, the nurses performed the 6MWT. During the test, electrocardiogram (ECG) signals, blood pressure, and walking distance were recorded simultaneously.

Inclusion Criteria:

• Female nurses aged ≥ 18 years who had undergone annual physical examinations, did not have serious cardiopulmonary diseases, and were able to walk normally were considered for inclusion in the study.

Exclusion Criteria:

• (ⅰ) having children at home who require night care; (ⅱ) current pregnancy; (ⅲ) engaging in activities that significantly impact heart rate, such as sexual activity, 24 hours before and 24 hours after working night shifts; (ⅳ) history of thyroid dysfunction, hypertension, diabetes, coronary heart disease, etc.; (ⅴ) experiencing upper respiratory tract infection, fever, cough, diarrhea, or other illnesses within 1 week before the planned enrollment; (ⅵ) consuming coffee or strong tea, smoking, drinking alcohol, or using other substances that affect heart rate 3 days before the planned enrollment; (ⅶ) taking β-receptor blockers, sleeping pills, psychotropic drugs, or other medications that affect heart rate; and (ⅷ) judged by the investigator to be unsuitable for participation in this study.

Patient self-report

The participants were nurses from Nanfang Hospital of Southern Medical University who worked ward shifts. The nurses in this study had one night shift every 5-10 days, from 00:00 a.m. to 8:00 a.m., followed by 2-3 days off.

The data of the study are available from the corresponding author upon reasonable request.