The “ECG modifications induced by the disturbance of the circadian rhythm in night-shift workers (ECGNoct)” study protocol

Abstract In many large cohort studies, the night shift constitutes a risk factor for developing cardiovascular disease and diabetes in workers. Current screening tests for people working in night shift include fasting glycaemia and electrocardiography. In fact, there are few studies focused on the description of the electrocardiographic changes after the night shift. This article describes the protocol of the “ECG modifications induced by the disturbance of the circadian rhythm in night-shift workers (ECGNoct)” study, which was initiated by the National Institute for Infectious Diseases “Prof. Dr. Matei Balș”. Nurses represent the target population. The protocol includes a full medical and occupational history, lifestyle habits (smoking, alcohol, nutrition), anthropometric and blood pressure measurements, blood tests (fasting glycemia, total cholesterol, triglycerides and high density lipoprotein cholesterol) and electrocardiogram recording. For nurses working in (night) shifts, we will record the electrocardiogram before and soon after the night shift. A cross sectional study will analyze the incidence of the metabolic syndrome criteria, the cardio-metabolic diseases and the electrocardiographic modifications and will compare the results between the group of nurses working and the group of nurse who do not. Based on these results, a longitudinal study will test the hypothesis that night shift increases the risk for cardio-metabolic diseases and that the electrocardiographic modifications precede the clinical symptoms. The results of the study will provide data on the association of night shifts and other non-occupational risk factors with the cardio-metabolic diseases in this specific population of healthcare workers that potentially will integrate into the occupational medicine policies.