Introduction Shift work has become essential to our modern 24-hour society. While night workers have been found to experience an increased risk of cardiometabolic diseases, such as diabetes mellitus (DM) and cardiovascular disease (CVD). Conceptual hypothesis: The night shift reduces melatonin levels and increases the risk of type II DM and cardiovascular diseases in health workers in a hospital.

Objective To analyze the association between low melatonin levels and increased risk of DM and cardiovascular diseases, and night shift in workers of a hospital.

Methods We used an analytical, longitudinal, retrospective study over a 5-year follow-up of a cohort in which the results of workers suffering from DM and cardiovascular diseases are compared in two groups: a) One group, exposed to night shifts, and b) a second group, not exposed to night shifts. The population of this study will be made up of health workers who voluntarily attend health examinations (ES) of the Occupational Service of Hospital from January 1, 2009 to December 31, 2019, incuding the apparently healthy and labor-active working population, between the ages of 19 and 65.

Results and conclusion are forthcoming