Melatonin Levels in Shift Nurses with ELISA and LCMS Methods, Jakarta, Indonesia

A nurse has a high enough stress level because it is directly related to coping with various kinds of patients on shift work schedules. So far, the detection of stress cases is based on a questionnaire in which validity and relativity are quite good, although subjective, such as the Perceived Stress Score (PSS) questionnaire. This study aimed to examine objective markers of stress in shift working nurses by measuring melatonin levels. Methods: The study was conducted from December 2019 to June 2020. The respondents were the shift and non-shift nurses from one of the public hospitals in Jakarta, Indonesia, by obtained through by consecutive sampling. Each group consisted of 40 people each. Melatonin was measured twice, at midnight on the last night shift (second night) in the shift group (pre-work), then at 08.00 am on the following day (post-work). The non-shift group was carried out on weekdays at 08.00 am pre-work and at 04.00 pm post-work. Measurements used Enzyme-Linked Immunosorbent Assay (ELISA) and Liquid Chromatography-Mass Spectrometry (LCMS). Results: The percentage of nurses who showed moderate stress level in the shift group (30%) is higher than the non-shift (25%). There was a significant difference in the mean pre-work melatonin levels, measured with ELISA, between the shift and the non-shift group (51.53 pg/ml vs 17.07 pg/ml, P = ≤ 0,001), as well as the postwork examination (24.30 pg/ml vs 10.84 pg/ml, P = ≤ 0,001). We acquired a new reference for mean melatonin levels at 04.00 pm of 10.48 pg/mL (2.15-38.30 pg/mL) using ELISA and 38.13 pg/mL (5.00-230.00 pg/ mL) using LCMS in non-shift nurses. In addition, a new reference for melatonin levels at 12.00 pm was 51.53 pg/mL (0.80-135.00 pg/mL) using ELISA and 52.35 pg/ mL (10.00-170.00 pg/mL) using LCMS in shift nurses. Discussion: This study showed differences in the results of measuring melatonin levels using ELISA and LCMS, which will be a good starting point for further research with a larger number of respondents. In addition, it is interesting to observe that a decrease in the mean level of melatonin from pre-work to post-work was found in both the nightshift and dayshift groups, using ELISA and LCMS.