The Impact of Job-Demand-Control-Support on Leptin and Ghrelin as Biomarkers of Stress in Emergency Healthcare Workers

Abstract

Despite the available literature on the consequences of night shiftwork on stress and food intake, its impact on leptin and ghrelin has never been studied. We previously demonstrated that leptin and ghrelin were biomarkers related to stress, and acute stress-induced a decrease in leptin levels and an increase in ghrelin levels. We performed a prospective observational study to assess the influence of night work, nutrition, and stress on the levels of ghrelin and leptin among emergency healthcare workers (HCWs). We took salivary samples at the beginning of a day shift and/or at the end of a night shift. We also monitored stress using the job demand-control-support model of Karasek. We recorded 24-h food intake during the day shift and the consecutive night shift and during night work and the day before. We included 161 emergency HCWs. Emergency HCWs had a tendency for decreased levels of leptin following the night shift compared to before the dayshift (p = 0.067). Furthermore, the main factors explaining the decrease in leptin levels were an increase in job-demand (coefficient -54.1, 95 CI -99.0 to -0.92) and a decrease in job control (-24.9, -49.5 to -0.29). Despite no significant changes in ghrelin levels between shifts, social support was the main factor explaining the increase in ghrelin (6.12, 0.74 to 11.5). Food intake (kcal) also had a negative impact on leptin levels, in addition to age. Ghrelin levels also decreased with body mass index, while age had the opposite effect. In conclusion, we confirmed that ghrelin and leptin as biomarkers of stress were directly linked to the job demand-control-support model of Karasek, when the main cofounders were considered.

Keywords: ghrelin; leptin; nutrients; quality of life; well-being; work.

Figure 1

Study design. Among five French Emergency Departments, we were able to recruit 161 emergency healthcare workers for a total of 185 salivary samples. Twenty-four were excluded because of a low quantity of saliva. Ghrelin and leptin levels were assessed from 161 samples.

Figure 2

Median [interquartile range] salivary levels of leptin and ghrelin before the beginning of a day shift and at the end of a night shift. The results of leptin are expressed in nanograms per deciliter. Results of ghrelin are expressed in picogram per milliliter. Ng = nanogram, pg = picogram, dL = deciliter, mL = milliliter, NS = not significant, n = number of samples studied, SD = standard deviation, IQR = interquartile range.

Figure 3

Impact of stress assessed using Karasek jobdemand-control-suport, night, sociodemographic status and nutrition on leptin and ghrelin salivary levels using a linear mixed model. Job demand refers to the psychological needs imposed by daily working activities, job control refers to the latitude of decision and is composed of two components: skill discretion and decision authority. Social support represents the support from colleagues and/or from the hierarchy. Results were expressed using coefficient regression (95% confidence interval). Results were considered significant for p-value < 0.05 and 95 CI not containing 0. BMI = body mass index, kg = kilogram, m² = square meter, g = gram, dL = deciliter.