Job Demand–Control–Support and diabetes risk: The moderating role of self-efficacy

Work-related stressors, including high demands and low control, play a significant role in the aetiology of diabetes. Nevertheless, most studies focus on main effects, and few consider individual differences that may moderate the stress–health association. Drawing from the Job Demands–Control-–Support (JDC-S) model, this study addresses this gap by testing how baseline levels of JDC-S affect an increase in two risk factors for diabetes—glycated haemoglobin (HbA1C) and fasting plasma glucose (FPG)—and by investigating the moderating role of self-efficacy. Participants (N = 1618) were Israeli employees who attended two consecutive routine health examinations. All were free of diabetes at baseline. JDC-S and self-efficacy were assessed at baseline (T1), and HbA1C and FPG were assessed at T1 and T2. Data were analysed with logistic and linear regressions, controlling for well-established diabetes risk factors. High demands and low support predicted an increase in HbA1C and FPG. In addition, high self-efficacy interacted with high demands and with low control in the prediction of an increase in HbA1C and FPG. Although employees with high self-efficacy might function well at work, overloading them may harm their physical health. Similarly, incongruence between employees’ sense of ability and the control given to them at work may result in physical impairment.