Job strain, social support in the workplace, and haemoglobin A1c in Japanese men

Objectives-To examine the association between job strain (defined in the mo del of job demands and job control) and social support at the workplace wit h levels of glycosylated haemoglobin Ale (HbA1c) Methods-All male employees aged 40-60 in a manufacturing firm, Japan, were invited to take part in the study. A blood sample was taken from the partic ipants and HbA1c (%) was measured. Job strain and social support at the wor kplace were assessed with the job content questionnaire (JCQ). After exclud ing those who had a history of diabetes mellitus or other chronic diseases, data from 268 male day workers were analyzed. Results-Age adjusted average concentrations of HbA1c were significantly hig her in the highest quartile group of job strain or the lowest quartile grou p of social support at the workplace (p<0.05). Multiple linear regression a nalysis indicated that job strain was significantly and positively related to HbA1c (p<0.05), whereas social support at the workplace was significantl y and negatively related to HbA1c (p<0.05), both after controlling for othe r covariates. Conclusions-Greater job strain and lower social support at the workplace ma y be associated with increased concentrations of HbA1c. Increased blood glu cose may be a physiological mediator between job strain or social support a t the workplace and coronary heart disease.