Objective: To investigate whether stimulated monocyte cytokine release and its inhibition by glucocorticoids differs between men and women.
Design: In vitro monocyte interleukin 6 (IL-6) and tumour necrosis factor α (TNFα) release after lipopolysaccharide stimulation were assessed with and without co-incubation with increasing doses of dexamethasone and hydrocortisone separately. Glucocorticoid sensitivity was defined as the amount of a particular glucocorticoid required to inhibit lipopolysaccharide stimulated monocyte cytokine release by 50%. The established cardiovascular risk factors of age, body mass index, number of cigarettes smoked daily, low density cholesterol to high density cholesterol ratio, systolic and diastolic blood pressure, and haemoglobin A1c were used as covariates.
Setting: Aircraft manufacturing plant in southern Germany.
Patients: 269 middle aged male and 36 middle aged female employees.
Results: Release of monocyte IL-6 and TNFα (each p = 0.001) was higher in samples from men than in those from women. Inhibition of lipopolysaccharide stimulated IL-6 and TNFα release by either glucocorticoid was less pronounced in samples from men than in those from women (IL-6: dexamethasone p = 0.033, hydrocortisone p = 0.029; TNFα: dexamethasone p < 0.001, hydrocortisone p = 0.089).
Conclusions: The finding suggests that proinflammatory activity of circulating monocytes is higher in men than in women independent of cardiovascular risk factors, thereby providing one explanation for the relatively greater coronary risk in men.
Keywords: glucocorticoid sensitivity, monocytes, cytokines, sex differences, cardiovascular disease