Background: Essential hypertension ranks among the strongest cardiovascular risk factors. Cytokine production by monocytes plays a key role in atherosclerosis development and acute coronary syndromes. We investigated whether stimulated monocyte cytokine release and its inhibition by glucocorticoids would differ between hypertensive and normotensive subjects.
Methods: Study participants were 222 middle-aged male employees with industrial jobs. Following the criteria of the World Health Organization/International Society for Hypertension, 76 subjects were classified as being hypertensive (systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg). In vitro monocyte tumor necrosis factor (TNF)-alpha release after lipopolysaccharide (LPS) stimulation was assessed with and without coincubation with incremental doses of dexamethasone. Monocyte glucocorticoid sensitivity was defined as the dexamethasone concentration inhibiting TNF-alpha release by 50%.
Results: Hypertensive subjects showed 11% higher LPS-stimulated TNF-alpha release than normotensive subjects (F(1,181)= 5.21, P =.024). In hypertensive subjects, monocyte glucocorticoid sensitivity was 21% lower than in normotensive subjects (F(1,178)= 4.94, P =.027), indicating that dexamethasone inhibited relatively less TNF-alpha release in hypertensive subjects. Results held significance when a set of classic cardiovascular risk factors was controlled for.
Conclusion: The findings suggest that proinflammatory activity of circulating monocytes is higher in hypertensive than in normotensive men, providing one potential pathway to explain the increased atherosclerotic risk with essential hypertension.