Background: Emerging evidence links inflammation to atherosclerosis (AS). Although some studies have addressed the role of inflammation in patients with arterial hypertension (AH), its overall contribution in AH is far from being understood. Therefore, the present pilot study was designed to examine the role of platelet P-selectin and various inflammatory mediators in young patients with moderate AH without signs of target organ damage.
Methods and results: Fifteen patients with mild AH [33.8 +/- 7.3 years, mean arterial pressure (MAP) 106.6 +/- 10.4 mmHg] and 15 healthy normotensive controls (31.7 +/- 10.6 years) were examined. Platelet P-selectin was analysed by flow cytometry. Plasma levels of monocyte-chemoattractant-protein-1 (MCP-1), high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, tumour necrosis factor alpha (TNFalpha), and IL-10 levels were measured by enzyme immunoassay (EIA). Patients with mild AH showed significantly enhanced expression of platelet P-selectin [17.2 +/- 5.4 versus 10.6 +/- 4.2 mean fluorescence intensity (MFI), P < 0.001]. P-selectin expression positively correlated with MAP (r = 0.43, P < 0.05). Furthermore, patients with mild AH had significantly enhanced plasma levels of hsCRP (2.7 +/- 3.8 versus 0.6 +/- 0.9 mg/l, P < 0.01), IL-6 (1.4 +/- 0.7 versus 0.6 +/- 0.3 pg/ml, P < 0.001), TNFalpha (2.8 +/- 0.7 versus 2.4 +/- 0.4 pg/ml, P < 0.05), and MCP-1 (291.3 +/- 100.7 versus 214.3 +/- 8.3 pg/ml, P < 0.05). IL-6 levels positively correlated with hsCRP levels (r = 0.47, P < 0.05) and mean arterial pressure (MAP) (r = 0.44, P < 0.05).
Conclusions: This pilot study demonstrates that in an early stage of AH, inflammatory pathways are already activated. Besides pro-inflammatory cytokines, platelets seem to play a significant role in mediating inflammation in AH, which could lead to target organ injury. Further investigations have to clarify the role of early anti-inflammatory therapy, in patients with mild to moderate AH, in alleviating hypertensive target organ damage.