Platelet activation and inflammatory response in patients with non-dipper hypertension

ObjectiveNon-dipper hypertensives had about three times the risk of atherosclerotic events than hypertensives whose blood pressure was >10% lower at night compared to daytime (dippers). Platelet activation and inflammatory response may derive from most atherosclerotic events. Mean platelet volume (MPV) is a determinant of platelet activation and high sensitive C-reactive protein (hs-CRP) is the best candidate assay to identify and monitor the inflammatory response. We aimed to determine whether MPV and hs-CRP levels are elevated in non-dipper patients compared to dippers and healthy controls. In addition, we tried to find out if MPV and CRP are related to each other or not in non-dipper hypertensives.MethodThe total 126 patients study group included 86 patients with hypertension and 40 healthy subjects (16 male, mean age; 51 ± 4) as control. Ambulatory blood pressure monitoring was performed for all patients. Hypertensive patients were divided into two groups; 46 dipper patients (18 male, mean age; 50 ± 9) and 40 non-dipper patients (17 male, mean age; 53 ± 11). Clinical baseline characteristics were similar between groups. We measured mean platelet volume in a blood sample collected in EDTA tubes and high-sensitive CRP was measured by using BN2 model nephlometer.ResultsNon-dipper patients demonstrated higher levels of MPV compared to dippers and normotensives (9.72 ± 0.52 fl vs 9.38 ± 0.33 fl and 8.92 ± 0.42 fl, p < 0.05, respectively). High-sensitive CRP levels were also significantly higher in non-dippers compared to dippers and normotensives (4.9 ± 1.7 mg/l vs 3.8 ± 1.5 mg/l and 2.7 ± 0.8 mg/l, p < 0.05, respectively). There was significant positive correlation between MPV and CRP levels (p = 0.002, r = 0.482) in non-dipper hypertensives.ConclusionOur results suggest that patients with non-dipping tend to have increased platelet activation and inflammatory response. Increased platelet activation and inflammatory response could contribute to increase the atherosclerotic risk in non-dipper patients compared to dippers.