The Relationships Among Vasodilatation, CA-IMT And LVMI In Patients With Essential Hypertension

Objectives:The study was to evaluate the vasodilatations of brachial and anterior tibial arteries in patients with essential hypertension(EH) through measuring both the endothelium-dependent (EDD) and endothelium-independent (EID) vasodilatations, and to investigate the relationships among vasodilatation, the intima media thickness of carotid artery (CA-IMT) and left ventricular mass index (LVMI) and their influencing factors.Methods:We studied 307 outpatients with EH from our hospital between August 2000 and March 2011. Before the measuring of vasodilatations, patients'height, weight, heart rate, blood pressure were recorded, as well as fasting blood glucose, blood lipid profile, liver and renal functions, complete blood count and fibrinogen. All patients received echocardiographic exam and their LVMIs were calculated. The dilatations of brachial and anterior tibial arteries induced by reactive hyperemia or nitroglycerin were examined by high-resolution vascular ultrasound; the results were used to determine the EDD and EID respectively. We also measured the intima media thickness of bilateral carotid artery. If there was one or more plaques on either side of carotid artery, CA-IMT was defined as 1.3mm. Based on the diagnostic criteria for left ventricular hypertrophy (LVH) [LVMI≥125 (male) or≥110 g/m² (female)], patients were divided into two groups: EH patients with LVH (n = 217) and without LVH (NLVH, n = 90).Results:1. Among 307 EH patients, 185 male, 122 female, mean age: 62.38±12.51. When LVH group was compared to NLVH group, we found that BA-EDD[(8.56±5.12)% vs (7.20±4.72)%, P<0.05], TA-EDD[(8.76±6.69)% vs (6.99±6.62)%, P<0.05], BA-EID[(16.48±9.71)% vs (12.39±6.23)%, P<0.01] and TA-EID[(17.19±11.92)% vs ( 12.51±9.44)%, P<0.01]were decreased significantly; while CA-IMT(mm), LVMI and LVM/H^2.7(g/m^2.7) were increased significantly(0.760±0.269 vs 0.921±0.227, 94.41±15.06 vs 138.02±21.65, 42.06±7.22 vs 61.91±10.77 respectively; all P <0.01).2. Stepwise multiple regression analysis showed that no matter whether LVH existed or not, EDD and EID from the same target artery influenced each other. Age was an influencing factor for BA-EID, CA-IMT and LVMI; CA-IMT an influencing factor for BA-EDD, BA-EID and LVMI.3. When patients getting older, TA-EDD, BA-EID and TA-EID gradually decreased; while CA-IMT, LVMI and LVM/H^2.7 gradually increased. BA-EDD was an influencing factor for CA-IMT and LVMI.4. In patients with thicken CA-IMT (CA-IMT≥1.0 mm), EDD and EID from the two target arteries decreased; while LVMI and LVM/H2.7 increased.5. No matter what patients'ages were, EDD and EID from the same target artery influenced each other, and CA-IMT was always associated with blood pressure.6. No matter whether thicken CA-IMT existed or not, EDD and EID from the same target artery influenced each other, and there was always an association between BA-EID and TA-EID.Conclusion:1. Age is an influencing factor for vasodilatation, CA-IMT and LVMI. There are interactions among vasodilatation, CA-IMT and LVMI. More intensive treatment is needed to improve the vasodilatation in EH patients with LVH or thicken CA-IMT. The improvement of the vasodilatation could protect patients against CA-IMT thickening and left ventricular hypertrophy.2. There exists an interaction between EDD and EID. When EDD is impaired, EID is also decreased in the meantime.