Objective To explore the effects of hypertensive early renal damage on the arterial endothelial function in patients with hypertension and carotid plaques.
Methods This cross-sectional study included 71 hypertensive patients with carotid plaques and 20 healthy people as normal control (NC group) aged 39 to 75 years. Seventy-one patients were divided into early renal damage group (RD group, n = 33) and no renal damage group (NRD group, n = 38) according to the level of the urinary albumin excretion rate (UAER). Early renal damage was defined as microalbuminuria which was a UAER > 30 and < 300 mg/24 hours. All patients underwent the following procedures: BP measurements, laboratory tests, the intima-media thickness (IMT) of common carotid artery and carotid plaques evaluation by ultrasonography, and endothelial function assessment by flow-mediated dilation (FMD) and Nitroglycerin-mediated dilation (NMD) in the brachial artery.
Results (1) The UAER and fasting blood glucose (FBG) in the RD group was obviously higher than the NRD and NC group (P < 0.01). The systolic blood pressure (SBP), diastolic blood pressure (DBP), IMT and low density lipoprotein (LDL) in the RD and NRD group were higher than NC group (p < 0.01), but there was no difference between RD and NRD group. There was an increasing trend of the uric acid in NC, NRD and RD groups without statistical significance (p > 0.05). (2) The FMD% of patients with hypertension and carotid plaques was obviously lower than the NC group (P < 0.01) and the RD group was lower than the NRD group (P < 0.01). The NMD% of hypertensive patients with carotid plaques had the same trend as FMD%, but there was no significant difference between NRD and NC group.(3) The FMD% showed a negative correlation with SBP, total cholesterol, UAER IMT, LDL, and FBG (r = –0.329, –0.324, –0.512, respectively P < 0.01; r = –0.223, –0.223, –0.230, respectively, P < 0.01). The NMD% showed a negative correlation with the age, IMT and UAER (r = –0.227, –0.227,-0.231, respectively, P < 0.05).
Conclusions Both endothelium-dependent and endothelium-independent vasodilatation are impaired in hypertensive patients with carotid plaques. Hypertensive early renal damage aggravated the arterial endothelial dysfunction.