Astragalus Membranaceus Improving Asymptomatic Left Ventricular Diastolic Dysfunction in Postmenopausal Hypertensive Women with Metabolic Syndrome: A Prospective, Open-Labeled, Randomized Controlled Trial

BACKGROUND: Postmenopausal women with metabolic syndrome (MetS) have increased cardiovascular morbidity and left ventricular diastolic dysfunction (LVDD). The various protective effects of astragalus membranaceus (AM) have been described in previous studies. Therefore, this study aimed to evaluate the effects of different doses of AM on diastolic function in postmenopausal hypertensive women with MetS. METHODS: This was a prospective, randomized controlled study. The postmenopausal hypertensive patients with MetS were enrolled from Lanzhou University Second Hospital from March 2014 to April 2015. Patients were divided into three groups: control group (received conventional medical treatment), AM Group 1 (received AM capsules at 5 g/d additionally), and AM Group 2 (received AM capsules at 10 g/d additionally). Echocardiographic and clinical characteristics were evaluated before and 12 months after treatment. Quantitative data were analyzed using unpaired t-test, analysis of variance, and multiple linear regression analysis. RESULTS: A total of 154 patients were subjected to final analysis. In the AM Group 2, significant improvements were noted in diastolic function 12 months after treatment than those of the control group, including the early diastolic mitral annular velocity (E’; 0.065 ± 0.007 m/s vs. 0.061 ± 0.008 m/s, P = 0.014), the ratio of the early diastolic mitral peak flow velocity to the late diastolic mitral peak flow velocity (E/A; 0.81 ± 0.05 vs. 0.80 ± 0.06, P = 0.012), the ratio of E’ to the late diastolic mitral annular velocity (E’/A’; 0.56 ± 0.12 vs. 0.51 ± 0.13, P = 0.048), and the ratio of the early diastolic mitral peak flow velocity (E) to E’ (E/E’; 10.70 ± 1.30 vs. 11.37 ± 1.73, P = 0.031). After treatment, E/E’ (10.70 ± 1.30 vs. 11.24 ± 1.56, P = 0.021), deceleration time (DT; 261.49 ± 44.41 ms vs. 268.74 ± 53.87 ms, P = 0.046), and E’/A’ (0.56 ± 0.12 vs. 0.52 ± 0.13, P = 0.019) values improved more significantly than those of AM Group 2 before treatment. Besides, waist circumference was positively correlated with E’ (r = 0.472; P = 0.003) and E’/A’ (r = 0.321; P = 0.047). In addition, the waist-to-hip ratio was a significant predictor of DT (r = 0.276; P = 0.041), E’ (r = −0.590; P < 0.001), E/E’ (r = 0.454; P = 0.004), and E’/A’ (r = −0.377; P = 0.018). CONCLUSIONS: Conventional medical plus AM therapy improved diastolic function. Moreover, WC and WHR might be risk factors for LVDD. CHINESE CLINICAL TRIAL REGISTER: ChiCTR-TRC-11001747. http://www.chictr.org.cn/showprojen.aspx?proj=7798.