Change in apelin level in response to treatment and relation with diastolic function in patients with newly diagnosed hypertension

Change in Apelin Level in Response to Treatment and Relation with Diastolic Function in Patients with Newly Diagnosed Hypertension Apelin is a novel endogenous peptide which has different functions in cardiovascular system. In this study we aimed to investigate the change in apelin levels in patients with newly diagnosed hypertension after one month of drug therapy and identify the relation between apelin level and improvement in left ventricular diastolic function. Ninety patients (50 men, 40 women) were enrolled who were diagnosed as stage 1 and 2 hypertension based on Eurepean Society of Cardiology guidelines. Patients who had coronary artery disease, diabetes mellitus, severe valvular disease, body mass index above 30 kg/ m2, left ventricle ejection fraction below 45 % and creatinine level above 1.6 mg/dl were excluded. Patients were randomized to treatment groups of 80 mg telmisartan and 10 mg amlodipine. At baseline, blood samples for apelin level were obtained and transthoracic echocardiography was performed. In addition to routine echocardiographic measurements, lateral and septal annular e' wave velocities were measured using tissue Doppler method. Transmitral flow propagation velocity (Vp) was measured by M-mode echocardiography. After 1 month of treatment, ambulatory blood pressure monitoring was performed and plasma apelin level measurement and echocardiography were repeated. Thirteen patients were excluded due to incomplete follow-up. Data from 77 patients with a mean age of 48 ± 10 were analyzed. Mean age, gender, baseline blood pressure, apelin levels and echocardiographic measurements were similar between the groups (p > 0,05 for all). When both amlodipin and telmisartan group evaluated together, there was a significant increase in apelin levels after one month of treatment (0,32±0,02 vs 0,38±0,02 ng/dl and 0,27±0,02 vs 0,34±0,02 ng/dl respectively; p<0,001). This increase was similar between both groups (p=0,671). In both amlodipin and telmisartan groups, there was a significant decrease in systolic (154±11 vs 123±10 mmHg and 155±7 vs 122±9 mmHg respectively) and diastolic blood pressure values (96±9 vs 76±8 mmHg and 92±6 vs 74±9 mmHg respectively)(p<0,001). This decrease was similar between both groups (p=0,628). Parameters indicating diastolic function were improved in both telmisartan and amlodipine groups (p<0,05). On spearman rank correlation test analysis, diastolic function indices which were improved with treatment were not significantly related to follow-up apelin level. Apelin levels were significantly increased in newly diagnosed hypertensive patients after one month of treatment and effective blood pressure control either with telmisartan or amlodipine. Change in apelin level was not related to improvement in diastolic function. Key Words: Apelin, hypertension, diastolic function