PS-C21-6: RENOPROTECTIVE EFFECT OF ALISKIREN MONOTHERAPY IN HYPERTENSIVE PATIENTS WITH OBESITY AND TYPE 2 DIABETES MELLITUS

Abstract

Objective: Renin-angiotensin system inhibitors have been reported to have protective effects from end-organ damages. However, roles of the direct renin inhibitor monotherapy have been still unknown. Therefore, in the present study, we compared effects of aliskiren monotherapy with those of amlodipine monotherapy on visceral fat area (VFA) and end-organ damages in hypertensive patients with obesity and type 2 diabetes. Design: A single-center, prospective, open-label and randomized study. Methods: Adult hypertensive patients with body mass index ≧ 25 kg/m2 and VFA ≧ 100 cm2 or those with type 2 diabetes, who had an office blood pressure 140–160/90–100 mmHg with or without antihypertensive drugs were randomly allocated to 24-week aliskiren or amlodipine monotherapy. The dose of amlodipine or aliskiren was increased up to 10 mg/day and 300 mg/day, respectively, and only doxazosin could be added at maximum to 8 mg/day if needed. The primary outcome of the study was the changes of waist circumference and VFA at 24 weeks of the study period. Changes in outcomes were analyzed using mixed-effects models for repeated measures, which included treatment, time, treatment-by-time interaction and the baseline values as fixed effects. Results: In a total of 62 participants (age, 57 ± 13 y.o.; 40 men; body mass index, 28.8 ± 4.8 kg/m2; waist circumference, 99.3 ± 11.9 cm; VFA, 134.8 ± 47.0 cm2; blood pressure, 141 ± 16/86 ± 13 mmHg), waist circumference and visceral fat area as a primary endpoint did not significantly change from baseline in both groups. Systolic blood pressure significantly decreased at 12 weeks (change in least squares means: -10 mmHg, P = 0.001) and 24 weeks (-10 mmHg, P = 0.001) in the amlodipine group and at 24 weeks (-11 mmHg, P = 0.001) in the aliskiren group. Diastolic blood pressure significantly decreased at 24 weeks (-6 mmHg, P = 0.009) only in the amlodipine group. Estimated glomerular filtration rates were not statistically different between the groups. Logarithm of urinary albumin excretion significantly decreased at 24 weeks only in the aliskiren group (-0.60, P < 0.001). The 24-weeks-changes in logarithm of serum pentraxin 3 levels, an inflammatory marker, were significantly lower in the aliskiren group than in the amlodipine group (-0.09 vs + 0.09, P = 0.017). Conclusions: These data suggested that aliskiren monotherapy may have a better renoprotective effect than amlodipine monotherapy while it does not affect VFA in hypertensive patients with obesity and type 2 diabetes mellitus.