Effects of ARB or ACE-inhibitor administration on plasma levels of aldosterone and adiponectin in hypertension.

Aldosterone production causes vascular injury and may occur despite the long-term administration of angiotensin converting enzyme-inhibitors (ACE-I) (ie, aldosterone breakthrough). The angiotensin II receptor blocker (ARB) telmisartan can function as a ligand for peroxisome proliferator-activated receptor (PPAR) gamma. Stimulation of PPAR gamma has been demonstrated to raise adiponectin production and suppress angiotensin II type 1 receptor expression. Thus, we investigated the effect of the ACE-I perindopril erbumin (perindopril) and the ARB telmisartan on plasma levels of aldosterone and adiponectin.Patients with essential hypertension were randomly assigned to receive 48 weeks of perindopril (2-8 mg/d) or telmisartan (20-80 mg/d). We measured adiponectin, aldosterone, angiotensin II, and renin at weeks 0, 8, 24, and 48.A total of 53 subjects were randomized. Data on 51 subjects (25 in the perindopril group and 26 in the telmisartan group; mean age, 65.1 years) were available for analyses. Plasma aldosterone decreased significantly in both the telmisartan (69.9+/-5.6 to 58.1+/-5.4 pg/mL) and perindopril (74.1+/-4.7 to 64.7+/-5.3 pg/mL) groups at 8 weeks, but returned toward the baseline in the perindopril group (67.9+/-4.1 pg/mL) at 24 weeks. Plasma glycated hemoglobin levels or urine albumin did not change significantly after the treatment in either group.Telmisartan seemed to be more effective at suppressing aldosterone and raising adiponectin levels than perindopril; however, improvements in insulin sensitivity and albuminuria were not detected. These results are consistent with the idea that the use of an ARB with PPAR gamma stimulating activity is equivalent to ACE-I for the treatment of hypertension.

Selective angiotensin receptor antagonism with valsartan decreases arterial stiffness independently of blood pressure lowering in hypertensive patients.

Angiotensin II plays a key role in the development of vascular disease. We examined the long-term effects of selective angiotensin II receptor (ATR) blockade with valsartan on arterial wall stiffness. Brachial to ankle pulse wave velocity (baPWV) was measured in 28 women and 25 men with hypertension (mean age: 62+/-2 years). The measurements were repeated after 24 weeks of treatment with valsartan, 40 to 160 mg/day, with (n=10) or without (n=36) concomitant statin therapy. By multiple regression analysis, baseline baPWV was correlated with age (p<0.001), systolic blood pressure (SBP, p<0.0001), body mass index (p=0.018), and pulse pressure (p=0.005), but not with total cholesterol (p=0.446). Valsartan lowered mean SBP and diastolic blood pressure (DBP) from 155+/-3 to 140+/-3 mmHg and from 90+/-2 to 82+/-2 mmHg, respectively, and mean baPWV from 1,853+/-49 to 1,682+/-52 cm/s. Lowering of baPWV was not influenced by statin therapy. An overlap analysis was performed to separate the effect of angiotensin II receptor blockade from that of blood pressure (BP) lowering. The decrease in the baPWV value of 1,794+/-46 cm/s before valsartan (n=39) vs. 1,663+/-45 cm/s during valsartan (p=0.048, n=31) at a similar mean SBP level (149+/-2 vs. 146+/-3 mmHg, p=0.304) confirmed that ATR blockade had a beneficial effect independent of BP lowering. SBP strongly influences baPWV. However, the decrease in baPWV with valsartan was independent of BP lowering. Statins had no synergistic effect on baPWV. Lowering of baPWV may account for the therapeutic benefit conferred by valsartan independent of its BP-lowering effect.