Telmisartan as a metabolic sartan for targeting vascular failure

PPARs: regulators of metabolism and as therapeutic targets in cardiovascular disease. Part II: PPAR-β/δ and PPAR-γ

The PPARs are a subfamily of three ligand-inducible transcription factors, which belong to the superfamily of nuclear hormone receptors. In mammals, the PPAR subfamily consists of three members: PPAR-α, PPAR-β/δ and PPAR-γ. PPARs control the expression of a large number of genes involved in metabolic homeostasis, lipid, glucose and energy metabolism, adipogenesis and inflammation. PPARs regulate a large number of metabolic pathways that are implicated in the pathogenesis of metabolic diseases such as metabolic syndrome, Type 2 diabetes mellitus, nonalcoholic fatty liver disease and cardiovascular disease. The aim of this review is to provide up-to-date information about the biochemical and metabolic actions of PPAR-β/δ and PPAR-γ, the therapeutic potential of their agonists currently under clinical development and the cardiovascular disease outcome of clinical trials of PPAR-γ agonists, pioglitazone and rosiglitazone.

Effect of tablets with a combination of telmisartan and amlodipine on patients with hypertension: the Cotalo study

Fixed-dose combination (FDC) therapy with telmisartan 40 mg+amlodipine 5 mg (T40/A5) is expected to achieve tight blood pressure (BP) control because of the strong efficacy and long half-life of each drug. The aims of this study were to evaluate the 24-h antihypertensive efficacy of T40/A5 FDC therapy and to explore differences that may arise owing to different administration times in Japanese patients whose hypertension was not controlled by 5 mg of amlodipine per day. In this randomized clinical trial, 44 patients who had been taking amlodipine 5 mg per day and did not achieve their optimal BP target were enrolled (mean age: 67.8±10.2 years). The subjects were then randomly assigned to a T40/A5 morning or evening administration group (22 patients per group). At baseline and 8 weeks after randomization, we evaluated clinical BP and various laboratory values and performed ambulatory BP monitoring (ABPM). Clinical and mean BP evaluated with ABPM at 8 weeks (24 h, daytime, nighttime and early morning) were significantly decreased compared with BP at baseline. There were no significant differences in the diurnal BP profile change from baseline to 8 weeks between subjects in the morning and evening administration groups. There were also no significant differences in the diurnal BP profile change from baseline to 8 weeks between subjects with or without metabolic syndrome. We conclude that T40/A5 FDC therapy significantly decreased the 24-h mean and clinical BP, independent of administration time, in patients whose hypertension was not controlled by 5 mg of amlodipine.

Irbesartan, an angiotensin receptor blocker, exhibits metabolic, anti-inflammatory and antioxidative effects in patients with high-risk hypertension

Irbesartan, an angiotensin II receptor blocker (ARB), acts as a selective PPAR-γ (peroxisome proliferator-activated receptor-γ) modulator, and thus may have anti-inflammatory and antioxidative effects, as well as beneficial effects on glucose and lipid metabolism. We enrolled 118 high-risk hypertensive outpatients, defined as those with the presence of at least one complication such as coronary artery disease, cerebrovascular disease or diabetes, and who were receiving any ARB except for irbesartan (67±10 years, 80% male subjects). After a 4-week control period, all ARBs were switched to an equivalent dose of irbesartan. We evaluated changes in lipid parameters, inflammatory markers and derivatives of reactive oxygen metabolites (d-ROMs) as an oxidative stress index. After 12 weeks of irbesartan, there were significant decreases in triglycerides (138±73 versus 123±65 mg dl(-1), P<0.05), high-sensitivity C-reactive protein (hs-CRP) (2.80±0.53 versus 2.66±0.50, log (ng ml(-1)), P<0.05) and d-ROMs (338±74 versus 305±62 U.CARR, P<0.001). There were significant increases in high-density lipoprotein cholesterol (50±13 versus 52±14 mg dl(-1), P<0.01) and adiponectin (9.4±6.2 versus 16.6±13.4 ng ml(-1), P<0.05). There were no significant changes in systolic and diastolic blood pressure. The change in d-ROMs from baseline to 12 weeks was positively correlated with the change in hs-CRP (R=0.34, P<0.01). Irbesartan appears to exert beneficial effects on oxidative stress, inflammation, lipid metabolism and metabolic syndrome, indicating that it may be useful in high-risk hypertensive patients.

Antihypertensive and metabolic effects of telmisartan in hypertensive HIV-positive patients

BACKGROUND

Hypertension is more prevalent among HIV-infected individuals than in the general population and contributes to increased cardiovascular risk. The angiotensin II receptor blocker telmisartan is also a partial peroxisome proliferator activated receptor-γ agonist with documented effects on glucose and lipid homeostasis. The aim of this study was to evaluate the antihypertensive and metabolic effects of telmisartan in hypertensive HIV-positive patients.

METHODS

A total of 18 HIV-positive men treated with antiretroviral therapy and recently diagnosed with hypertension were administered 80 mg telmisartan daily. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), viroimmunological and metabolic parameters, insulin resistance, C-reactive protein, microalbuminuria, cystatin C and plasma levels of interleukin-18 and endothelin-1 were measured at baseline (T0), 1 month (T1), 3 months (T3) and 6 months (T6).

RESULTS

Treatment with telmisartan not only decreased SBP and DBP levels, but also improved insulin resistance and microalbuminuria by T1. Levels of triglycerides significantly decreased and high-density lipoprotein cholesterol increased at T1, whereas total and low-density lipoprotein cholesterol levels were statistically reduced at T3 and T6. Cystatin C and endothelin-1 showed a significant reduction at T1, whereas interleukin-18 decreased at both T3 and T6.

CONCLUSIONS

Telmisartan was effective in reducing blood pressure and improving lipid metabolism and renal function. Reduction of endothelin-1 might be related to an endothelial protective effect. On the basis of these findings, and because of properties unrelated to blood pressure lowering, telmisartan might be the first choice antihypertensive drug for the treatment of HIV-positive patients.

An angiotensin II type 1 receptor blocker prevents renal injury via inhibition of the Notch pathway in Ins2 Akita diabetic mice

Recently, it has been reported that the Notch pathway is involved in the pathogenesis of diabetic nephropathy. In this study, we investigated the activation of the Notch pathway in Ins2 Akita diabetic mouse (Akita mouse) and the effects of telmisartan, an angiotensin II type1 receptor blocker, on the Notch pathway. The intracellular domain of Notch1 (ICN1) is proteolytically cleaved from the cell plasma membrane in the course of Notch activation. The expression of ICN1 and its ligand, Jagged1, were increased in the glomeruli of Akita mice, especially in the podocytes. Administration of telmisartan significantly ameliorated the expression of ICN1 and Jagged1. Telmisartan inhibited the angiotensin II-induced increased expression of transforming growth factor β and vascular endothelial growth factor A which could directly activate the Notch signaling pathway in cultured podocytes. Our results indicate that the telmisartan prevents diabetic nephropathy through the inhibition of the Notch pathway.

Inhibition of intestinal cholesterol absorption might explain cholesterol-lowering effect of telmisartan

WHAT IS KNOWN AND OBJECTIVE

Telmisartan, an angiotensin II type 1 receptor blocker (ARB), acts as a partial agonist for peroxisome proliferator-activated receptor-γ, and thus improves abnormalities of glucose metabolism and hypertriglyceridaemia in addition to its documented blood pressure-lowering effects. Recently, it has been demonstrated that telmisartan also lowers the levels of total cholesterol and low-density lipoprotein (LDL) cholesterol levels. This study was designed to investigate the mechanism of cholesterol reduction.

METHODS

We measured serum levels of cholestanol, a cholesterol absorption marker, and lathosterol, a cholesterol synthesis marker, in 20 patients with both hypercholesterolaemia and hypertension. Ten patients were treated with telmisartan and the remaining 10 with fluvastatin.

RESULTS

After 3 months of treatment, total and LDL cholesterol levels decreased in the telmisartan group (P<0.01 for both total and LDL cholesterol levels) and the fluvastatin group (P<0.001 for both total and LDL cholesterol levels). The change in cholestanol level after 3 months of treatment was positively correlated with the levels of total (R=0.72, P<0.05) and LDL cholesterol (R=0.81, P<0.01) in the telmisartan group. The change in lathosterol level was positively correlated with the levels of total (R=0.88, P=0.001) and LDL cholesterol (R=0.89, P=0.001) in the fluvastatin group.

WHAT IS NEW AND CONCLUSIONS

Our results suggest that the cholesterol-lowering effect of telmisartan might be caused by inhibition of cholesterol absorption, whereas that of statins is by inhibition of cholesterol synthesis. If confirmed, co-treatment with the two agents may be useful for synergistically lowering cholesterol in hypertensive patients.