Metabolic effects of telmisartan and irbesartan in type 2 diabetic patients with metabolic syndrome treated with rosiglitazone

Effects of telmisartan on metabolic syndrome components: a comprehensive review

Telmisartan is an antagonist of the angiotensin II receptor used in the management of hypertension (alone or in combination with other antihypertensive agents. It belongs to the drug class of angiotensin II receptor blockers (ARBs). Among drugs of this class, telmisartan shows particular pharmacologic properties, including a longer half-life than any other angiotensin II receptor blockers that bring higher and persistent antihypertensive activity. In hypertensive patients, telmisartan has superior efficacy than other antihypertensive drugs (losartan, valsartan, ramipril, atenolol, and perindopril) in controlling blood pressure, especially towards the end of the dosing interval. Telmisartan has a partial PPARγ-agonistic effect whilst does not have the safety concerns of full agonists of PPARγ receptors (thiazolidinediones). Moreover, telmisartan has an agonist activity on PPARα and PPARδ receptors and modulates the adipokine levels. Thus, telmisartan could be considered as a suitable alternative option, with multi-benefit for all components of metabolic syndrome including hypertension, diabetes mellitus, obesity, and hyperlipidemia. This review will highlight the role of telmisartan in metabolic syndrome and the main mechanisms of action of telmisartan are discussed and summarized. Many studies have demonstrated the useful properties of telmisartan in the prevention and improving of metabolic syndrome and this well-tolerated drug can be greatly proposed in the treatment of different components of metabolic syndrome. However, larger and long-duration studies are needed to confirm these findings in long-term observational studies and prospective trials and to determine the optimum dose of telmisartan in metabolic syndrome.

TAILoR (TelmisArtan and InsuLin Resistance in Human Immunodeficiency Virus [HIV]): An Adaptive-design, Dose-ranging Phase IIb Randomized Trial of Telmisartan for the Reduction of Insulin Resistance in HIV-positive Individuals on Combination Antiretroviral Therapy

BACKGROUND

Combination antiretroviral therapy results in metabolic abnormalities which increase cardiovascular disease risk. We evaluated whether telmisartan reduces insulin resistance in human immunodeficiency virus (HIV)-positive individuals on antiretrovirals.

METHODS

We conducted a multicenter, randomized, open-label, dose-ranging controlled trial of telmisartan. Participants with HIV infection receiving combination antiretroviral therapy were randomized equally to either no intervention (control) or 20, 40, or 80 mg telmisartan once daily. The adaptive design allowed testing of all dose(s) of telmisartan in stage I, with the promising dose(s) being taken into stage II. The primary outcome measure was reduction in homeostasis model assessment of insulin resistance (HOMA-IR) at 24 weeks.

RESULTS

A total of 377 patients were recruited. In stage I, 48, 49, 47, and 45 patients were randomized to control and 20, 40, and 80 mg telmisartan, respectively (total n = 189). At the interim analysis, 80 mg telmisartan was taken forward into stage II. At the end of stage II (n = 105, control; 106, 80-mg arm), there were no differences in HOMA-IR (estimated effect, 0.007; SE, 0.106) at 24 weeks between the telmisartan (80 mg) and nonintervention arms. Longitudinal analysis over 48 weeks showed no change in HOMA-IR, lipid or adipokine levels. There were significant (P ≤ .05), but marginal, improvements in revised Quantitative Insulin Sensitivity Check Index (QUICKI) (0.004) and plasma hs-CRP (-0.222 mg/L) and reduction in liver fat content (1.714 mean reduction; P = .005).

CONCLUSIONS

No significant effect of telmisartan was demonstrated on the primary outcome (HOMA-IR), but there were marginal improvements with some secondary outcome measures. Further studies in this population are warranted to identify novel strategies for preventing cardiovascular morbidity and mortality.

CLINICAL TRIAL REGISTRATION

ISRCTN registry (51069819).

Even Short-Term Telmisartan Treatment Ameliorated Insulin Resistance But Had No Influence on Serum Adiponectin and Tumor Necrosis Factor-Alpha Levels in Hypertensive Patients with Metabolic Syndrome

BACKGROUND

We investigated the effect of short-term telmisartan usage in addition to lifestyle changes such as diet and exercise on insulin resistance, lipid metabolism, and serum adiponectin and tumor necrosis factor-alpha (TNF-α) levels in hypertensive patients with metabolic syndrome (MetS).

METHODS

A total of 36 hypertensive patients with MetS were randomized to telmisartan and control groups in an open-labeled prospective study.

RESULTS

There were significant decreases in anthropometric variables of patients according to baseline measurements in both groups at the end of the study. Serum insulin level and insulin resistance assessed by homeostasis model assessment-insulin resistance were decreased significantly in the telmisartan group (P = 0.040 and P = 0.034, respectively) compared with the controls, while there was no statistically significant change in the lipid profiles of the two groups. Serum adiponectin level was increased by 19.1% ± 41.7% in the telmisartan group, but intergroup analysis revealed no significant change. There was also no significant change in serum TNF-α level in either group.

CONCLUSION

It has been observed that even short-term telmisartan treatment had favorable effects on insulin resistance and glucose metabolism compared with lifestyle changes alone. The fundamental effect of telmisartan treatment on insulin resistance renders it a good therapeutic option for hypertensive patients with MetS.

Dyslipidaemia in type 2 diabetes mellitus: bad for the heart

PURPOSE OF REVIEW

Type 2 diabetes mellitus (T2DM) is associated with increased coronary heart disease (CHD) morbidity and mortality. These patients are also more prone to heart failure, arrhythmias and sudden cardiac death. Furthermore, coronary interventions performed in such high-risk patients have worse outcomes. In this narrative review, we discuss the role of diabetic dyslipidaemia on the risk of CHD in patients with T2DM. The effects of hypolipidaemic, antihypertensive and antidiabetic drugs on lipid and glucose metabolism in T2DM are also considered.

RECENT FINDINGS

Among CHD risk factors, diabetic dyslipidaemia characterized by moderately elevated low-density lipoprotein (LDL) cholesterol, increased triglycerides and small, dense LDL particles as well as decreased high-density lipoprotein cholesterol levels may contribute to the increased CHD risk associated with T2DM. Hypolipidaemic, antihypertensive and antidiabetic drugs can affect lipid and glucose parameters thus potentially influencing CHD risk. Such drugs may improve not only the quantity, but also the quality of LDL as well as postprandial lipaemia.

SUMMARY

Current data highlight the importance of treating diabetic dyslipidaemia in order to minimize CHD risk. Both fasting and postprandial lipids are influenced by drugs in patients with T2DM; physicians should take this into consideration in clinical decision making.

Telmisartan reverses antiretroviral-induced adipocyte toxicity and insulin resistance in vitro

BACKGROUND

Antiretroviral therapy in HIV-positive patients leads to insulin resistance which is central to the pathogenesis of various metabolic abnormalities and cardiovascular disease seen in this patient group. We have investigated the dose-response relationship of telmisartan, an antihypertensive, on adipocytes in vitro in order to determine whether it may have metabolic beneficial effects.

METHODS

Using in vitro chronic toxicity models (3T3-F442A murine and primary human adipocytes), we evaluated the effects of different concentrations of telmisartan on adipocyte differentiation and adipogenic gene expression using lipid accumulation assays and real-time polymerase chain reaction, respectively. Adipokine secretion and expression of insulin signalling mediators were evaluated using enzyme-linked immunosorbent assays.

RESULTS

Telmisartan partially reversed the deleterious effects of antiretrovirals on adipocyte lipid accumulation, expression of adipogenic regulators (peroxisome proliferator receptor-gamma and lipin 1), adipokine secretion and expression of the insulin signalling mediator pAkt_Ser473. The metabolic effects of telmisartan followed a non-monotonic response with the maximal effect observed at 5 µM in the primary human adipocyte model.

CONCLUSION

Telmisartan has beneficial metabolic effects in adipocytes in vitro, but its potential to reduce antiretroviral-induced cardiometabolic disease in HIV-infected individuals needs to be evaluated in a well-designed adequately powered clinical trial.

Comparative Efficacy of Angiotensin II Antagonists in Essential Hypertension: Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Evidence on the long-term clinical benefits of individual members of angiotensin II receptor blockers is limited given the lack of head-to-head studies. We conducted a network meta-analysis to determine the comparative efficacy of different members within this drug class with respect to outcomes of (i) blood pressure reduction (at 24 and 52 weeks) and (ii) prevention of cardiovascular disease (>104 weeks).

METHODS

A systematic literature review was conducted - Protocol registration: (PROSPERO - CRD42014007067) - to identify relevant literature from the following databases: Cochrane Library, PubMed, Medline and EMBASE; searched from inception to July 2016. Randomised controlled trials (RCTs) were included if they reported long-term effectiveness relating to blood pressure, mortality, myocardial infarction or stroke. Eligible studies included those with placebo or specific active-treatment comparators (either another angiotensin II receptor blockers or hydrochlorothiazide). A Bayesian random-effects network model was used to combine direct within-trial comparisons between treatment groups with indirect evidence from other trials.

RESULTS

Thirty-six studies were identified, representing 28 unique trials. Blood pressure reduction, based on 12 studies (n=807) with fixed dosing regimen, was found to be similar amongst members of the angiotensin receptor blocker drug class at both 24 and 52 weeks. A network meta-analysis of five studies (n=16,716) with a treat-to-target approach found that prevention of all-cause mortality, stroke and myocardial infarction was similar across the angiotensin-receptor blockers therapies initiated.

CONCLUSIONS

Current evidence is insufficient to show differences in any members within the angiotensin II receptor blocker drug class with respect to blood pressuring lowering effects or a reduction in cardiovascular diseases.

Urine Eicosanoids in the Metabolic Abnormalities, Telmisartan, and HIV Infection (MATH) Trial

OBJECTIVES

Arachidonic acid metabolites (eicosanoids) reflect oxidative stress and vascular health and have been associated with anthropometric measures and sex differences in cross-sectional analyses of HIV-infected (HIV+) persons. Telmisartan is an angiotensin receptor blocker and PPAR-γ agonist with potential anti-inflammatory and metabolic benefits. We assessed telmisartan's effects on urine eicosanoids among HIV+ adults with central adiposity on suppressive antiretroviral therapy enrolled in a prospective clinical trial.

METHODS

Thirty-five HIV+ adults (15 women; 20 men) completed 24 weeks of open-label oral telmisartan 40mg daily. Lumbar computed tomography quantified visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue. Urine F2-isoprostane (F2-IsoP), prostaglandin E2 (PGE-M), prostacyclin (PGI-M), and thromboxane B2 (TxB-M) were quantified at baseline and 24 weeks using gas/liquid chromatography-mass spectroscopy. Mann-Whitney-U tests compared sub-group differences; Spearman's rho assessed correlations between clinical factors and eicosanoid levels.

RESULTS

Median PGE-M increased on telmisartan (p<0.01), with greater changes in men (+4.1 [p = 0.03] vs. +1.0 ng/mg cr in women; between-group p = 0.25) and participants losing >5% VAT (+3.7 ng/mg cr, p<0.01) and gaining >5% SAT (+1.7 ng/mg cr, p = 0.04). Median baseline F2-IsoP and TxB-M were slightly higher in women (both between-group p = 0.08) and did not change on telmisartan.

CONCLUSIONS

Urine PGE-M increased with 24 weeks of telmisartan in virally suppressed, HIV+ adults with central adiposity. Associations with favorable fat redistribution suggest increased PGE-M may reflect a beneficial response.

Identification of dual ligands targeting angiotensin II type 1 receptor and peroxisome proliferator-activated receptor-γ by core hopping of telmisartan

It has been reported previously that some angiotensin II receptor blockers not only antagonize angiotensin II type 1 receptor (AT₁R), but also exert stimulation in peroxisome proliferator-activated receptor γ (PPARγ) partial activation, among which telmisartan displays the best. Telmisartan has been tested as a bifunctional ligand with antihypertensive and hypoglycemic activity. Aiming at more potent leads with selective AT₁R antagonism and PPARγ partial agonism, the three parts of telmisartan including the distal benzimidazole ring, the biphenyl moiety, and the carboxylic acid group experienced modification by core hopping method in our study. The central benzimidazole ring, however, remained intact considering its great affinity toward AT₁R and PPARγ. We utilized computational techniques for the sake of details on the binding interactions and conformational stability. Standard precision docking analysis and absorption, distribution, metabolism, excretion, and toxicity prediction received 10 molecules with higher Glide scores, similar interactions, and improved pharmacokinetic profiles compared to telmisartan. Comp#91 with highest scores for AT₁R (-11.92 kcal/mol) and PPARγ (-13.88 kcal/mol) exhibited excellent binding modes and pharmacokinetic parameters. Molecular dynamics trajectories on best docking pose of comp#91 confirmed the docking results and verified the conformational stability with both receptors throughout the course of 20-ns simulations. Thus, comp#91 could be identified as a promising lead in the development of dual AT₁R antagonist and PPARγ partial agonist against hypertension and type 2 diabetes.

Telmisartan and Insulin Resistance in HIV (TAILoR): protocol for a dose-ranging phase II randomised open-labelled trial of telmisartan as a strategy for the reduction of insulin resistance in HIV-positive individuals on combination antiretroviral therapy

INTRODUCTION

Telmisartan, an angiotensin receptor blocker, has beneficial effects on insulin resistance and cardiovascular health in non-HIV populations. This trial will evaluate whether telmisartan can reduce insulin resistance in HIV-positive individuals on combination antiretroviral therapy.

METHODS AND ANALYSIS

This is a phase II, multicentre, randomised, open-labelled, dose-ranging trial of telmisartan in 336 HIV-positive individuals over a period of 48 weeks. The trial will use an adaptive design to inform the optimal dose of telmisartan. Patients will be randomised initially 1:1:1:1 to receive one of the three doses of telmisartan (20, 40 and 80 mg) or no intervention (control). An interim analysis will be performed when half of the planned maximum of 336 patients have been followed up for at least 24 weeks. The second stage of the study will depend on the results of interim analysis. The primary outcome measure is a reduction in insulin resistance (as measured by Homeostatic Model Assessment-Insulin Resistance (HOMA-IR)) in telmisartan treated arm(s) after 24 weeks of treatment in comparison with the non-intervention arm. The secondary outcome measures include changes in lipid profile; body fat redistribution (as measured by MRI); plasma and urinary levels of various biomarkers of cardiometabolic and renal health at 12, 24 and 48 weeks. Serious adverse events will be compared between different telmisartan treated dose arm(s) and the control arm.

ETHICS AND DISSEMINATION

The study, this protocol and related documents have been approved by the National Research Ethics Service Committee North West-Liverpool Central (Ref: 12/NW/0214). On successful completion, study data will be shared with academic collaborators. The findings from TAILoR will be disseminated through peer-reviewed publications, at scientific conferences, the media and through patient and public involvement.

TRIAL REGISTRATION NUMBERS

04196/0024/001-0001;

EUDRACT

2012-000935-18;

ISRCTN

51069819.

A meta-analysis of randomized trials of telmisartan versus active controls for insulin resistance in hypertensive patients

To determine whether telmisartan improves insulin resistance compared with other antihypertensive drugs, we performed a meta-analysis of randomized controlled trials (RCTs) of telmisartan. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through December 2013. Eligible studies were prospective RCTs of telmisartan versus other antihypertensive drugs, enrolling individuals with hypertension and reporting insulin levels and/or homeostasis model assessment-insulin resistance (HOMA-IR) as outcomes. Of 67 potentially relevant articles screened initially, 33 reports of RCTs enrolling a total of 2033 patients with hypertension were identified and included. Pooled analyses of only the eight double-blind-design trials demonstrated statistically significant reductions in percent changes of insulin levels (mean difference, -5.19%; 95% confidence interval, -8.94% to -1.43%; P = .007) and HOMA-IR (-15.34%; -26.39% to -4.28%; P = .007) with telmisartan relative to other antihypertensive drugs. When data from all the 33 trials were pooled, telmisartan was associated with statistically significant reductions in percent changes of insulin levels (-10.92%; -15.60% to -6.23%; P < .00001) and HOMA-IR (-15.89%; -22.01% to -9.78%; P < .00001) relative to other antihypertensive drugs. In conclusion, telmisartan appears to significantly improve insulin resistance compared with other antihypertensive drugs in patients with hypertension.

Variation of some inflammatory markers in hypertensive patients after 1 year of olmesartan/amlodipine single-pill combination compared with olmesartan or amlodipine monotherapies

The purpose of this study was to evaluate a fixed olmesartan/amlodipine combination on blood pressure control, lipid profile, insulin sensitivity, and some inflammatory markers compared with single-drug monotherapy. A total of 276 hypertensive patients were randomly assigned to olmesartan 20 mg, amlodipine 10 mg, or a single pill containing olmesartan/amlodipine combination 20/5 mg for 12 months. We evaluated the following at baseline and after 6 and 12 months: body weight, body mass index, systolic (SBP) and diastolic blood pressures (DBP), fasting plasma glucose (FPG), fasting plasma insulin (FPI), lipid profile, tumor necrosis factor-α (TNF-α), retinol binding protein-4 (RBP-4), and interleukins 6 and 7 (IL-6 and IL-7). At baseline, and after 6 and 12 months, patients underwent an euglycemic, hyperinsulinemic clamp. The olmesartan/amlodipine combination provided a greater decrease of SBP and DPB compared with amlodipine and olmesartan monotherapies. The olmesartan/amlodipine combination decreased FPG after 12 months compared with amlodipine monotherapy. The combination decreased FPI and homeostasis model assessment index and increased M value both compared with baseline and with olmesartan and amlodipine monotherapies. Olmesartan/amlodipine decreased IL-7, but not IL-6, compared with single drug components. The olmesartan/amlodipine combination is effective and safe in reducing blood pressure and has some additive effects not shown by single drugs, such as an improvement of IL-7.

Comparative effectiveness of angiotensin-receptor blockers for preventing macrovascular disease in patients with diabetes: a population-based cohort study

BACKGROUND

Telmisartan, unlike other angiotensin-receptor blockers, is a partial agonist of peroxisome proliferator-activated receptor-γ, a property that has been associated with improvements in surrogate markers of cardiovascular health in small trials involving patients with diabetes. However, whether this property translates into a reduced risk of cardiovascular events and death in these patients is unknown. We sought to explore the risk of myocardial infarction, stroke and heart failure in patients with diabetes who were taking telmisartan relative to the risk of these events occurring in patients taking other angiotensin-receptor blockers.

METHODS

We conducted a population-based, retrospective cohort study of Ontario residents with diabetes aged 66 years and older who started treatment with candesartan, irbesartan, losartan, telmisartan or valsartan between Apr. 1, 2001, and Mar. 31, 2011. Our primary outcome was a composite of admission to hospital for acute myocardial infarction, stroke or heart failure. We examined each outcome individually in secondary analyses, in addition to all-cause mortality.

RESULTS

We identified 54,186 patients with diabetes who started taking an angiotensin-receptor blocker during the study period. After multivariable adjustment, patients who took either telmisartan (adjusted hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.74-0.97) or valsartan (adjusted HR 0.86, 95% CI 0.77-0.95) had a lower risk of the composite outcome compared with patients who took irbesartan. In contrast, no significant difference in risk was seen between other angiotensin-receptor blockers and irbesartan. In secondary analyses, we found a reduced risk of admission to hospital for heart failure with telmisartan compared with irbesartan (adjusted HR 0.79, 95% CI 0.66-0.96), but no significant differences in risk were seen between angiotensin-receptor blockers in our other secondary analyses.

INTERPRETATION

Compared with other angiotensin-receptor blockers, telmisartan and valsartan were both associated with a lower risk of admission to hospital for acute myocardial infarction, stroke or heart failure among older adults with diabetes and hypertension. Telmisartan and valsartan may therefore be the preferred angiotensin-receptor blockers for use in these patients.

Acute regulation of pancreatic islet microcirculation and glycaemia by telmisartan and ramipril: discordant effects between normal and Type 2 diabetic rats

Diabetic patients are often treated with an ACEi (angiotensin-converting enzyme inhibitor) or angiotensin receptor antagonist against hypertension or albuminuria. These drugs also have a positive impact on glucose tolerance, but the mechanism for this remains elusive. Hypothesizing a positive non-additive effect, we studied whether the angiotensin receptor antagonist telmisartan or the ACEi ramipril acutely influence insulin secretion and glycaemia in vivo in healthy and Type 2 diabetic rats through effects on islet blood perfusion. Telmisartan and ramipril were injected intravenously into anaesthetized non-diabetic Wistar rats or Type 2 diabetic GK (Goto–Kakizaki) rats. In non-diabetic Wistar rats, neither whole PBF (pancreatic blood flow) nor IBF (islet blood flow) were significantly influenced by telmisartan and ramipril, alone or in combination. Renal blood flow was enhanced significantly by telmisartan and ramipril when used in combination, whereas ABF (adrenal blood flow) was not affected by any of the drugs. Telmisartan and ramipril both significantly increased serum insulin levels, but did not influence glycaemia. In Type 2 diabetic GK rats, both whole PBF and IBF were significantly decreased by telmisartan and ramipril, but only when used in combination. Renal blood flow was enhanced significantly by telmisartan and ramipril alone, but not when used in combination, whereas ABF was not affected by any of the drugs. Telmisartan and ramipril both significantly decreased serum insulin levels, and non-additively elevated blood glucose levels. In conclusion, the present study suggests that a local pancreatic RAS (renin–angiotensin system), sensitive to acute administration of telmisartan and ramipril, controls pancreatic IBF and insulin secretion and thereby has an impact on glucose tolerance. Our findings indicate unexpected significant differences in the effects of these agents on islet microcirculation, in vivo insulin secretion and glycaemia between healthy and Type 2 diabetic rats.

A pilot study of telmisartan for visceral adiposity in HIV infection: the metabolic abnormalities, telmisartan, and HIV infection (MATH) trial

Background

Visceral adiposity in the setting of HIV infection and antiretroviral therapy (ART) is not fully understood, and treatment options remain limited. Telmisartan, an angiotensin receptor blocker and partial PPAR-γ agonist, has been shown to decrease visceral fat and improve metabolic and inflammatory parameters in HIV-uninfected subjects.

Methods

HIV-infected subjects with HIV-1 RNA <50 copies/mL on ART and (women/men) waist circumference >94/95 cm or waist: hip ratio >0.88/0.94 received open-label telmisartan 40 mg po daily for 24 weeks. Adipose tissue (AT) volumes were quantified by L4–L5 single slice computed tomography. Metabolic and inflammatory markers were obtained fasting. Thirty-five subjects provided 80% power to detect a 10% 24-week decrease in visceral AT (VAT, two-sided α = 0.05).

Results

Thirty-five subjects enrolled and completed the protocol. At entry (median or %): age 49 years, 43% female, 77% non-white, 91% non-smokers, CD4+ T cell count 590 cells/mm³, BMI 31 kg/m². AT responses were heterogeneous, with statistically significant losses of median (IQR) total (TAT, 2.9% (−9.8, 0.7), p = 0.03) and subcutaneous (SAT, −2.7% (−9.8, 1.1), p = 0.03) AT, but not VAT (−2.7% (−20.5, 14.2), p = 0.53). Significant decreases in waist circumference and waist:hip ratio occurred (both p<0.001) without BMI or weight changes. In an exploratory analysis, significant increases in TNF-α occurred among female subjects without changes in other inflammatory or metabolic markers. No related adverse events occurred.

Conclusions

Telmisartan was well tolerated. Small losses of AT from all depots were observed after 24 weeks of telmisartan therapy. Further study is needed to determine whether HIV-infected patients can receive metabolic benefits from telmisartan.

Trial Registration

ClinicalTrials.gov NCT01088295

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.

Relationship between telmisartan dose and glycaemic control in Japanese patients with type 2 diabetes mellitus and hypertension: a retrospective study

BACKGROUND AND OBJECTIVES

Telmisartan has been reported to have beneficial effects on insulin resistance and lipid profiles by acting as a peroxisome proliferator-activated receptor-γ (PPARγ) agonist. In this study we investigated the relationship between telmisartan dose and glycaemic control in Japanese subjects with type 2 diabetes mellitus and hypertension.

METHODS

Patients (n = 263) who were prescribed telmisartan 20, 40 or 80 mg/day at our clinic were retrospectively identified from our clinical database. Only patients without changes in their treatments for diabetes and hypertension for 6 months after starting telmisartan were included in this study. Glycosylated haemoglobin A(1c) (HbA(1c)) levels were measured at 0, 3 and 6 months after starting telmisartan.

RESULTS

At 3 and 6 months after starting telmisartan, HbA(1c) levels were significantly decreased in patients treated with telmisartan 40 or 80 mg/day but not in patients treated with telmisartan 20 mg/day (mean ± standard error change at 6 months: -0.29 ± 0.10%, p < 0.001; -0.48 ± 0.15%, p < 0.001; and -0.03 ± 0.10%, p = 0.33; respectively). When patients were classified into two groups by telmisartan dose (20 vs ≥40 mg/day), there was no significant correlation between baseline HbA(1c) and change in HbA(1c) levels over time in the 20 mg/day group. However, in patients treated with ≥40 mg/day of telmisartan, baseline HbA(1c) was negatively correlated with the change in HbA(1c) at 6 months. Multiple regression analysis confirmed that baseline HbA(1c) and telmisartan dose were the predictive factors.

CONCLUSION

Our results suggest that telmisartan influences glycaemic control in a dose-dependent manner; doses ≥40 mg/day may be needed to improve glycaemic control. Our data also suggest that patients with higher baseline HbA(1c) may experience greater improvements in glycaemic control with telmisartan.

Relationship between telmisartan dose and glycaemic control in Japanese patients with type 2 diabetes mellitus and hypertension: a retrospective study

BACKGROUND AND OBJECTIVES

Telmisartan has been reported to have beneficial effects on insulin resistance and lipid profiles by acting as a peroxisome proliferator-activated receptor-γ (PPARγ) agonist. In this study we investigated the relationship between telmisartan dose and glycaemic control in Japanese subjects with type 2 diabetes mellitus and hypertension.

METHODS

Patients (n = 263) who were prescribed telmisartan 20, 40 or 80 mg/day at our clinic were retrospectively identified from our clinical database. Only patients without changes in their treatments for diabetes and hypertension for 6 months after starting telmisartan were included in this study. Glycosylated haemoglobin A(1c) (HbA(1c)) levels were measured at 0, 3 and 6 months after starting telmisartan.

RESULTS

At 3 and 6 months after starting telmisartan, HbA(1c) levels were significantly decreased in patients treated with telmisartan 40 or 80 mg/day but not in patients treated with telmisartan 20 mg/day (mean ± standard error change at 6 months: -0.29 ± 0.10%, p < 0.001; -0.48 ± 0.15%, p < 0.001; and -0.03 ± 0.10%, p = 0.33; respectively). When patients were classified into two groups by telmisartan dose (20 vs ≥40 mg/day), there was no significant correlation between baseline HbA(1c) and change in HbA(1c) levels over time in the 20 mg/day group. However, in patients treated with ≥40 mg/day of telmisartan, baseline HbA(1c) was negatively correlated with the change in HbA(1c) at 6 months. Multiple regression analysis confirmed that baseline HbA(1c) and telmisartan dose were the predictive factors.

CONCLUSION

Our results suggest that telmisartan influences glycaemic control in a dose-dependent manner; doses ≥40 mg/day may be needed to improve glycaemic control. Our data also suggest that patients with higher baseline HbA(1c) may experience greater improvements in glycaemic control with telmisartan.

Double blockade of angiotensin II (AT(1) )-receptors and ACE does not improve weight gain and glucose homeostasis better than single-drug treatments in obese rats

BACKGROUND AND PURPOSE

Combination therapies are becoming increasingly important for the treatment of high blood pressure. Little is known about whether double blockade of angiotensin II (AT(1) ) receptors and angiotensin-converting enzyme (ACE) exert synergistic metabolic effects.

EXPERIMENTAL APPROACH

Spontaneously hypertensive rats were allowed to choose between palatable chocolate bars and standard chow and were simultaneously treated with the AT(1) blocker telmisartan (8 mg·kg(bw) (-1) ·day(-1) ), the ACE inhibitor ramipril (4 mg·kg(bw) (-1) ·day(-1) ) or a combination of the two (8 + 4 mg·kg(bw) (-1) ·day(-1) ) for 12 weeks.

KEY RESULTS

Although food-dependent energy intake was increased by telmisartan and telmisartan + ramipril compared with ramipril or controls, body weight gain, abundance of fat and plasma leptin levels were decreased. Increased insulin levels in response to an oral glucose tolerance test were comparably attenuated by telmisartan and telmisartan + ramipril, but not by ramipril. During an insulin tolerance test, glucose utilization was equally as effectively improved by telmisartan and telmisartan + ramipril. In response to a stress test, ACTH, corticosterone and glucose increased in controls. These stress reactions were attenuated by telmisartan and telmisartan + ramipril.

CONCLUSIONS AND IMPLICATIONS

The combination of telmisartan + ramipril was no more efficacious in regulating body weight and glucose homeostasis than telmisartan alone. However, telmisartan was more effective than ramipril in improving metabolic parameters and in reducing body weight. The association between the decrease in stress responses and the diminished glucose levels after stress supports our hypothesis that the ability of telmisartan, as an AT(1) receptor blocker, to alleviate stress reactions may contribute to its hypoglycaemic actions.

Adiponectin elevation by telmisartan ameliorates ischaemic myocardium in Zucker diabetic fatty rats with metabolic syndrome

AIM

This study investigated whether telmisartan, a selective angiotensin type 1 (AT1) receptor antagonist and gamma peroxisome proliferator-activated receptor (PPAR-γ) partial agonist, reduces myocardial ischaemia/reperfusion (I/R) injury in an experimental model of metabolic syndrome.

METHODS

Zucker Diabetic Fatty (ZDF) rats were treated for 3 weeks with telmisartan at doses of 2, 7 and 12 mg/kg/day. After treatment, rats were subjected to a 25-min occlusion of the left descending coronary artery followed by 2-h reperfusion (I/R).

RESULTS

Telmisartan reduced the extension of the infarct size in a dose-dependent fashion and decreased the levels of plasma troponin I, a specific marker of myocardial damage. Telmisartan also caused a dose-dependent increase in adiponectin both in plasma and cardiac tissue of infarcted ZDF rats. These levels were minimally increased (p < 0.05 vs. vehicle) by telmisartan 7 mg/kg/day and reached the maximum values with the highest dose of 12 mg/kg/day (p < 0.01 vs. vehicle). In contrast, within the infarcted tissue telmisartan decreased the expression of markers of inflammation such as the transcription factor NF-κB, the toll-like receptors TLR2 and TLR4 as well as TNF-α cytokine. Nitrosative stress was maximal in vehicle-treated infarcted hearts as evidenced by increased expression of iNOS, which was almost abolished after treatement with telmisartan.

CONCLUSIONS

Treatment of ZDF rats for 3 weeks with telmisartan, a dual angiotensin II receptor antagonist and partial PPAR-γ receptor agonist, resulted in a significant reduction of myocardial damage induced by I/R and was associated with increased adiponectin and a decrease in inflammatory markers.

Improved insulin sensitivity after long-term treatment with AT1 blockers is not associated with PPARγ target gene regulation

In both cell culture experiments and in vivo studies, a number of angiotensin II type 1 (AT(1)) receptor antagonists activated the peroxisome proliferator-activated receptor-γ (PPARγ). This mechanism has been discussed to be, at least in part, responsible for the improvement in glucose metabolism observed in animal studies and clinical trials. To investigate whether the PPARγ-dependent mechanism may represent a valid target for chronic therapy, spontaneously hypertensive rats (SHR) were fed either with a cafeteria diet (CD) or standard chow. CD-fed SHR were simultaneously treated with either telmisartan (TEL; 8 mg/kg(body weight)· d) or candesartan (CAND; 10 mg/kg(body weight)· d) for 3 months because TEL, but not CAND, has been demonstrated to be a strong activator of PPARγ. After 3 months, chow- and CD-fed controls were hypertensive, whereas TEL and CAND treatment resulted in normalized blood pressures in SHR. Body weight and the amount of abdominal fat (determined by magnetic resonance imaging) were higher in CD- than in chow-fed SHR. After TEL or CAND, body weight, abdominal fat quantity, and adipocyte size returned to normal. In glucose tolerance tests, the glucose responses were comparable in the TEL- and CAND-treated SHR and obese controls, whereas the insulin response was almost halved by AT(1) blockade. Expression of PPARγ target genes aP2, FAT CD36, FASn, and PEPCK remained unaltered at the protein level in visceral fat after TEL and CAND compared with the CD-fed controls. Because the expression of examined PPARγ target genes was not affected, we concluded that improved insulin sensitivity after long-term treatment with AT(1) blockers was not related to a PPARγ-dependent mechanism.

Telmisartan: just an antihypertensive agent? A literature review

INTRODUCTION

The modulation of the renin angiotensin aldosterone system (RAAS) is an important pathway in managing high blood pressure, and its overexpression plays a key role in target end-organ damage. Telmisartan is an angiotensin II receptor blocker (ARB) with unique pharmacologic properties, including the longest half-life among all ARBs; this leads to a significant and 24-h sustained reduction of blood pressure. Telmisartan has well-known antihypertensive properties, but there is also strong clinical evidence that it reduces left ventricular hypertrophy, arterial stiffness and the recurrence of atrial fibrillation, and confers renoprotection.

AREAS COVERED

This paper reviews telmisartan's pharmacological properties in terms of efficacy for hypertension control and, importantly, focuses on its new therapeutic indications and their clinical implications.

EXPERT OPINION

ONTARGET (ongoing telmisartan alone and in combination with ramipril global endpoint trial) demonstrated, that telmisartan confers cardiovascular protective effects similar to those of ramipril, but with a better tolerability. Moreover, recent investigations focused on the capability of telmisartan to modulate the peroxisome proliferator-activated receptor-gamma (PPAR-γ), an established target in the treatment of insulin resistance, diabetes and metabolic syndrome, whose activation is also correlated to anti-inflammatory and, finally, anti-atherosclerotic properties. Telmisartan shows peculiar features that go beyond blood pressure control. It presents promising and unique protective properties against target end-organ damage, potentially able to open a scenario of new therapeutic approaches to cardiovascular disease.

Telmisartan improves cardiometabolic profile in obese patients with arterial hypertension

OBJECTIVE

There are several lines of evidence that telmisartan may improve cardiometabolic profile. The aim of the study was to estimate changes of insulin resistance and plasma concentrations of adipokines after long-term antihypertensive treatment with telmisartan in obese hypertensive patients.

METHODS

34 previously untreated obese adults with arterial hypertension were enrolled. Glucose cellular uptake (M value) and the M to insulin ratio (M/I value) were measured by euglycemic-hyperinsulinemic clamp technique, body fat content (by dual-energy X-ray absorptiometry method), as well as plasma concentrations of selected adipokines and cytokines were estimated before and after 6-month telmisartan therapy in 25 patients who completed the study.

RESULTS

Telmisartan therapy was followed by 14.2% decrease of systolic and by 19.6% decrease of diastolic blood pressure. Body fat mass did not change significantly. Both M and M/I values (by 24.4 and by 38.6%, respectively) as well as plasma levels of total and high-molecular-weight adiponectin (by 10.8 and by 23.5%, respectively) increased significantly. Plasma concentrations of high-sensitivity C- reactive protein and interleukin-8 decreased significantly, while those of interleukin-6 and tumor necrosis factor-α tended to decline.

CONCLUSIONS

Telmisartan monotherapy improves cardiometabolic profile in obese hypertensive patients by improving insulin sensitivity and increasing of plasma adiponectin concentration, including its high-molecular-weight fraction, and by suppressing of microinflammation.

Prophylactic treatment with telmisartan induces tissue-specific gene modulation favoring normal glucose homeostasis in Cohen-Rosenthal diabetic hypertensive rats

The objectives were to assess the potential of long-term prophylactic administration of telmisartan, an angiotensin II receptor antagonist and a partial peroxisome proliferator activator receptor (PPAR)γ agonist, in preventing the development of hypertension and hyperglycemia and to demonstrate the alteration in gene expression associated with the development of hyperglycemia and insulin resistance in Cohen-Rosenthal diabetic hypertensive rat, a unique model of hypertension and type 2 diabetes mellitus comorbidity. Cohen-Rosenthal diabetic hypertensive rats were continuously treated with telmisartan (3 mg/[kg d]) starting at age 6 to 8 weeks before developing hypertension or diabetes. Weight changes, blood pressure, blood insulin, adiponectin, glucose tolerance, and insulin sensitivity were monitored. Fat, liver, and muscle messenger RNAs were examined for the expression of genes potentially involved in the onset of insulin resistance. In addition to the expected antihypertensive effect of prophylactic telmisartan, diabetes was blunted, evidenced at the end of the study by a significantly lower glucose level. This was accompanied by improved glucose tolerance, increased sensitivity to insulin, reduction in fasting insulin levels and homeostasis model assessment index, as well as an increase in serum adiponectin. Telmisartan also prevented the increase in serum triglycerides and the associated appearance of lipid droplets in the liver. Diabetes induced tissue-specific changes in messenger RNAs expression of the following selected genes, which were restored by telmisartan treatment: PPARγ, PPARδ, PPARγ coactivator 1α, adiponectin, adiponectin receptor 1, adiponectin receptor 2, phosphotyrosine binding domain and a pleckstrin homology domain-containing adaptor protein, adenosine monophosphate kinase, and glucose translocator 4. Telmisartan blunted the development of hypertension, insulin resistance, and diabetes in prediabetic Cohen-Rosenthal diabetic hypertensive rats through pleiotropic activity, involving specific gene regulation of target organs.

The effect of amlodipine besylate, losartan potassium, olmesartan medoxomil, and other antihypertensives on central aortic blood pressure and biomarkers of vascular function

Biomarkers are being increasingly used in the study of cardiovascular disease because they provide readily quantifiable surrogate endpoints and allow accurate assessment of the effects of therapy on particular pathological processes. However, in order to be useful, biomarkers must be relevant, predictable, accurate, and reproducible. There is compelling evidence from large-scale clinical trials that inhibitors of the renin-angiotensin system [angiotensin-converting enzyme inhibitors and angiotensin type II receptor blockers (ARBs)] and calcium channel blockers (CCBs) may have beneficial effects beyond blood pressure control in the treatment of hypertension. Biomarkers are expected to provide further insight into these beneficial effects and allow for quantitative assessment. This review summarizes the published clinical evidence on the effects of various antihypertensive drugs, particularly ARBs (e.g. losartan and olmesartan medoxomil) and CCBs (e.g. amlodipine), alone and in combination with other agents (e.g. hydrochlorothiazide), on central aortic pressure and the biomarkers high-sensitivity C-reactive protein (hsCRP), adiponectin, cystatin C, homeostasis model assessment of insulin resistance (HOMA-IR), procollagen, tumor necrosis factor-α, and interleukin-6. Of these biomarkers, the benefits of antihypertensive therapy on hsCRP, adiponectin, and HOMA-IR reflect a potential for quantifiable long-term vascular benefits.

PPARgamma Agonists: Potential as Therapeutics for Neovascular Retinopathies

The angiogenic, neovascular proliferative retinopathies, proliferative diabetic retinopathy (PDR), and age-dependent macular degeneration (AMD) complicated by choroidal neovascularization (CNV), also termed exudative or “wet” AMD, are common causes of blindness. The antidiabetic thiazolidinediones (TZDs), rosiglitazone, and troglitazone are PPARγ agonists with demonstrable antiproliferative, and anti-inflammatory effects, in vivo, were shown to ameliorate PDR and CNV in rodent models, implying the potential efficacy of TZDs for treating proliferative retinopathies in humans. Activation of the angiotensin II type 1 receptor (AT1-R) propagates proinflammatory and proliferative pathogenic determinants underlying PDR and CNV. The antihypertensive dual AT1-R blocker (ARB), telmisartan, recently was shown to activate PPARγ and improve glucose and lipid metabolism and to clinically improve PDR and CNV in rodent models. Therefore, the TZDs and telmisartan, clinically approved antidiabetic and antihypertensive drugs, respectively, may be efficacious for treating and attenuating PDR and CNV humans. Clinical trials are needed to test these possibilities.

Dyslipidemia induced by drugs used for the prevention and treatment of vascular diseases

Dyslipidemia is a major vascular risk factor. Interestingly, several agents used for the prevention and treatment of vascular diseases have an adverse effect on the lipid profile. In addition, agents belonging to the same class (e.g. beta blockers) can have significantly different actions on lipid levels. We summarize the effects of drugs used for the prevention and treatment of vascular diseases on the lipid profile. These effects should be considered when selecting a specific agent, particularly in high-risk patients.

Effect of telmisartan on selected adipokines, insulin sensitivity, and substrate utilization during insulin-stimulated conditions in patients with metabolic syndrome and impaired fasting glucose

Objective

Telmisartan improves glucose and lipid metabolism in rodents. This study evaluated the effect of telmisartan on insulin sensitivity, substrate utilization, selected plasma adipokines and their expressions in subcutaneous adipose tissue (SAT) in metabolic syndrome.

Design and methods

Twelve patients with impaired fasting glucose completed the double-blind, randomized, crossover trial. Patients received telmisartan (160 mg/day) or placebo for 3 weeks and vice versa with a 2-week washout period. At the end of each period, a hyperinsulinemic euglycemic clamp (HEC) combined with indirect calorimetry was performed. During HEC (0, 30, and 120 min), plasma levels of adipokines were measured and a needle biopsy (0 and 30 min) of SAT was performed.

Results

Fasting plasma glucose was lower after telmisartan compared with placebo (P<0.05). There were no differences in insulin sensitivity and substrate utilization. We found no differences in basal plasma adiponectin, resistin and tumour necrosis factor α (TNFα), but an increase was found in basal leptin, after telmisartan treatment. Insulin-stimulated plasma adiponectin (P<0.05), leptin and resistin (P<0.001) were increased, whereas TNFα was decreased (P<0.05) after telmisartan treatment. Expression of resistin, but not adiponectin, TNFα and leptin was increased after telmisartan treatment.

Conclusions

Despite the decrease in fasting plasma glucose, telmisartan does not improve insulin sensitivity and substrate utilization. Telmisartan increases plasma leptin as well as insulin-stimulated plasma adiponectin, leptin and resistin, and decreases plasma TNFα during HEC. Changes in plasma adipokines cannot be explained by their expressions in SAT. The changes in plasma adipokines might be involved in the metabolic effects of telmisartan in metabolic syndrome.

Serum resistin: physiology, pathophysiology and implications for heart failure

Resistin, a 12.5-kDa polypeptide, has been associated with both insulin resistance and inflammation in animal models. Although initially discovered in the adipocytes, it has subsequently been found in other tissues. In humans, controversy still exists regarding the role of resistin but serum resistin concentration has been correlated with risk factors for coronary heart disease, renal dysfunction and outcomes among stroke patients. Both inflammation and insulin resistance are associated with the development of incident heart failure, with worse outcomes among those with prevalent cardiomyopathy. Therefore, it is interesting to note that recent literature suggests a significant relationship between serum resistin concentrations and heart failure. In this article, we discuss the physiology, pathophysiology, and the direct and indirect role of resistin in determining heart failure risk and worse outcomes among these patients. Some of the salient points reviewed include the possible association of resistin with hyperglycemia and substrate metabolism, inflammation through TNF-alpha and direct cardiac effects.

The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.

Telmisartan: a different angiotensin II receptor blocker protecting a different population?

The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET()) showed that the angiotensin II receptor blocker (ARB) telmisartan was as protective as the reference-standard ramipril in a broad cross-section of patients at increased cardiovascular risk, but was better tolerated. Telmisartan has a unique profile among ARBs, with a high affinity for the angiotensin II type 1 receptor, a long duration of receptor binding, a high lipophilicity and a long plasma half life. This leads to sustained and powerful blood pressure lowering when compared with the first marketed ARBs, such as losartan and valsartan. Some pharmacological properties of telmisartan clearly distinguish it from other members of the ARB class and may contribute to the clinical effects seen with telmisartan. A class effect for ARBs cannot be assumed. To date, telmisartan is the only ARB that has been shown to reduce cardiovascular risk in at-risk cardiovascular patients.

The insulin sparing effect of telmisartan in a case of type 2 diabetes mellitus associated with schizophrenia under treatment of risperidone

A male patient was diagnosed with diabetes mellitus at age 37 and insulin treatment was introduced at age 49. About 2 years after the introduction of insulin, the antihypertensive agent was switched from candesartan (4 mg/day) to telmisartan (20 mg/day). The alteration improved his glycemic control dramatically, with the HbA1c levels decreasing from 8.3% to 6.0% in 6 months. Gradual marked reduction in insulin requirement was observed as it was reduced from 62 U/day to 46 U/day in 6 months and to 18 U/day in 15 months. Also his body weight was reduced from 81 kg to 65 kg in 15 months without remarkable life-style modification. Throughout the whole clinical course mentioned above, he was under treatment for schizophrenia with drugs including risperidone which possibly affects glucose metabolism. The medication for schizophrenia was not changed during this period. We present here the marked glycemia improvement effect and insulin sparing effect of telmisartan in a case of type 2 diabetes mellitus.

Beneficial Effects of Telmisartan in an HIV+ Diabetic Insulin-Dependent Patient

In HIV-infected patients with metabolic disorders, as in the general population, there is evidence of hypertension requiring pharmacological treatment. The presence of diabetes constitutes a cluster of particularly high cardiovascular risks in patients, both regarding diabetic damage and hypertensive damage. We used telmisartan to manage high blood pressure values in an HIV-positive patient with insulin-dependent diabetes. Surprisingly, insulin therapy had to be suspended because of hypoglycemic fits and treatment with metformin was started. In conclusion, telmisartan was effective and well-tolerated for the control of hypertension in this case and improved sensitivity to insulin. There are interesting effects of this drug in HIV-positive diabetic patients. Thus, if further studies confirm these effects, telmisartan may be the anti-hypertensive drug of first choice in HIV-infected subjects on combined antiretroviral therapy affected with diabetes and metabolic disorders.

Effects of telmisartan and ramipril on adiponectin and blood pressure in patients with type 2 diabetes

BACKGROUND

Adiponectin is secreted by adipose tissue and may play a role in cardiovascular disease. We examined adiponectin levels in patients with type 2 diabetes who participated in the Telmisartan vs. Ramipril in Renal Endothelial Dysfunction (TRENDY) study.

METHODS

A total of 87 patients were assessed at baseline and following 9 weeks treatment with the angiotensin-receptor blocker telmisartan (final dose, 80 mg; n = 45) or the angiotensin-converting enzyme inhibitor ramipril (final dose, 10 mg; n = 42). Adiponectin levels were measured in plasma by radioimmunoassay.

RESULTS

Adiponectin levels were inversely correlated with systolic (SBP; r = -0.240, P < 0.05) and diastolic (DBP; r = -0.227, P < 0.05) blood pressure at baseline and following treatment with telmisartan or ramipril (SBP: r = -0.228, P < 0.05; DBP: r = -0.286, P < 0.05). Changes in adiponectin levels were related to changes in SBP (r = -0.357, P < 0.01) and DBP (r = -0.286, P < 0.01). There was a significant increase in adiponectin levels in the telmisartan (0.68 (95% confidence interval (CI), 0.27 to 1.10) microg/ml, P < 0.01) but not in the ramipril group (0.17 (95% CI, -0.56 to 0.90) microg/ml, P = 0.67). Blood pressure reduction in the telmisartan group (DeltaSBP: -13.5 (95% CI, -17.0 to -10.0) mm Hg; DeltaDBP: -7.6 (95% CI, -9.8 to -5.3) mm Hg, each P < 0.001) was significantly (P < or = 0.01 for SBP and P < 0.01 for DBP) greater than in the ramipril group (DeltaSBP: -6.1 (95% CI, -6.2 to -2.0) mm Hg; DeltaDBP: -2.7 (95% CI, -5.0 to -0.5) mm Hg; P < 0.01 and P < 0.05, respectively).

CONCLUSION

Adiponectin is correlated with blood pressure in patients with type 2 diabetes. Whether increased adiponectin contributes to the blood pressure-lowering effect of telmisartan needs further study.

Telmisartan but not candesartan affects adiponectin expression in vivo and in vitro

To examine the effects of telmisartan on peroxisome proliferator-activated receptor gamma activation, we compared the effects of telmisartan with those of candesartan on adipocytokines and glucose and lipid metabolism in vivo and in vitro. In vivo, 56 patients with both type 2 diabetes and hypertension were enrolled and randomized to receive either telmisartan (40 mg) or candesartan (8 mg) for 3 months. Serum adiponectin, HbA1c levels, lipid profiles and blood pressure were recorded at the beginning and 3 months later. In vitro, differentiated 3T3-L1 adipocytes were treated with telmisartan, candesartan, pioglitazone or vehicle for 24 h, and then adiponectin mRNA and protein levels were measured. The results showed that most of the metabolic parameters, including the lipid profiles, did not change significantly during the study in either group. However, the changes in serum adiponectin and plasma glucose over 3 months were significantly greater in the telmisartan group than in the candesartan group. In vitro, although the protein level of adiponectin was not significantly elevated, the mRNA expression of adiponectin was elevated 1.5-fold by telmisartan in 3T3-L1 adipocytes. Our findings suggest that telmisartan may have beneficial effects in type 2 diabetes beyond its antihypertensive effect.

Serum resistin is positively correlated with the accumulation of metabolic syndrome factors in type 2 diabetes

OBJECTIVE

Resistin, secreted from adipocytes, causes insulin resistance in rodents. We reported that the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at -420 increases type 2 diabetes (T2DM) susceptibility by enhancing promoter activity. We also showed that serum resistin was positively correlated with G at SNP-420, the duration of T2DM, and HbA1c in T2DM. The aim of this study was to determine the relation between serum resistin and factors related to the metabolic syndrome (MetS) in T2DM.

DESIGN, PATIENTS AND MEASUREMENTS

We analysed 238 Japanese T2DM subjects (124 males and 114 females, age 60.2 +/- 11.3 years, body mass index (BMI) 24.1 +/- 3.9) whose overnight fasting sera were available. Serum resistin was measured using ELISA.

RESULTS

Serum resistin was higher in subjects with either obesity (P = 0.041), low HDL (P = 0.004), high triglycerides (TG) (P = 0.019), hypertension (HT) (P = 0.001) or atherosclerosis (P = 0.012). Simple regression analysis revealed that serum resistin was correlated with lower HDL, TG and high-sensitivity C-reactive protein (hsCRP). Multiple regression analysis (or logistic regression analysis for HT), adjusted for age, gender, BMI and the duration of T2DM, revealed that serum resistin was correlated with lower HDL (P = 0.008), TG (P = 0.041), HT (P = 0.031) and hsCRP (P = 0.004). Serum resistin was positively correlated with the number of MetS factors, independent of age, gender and the duration of T2DM (P < 0.001). Adjustment by either thiazolidinedione (TZD) treatment or hsCRP had no effects on these findings.

CONCLUSIONS

Serum resistin was positively correlated with the accumulation of MetS factors in T2DM.