Antihypertensive and metabolic effects of high-dose olmesartan and telmisartan in type 2 diabetes patients with hypertension

New C2- and N3-Modified Thieno[2,3-d]Pyrimidine Conjugates with Cytotoxicity in the Nanomolar Range

AIMS

The aim of the current study was to develop and explore a series of new cytotoxic agents based on the conjugation between the thieno[2,3-d]pyrimidine moiety and a second pharmacophore at the C2 or N3 position.

BACKGROUND

As the thieno[2,3-d]pyrimidine core is a bioisostere of the 4-anilinoquinazoline, various new thienopyrimidine derivatives were synthesized by modifying the structure of the clinically used anticancer quinazoline EGFR inhibitors of the first generation - gefitinib, and second generation - dacomitinib and canertinib. It was reported that some thieno[2,3-d]pyrimidine derivatives showed improved EGFR inhibitory activity. On the other hand, the benzimidazole heterocycle is present as a pharmacophore unit in the structure of many clinically used chemotherapeutic agents. Some 2-aminobenzimidazole derivatives, possessing anticancer activity, demonstrated EGFR inhibition and the benzimidazole derivative EGF816 is currently in the second phase of clinical trials.

OBJECTIVE

The objectives of the study were design of a novel series thieno[2,3-d]pyrimidines, synthesis of the compounds and investigation of their effects towards human cancer HT-29, MDA-MB-231, HeLa, HepG2 and to normal human Lep3 cell lines. (American Type Culture Collection, ATCC, Rockville, MD, USA) Methods: The synthetic protocol implemented cyclocondensation of 2-amino-thiophenes and nitriles in inert medium, aza-Michael addition to benzimidazole derivatives and nucleophylic substitution at the N3 place. MTS test was used in order to establish the cytotoxicity of the tested compounds. SAR analysis and in silico assessment of the inhibitory potential towards human oncogenic V^599EB-Raf were performed using Molinspiration tool and Molecular Operating environment software.

RESULTS

The MTS test data showed that almost all studied thieno[2,3-d]pyirimidines (9-13, 21-22 and 25) manifest high inhibiting effect on the cell proliferation at nanomolar concentrations, whereat compounds 9 (IC₅₀ = 130 nM) and 10 (IC₅₀ = 261 nM) containing amino acid moiety, and 21 (IC₅₀ = 108 nM) possesing two thienopyrimidine moieties attached to a 1,3-disubstituted benzimidazole linker, revealed many times lower toxicity against Lep3 cells compared to the cancer cells. Thienopyrimidines 11-13 possessed high selectivity against HeLa cells. Compound 13 showed high inhibitory activity against MDA-MB-231 and HepG2, with IC50 1.44 nM and 1.11 nM respectively. To outline the possible biological target of the studied coumpounds, their potential to interact with human oncogenic V^599EB-Raf was explored by a docking study. As a result, it was suggested that the benzimidazolyl and glycyl fragments could enhance the binding ability of the new compounds by increasing the number of hydrogen bond acceptors and by stabilizing the inactive form of the enzyme.

CONCLUSION

The thienopyrimidines tested in vitro towards human cancer HT-29, MDA-MB-231, HeLa, HepG2 and normal human Lep3 cell lines demonstrated cytotoxicity in nanomolar range. It was established that compounds 9, 10 and 21 showed many times lower toxicity against normal Lep3 cells that can provide a high selectivity towards all four cancer cell lines at small concentrations. Based on the analysis of the structure-activity relationship, the observed trends in the cytotoxicity could be related to the lipophilicity and the topological polar surface area of the tested compounds. The docking study on the potential of the new thieno[2,3-d]pyrimidine-4-ones to interact with mutant V^599EB-Raf showed that the compounds might be able to stabilize the enzyme in its inactive form.

Angiotensin Receptor Blockers Are Not Just for Hypertension Anymore

Beyond blood pressure control, angiotensin receptor blockers reduce common injury mechanisms, decreasing excessive inflammation and protecting endothelial and mitochondrial function, insulin sensitivity, the coagulation cascade, immune responses, cerebrovascular flow, and cognition, properties useful to treat inflammatory, age-related, neurodegenerative, and metabolic disorders of many organs including brain and lung.

Effects of azilsartan compared with telmisartan on insulin resistance in patients with essential hypertension and type 2 diabetes mellitus: An open-label, randomized clinical trial

Background

Based on non-clinical data, it is expected that azilsartan, an angiotensin II receptor blocker, will help improve insulin resistance in addition to its hypotensive action. The present study is aimed to explore the effect of azilsartan compared to telmisartan on insulin sensitivity in hypertensive patients in the clinical setting.

Methods

This multicenter, randomized, open-label, parallel-group exploratory study was conducted in Japan. We randomized adult patients (≥20 years old) with grade I or II essential hypertension and coexisting type 2 diabetes (1:1) to receive either oral azilsartan (20 mg/day;17 patients) or telmisartan (40 mg/day;16 patients) for 12 weeks. The primary endpoint was the change in the homeostasis model assessment ratio of insulin resistance (HOMA-R) from the baseline at the end of the treatment period. We also evaluated its safety and efficacy on other diabetes-related variables and blood pressure.

Findings

The mean changes in HOMA-R at the end of treatment were 0.22 (95% CI, −1.09–1.52) in the azilsartan group and −0.23 (95% CI, −0.72–0.27) in the telmisartan group. We found no clinically remarkable changes between the groups in diabetes-related variables such as fasting blood glucose, fasting insulin, HbA1c (NGSP), HOMA-β, or 1,5-anhydroglucitol. Reductions in clinic systolic and diastolic blood pressure were observed at week 4 and the reduced levels were maintained throughout the treatment period in both groups. No serious treatment-emergent adverse events (TEAEs) were observed. Only one drug-related TEAE (mild decrease in blood pressure) was reported in one patient in the azilsartan group.

Conclusion

Neither azilsartan nor telmisartan had any clinically remarkable effects on insulin resistance parameters when administered for 12 weeks to patients with grade I or II essential hypertension and coexisting type 2 diabetes mellitus. Azilsartan (20 mg/day) and telmisartan (40 mg/day) exerted comparable antihypertensive effects.

Trial registration

ClinicalTrials.gov NCT02079805

Effects of azilsartan medoxomil compared with olmesartan and valsartan on ambulatory and clinic blood pressure in patients with type 2 diabetes and prediabetes

BACKGROUND

Angiotensin receptor blockers (ARBs) are preferred antihypertensive therapies in patients with type 2 diabetes mellitus (T2DM). Azilsartan medoxomil (AZL-M) is a potent ARB for the treatment of stages 1-2 hypertension. We compared the efficacy, safety, and metabolic effects of AZL-M to both valsartan (VAL) and olmesartan (OLM), separately in patients with impaired fasting glucose (prediabetes mellitus) and T2DM.

METHODS

A pooled analysis of 3821 patients from three separate randomized placebo-controlled trials comparing the effects of AZL-M (40 and 80 mg), OLM (40 mg), VAL (320 mg), and placebo on changes in ambulatory and clinic blood pressure (BP) among patients with hypertension and prediabetes mellitus or T2DM was performed. Two analysis pools were created to facilitate comparisons: Pool A included patients who received placebo, AZL-M or OLM and Pool B included those who received AZL-M or VAL. Within each pool, patients were stratified by glycemic subgroups (normoglycemic, prediabetes mellitus, or T2DM) based on hemoglobin A1c values. Changes from baseline in both 24-h and clinic SBP were the primary efficacy assessments.

RESULTS

Baseline 24-h mean SBPs were approximately 145 and 146 mmHg in the prediabetes mellitus and T2DM subgroups, respectively; corresponding clinic SBPs were approximately 158 and 159 mmHg. Baseline hemoglobin A1c values for each subgroup (both pools) were normoglycemic, 5.3%; prediabetes mellitus, 6.0%; and T2DM, 6.9%. Changes from baseline in 24-h or clinic SBP were significantly greater with AZL-M, 80 mg compared with either OLM 40 mg or VAL 320 mg in all subgroups in each pool. Safety and tolerability were similar among the active treatment and placebo subgroups.

CONCLUSION

These analyses indicate that AZL-M, 80 mg/day lowers SBP by a greater magnitude than OLM or VAL at maximally approved doses in patients with prediabetes mellitus and T2DM. These findings have important clinical implications for this high-risk patient group.

Improvement of Plasma Biomarkers after Switching Stroke Patients from Other Angiotensin II Type I Receptor Blockers to Olmesartan

BACKGROUND

Managing hypertension is crucial for preventing stroke recurrence. Some stroke patients experience resistant hypertension. In our experimental stroke model, olmesartan increased the expression of angiotensin (Ang) II converting enzyme-2. We hypothesized that switching to olmesartan affects biomarkers and the blood pressure (BP) in stroke patients whose BP is insufficiently controlled by standard doses of Ang II type I receptor blockers (ARBs) other than olmesartan.

METHODS

We recruited 25 patients to study our hypothesis. All had a history of stroke or silent cerebral infarction. We switched them to olmesartan (10-40 mg per day) for 12 weeks and determined their plasma level of Ang-(1-7), peroxiredoxin, oxidized low-density lipoprotein (oxLDL)/β-2-glycoprotein I (β2GPI) complex, adiponectin, high mobility group box 1 (HMGB1), and tumor necrosis factor-α (TNFα) and recorded their BP before and after olmesartan treatment.

RESULTS

After switching the patients to olmesartan, their plasma level of Ang-(1-7) as a vasoprotective indicator and adiponectin regulating metabolic syndrome was increased, and peroxiredoxin and the oxLDL/β2GPI complex indicating its antioxidative stress and its proatherogenicity were lower than their baseline. This suggests that olmesartan may be more effective than other ARBs to improve these conditions. Neither HMGB1 nor TNFα reflecting an inflammatory response was affected, suggesting that the anti-inflammatory effects of olmesartan are similar to those of other ARBs. The recommended BP (<140/90) was obtained in 10 of the 25 patients after switching to olmesartan. No adverse events occurred.

CONCLUSIONS

Switching from other ARBs to olmesartan may be a promising therapeutic option in patients with resistant hypertension.

Inflammation and vitamin D: the infection connection

INTRODUCTION

Inflammation is believed to be a contributing factor to many chronic diseases. The influence of vitamin D deficiency on inflammation is being explored but studies have not demonstrated a causative effect.

METHODS

Low serum 25(OH)D is also found in healthy persons exposed to adequate sunlight. Despite increased vitamin D supplementation inflammatory diseases are increasing. The current method of determining vitamin D status may be at fault. The level of 25(OH)D does not always reflect the level of 1,25(OH)2D. Assessment of both metabolites often reveals elevated 1,25(OH)2D, indicating abnormal vitamin D endocrine function.

FINDINGS

This article reviews vitamin D's influence on the immune system, examines the myths regarding vitamin D photosynthesis, discusses ways to accurately assess vitamin D status, describes the risks of supplementation, explains the effect of persistent infection on vitamin D metabolism and presents a novel immunotherapy which provides evidence of an infection connection to inflammation.

CONCLUSION

Some authorities now believe that low 25(OH)D is a consequence of chronic inflammation rather than the cause. Research points to a bacterial etiology pathogenesis for an inflammatory disease process which results in high 1,25(OH)2D and low 25(OH)D. Immunotherapy, directed at eradicating persistent intracellular pathogens, corrects dysregulated vitamin D metabolism and resolves inflammatory symptoms.

Dose-dependent arterial destiffening and inward remodeling after olmesartan in hypertensives with metabolic syndrome

Whether angiotensin receptor blockers can dose-dependently remodel the arterial wall during long-term treatment has been largely debated. In this phase III, multicenter, randomized, double-blind, parallel-group study, 133 subjects with hypertension and metabolic syndrome were assigned to olmesartan, either 20 mg (n=44), 40 mg (n=42), or 80 mg (n=47) once a day, according to a force titration design during a 1-year period. Office blood pressure, 24-hour blood pressure, aortic stiffness (carotid-femoral pulse wave velocity), and carotid parameters were measured at baseline, 24 weeks, and 52 weeks. Pulse wave velocity significantly decreased (P<0.001) with time in each group, with no significant time-dose interaction, despite a tendency (P=0.0685) for a smaller effect of 20 mg, compared with 40 and 80 mg at week 52. When the 40 and 80 mg doses were combined (40/80 mg versus 20 mg), a significant blood pressure-independent reduction in pulse wave velocity (-0.61 m/s) was observed at week 52 (P=0.0066), whereas the nonadjusted reduction was -1.31 m/s (P<0.0001). By contrast, after 20 mg, the blood pressure-independent reduction in pulse wave velocity was not significant. Patients receiving the highest dose of olmesartan (40 and 80 mg) had an inward carotid remodeling and were shifted toward a lower elastic modulus at a given circumferential wall stress, indicating an improvement in the intrinsic elastic properties of the carotid artery wall material. These data suggest that 40 and 80 mg olmesartan were able to significantly remodel and destiffen the arterial wall material during long-term treatment, partly independently of blood pressure, compared with 20 mg.

Candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg in unselected patients with high or very high cardiovascular risk: efficacy, safety, and metabolic impact

BACKGROUND AND OBJECTIVES

Safety and efficacy of the fixed-dose combination candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg has been demonstrated in a number of randomized clinical trials. Because stringent inclusion and exclusion criteria prohibit many high-risk patients from being investigated in clinical trials we aimed to assess the effectiveness, tolerability, and safety in a large unselected cohort of high-risk patients in primary care. The primary objective was the efficacy of candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg in lowering the office-based blood pressure (BP). Secondary objectives were changes of metabolic parameters and safety.

METHODS

A multicenter, non-interventional study of patients with a BP ≥ 140 mmHg systolic and/or 90 mmHg diastolic and additional cardiovascular risk factors. Patients received the fixed-dose combination of candesartan cilexetil 32 mg and hydrochlorothiazide 25 mg for 24 weeks.

RESULTS

A total of 3,390 patients with a mean age of 61.7 ± 10.6 years, 57.8 % being male, and a mean body mass index of 29.7 kg/m(2) were documented. Of these, 70.9 % had at least one additional cardiovascular risk factor such as coronary artery disease (45.5 %) or diabetes mellitus (44.5 %). Baseline BP was 159.6 ± 15.3 over 93.5 ± 9.5 mmHg. BP at 24 weeks was reduced by 32.3 ± 15.8 systolic and 16.1 ± 10.2 mmHg diastolic compared with baseline (p < 0.001 each). Systolic BP (SBP) and diastolic BP (DBP) was normalized (<140/<90 mmHg) in 57.4 % of non-diabetic patients. An SBP <140 mmHg or SBP reduction of ≥ 20 mmHg was achieved by 77.9 % non-diabetic patients. Fasting plasma glucose (-5.9 mg/dL), glycosylated hemoglobin (-0.18 %), low-density lipoprotein cholesterol (-8.5 mg/dL) and triglycerides (-20.3 mg/dL) were reduced significantly, high-density lipoprotein was increased by 0.18 %, while potassium and creatinine levels remained stable. The proportion of patients with adverse drug reactions (ADRs) was 1.3 % (n = 61 events in 45 patients). There were ten serious ADRs in eight patients; four patients died without causal relationship to study drug.

CONCLUSIONS

The results confirm previous randomized clinical trial data supporting the effectiveness, tolerability, and safety of this fixed-dose combination in an unselected patient population with high cardiovascular risk.

Prediction of the presence of insulin resistance using general health checkup data in Japanese employees with metabolic risk factors

AIM

The aim of the current study was to develop a predictive model of insulin resistance using general health checkup data in Japanese employees with one or more metabolic risk factors.

METHODS

We used a database of 846 Japanese employees with one or more metabolic risk factors who underwent general health checkup and a 75-g oral glucose tolerance test (OGTT). Logistic regression models were developed to predict existing insulin resistance evaluated using the Matsuda index. The predictive performance of these models was assessed using the C statistic.

RESULTS

The C statistics of body mass index (BMI), waist circumference and their combined use were 0.743, 0.732 and 0.749, with no significant differences. The multivariate backward selection model, in which BMI, the levels of plasma glucose, high-density lipoprotein (HDL) cholesterol, log-transformed triglycerides and log-transformed alanine aminotransferase and hypertension under treatment remained, had a C statistic of 0.816, with a significant difference compared to the combined use of BMI and waist circumference (p＜0.01). The C statistic was not significantly reduced when the levels of log-transformed triglycerides and log-transformed alanine aminotransferase and hypertension under treatment were simultaneously excluded from the multivariate model (p=0.14). On the other hand, further exclusion of any of the remaining three variables significantly reduced the C statistic (all p＜0.01).

CONCLUSIONS

When predicting the presence of insulin resistance using general health checkup data in Japanese employees with metabolic risk factors, it is important to take into consideration the BMI and fasting plasma glucose and HDL cholesterol levels.

ANGIOTENSIN RECEPTOR ANTAGONISTS: GOING WITH THE TIMES

This literature review focuses on the angiotensin II receptor antagonists as one of the new and promising classes of antihypertensive medications. Apart from their antihypertensive activity, these agents possess a number of other beneficial effects. The results of multiple studies, including large multi-centre clinical trials, are presented for olmesartan, an angiotensin receptor antagonist with additional beneficial properties.