Effect of valsartan addition to amlodipine on insulin sensitivity in overweight-obese hypertensive patients

Insulinotropic Effects of Neprilysin and/or Angiotensin Receptor Inhibition in Mice

Treatment of heart failure with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan improved glycemic control in individuals with type 2 diabetes. The relative contribution of neprilysin inhibition versus angiotensin II receptor antagonism to this glycemic benefit remains unknown. Thus, we sought to determine the relative effects of the neprilysin inhibitor sacubitril versus the angiotensin II receptor blocker valsartan on beta-cell function and glucose homeostasis in a mouse model of reduced first-phase insulin secretion, and whether any beneficial effects are additive/synergistic when combined in sacubitril/valsartan. High fat-fed C57BL/6J mice treated with low-dose streptozotocin (or vehicle) were followed for eight weeks on high fat diet alone or supplemented with sacubitril, valsartan or sacubitril/valsartan. Body weight and fed glucose levels were assessed weekly. At the end of the treatment period, insulin release in response to intravenous glucose, insulin sensitivity, and beta-cell mass were determined. Sacubitril and valsartan, but not sacubitril/valsartan, lowered fasting and fed glucose levels and increased insulin release in diabetic mice. None of the drugs altered insulin sensitivity or beta-cell mass, but all reduced body weight gain. Effects of the drugs on insulin release were reproduced in angiotensin II-treated islets from lean C57BL/6J mice, suggesting the insulin response to each of the drugs is due to a direct effect on islets and mechanisms therein. In summary, sacubitril and valsartan each exert beneficial insulinotropic, glycemic and weight-reducing effects in obese and/or diabetic mice when administered alone; however, when combined, mechanisms within the islet contribute to their inability to enhance insulin release.

Barnidipine compared to lercanidipine in addition to losartan on endothelial damage and oxidative stress parameters in patients with hypertension and type 2 diabetes mellitus

Background

Essential hypertension has been extensively reported to cause endothelial dysfunction. The aim of this study was to evaluate the effects of barnidipine or lercanidipine, in addition to losartan, on some parameters indicative of endothelial damage and oxidative stress in hypertensive, type 2 diabetic patients.

Methods

One hundred and fifty one patients were randomised to barnidipine, 20 mg/day, or lercanidipine, 20 mg/day, both in addition to losartan, 100 mg/day, for 6 months. We assessed BP every month, in addition, patients underwent ambulatory blood pressure monitoring (ABPM). We also assessed: fasting plasma glucose (FPG), glycated hemoglobin (HbA_1c), some markers such as high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis factor-α (TNF-α), metalloproteinase-2 (MMP-2) and -9 (MMP-9), soluble vascular adhesion protein-1 (sVCAM-1), soluble intercellular adhesion protein-1 (sICAM-1), isoprostanes and paraoxonase-1 (PON-1).

Results

Both barnidipine and lercanidipine resulted in a significant reduction in blood pressure, even if the reduction obtained with barnidipine + losartan was greater than that obtained with lercanidipine + losartan. Data recorded with ABPM also showed a similar trend. Barnidipine + losartan reduced the levels of Hs-CRP, TNF-α, sVCAM-1, sICAM-1, and isoprostanes both compared to baseline and to lercanidipine + losartan.

Conclusions

Barnidipine + losartan gave an improvement of some parameters indicative of endothelial damage and oxidative stress in diabetic and hypertensive patients.

Trial registration

NCT02064218, ClinicalTrials.gov

Results from a 12 months, randomized, clinical trial comparing an olmesartan/amlodipine single pill combination to olmesartan and amlodipine monotherapies on blood pressure and inflammation

AIM

Hypertension affects nearly 1 in 3 adults in the United States, and it is an important modifiable risk factor for coronary artery disease, heart failure, renal failure, and stroke. The aim of this study was to evaluate the effects of a fixed-dose olmesartan/amlodipine combination on blood pressure control, lipid profile, insulin sensitivity, and inflammation compared to singles monotherapies.

METHODS

We randomized 276 hypertensive patients to olmesartan 20 mg, amlodipine 10mg or a single pill containing a fixed-dose olmesartan/amlodipine combination 20/5mg for 12 months. We evaluated: body weight, body mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), fasting plasma glucose (FPG), fasting plasma insulin (FPI), lipid profile, omentin, chemerin, high sensitivity C-reactive protein (Hs-CRP). At baseline, and after 6 and 12 months, patients underwent an euglycemic, hyperinsulinemic clamp to assess insulin sensitivity (M value).

RESULTS

Olmesartan/amlodipine combination was more effective than amlodipine or olmesartan in reducing blood pressure. Olmesartan/amlodipine combination, but not amlodipine, decreased FPG after 12 months. Olmesartan/amlodipine combination better decreased FPI and HOMA index and increased M value compared to olmesartan and amlodipine monotherapies. Olmesartan/amlodipine significantly decreased chemerin and omentin compared to olmesartan and amlodipine.

CONCLUSION

Other than to be more effective in reducing blood pressure, olmesartan/amlodipine single pill combination gave also a major increase of insulin sensitivity and a decrease of inflammatory markers compared to single monotherapies.

Comparison of the efficacy and safety profiles of two fixed-dose combinations of antihypertensive agents, amlodipine/benazepril versus valsartan/hydrochlorothiazide, in patients with type 2 diabetes mellitus and hypertension: a 16-week, multicenter, randomized, double-blind, noninferiority study

BACKGROUND

Hypertension is a prevalent condition that is closely associated with chronic complications in patients with diabetes. Fixed-dose combination therapy is currently recommended for the treatment of hypertension due to the advantage of reducing the pill burden. However, the effects of combination therapy may be diverse because of the different components.

OBJECTIVES

We examined blood pressure reduction and metabolic alterations after amlodipine/benazepril and valsartan/hydrochlorothiazide treatment in patients with type 2 diabetes mellitus and hypertension and microalbuminuria.

METHODS

This randomized, double-blind, parallel comparison, noninferiority clinical trial included patients with type 2 diabetes mellitus and hypertension and microalbuminuria detected within the past year. After a 2-week, placebo run-in period, patients were assigned to treatment with amlodipine/benazepril or valsartan/hydrochlorothiazide for 16 weeks. The primary end point was mean change in diastolic blood pressure. The prespecified boundary for noninferiority was 3.5 mm Hg of the mean change in diastolic blood pressure between treatments (amlodipine/benazepril minus valsartan/hydrochlorothiazide). If the upper limit of the 95% CI fell within 3.5 mm Hg, amlodipine/benazepril would be considered noninferior to valsartan/hydrochlorothiazide.

RESULTS

Of the 226 patients assessed for eligibility, 169 satisfied the inclusion/exclusion criteria and were assigned to a treatment group; 83 patients (54.2% male, mean age of 60.5 [10.0] years) in the amlodipine/benazepril group and 84 patients (64.3% male, mean age of 59.0 [10.6] years) in the valsartan/hydrochlorothiazide group received at least 1 dose of study medication and were included in the intention-to-treat population. In the per-protocol population, amlodipine/benazepril (n = 74) was noninferior to valsartan/hydrochlorothiazide (n = 78) with regard to the mean change in diastolic blood pressure (difference, -0.9 mm Hg; 95% CI, -3.5 to 1.6). The mean change in systolic blood pressure was not significantly different (2.4 mm Hg; 95% CI, -1.2 to 6.0) between study groups (P = 0.195) in the per-protocol population. However, data from the intention-to-treat population suggest that patients in the amlodipine/benazepril group may have better metabolic outcomes than those in the valsartan/hydrochlorothiazide group; specifically, a preservation of the estimated glomerular filtration rate (5.7 mL/min/1.73 m(2) [95% CI, 1.9 to 9.6]; P = 0.004) and improvements in glycosylated hemoglobin (-0.5% [95% CI, -0.7 to -0.2]; P < 0.001), fasting triglycerides (-0.4 mmol/L [95% CI, -0.7 to -0.2]; P = 0.002), HDL-C (0.07 mmol/L [95% CI, 0.01 to 0.12]; P = 0.022), and uric acid (-57.5 μmol/L [95% CI, -74.8 to -40.3]; P < 0.001). There were no significant differences in adverse effects between groups, with the exception of more respiratory disorders in the amlodipine/benazepril group than in the valsartan/hydrochlorothiazide group (17 vs 5; P = 0 .006).

CONCLUSIONS

The study results suggest that amlodipine/benazepril is noninferior to valsartan/hydrochlorothiazide with regard to blood pressure reduction and that this combination exerts beneficial effects on renal function, glucose control, HDL-C, and triglyceride levels compared with valsartan/hydrochlorothiazide. However, respiratory adverse events (particularly coughing) were more frequently reported in the amlodipine/benazepril group. ClinicalTrials.gov identifier: NCT01375322.

Valsartan-induced improvement in insulin sensitivity is not paralleled by changes in microvascular function in individuals with impaired glucose metabolism

BACKGROUND

Individuals with impaired glucose metabolism (IGM) are at high risk of developing type 2 diabetes (T2DM). The renin-angiotensin system (RAS) is activated in insulin-resistant states and its inhibition resulted in delayed onset of T2DM. The underlying mechanisms may include improvement in microvascular structure and function, which may increase glucose and insulin delivery to insulin-sensitive tissues. We hypothesized that functional and structural capillary density is impaired in insulin-resistant individuals with IGM and that treatment with the angiotensin-receptor blocker valsartan (VAL) will improve insulin sensitivity and microvascular function.

METHODS

In this randomized controlled trial, individuals with IGM (n = 48) underwent a hyperinsulinaemic-euglycaemic clamp to assess insulin sensitivity (M-value) and capillaroscopy to examine baseline skin capillary density (BCD), capillary density after arterial occlusion (PRH) and capillary density during venous occlusion (VEN) before and after 26 weeks of VAL or placebo (PLB). Sixteen BMI-matched individuals with normal glucose metabolism (NGM) served as controls.

RESULTS

Individuals with IGM were more insulin resistant (P < 0.001) and had impaired microvascular function compared with those with NGM (all P < 0.01). Univariate associations were found for microvascular function (BCD, PRH, VEN) and M-value (all P < 0.005). The relations were independent of age, sex and BMI. VAL improved insulin sensitivity (P = 0.034) and lowered blood pressure as compared with PLB, whereas microvascular function remained unchanged.

CONCLUSION

In insulin-resistant individuals with IGM, impaired functional and structural capillary density was inversely associated with insulin sensitivity. VAL improved insulin sensitivity without affecting the functional and structural capillary density, indicating that other mechanisms may be stronger determinants in the VAL-mediated insulin-sensitizing effect.

Acute angiotensin II receptor blockade improves insulin-induced microvascular function in hypertensive individuals

OBJECTIVE

An effect of insulin that is crucial for stimulating glucose uptake is its ability to increase the number of perfused capillaries, and thereby enhance its own delivery, and that of glucose, to muscle cells. To unravel possible mechanisms involved in the insulin-sensitizing effects of angiotensin II receptor blockers (ARBs) in hypertensive individuals we investigated the effect of single-dose ARB administration on insulin-mediated microvascular perfusion in hypertensive individuals.

METHODS

We examined the effects of ARB administration on hyperinsulinemia-associated capillary density by measuring baseline skin capillary density, capillary density during reactive hyperemia (hyperemic capillary recruitment), and capillary density during venous congestion in 17 hypertensive individuals in the basal state, during a hyperinsulinemic euglycemic clamp, and during a hyperinsulinemic clamp with acute ARB administration (600 mg irbesartan), acute calcium channel blockade (CCB; 10mg felodipine ER), as a control for the reduction in blood pressure, or placebo. In addition, insulin sensitivity and blood pressure were measured.

RESULTS

Compared to the basal state, hyperinsulinemia increased baseline capillary density (57.3 ± 6.8 vs. 60.3 ± 7.9 n/mm(2), P<0.01), but not hyperemic capillary recruitment. ARB and CCB treatment induced similar blood pressure reductions. Compared to placebo, ARB, but not CCB, increased hyperinsulinemia-associated baseline capillary density (+2.3 ± 3.4 (P=0.02) and -0.4 ± 4.4n/mm(2), respectively). Hyperinsulinemia-associated hyperemic capillary recruitment was not altered by either treatment. Compared to placebo, neither ARB nor CCB treatment enhanced insulin sensitivity.

CONCLUSIONS

Acute ARB administration increases insulin-induced microvascular perfusion in mildly hypertensive individuals; this beneficial effect on microvascular perfusion was however not associated with increased insulin-mediated glucose uptake.

Valsartan improves {beta}-cell function and insulin sensitivity in subjects with impaired glucose metabolism: a randomized controlled trial

OBJECTIVE

Recently, the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research Trial demonstrated that treatment with the angiotensin receptor blocker (ARB) valsartan for 5 years resulted in a relative reduction of 14% in the incidence of type 2 diabetes in subjects with impaired glucose metabolism (IGM). We investigated whether improvements in β-cell function and/or insulin sensitivity underlie these preventive effects of the ARB valsartan in the onset of type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this randomized controlled, double-blind, two-center study, the effects of 26 weeks of valsartan (320 mg daily; n = 40) or placebo (n = 39) on β-cell function and insulin sensitivity were assessed in subjects with impaired fasting glucose and/or impaired glucose tolerance, using a combined hyperinsulinemic-euglycemic and hyperglycemic clamp with subsequent arginine stimulation and a 2-h 75-g oral glucose tolerance test (OGTT). Treatment effects were analyzed using ANCOVA, adjusting for center, glucometabolic status, and sex.

RESULTS

Valsartan increased first-phase (P = 0.028) and second-phase (P = 0.002) glucose-stimulated insulin secretion compared with placebo, whereas the enhanced arginine-stimulated insulin secretion was comparable between groups (P = 0.25). In addition, valsartan increased the OGTT-derived insulinogenic index (representing first-phase insulin secretion after an oral glucose load; P = 0.027). Clamp-derived insulin sensitivity was significantly increased with valsartan compared with placebo (P = 0.049). Valsartan treatment significantly decreased systolic and diastolic blood pressure compared with placebo (P < 0.001). BMI remained unchanged in both treatment groups (P = 0.89).

CONCLUSIONS

Twenty-six weeks of valsartan treatment increased glucose-stimulated insulin release and insulin sensitivity in normotensive subjects with IGM. These findings may partly explain the beneficial effects of valsartan in the reduced incidence of type 2 diabetes.

Olmesartan/amlodipine vs olmesartan/hydrochlorothiazide in hypertensive patients with metabolic syndrome: the OLAS study

We studied the effects of treatment with olmesartan/amlodipine and olmesartan/hydrochlorothiazide on inflammatory and metabolic parameters (including new-onset diabetes as a secondary endpoint) in non-diabetic hypertensive patients with metabolic syndrome (MetS). A total of 120 patients with MetS and stage I and II hypertension were randomized to olmesartan 20 mg/amlodipine 5 mg or olmesartan 20 mg/hydrochlorothiazide 12.5 mg. If target systolic blood pressure (<140 mm Hg) was not reached, doses were doubled after 13 weeks; doxazosin 4 mg was added after 26 weeks, and doubled after 39 weeks; follow-up ended at 78 weeks. At each visit, blood pressure (BP), fasting plasma glucose, insulin, adiponectin, tumour necrosis factor-α, C-reactive protein (CRP), intercellular adhesion molecule-1, vascular cell adhesion molecule-1, interleukins-1β, -6 and -8, and albuminuria were measured; BP was similarly reduced in both groups; 80% of patients reached target BP. Reductions in albuminuria were also similar (50%). Only olmesartan/amlodipine reduced the insulin resistance index (24%, P<0.01), increased plasma adiponectin (16%, P<0.05) and significantly reduced all of the inflammation markers studied, except CRP, which showed a similar reduction in each group. The risk of new-onset diabetes was significantly lower with olmesartan/amlodipine (P=0.02). Both olmesartan-based combinations were effective, but the amlodipine combination resulted in metabolic and anti-inflammatory effects that may have advantages over the hydrochlorothiazide combination.

Irbesartan has no short-term effect on insulin resistance in hypertensive patients with additional cardiometabolic risk factors (i-RESPOND)

AIMS

Intervention studies have shown that angiotensin receptor blockers (ARB) may reduce the incidence of type 2 diabetes mellitus. It is currently unclear whether short-term therapy with ARBs affects metabolic parameters.

METHODS

i-RESPOND, a randomised, controlled, multicentre, double-blind study evaluated the effect of 16 weeks of irbesartan vs. hydrochlorothiazide (HCTZ) on insulin resistance as well as on lipid and inflammatory parameters in hypertensive subjects with metabolic syndrome. Patients received irbesartan (150 mg/d; n = 211) or HCTZ (12.5 mg/d; n = 215), titrated to 300 mg/day and 25 mg/day respectively. In a second part of the study (weeks 16-28), patients initially randomised to irbesartan received additional HCTZ and vice versa.

RESULTS

At week 16 both irbesartan and HCTZ had no effect on insulin resistance measured by the Matzuda index and beta-cell function. Similarly, in the second part of the study (week 16-28) no differences between irbesartan and HCTZ with respect to glucose metabolism were observed. However, irbesartan induced beneficial changes in high-sensitivity-C-reactive protein (hs-CRP) (irbesartan: -5.5 +/- 5.2%; HCTZ + 19.9 +/- 6.5%, p = 0.0024) and in urinary albumin/creatinine ratio (ACR) (irbesartan: -13%; HCTZ + 9%; p = 0.0041) compared with HCTZ despite a similar decrease in blood pressure in both treatment groups. Irbesartan and HCTZ were well tolerated and adverse events were comparable.

CONCLUSION

Irbesartan did not show significant favourable effects on insulin resistance compared with HCTZ in this study; however, may have beneficial effects on inflammation and microalbuminuria in hypertensive patients with metabolic syndrome.