Effects of Angiotensin II on Insulin Sensitivity: A Placebo-Controlled Study

1993 ◽  
Vol 85 (4) ◽  
pp. 431-436 ◽  
Author(s):  
A. D. Morris ◽  
J. R. Petrie ◽  
J. Anderson ◽  
J. M. C. Connell ◽  
R. Donnelly
Keyword(s):  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Angiotensin Ii ◽  
Enzyme Inhibitor ◽  
Serum Insulin ◽  
Whole Body ◽  
Controlled Study ◽  
High Dose ◽  
Double Blind ◽  
Plasma Angiotensin

1. There is evidence that hyperinsulinaemia increases the aldosterone response to angiotensin II, and that angiotensin-converting enzyme inhibitor drugs enhance peripheral glucose utilization, but the direct effects of angiotensin II on insulin sensitivity have not been reported previously. 2. In a randomized, double-blind, placebo-controlled, cross-over study, 12 healthy male subjects attended on 3 study days for the evaluation of the effects of a subpressor (1 ng min−1 kg−1) and pressor (5 ng min−1 kg−1) infusion of angiotensin II on whole-body insulin sensitivity using the euglycaemic hyperinsulin-aemic clamp. Frequent measurements of blood pressure and heart rate were recorded and blood samples were collected for determination of serum insulin, C-peptide and K+ concentration, plasma renin activity and plasma angiotensin II concentration. 3. Plasma angiotensin II concentrations (means +SD) were 11+5 pg/ml after placebo, and 27+9 and 125+28 pg/ml after low and high dose angiotensin II, respectively. The higher dose of angiotensin II was associated with significant increases in blood pressure (e.g. 13 mmHg systolic blood pressure at 150 min) and serum aldosterone concentration. Whole-body insulin sensitivity was 10.5 + 2 mg of glucose min−1 kg−1 after placebo, and 10.5 +2.2 and 10.9+3.4 mg of glucose min−1 kg−1 after low and high dose angiotensin II (not significant). 4. Angiotensin II had no effect on hyperinsulinaemia-induced reductions in serum potassium and triacyl-glycerol concentrations. 5. Thus, acute infusion of angiotensin II for 3 h, with or without an increase in blood pressure, has no effect on whole-body insulin sensitivity.

Abstract 617: Impact Of Pterostilbene On Blood Pressure and Other Metabolic Parameters In Adults

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Daniel M Riche ◽  
David Deschamp ◽  
Michael E Griswold ◽  
Corey L McEwen ◽  
Krista D Riche ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Reproductive Potential ◽  
Metabolic Parameters ◽  
Controlled Study ◽  
High Dose ◽  
Double Blind ◽  
Tract Disease ◽  
Cholesterol Therapy ◽  
Fibric Acids ◽  
Over Time

Objective: Pterostilbene is a polyphenol that is chemically related to resveratrol and commonly found in berries, such as blueberries. The purpose of this trial was to evaluate the effect of pterostilbene on metabolic parameters. METHODS: The trial was a prospective, randomized, double-blind, placebo-controlled study of patients with a total cholesterol ≥200 mg/dL and/or LDL ≥100 mg/dL. Patients were included if they were ≥18 years old and on either no cholesterol therapy or cholesterol medication at a stable dose for at least 2 months prior to baseline laboratory. Patients were excluded if they had significant hepatic, renal or GI tract disease or current overt cardiovascular disease; were receiving thiazolidinediones or fibric acids; were women who were pregnant or of reproductive potential. Eighty subjects were divided equally into one of four groups: (1) pterostilbene 125 mg twice daily; (2) pterostilbene 50 mg twice daily; (3) pterostilbene 50 mg + grape extract (GE) 100 mg twice daily; (4) matching placebo twice daily for 6-8 weeks. Patients received identical counseling on lifestyle intervention. Metabolic endpoints included blood pressure, body weight, and lipids. Linear mixed models were used to examine changes in metabolic parameters over time within treatment groups and compare changes over time across groups. Models were adjusted for age, sex and race. Results: The majority of patients completed the study (73/80; 91%). The average age was 54 years. The majority of patients were female (57/80; 71%), Caucasian (56/80; 70%), and had HTN (44/80; 55%). Both systolic (-7.8 mmHg; p<0.01) and diastolic blood pressure (-7.3 mmHg; p<0.001) were reduced with high dose pterostilbene. The only change in lipids was an increase in LDL with pterostilbene monotherapy (24.9 mg/dL; p<0.001) which was not seen with GE combination (p=0.47). Presence of a baseline cholesterol medication appeared to attenuate LDL effects. Patients not on cholesterol medication (n=51) exhibited minor weight loss with pterostilbene (-0.59 kg/m2; p=0.014). Conclusion: Pterostilbene reduces blood pressure in adults. Future studies should evaluate high dose pterostilbene with GE in a hypertensive population. Clinicaltrials.gov identifier NCT 01267227.

Combination Oral Antioxidant Supplementation Reduces Blood Pressure

1997 ◽  
Vol 92 (4) ◽  
pp. 361-365 ◽  
Author(s):  
Helen F. Galley ◽  
Judith Thornton ◽  
Peter D. Howdle ◽  
Barry E. Walker ◽  
Nigel R Webster
Keyword(s):  
Blood Pressure ◽  
Sodium Succinate ◽  
Controlled Study ◽  
High Dose ◽  
Antioxidant Supplementation ◽  
Short Term ◽  
Double Blind ◽  
Increased Risk ◽  
Hypertensive Therapy ◽  
Β Carotene

1. Hypertension affects 30% of adults and low intakes of antioxidants have been associated with increased risk of hypertension and cardiovascular disease. To investigate the effect of short-term high-dose antioxidant supplementation on blood pressure in hypertensive and normotensive outpatients, we undertook a randomized, double-blind, crossover design placebo-controlled study. 2. Forty subjects were recruited from medical outpatient clinics, of whom 38 completed the study. Twenty-one were attending for treatment of hypertension and 17 were normotensive, attending for minor gastrointestinal complaints. Subjects were randomly assigned to receive either 8 weeks placebo followed by 2 weeks washout then 8 weeks antioxidants or vice versa. The combination of antioxidants consisted of 200 mg of zinc sulphate, 500 mg of ascorbic acid, 600 mg of α-tocopherol (sodium succinate salt) and 30 mg of β-carotene daily. 3. Systolic blood pressure fell at the end of the antioxidant phase compared with the placebo phase both in subjects receiving anti-hypertensive therapy (P < 0.01) and those who were normotensive (P = 0.067). Circulating levels of β-carotene and α-tocopherol increased in all subjects during supplementation (P < 0.01) and urine nitrite increased in hypertensive patients (P < 0.05). 4. Short-term oral high-dose combination antioxidant therapy reduces blood pressure, possibly via increased availability of nitric oxide. This study may have implications for the innovative use of antioxidants as an adjunct to anti-hypertensive therapy.

Randomized double-blind placebo-controlled study of an angiotensin immunotherapeutic vaccine (PMD3117) in hypertensive subjects

2004 ◽  
Vol 107 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Morris J. BROWN ◽  
John COLTART ◽  
Kulasiri GUNEWARDENA ◽  
James M. RITTER ◽  
Timothy R. AUTON ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Antibody Titre ◽  
Enzyme Inhibitor ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Primary Objective ◽  
Controlled Study ◽  
Double Blind ◽  
Show Evidence

Immunization against components of the renin–angiotensin system offers a potential alternative to daily medication in some patients with hypertension or heart failure. Our primary objective was to determine whether a sustained antibody titre to Ang I (angiotensin I) can be achieved in hypertensive patients. The secondary objective was to determine whether the antibodies block the renin system. Patients (n=27) with essential hypertension responsive to an ACEi (angiotensin-converting enzyme inhibitor) or ARB (angiotensin blocker) were randomly assigned to receive three or four injections of the Ang I vaccine PMD3117 or aluminium hydroxide (Alhydrogel™) over a 6 week period. Antibody titre was measured prior to each injection and every 30 days until disappearance. Indices of renin blockade were changes in renin and aldosterone (blood and urine) and a within-patient comparison of the pre- and post-vaccination rise in 24 h ambulatory blood pressure after 2 weeks of withdrawal of ACEi or ARB. The anti-(Ang I) antibody titre rose from the second injection in both regimes and peaked on day 64. Median half-life was 85 (95% CI, 44 and 153) days (where CI is confidence interval). Vaccination did not influence blood pressure, but significantly blunted the fall in plasma renin following withdrawal of ACEi or ARB. At 42 days after the first injection, aldosterone excretion was decreased by PMD3117 to 6 (95% CI, 1 and 31)% of values in patients receiving Alhydrogel™ (P=0.012). In patients with essential hypertension, PMD3117 generated a prolonged antibody response to Ang I. Biochemical measurements show evidence of blockade of the renin system, but higher titres will be required to achieve a decrease in blood pressure.

scholarly journals Pterostilbene on Metabolic Parameters: A Randomized, Double-Blind, and Placebo-Controlled Trial

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Daniel M. Riche ◽  
Krista D. Riche ◽  
Chad T. Blackshear ◽  
Corey L. McEwen ◽  
Justin J. Sherman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Weight Loss ◽  
Total Cholesterol ◽  
Mixed Models ◽  
Controlled Trial ◽  
Metabolic Parameters ◽  
Controlled Study ◽  
High Dose ◽  
Double Blind ◽  
Over Time

Introduction. The purpose of this trial was to evaluate the effect of pterostilbene on metabolic parameters.Methods. A prospective, randomized, double-blind, and placebo-controlled study that enrolled 80 patients with a total cholesterol ≥200 mg/dL and/orLDL≥100 mg/dL. Subjects were divided into four groups: (1) pterostilbene 125 mg twice daily; (2) pterostilbene 50 mg twice daily; (3) pterostilbene 50 mg + grape extract (GE) 100 mg twice daily; (4) matching placebo twice daily for 6–8 weeks. Endpoints included lipids, blood pressure, and weight. Linear mixed models were used to examine and compare changes in parameters over time. Models were adjusted for age, gender, and race.Results. LDL increased with pterostilbene monotherapy (17.1 mg/dL;P=0.001) which was not seen with GE combination (P=0.47). Presence of a baseline cholesterol medication appeared to attenuate LDL effects. Both systolic (−7.8 mmHg;P<0.01) and diastolic blood pressure (−7.3 mmHg;P<0.001) were reduced with high dose pterostilbene. Patients not on cholesterol medication (n=51) exhibited minor weight loss with pterostilbene (−0.62 kg/m2;P=0.012).Conclusion. Pterostilbene increases LDL and reduces blood pressure in adults. This trial is registered with Clinicaltrials.govNCT01267227.

The Hypotensive Effect of Propranolol in Captopril-Treated Patients Does Not Involve the Plasma Renin—Angiotensin—Aldosterone System

1981 ◽  
Vol 61 (s7) ◽  
pp. 441s-444s ◽  
Author(s):  
J. Staessen ◽  
R. Fagard ◽  
P. Lijnen ◽  
L. J. Verschueren ◽  
A. Amery
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Serum Potassium ◽  
Plasma Renin ◽  
Hypotensive Effect ◽  
Placebo Treatment ◽  
Plasma Aldosterone ◽  
Double Blind ◽  
Plasma Aldosterone Concentration ◽  
Plasma Angiotensin

1. With a double-blind cross-over protocol, 20 hypertensive captopril-treated patients were studied by adding in a variable sequence a placebo and propranolol (80 mg three times a day) to their captopril regimen (200 mg three times a day), during periods each lasting 1 month. During captopril—placebo treatment their diastolic blood pressure remained elevated between 90 and 114 mmHg. 2. The additional administration of propranolol produced a significant hypotensive effect, but no alterations of the plasma angiotensin II and aldosterone concentrations and of the urinary aldosterone excretion occurred. The present data indicate that in captopril-treated patients the hypotensive effect of propranolol is achieved independently of changes in the plasma angiotensin II and aldosterone concentration. 3. The additional administration of propranolol also produced an increase in the serum potassium levels in the absence of any change in the plasma aldosterone concentration or in the urinary aldosterone excretion.

Pressor and subpressor doses of angiotensin II increase insulin sensitivity in NIDDM. Dissociation of metabolic and blood pressure effects

Diabetes ◽  
1994 ◽  
Vol 43 (12) ◽  
pp. 1445-1449 ◽  
Author(s):  
A. D. Morris ◽  
J. R. Petrie ◽  
S. Ueda ◽  
J. M. Connell ◽  
H. L. Elliott ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Angiotensin Ii ◽  
Pressure Effects ◽  
Increase Insulin Sensitivity ◽  
Blood Pressure Effects
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