trandolapril and Hyperinsulinism

Angiotensin-converting enzyme (ACE) inhibitors are increasingly used as first-line therapy for hypertension in type 2 diabetes mellitus and are widely believed to improve insulin sensitivity (M). However, the evidence for the latter effect does not stand close scrutiny. We have assessed the effect of the ACE inhibitor trandolapril on M in 16 patients (mean +/- SD age, 58 +/- 10.6 yr) with mild-to-moderate essential hypertension (initial blood pressure, 173 +/- 14.5/93 +/- 8.0 mm Hg), obesity (body mass index, 30 +/- 5.4 kg/m2), and impaired glucose intolerance (n = 4) or type 2 diabetes (n = 12) in a double-blind, placebo-controlled crossover design. All patients underwent three 3-h euglycemic hyperinsulinemic clamp studies (soluble insulin, 1.5 mU/kg x min) after a 2-week placebo run-in and at the end of two 4-week periods of treatment with 2 mg trandolapril or placebo (2-week washout). M (mean +/- SD) did not change with trandolapril: placebo (run-in), 5.2 +/- 1.98 mg/kg x min; placebo, 5.3 +/- 1.70 mg/kg x min; trandolapril, 5.1 +/- 1.65 mg/kg x min; P = 0.58; 95% confidence intervals, -0.74, 0.43 (trandolapril vs. placebo); 95% power to exclude an 8% increase in M. In conclusion, trandolapril had no clinically relevant effect on M in patients with hypertension and type 2 diabetes. Previous reports of improved M during ACE inhibitor treatment may be attributable to suboptimal study design and/or use of surrogate measures of M.

Topics: Adult; Aged; Aldosterone; Angiotensin-Converting Enzyme Inhibitors; Blood Glucose; Blood Pressure; Cross-Over Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Double-Blind Method; Female; Glucose; Glucose Clamp Technique; Heart Rate; Humans; Hyperinsulinism; Hypertension; Indoles; Insulin; Male; Middle Aged; Peptidyl-Dipeptidase A; Placebos; Renin

In view of the demonstrated interaction between endothelin and the renin-angiotensin system, the antihypertensive effect of combined therapy with an endothelin antagonist LU-135252 and the angiotensin converting enzyme inhibitor trandolapril, was studied in fructose-induced hypertensive, hyperinsulinemic, hypertriglyceridemic male Sprague-Dawley rats.. Forty animals were fed a fructose-enriched diet (Tekled, Harlan) for 5 weeks, as follows: group A, fructose only; group B, trandolapril 0.1 mg/kg/day added during the last 2 weeks; group C, LU-135252 100 mg/kg/day added during the last 2 weeks; group D, both trandolapril and LU-135252 added the last 2 weeks. Systolic blood pressure (BP) was measured weekly in conscious rats by the indirect tail-cuff method. Blood samples from a retro-orbital sinus puncture were taken at the beginning of the experiment and after 3 and 5 weeks and examined for insulin and triglyceride concentrations.. Systolic BP decreased in group B (trandolapril) from 148.8 +/- 9.8 at 3 weeks to 138.3 +/- 8.7 mm Hg after 5 weeks; in group C (endothelin antagonist) from 155.1 +/- 5.5 to 142.5 +/- 10.6 mm Hg; and in group D (combination) from 154.6 +/- 10.9 to 121.2 +/- 8.9 mm Hg. Triglyceride levels decreased only in the combined trandolapril/endothelin antagonist group from 167.6 +/- 55.3 in the third week to 134.9 +/- 53.7 mg/dL after 5 weeks. Insulin levels decreased only on combination therapy from 7.4 +/- 3.6 to 5.3 +/- 3.8 ng/mL during the same period. The BP decrease was additive compared with the respective individual substances.. The trandolapril/endothelin antagonist combination appears to offer a rational antihypertensive combination that is superior to that of either drug alone. This finding applies to the specific rat model studied in which BP, insulin, and triglycerides were increased by fructose diet.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Drug Synergism; Endothelin Receptor Antagonists; Fructose; Hyperinsulinism; Hypertension; Hypertriglyceridemia; Indoles; Insulin; Male; Phenylpropionates; Pyrimidines; Rats; Rats, Sprague-Dawley; Time Factors; Triglycerides