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Treatment with Sildenafil Improves Insulin Sensitivity in Prediabetes: A Randomized, Controlled Trial

Claudia E. Ramirez, Nian Hui, Chang Yu, J. Gamboa, J. M. Luther, N. Brown, C. Shibao

Journal of Clinical Endocrinology and Metabolism, 2015

69 citations

Abstract

CONTEXT: Sildenafil increases insulin sensitivity in mice. In humans, phosphodiesterase 5 inhibition improves disposition index, but the mechanism of this effect has not been elucidated and may depend on duration. In addition, increasing cyclic GMP without increasing nitric oxide could have beneficial effects on fibrinolytic balance.

OBJECTIVE: The objective was to test the hypothesis that chronic phosphodiesterase 5 inhibition with sildenafil improves insulin sensitivity and secretion without diminishing fibrinolytic function.

DESIGN: This was a randomized, double-blind, placebo-controlled study.

SETTING: This trial was conducted at Vanderbilt Clinical Research Center.

PARTICIPANTS: Participants included overweight individuals with prediabetes.

INTERVENTIONS: Subjects were randomized to treatment with sildenafil 25 mg three times a day or matching placebo for 3 months. Subjects underwent a hyperglycemic clamp prior to and at the end of treatment.

MAIN OUTCOME MEASURES: The primary outcomes of the study were insulin sensitivity and glucose-stimulated insulin secretion.

RESULT: Twenty-one subjects completed each treatment arm. After 3 months, the insulin sensitivity index was significantly greater in the sildenafil group compared to the placebo group by 1.84 mg/kg/min per μU/mL*100 (95% confidence interval, 0.01 to 3.67 mg/kg/min per μU/mL*100; P = .049), after adjusting for baseline insulin sensitivity index and body mass index. In contrast, there was no effect of 3-month…

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Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

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