Efeito da suplementação de zinco sobre a resistência à insulina e os parâmetros glicêmicos: revisando as evidências científicas

Abstract

Insulin resistance is a metabolic disorder characterized by a reduction in insulin sensitivity in adipose, muscle and liver tissues, originated from genetic and environmental factors. Zinc supplementation appears to have a promising effect on insulin resistance. Thus, this study aimed to review the effects of zinc supplementation on insulin resistance, as well as on glycemic and insulinemic parameters in pre-diabetic, diabetic and obese individuals. The study were carried out in the Pubmed, Web of Science and Scopus databases, in the last 20 years, using the keywords: insulin-resistance, zinc supplementation obesity, zinc supplementation insulin resistance, zinc supplementation prediabetes, zinc and insulin resistance, zinc. A critical analysis and evaluation of the articles was carried out using the Jadad scale, including those with a score greater than two. Sixteen articles were included, in which it was observed that the dose ranged from 20 mg to 660 mg, with more effective results in doses less than or equal to 50 mg. Zinc supplementation reduced insulin resistance in most studies, regardless of duration, particularly in pre-diabetic and obese patients. The effect of supplementation on fasting blood glucose results were not conclusive, since only half of the studies in diabetics observed improvement. The effect of supplementation on serum HbA1c levels has been demonstrated in a few studies. The improvement in basal insulin levels was more promising in obese people. Zinc proved to be a therapeutic alternative in the management of insulin resistance, although further studies are required to define the doses and duration of supplementation.