Magnesium-deficient high-fat diet: Effects on adiposity, lipid profile and insulin sensitivity in growing rats

Author(s)

Sales, Cristiane Hermes ^[1] ; dos Santos, Adriana Rodrigues ^[1] ; Correa Cintra, Dennys Esper ^[2] ; Colli, Celia ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Food & Expt Nutr, BR-05508000 Sao Paulo - Brazil

^[2] Univ Estadual Campinas, Fac Sci Appl, BR-13083887 Limeira, SP - Brazil

• Document type: Journal article
• Source: Clinical Nutrition; v. 33, n. 5, p. 879-888, OCT 2014.
• Web of Science Citations: 15

Abstract

Background \& aims: To determine if magnesium deficiency aggravates the effects of a high-fat diet in growing rats in terms of obesity, lipid profile and insulin resistance. Methods: The study population comprised 48 newly weaned male Wistar Hannover rats distributed into four groups according to diet, namely, control group (CT; n = 8), control diet provided ad libitum; pair-feeding control group (PF; n = 16), control diet but in the same controlled amount as animals that received high-fat diets; high-fat diet group (HF; n = 12), and magnesium-deficient high-fat diet group (HFMg-; n = 12). The parameters investigated were adiposity index, lipid profile, magnesium status, insulin sensitivity and the phosphorylation of proteins involved in the insulin-signaling pathway, i.e. insulin receptor beta-subunit, insulin receptor substrate 1 and protein kinase B. Results: The HF and HFMg- groups were similar regarding gain in body mass, adiposity index and lipid profile, but were significantly different from the PF group. The HFMg- group exhibited alterations in magnesium homeostasis as revealed by the reduction in urinary and bone concentrations of the mineral. No inter-group differences were observed regarding glucose homeostasis. Protein phosphorylation in the insulin-signaling pathway was significantly reduced in the high-fat groups compared with the control groups, demonstrating that the intake of fat-rich diets increased insulin resistance, a syndrome that was aggravated by magnesium deficiency. Conclusions: Under the experimental conditions tested, the intake of a magnesium-deficient high-fat diet led to alterations in the insulin-signaling pathway and, consequently, increased insulin resistance. (C) 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. (AU)

• FAPESP's process: 09/05624-7 - Effect of dietary magnesium deficiency in the insulin resistance and in the inflammatory response in rats fed with high-fat diet
• Grantee: Cristiane Hermes Sales
• Support Opportunities: Scholarships in Brazil - Doctorate