Influence of zinc on insulin sensitivity in rats fed with high sucrose and fat diet

Objective To investigate the effect of different dose of zinc on insulin sensitivity in rats fed with high sucrose and fat diet.Methods Totally 68 healthy male Sprague-Dawley rats were randomly allocated to two groups:normal diet group(n=29) and high-sucrose-fat diet group(n=39).After 17 weeks,the rats of the two groups were randomly assigned to five groups,each group was administered with distilled water or zinc at dose of 5,10,15 or 30 mg/kg daily by gavage for 7 weeks.Fasting plasma glucose,fasting plasma insulin(FINS) and glycohemoglobin(HbA₁c) were detected.Then the homeostasis model assessment for insulin resistant(HOMA-IR) and insulin sensitiveiy index(ISI) of each group were calculated.Results Compared with normal diet group,the glucose of high-sucrose-fat diet groups was insignificantly different before or after the gavage.FINS and HOMA-IR were significantly increased among high-sucrose-fat diet groups after zinc administration(P<0.05),while the FINS for the group of 10 mg zinc was 13.574± 2.297 μIU/ml and that of 15 mg zinc group was 11.050± 1.654 μIU/ml,both lower than other zinc level groups(P<0.05).ISI were significantly decreased among high-sucrose-fat diet groups after zinc administration,and that for the group with 15 mg zinc gavage was-1.733± 0.07530,significantly lower than that of other groups(P<0.05).Conclusion Zinc could at some degree improve insulin sensitivity in rats fed with high-sucrose-fat diet,depending on the dose.