RESUMO
To evaluate the effect of diet on metabolic control and zinc metabolism in patients with type 2 diabetes mellitus (T2DM). One-week balanced diet was provided to 10 Brazilians patients with T2DM. Nutritional assessment, laboratorial parameters and expression of zinc transporter and inflammatory genes in peripheral blood mononuclear cells (PBMC) were performed. Healthy non-diabetic subjects of the same demographic were recruited to provide baseline data. Diabetic patients had higher body mass index and greater fasting plasma glucose, plasma tumor necrosis factor α (TNFα) and plasma interleukin 6 (IL6) levels compared with healthy subjects. In addition, the expression of transporters 4 (ZnT4) mRNA was lower and IL6 mRNA was higher in PBMC of these diabetic patients than in healthy subject. One week after a balanced diet was provided, fasting plasma glucose decreased significantly as did TNFα, IL6 and Metallothionein 1 (MT1) mRNAs. No change was observed in zinc transporter expression in PBMC after the dietary intervention. A healthy eating pattern maintained for one week was able to improve metabolic control of diabetic patients by lowering fasting plasma glucose. This metabolic control may be related to down-regulation of zinc-related transcripts from PBMCs, as TNFα, IL6 and MT1 mRNA.
RESUMO
The recognized antagonistic actions between zinc and iron prompted us to study this subject in children. A convenience sample was used. Thirty healthy children between 8 and 9 years of age were studied with the aim of establishing the effect of a 3-mo oral zinc supplementation on iron status. Fifteen individuals were given a placebo (control group), and 15 were given 10 mg Zn/day (experimental group). Blood samples were collected at 0, 60, 120, 180 and 210 min after a 12-h overnight fast, before and after placebo or zinc supplementation. This supplementation was associated with significant improvements in energy, protein, fat, carbohydrate, fiber, calcium, iron, and zinc intake in accordance with the recommendations for age and sex. The basal serum zinc concentration significantly increased after oral zinc supplementation (p < 0.001). However, basal serum iron concentrations and area under the iron curves significantly decreased in the experimental group (p < 0.0001) and remained at the same level throughout the 210-min study. The values obtained for hemoglobin, mean corpuscular volume, ferritin, transferrin, transferrin saturation, ceruloplasmin and total protein were within normal reference ranges. In conclusion, the decrease in serum iron was likely due to the effects of chronic zinc administration, and the decrease in serum iron was not sufficient to cause anemia.
