Portal de Periódicos da CAPES

Artigo Produção Nacional Revisado por pares

BIBTEX RIS

Zinc pharmacokinetics in insulin-dependent diabetes mellitus patients after oral zinc tolerance test

2003; Elsevier BV; Volume: 23; Issue: 2 Linguagem: Inglês

10.1016/s0271-5317(02)00493-1

1879-0739

José Brandão‐Neto, Carlos A.B. Silva, Adriana Augusto de Rezende, Maria das Graças Almeida, Valéria Sf Sales, Júlio Sérgio Marchini,

Pharmacological Effects and Toxicity Studies

Zinc is an essential micronutrient that is directly involved in the physiology of insulin, and zinc metabolism could play a role in the pathogenesis of diabetes mellitus and its complications. On the other hand, low zinc absorption and hyperzincuria in diabetic animals and humans have indicated that diabetics are more susceptible to zinc deficiency. This study was designed to compare zinc metabolism in ten insulin-dependent diabetic patients with ten healthy controls, using an oral zinc tolerance test. Pharmacokinetic parameters were performed to study intestinal zinc absorption and urinary zinc excretion. Absorption of zinc was extensive during the first two hours after administration of a single oral dose of 25 mg Zn++. The area under the serum zinc curve (AUC) and maximum concentration of zinc (Cmax) did not differ in both control and experimental groups, p < 0.05. In addition, absorption rate constant (Ka), elimination rate constant (Kel), absorption half-life (T1/2a), elimination half-life (T1/2el), and time of maximum concentration (Tmax) were not significantly different between the diabetic patients and controls (p > 0.05). All these kinetic parameters suggest that there is no malabsorption of zinc in diabetic patients. Conversely, zinc clearance/creatinine clearance ratio (CZn++/Ccr ratio) in diabetic patients differed significantly in comparison to controls, p < 0.05, indicating renal dysfunction in these patients. We conclude that a single oral dose of zinc can be used to investigate zinc absorption and zinc clearance, and that diabetic patients have a specific normal gastrointestinal function and renal dysfunction in terms of zinc clearance.