ABSTRACT
The relationship between zinc and the metabolism of carbohydrates has generally been linked to lipids and insulin. This chapter discusses the effects of zinc deficiency on hexose absorption and interactions of zinc with insulin in relation to glucose tolerance. Zinc-deficient rats have been shown to have impaired glucose tolerance. In fasted zinc-deficient rats, however, plasma glucose and insulin were essentially normal. The impaired glucose tolerance was later suggested to be related to insulin resistance in the presence of elevated plasma levels of free fatty acids. Impaired glucose tolerance in zinc-deficient rats was also demonstrated to be dependent on the dietary carbohydrate source, starch, causing much greater impairment than sucrose. In view of the possible zinc depletion in noninsulin-dependent diabetic mice, a physiologically important interaction of zinc with insulin, perhaps at the insulin receptor, may exist, which controls glucose uptake by adipocytes.
