Gestational Hyperglycemia, Zinc, Selenium, and Antioxidant Vitamins

Objective: Lower levels of selenium and vitamin E have been described in gestational diabetes, a condition similar to type 2 diabetes, but few data are available about zinc (known to be associated with diabetes) and gestational hyperglycemia. This study evaluated the dietary intake of antioxidant vitamins, zinc, selenium, and serum levels of zinc and selenium in women with gestational hyperglycemia and normoglycemia.

Methods: A food-frequency questionnaire was administered to 504 pregnant women (210 with hyperglycemia and 294 with normoglycemia). Serum levels of zinc and selenium were analyzed during pregnancy in a second cohort of 71 hyperglycemic and 123 normoglycemic women, with a mean age and body mass index similar to those in the first cohort.

Results: Dietary intakes of zinc and selenium were significantly lower in hyperglycemic patients. In multiple logistic regression analysis, intakes were negatively associated with gestational hyperglycemia (odds ratios of 0.89 for zinc and 0.97 for selenium) after multiple adjustments. There were no significant differences in vitamin intakes. In the second cohort of 194 patients, serum levels of zinc and selenium were significantly lower in patients who had impaired glucose tolerance and negatively associated with gestational hyperglycemia in a multiple logistic regression model (odds ratios of 0.93 for serum zinc and 0.92 for serum selenium).

Conclusions: Our data suggested a significant inverse association of dietary intakes and serum levels of zinc and selenium with gestational hyperglycemia. If future studies confirm these results, it might be a useful interventional approach to appropriate dietary counseling in order to evaluate the possible decrease in gestational metabolic abnormalities and their adverse consequences.