Zinc status in plasma of obese individuals during glucose administration.

To know whether plasma zinc status is altered under acute hyperglycemic state, the interrelationships among plasma glucose, insulin, and zinc concentrations during oral glucose tolerance test (OGTT) in obese individuals and their lean controls were studied. Plasma glucose and insulin concentrations under fasting as well as those values in response to OGTT were significantly higher in obese individuals than those in lean controls. On the other hand, the obese had lower fasting plasma zinc concentrations compared to lean controls (13.5 vs 18.1 mumol/L, p < 0.005). Under fasting, plasma zinc concentrations in overall individuals inversely correlated to their body mass index (BMI) (r = -0.516), plasma glucose (r = -0.620), and plasma insulin (r = -0.510). However, there were no significant changes in plasma zinc and copper values during OGTT in both obese individuals and lean controls. This study showed that plasma zinc values had no changes during OGTT in obese individuals. The results also indicated that lower fasting plasma zinc concentrations in obese individuals were not the short-term metabolic result.