Effect of serum zinc and copper levels on insulin secretion, insulin resistance and pancreatic β cell dysfunction in US adults: Findings from the National Health and Nutrition Examination Survey (NHANES) 2011-2012.

AIM:To compare zinc (Zn) and copper (Cu) levels in US adults with normoglycemia, prediabetes and diabetes, and study the association of serum Zn and Cu levels with pancreatic β cell insulin secretion, pancreatic dysfunction and insulin resistance in US adults with normoglycemia and prediabetes. METHOD:Homeostatic Model Assessment (HOMA2) calculator was used to compute estimates of steady state β cell insulin secretion (HOMA2-B), peripheral insulin sensitivity (HOMA2-S), insulin resistance (HOMA-IR), and disposition index (HOMA-DI) in 804 adult individuals from the National Health and Nutrition Examination Survey (NHANES 2011-2012). RESULTS:There was no significant difference between serum Zn and Cu levels among subjects with normoglycemia, prediabetes, and diabetes. After adjusting for multiple possible confounders, higher serum Zn concentrations were associated with lower β cell insulin secretion (HOMA2-B; p = 0.01) and lower insulin resistance (HOMA-IR; p = 0.04) in the prediabetic subjects. In normoglycemic group, higher serum Zn levels were associated with improved pancreatic function (HOMA-DI; P = 0.02). On the other hand, higher serum Cu levels were associated with increased β cell insulin secretion (HOMA2-B, P = 0.03) only in the subjects with prediabetes. CONCLUSION:These findings support the need for further studies to investigate the role of trace elements in diabetes pathogenesis.