Cross-sectional associations between plasma copper, zinc and prediabetes among rural Indian adolescent girls: baseline data from the DERVAN cohort (DERVAN-8)

Copper and zinc are essential minerals for proper metabolic function, and their imbalance could potentially cause prediabetic conditions. We investigated associations of copper and zinc with glycaemic parameters in 1473 adolescent girls (age 15–18 years) at the baseline in a longitudinal DERVAN (aDolescent and prEconception health peRspectiVe of Adult Non-communicable diseases) cohort study. We also measured anthropometric and obesity indices. In addition, glucose, insulin and glycated haemoglobin were measured in serum, and prediabetes was diagnosed according to the American Diabetes Association criteria. Insulin resistance, β-cell function and insulin sensitivity were estimated using the homeostasis model. The median age of girls was 16.6 years. Prevalence of deficiency was 11.6% for copper and 13.6% for zinc, and 38.6% were prediabetic. Copper was associated positively with fasting glucose, insulin, and insulin resistance, and inversely with insulin sensitivity. Zinc was associated positively with fasting glucose and inversely with β-cell function. In a multivariate analysis containing quartiles of both copper and zinc, girls in the third and fourth quartiles of plasma copper had significantly higher odds ratios (1.810 and 2.188, respectively) for prediabetes, thus demonstrating their positive link with prediabetes. Longitudinal follow-up of this cohort will demonstrate whether these trace minerals play any role in progression to diabetes.