Here we present in a population of 81 overweight and obese yet normoglycemic subjects that (1) independent of sex, obesity and body composition, plasma apoB was positively associated with hyperinsulinemia, IR and plasma IL-1Ra and (2) the association of plasma apoB to hyperinsulinemia and IR was eliminated when adjusted for plasma IL-1Ra suggesting the involvement of an activated IL-1 family. The gene discussed is APOB; the disease is obesity due to melanocortin 4 receptor deficiency.