IGF1 and chronic obstructive pulmonary disease: Twenty-five serum analytes were significantly elevated by ≥ 50% (FDR < 0.05 and fold/control > 1.50) in the COPD cohorts relative to healthy controls for each of the 4 comparisons, whereas 2 analytes (insulin-like growth factor [IGF]-1 and immunoglobulin [Ig]E) were significantly lower by ≥ 50% in the COPD cohorts (Table 2, Figure 1).