Compared to its concentration in the healthy subjects [133.2 (124–164.5)] ng/ml), plasma IGF-I was significantly lower in COPD patients on D1 of the exacerbation and remained lower on D15 [59.7 (44.3–76)] ng/ml, p <0.001 and [96.6 (82.9–116.8)] ng/ml, p < 0.001 respectively versus healthy subjects). Here, IGF1 is linked to chronic obstructive pulmonary disease.