Similarly, the difference in GH between COPD patients and controls was, on average, 0.42 ng/mL, indicating that the biological age of a COPD patient is, on average, about 0.42/0.032 = 13.1, that is, 13.1 years older than that of a control subject of the same age (Figure 4 and Figure 5). This evidence concerns the gene GH1 and chronic obstructive pulmonary disease.