The purpose of a study by Maltais et al. (A-29) was to compare and correlate the increase in arterial lactic acid (La) during exercise and the oxidative capacity of the skeletal muscle in patients with chronic obstructive pulmonary disease (COPD) and control subjects (C). There were nine subjects in each group. The mean age of the patients was 62 years with a standard deviation of 5.

Control subjects had a mean age of 54 years with a standard deviation of 3. Among the data collected were the following values for the activity of phosphofructokinase (PFK), hexokinase

(HK), and lactate dehydrogenase (LDH) for the two groups:

PFK HK LDH C COPD C COPD C COPD 106.8 49.3 2.0 2.3 241.5 124.3 19.6 107.1 3.2 1.4 216.8 269.6 27.3 62.9 2.5 1.0 105.6 247.8 51.6 53.2 2.6 3.6 133.9 200.7 73.2 105.7 2.4 1.3 336.4 540.5 89.6 61.3 2.4 2.9 131.1 431.1 47.7 28.2 3.5 2.2 241.4 65.3 113.5 68.5 2.2 1.5 297.1 204.7 46.4 40.8 2.4 1.6 156.6 137.6