Plasma malondialdehyde in coronary patients and in "normal" people at rest and after exercise.

The behavior of plasma lipid peroxides, expressed as plasma malondialdehyde, was studied in 27 patients with documented coronary artery disease and 17 volunteers without coronary artery disease (henceforth designated "normal"), after a standardized exercise on a bicycle ergometer. In the control group, the basal values of malondialdehyde were significantly lower than in coronary patients. Persons in the control group did not show any significant variation of malondialdehyde after exercise and recovery, whereas patients with coronary artery disease showed malondialdehyde levels significantly higher than the baseline, both after exercise and after recovery. In the control group, a significant inverse correlation between the malondialdehyde variations during the exercise and the total work produced was ten times lower than in coronary patients. It seems probable that the higher levels of lipid peroxides in these patients may leave some long-term unwanted effects. Furthermore, the increased values of lipid peroxides after exercise may be regarded as a possible trigger of fatal myocardial malfunction occurring during physical activity.