Improvements of the lipoprotein profile after coronary bypass surgery: additional effects of an exercise training program

We have followed physical working capacity and the plasma lipoprotein pattern in 37 males who underwent coronary artery surgery for severe disabling angina pectoris. In order to evaluate the effect of exercise training, 18 patients were randomized to a supervised bicycle training programme three times a week for 12 weeks starting 6 weeks after surgery. Before surgery, working capacity was severely reduced in all subjects. The mean HDL cholesterol level was low (0.8 ± 0.2 mmol l-1) and the mean plasma LDL concentration moderately elevated (4.6 ± 0.9 mmol l-1). In the non-training group, physical working capacity increased significantly, and 18 weeks after surgery reached a plateau about 45% above the preoperative values. In the training group, a further improvement to about 60% above preoperative levels was registered at the end of the training program. In the non-training group, HDL cholesterol concentrations rose rapidly to levels between 10 and 15% above the preoperative values. One year after surgery, HDL cholesterol levels were 20% higher than before surgery. There was a parallel rise in apolipoprotein A1 concentrations by about 10% which indicates that the increase in HDL occurred mainly in the lipidrich HDL2 subfraction. There were no changes in plasma lipids or in LDL cholesterol concentrations. In the training group, the increase in HDL was about 20% during the first 26 weeks. One year after surgery, HDL levels were 23% above preoperative values. In this group, we also registered a significant decrease in plasma triglyceride levels by about 25% after two months of exercise. We conclude that patients with advanced coronary artery disease have low physical working capacity and severe derangements in plasma lipoprotein patterns. Coronary artery surgery leads to rapid, marked improve–ments in several physiological and biochemical variables. A short–term training program after surgery may enhance the physiological and metabolic improvements that occur spontaneously after surgery.