SEOUL NATIONAL UNIVERSITY HOSPITAL

- Seoul National University Hospital, large-scale analysis of 8,225 diabetic patients undergoing percutaneous coronary intervention

- Optimal exercise of 1,000-1,499 MET-min per week. However, excessive exercise reduces the positive effect.

Patients with diabetes who consistently maintained aerobic exercise before and after percutaneous coronary intervention had a 22% reduced risk of cardiovascular events (death, myocardial infarction, revascularization, and heart failure) compared to patients who did not exercise at all. In particular, patients who started exercising again after the procedure or even those who only exercised before the procedure also showed risk reduced by approximately 10%. However, this effect was decreased with excessive exercise, thus it appears that patients with diabetes should consistently maintain an appropriate amount of aerobic exercise to improve their cardiovascular disease prognosis.

 

On April 17, Professor Han Jung-Kyu’s team at the Department of Cardiology at Seoul National University Hospital (with Professor Han Kyungdo of Soongsil University) reported these findings after analyzing aerobic exercise habits and cardiovascular outcomes in diabetic patients who underwent percutaneous coronary intervention.

 

Coronary artery disease is a disease in which the coronary arteries that supply blood to the heart become narrowed or blocked, and diabetes is a major factor that increases the risk of this disease. Percutaneous coronary intervention (PCI) is performed to widen the narrowed blood vessels for treatment. However, diabetic patients have a poor prognosis, as they are prone to restenosis even after the procedure. Therefore, continuous exercise is important to improve diabetes and cardiovascular disease. According to the current guidelines, patients with diabetes are recommended to engage in moderate-to-high intensity aerobic exercise for at least 150 minutes per week, and patients with cardiovascular disease are recommended to engage in moderate-intensity aerobic exercise for at least 150 minutes per week or high-intensity exercise for at least 75 minutes per week.

 

Based on national health examination data, the research team divided 8,225 diabetic patients who underwent percutaneous coronary intervention between 2009 and 2012 into the control group (exercise X → exercise X), start group (exercise X → exercise O), stop group (exercise O → exercise X) and continuation group (exercise O → exercise O) according to changes in aerobic exercise habits. After that, the propensity score weighting (IPW) model was applied to adjust for variables such as age, underlying disease and medication, and the patients were followed up for an average of 4.9 years.

 

As a result of comparing the risk of major cardiovascular events (MACE, all-cause death, myocardial infarction, revascularization and heart failure), the risk in the continuous aerobic exercise group was reduced by 22% compared to the control group. The risk in the stop and start groups was also reduced by 12% and 11%, respectively.

 

Additionally, the cardiovascular events protective effect of exercise decreased when excessive aerobic exercise was performed. As a result of analyzing the weekly exercise amount (exercise intensity (MET*) × exercise time (min)) and treatment outcome, a J-curve relationship was shown in which the risk of cardiovascular events was lowest at 1000–1499 MET-min and increased again from 1500 MET-min or more. ‘More than 1500 MET-min per week’ means about 6 hours or more of moderate-intensity exercise (brisk walking, tennis, etc.) or about 3.5 hours or more of high-intensity exercise (running, aerobics, mountain climbing, etc.) per week. In other words, if the exercise guideline level for patients with diabetes and cardiovascular disease is exceeded by 1.5-2 times, the positive effects of aerobic exercise may decrease.

*MET (Metabolic equivalents of task): Exercise intensity measured by metabolic rate and energy expenditure. Low-intensity exercise can be converted into 2.9 METs, moderate-intensity exercise into 4 METs, and high-intensity exercise into 7 METs.

Prof Han Jung-Kyu said, “This is the first large-scale population-based study to demonstrate that diabetic patients who have undergone percutaneous coronary intervention can improve their cardiovascular outcomes through regular exercise after the procedure. In particular, patients who resumed aerobic exercise after the procedure or those who exercised only before the procedure showed a better prognosis than the control group that did not exercise at all, further confirming the positive effects of aerobic exercise.”

[Pictures from left] Professor Han Jung-Kyu from SNUH Department of Cardiovascular Medicine and Professor Han Kyungdo from Soongsil University