CHICAGO — Low bone mineral density was associated with exercise-induced myocardial ischemia in a retrospective analysis of more than 1,000 patients.
These are the first study results to show a link between bone mineral density (BMD) and exercise-induced ischemia using exercise echocardiography, Dr. Aaron M. From and his associates said in a poster presented at the annual scientific sessions of the American Heart Association.
Results from prior studies had linked low BMD and an increased risk of stroke, atherosclerosis, and cardiovascular death, said Dr. From, a physician at the Mayo Clinic in Rochester, Minn.
The analysis included all patients who underwent dual-energy x-ray absorptiometry of the femoral neck at the Mayo Clinic during August 1998-October 2003 who also had an exercise echocardiography examination soon after the bone scan. The researchers identified 1,142 patients who fulfilled these criteria. All of the patients were referred for both studies by their physicians.
The group included a total of 643 patients with low BMD, including 126 with osteoporosis and 517 with osteopenia. The remaining 499 patients had BMDs in the normal range. The most common reason for the exercise echo examination was chest pain/dyspnea, in 57% of the patients; 6% had known coronary artery disease.
The analysis showed that patients with the lowest BMD (a T score of -4 to -3) had the shortest exercise duration, 5.8 minutes, while patients with the highest T scores (+1 to +2) had the longest exercise duration, 8.9 minutes.
In a multivariate analysis that controlled for baseline clinical and demographic differences, the risk of having exercise-induced ischemia rose by 22% for every one-point decrease in T score (representing one standard-deviation decrease in T score) a statistically significant difference, Dr. From and his associates reported in the poster.