RISK-FACTORS FOR EXERCISE-INDUCED SILENT-MYOCARDIAL-ISCHEMIA IN HEALTHY-VOLUNTEERS

This study determined the risk factors for exercise-induced silent isc hemia (SI) in 281 apparently healthy volunteers aged 40 to 87 years an d compared their risk factor profiles with those of 132 patients with overt coronary artery disease (CAD). SI (concordant exercise-induced a symptomatic ST-segment depression on electrocardiography and perfusion defects on tomographic thallium-201 scintigraphy) was detected in 37 of 225 men (16%), versus 2 of 56 women (4%, p <0.05). The prevalence o f SI increased with age from 6% in men aged <55 years to 18% in men ag ed 55 to 70 years, and to 25% in men aged >70 years (p <0.001). Compar ed with the 118 men with concordant normal exercise electrocardiogram and thallium scan (normals), men with SI were older (p <0.001), and ha d a higher waist-to-hip ratio (p <0.005), higher plasma triglyceride l evels (p <0.001), and lower high-density lipoprotein (HDL) cholesterol levels (p <0.001). In stepwise logistic regression analysis, age, wai st-to-hip ratio, and HDL levels were independent predictors of SI in m en. Compared with 108 men with overt CAD, men with SI were younger (67 +/- 2 vs 73 +/- 1 years, p <0.001) but had similar plasma lipids and waist-to-hip ratio. Thus, older age, male gender, abdominal obesity, a nd reduced HDL levels-all well-established risk factors for overt CAD- were risk factors for exercise-induced SI in these asymptomatic volunt eers.