16. Any of the following concurrent severe and/or uncontrolled medical conditions which could compromise participation in the study: Uncontrolled high blood pressure (systolic blood pressure >/= 140 and diastolic blood pressure >/= 90), history of labile hypertension, or history of poor compliance with an antihypertensive regimen. Unstable angina or stable angina markedly limiting ordinary physical activity. (Angina occurs on walking one to two blocks on the level and climbing one flight of stairs in normal conditions and at a normal pace) .