<qa>  What is the minimum blood pressure for volunteers?- If a person has been found to have elevated blood pressure or hypertension during screening or previously, exclude for blood pressure that is not well controlled. Well-controlled blood pressure is defined as consistently less than or equal to 140 mm Hg systolic and less than or equal to 90 mm Hg diastolic, with or without medication, with only isolated, brief instances of higher readings, which must be less than or equal to 150 mm Hg systolic and less than or equal to 100 mm Hg diastolic. For these volunteers, blood pressure must be less than or equal to 140 mm Hg systolic and less than or equal to 90 mm Hg diastolic at enrollment. 