Cardiologists at UT Southwestern Medical Center have found that sedentary behavior is associated with increased amounts of calcium deposits in heart arteries, which in turn is associated with a higher risk of heart attack.Researchers at UT Southwestern have previously shown that excessive sitting is associated with reduced cardiorespiratory fitness and a higher risk of heart disease. The latest research – part of UT Southwestern’s Dallas Heart Study – points to a likely mechanism by which sitting leads to heart disease.“This is one of the first studies to show that sitting time is associated with early markers of atherosclerosis buildup in the heart,” said senior author Dr. Amit Khera, Associate Professor of Internal Medicine and Director of the Preventive Cardiology Program. “Each additional hour of daily sedentary time is associated with a 12 percent higher likelihood of coronary artery calcification.”