Sedentary Lifestyle Increased Coronary Artery Calcification

Results from a new study suggest that increasing sedentary time may be associated with coronary artery calcification (CAC), independent of exercise activity and traditional cardiovascular disease (CVD) risk factors.

The study data were presented at the American College of Cardiology (ACC) Scientific Sessions 2015.

“It’s clear that exercise is important to reduce your cardiovascular risk and improve your fitness level,” lead study author Jacquelyn Kulinski, MD, from the Medical College of Wisconsin, Milwaukee, in a press release. “But this study suggests that reducing how much you sit every day may represent a more novel, companion strategy (in addition to exercise) to help reduce your cardiovascular risk.”

For the Dallas Heart Study, Dr. Kulinski and fellow researchers included 2,031 patients (62% women; mean age, 50 years) who were free of known CVD and had accelerometer-measured physical activity (≥4 days) and computed tomography-assessed CAC scoring.

Patients spent a mean of 5.1 hours in sedentary time — defined as an intensity threshold of <100 counts-per-minute (CPM) — during waking hours. Moderate-to-vigorous physical activity (MVPA) was defined as >1,500 CPM, according to established intensity thresholds.

Researchers assessed the association between sedentary time and CAC prevalence (CAC >10) and continuous CAC score.

After adjusting for covariates, there was no association between MVPA and CAC, whereas sedentary time was associated with CAC >10 (OR=1.1 per hour; P<.05) in multivariable analysis that adjusted for MVPA. With each hour of sedentary time, researchers reported a 14% increase in CAC (P<.05).

Predictors of higher sedentary time included older age, higher BMI, diabetes and hypertension.

Dr. Kulinski noted that the study emphasizes the importance of moving as much as possible throughout the day, and suggests taking walks during lunch, pacing while talking on the phone, taking the stairs instead of the elevator and using a pedometer to track daily steps, as ways to decrease sedentary time.

“The study offers a promising message: Reducing the amount of time you sit by even an hour or 2 a day could have a significant and positive impact on your future cardiovascular health,” Dr. Kulinski said, adding that future studies should further investigate this.

Reference

1. Kulinski J et al. Abstract 1178-114. Presented at: American College of Cardiology (ACC) 64th Scientific Session & Expo; March 14-16, 2015; San Diego.