Sedentary time ups coronary artery calcification risk

Prolonged sedentary time increases the likelihood of a positive coronary artery calcium score (CACS), reports a recent Korea study.

“CACS is also an effective screening tool for predicting future cardiovascular events in asymptomatic patients,” the researchers said. “Therefore, CACS can be an effective method for predicting coronary artery diseases in people with prolonged sedentary time, especially in metabolically healthy people.”

A total of 14,949 men (mean age 37.3 years) with negative CACS at baseline participated in this cohort study and were grouped according to daily sedentary time: <7 hours (n=3,646), 7–8 hours (n=3,205), and ≥9 hours (n=8,089). Cardiac tomography was used to calculate CACS. All participants were followed up at least once.

Over 60,112.1 person-years of follow-up, 569 incident cases of positive CACS were reported, yielding an incidence rate of 9.5 per 1,000 person-years.

Multivariable regression analysis revealed a significant interaction between sedentary time and CACS score positivity, such that men with ≥9 vs <7 hours/day of sedentary timer were nearly 30 percent more likely to show such outcome (hazard ratio [HR], 1.28, 95 percent confidence interval [CI], 1.03–1.59; p_trend=0.036).

The same remained true when sedentary time was taken as a continuous variable. Each additional hour of sedentary time increased CACS positivity risk by 3 percent (HR, 1.03, 95 percent CI, 1.001–1.050).

The effect of sedentary time on CACS score was stronger among nonobese participants, with those in the highest category of sedentary time being around 50 percent more likely to have positive CACS score (HR, 1.47, 95 percent CI, 1.06–2.04).