heart disease

Study: Sedentary Time Linked to Increased Waist Circumference and CHD Risk

Longer sedentary time is associated with a larger waist circumference and an increased risk of coronary heart disease (CHD), according to a new study.1

In their study, researchers sought to define the relationship between objectively measured time spent sitting, standing, and stepping and metabolic risk. They performed a cross-sectional study that included 111 healthy non-smoking Glasgow postal workers. Fifty-five of the participants in the study worked in an office, and 56 of the participants were walking/delivery workers. Participants wore an activePAL physical activity monitor for 7 days, and researchers assessed cardiovascular risks using metabolic syndrome categorization and 10-year PROCAM risk score.
______________________________________________________________________________________________________________________________________________________________________________

RELATED CONTENT
Study: Abdominal Adiposity Associated with Increased Risk for Diabetes and Coronary Heart Disease
Could Coronary Heat Disease Increase the Risk of Osteoporosis?
______________________________________________________________________________________________________________________________________________________________________________

The mean (standard deviation [SD]) age of the participants was 40 (8) years, mean (SD) body mass index was 26.9 (3.9) kg/m2, mean (SD) waist circumference was 95.4 (11.9) cm, mean (SD) HDL-cholesterol was 1.33 (0.31), mean (SD) LDL-cholesterol was 3.11 (0.87), mean (SD) triglycerides was 1.23 (0.64) mmol/l, and mean (SD) 10-year PROCAM risk was 1.8% (1.7%) .

Overall, participants spent an average (SD) of 9.1 (1.8) hours per day sitting, 7.6 (1.2) hours per day sleeping, 3.9 (1.1) hours per day standing, and 3.3 (0.9) hours per day stepping, and accumulated 14,708 (4984) steps per day in 61 (25) sit-to-stand transitions per day.

The participants with metabolic syndrome were significantly less active compared with participants without metabolic syndrome, and had fewer steps, shorter stepping duration, and longer sedentary time. Participants without metabolic syndrome walked over 15,000 steps per day or spent over 7 hours a day standing.

“In univariate regressions—adjusting for age, sex, family history of CHD, shift worked, job type and socio-economic status—waist circumference (P=0.005), fasting triglycerides (P=0.002), HDL-cholesterol (P=0.001) and PROCAM-risk (P=0.047) were detrimentally associated with sedentary time,” the researchers wrote.

After adjusting for sleep, standing, and stepping in stepwise regression models, the associations between sedentary time and cardiovascular risk factors remained significant, but after adjustments for waist circumference, these associations were no longer significant.

“Our findings could be used as the basis of new public health targets for sitting, lying, standing and stepping to avoid metabolic risks,” said lead researcher Dr William Tigbe of the University of Warwick Medical School. “However, the levels suggested in our research would be very challenging to achieve unless incorporated into people’s occupations.”2

—Melissa Weiss

Reference:

1. Tigbe WW, Granat MH, Sattar N, and Lean MEJ. Time spent in sedentary posture is associated with waist circumference and cardiovascular risk [published online January 31, 2017]. Int J Obes. doi:10.1038/ijo.2017.30.

2.  Desk jobs are bad for your heart and your waist [press release]. Coventry, United Kingdom: University of Warwick; February 28, 2017. http://www2.warwick.ac.uk/newsandevents/pressreleases/desk_jobs_are/