Cardiometabolic risk markers such as insulin resistance, glycated hemoglobin (HbA1c), fasting insulin, and liver enzyme concentrations improved significantly in adults diagnosed with metabolic syndrome who reduced their sedentary behaviors by 50 min/d by increasing their physical activity levels, according to study findings published in the Journal of Science and Medicine in Sport

Researchers conducted a randomized controlled trial at the Turku PET Centre in Finland between April 2017 and November 2019. They randomly separated 64 sedentary, middle-aged adults diagnosed with metabolic syndrome into intervention (n=33) and control (n=31) groups; one person dropped out of the study for personal reasons, and the remaining 63 completed the study. 

While the control group continued their usual daily sedentary habits, the researchers instructed the intervention group to reduce their sedentary behaviors by at least 1 h/d for 3 months. The intervention group was encouraged to stand more at work and during phone calls, to take the stairs instead of the elevator, and to increase their physical activity levels. The investigators remotely monitored adherence to the program via hip-worn accelerometers, although some technical challenges limited the amount of data obtained. 


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The researchers analyzed the effects of the intervention on cardiometabolic risk factors by performing fasting blood sample analysis and measuring blood pressure, body composition using air displacement plethysmography, and anthropometrics such as body mass index and waist circumference.  Values were obtained at baseline and again at 3 months.

The intervention group reduced their sedentary behaviors by 50 min/d and increased their activity levels by 24 min/d. Standing did not significantly alter the outcomes.

Fasting insulin (83.4 [95% CI, 68.7-101.2] vs 102.0 [95% CI, 83.3-125.0] pmol/L), insulin resistance (3.2 [95% CI, 2.6-3.9] vs 4.0 [95% CI, 3.2-4.9]), HbA1c (37 [95% CI, 36-38] vs 38 [95% CI, 37-39] mmol/mol), and alanine aminotransferase concentrations (28 [95% CI, 24-33] vs 33 [95% CI, 28-38] U/L) improved significantly in the intervention group compared with the control group. 

Although within-group changes did not reach statistical significance, resting heart rate and triglyceride levels decreased notably in the intervention group compared with the control group. Body composition, blood pressure, and waist circumference also slightly decreased in the intervention group, although these values were not significantly different compared with the control group.

Limitations of the study included technical difficulties collecting data from the accelerometers, the small sample size, potential confounding factors such as food intake, and lack of follow-up after 3 months to determine retention of the intervention effects. 

“Reducing daily sedentary behavior may be helpful in cardiometabolic disease prevention in risk populations, but a more substantial sedentary behavior reduction and/or higher volume and intensity of physical activity is likely needed for sedentary individuals to achieve greater health benefits,” the authors said.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Garthwaite T, Sjöros T, Laine S, et al. Effects of reduced sedentary time on cardiometabolic health in adults with metabolic syndrome: a three-month randomized controlled trial.J Sci Med Sport. Published online April 7, 2022. doi:10.1016/j.jsams.2022.04.002