In the past, we've learned a lot about the potential genetic, environmental, and lifestyle risk factors associated with type 2 diabetes — but how does sedentary behavior influence the disorder? That's the focus of a recent study published in Diabetologia.
Prior research has shown "unfavorable associations" between sedentary time, such as sitting and reclining to watch TV or work on a computer, and metabolic health outcomes, according to the current study. But few large-scale studies have been done to objectively measure sedentary behavior among people with type 2 diabetes. So researchers used data from The Maastricht Study, an extensive, population-based study that focuses on the etiology of type 2 diabetes. Specifically, it investigates possible associations between total duration and patterns of sedentary behavior, and participants’ resulting glucose metabolism and metabolic syndrome.
More than 2,000 participants, who were 52 percent male and a mean age of 60, were given a standard glucose tolerance test after an overnight fast to determine their diabetes status. To determine metabolic syndrome, researchers measured waist circumference, HDL-cholesterol levels, fasting glucose levels, blood pressure, and medication use. Researchers also noted health status, such as smoking, alcohol consumption, and mobility limitation.
Next, participants were given an activPAL3 accelerometer to wear on their thigh all day for eight consecutive days. The accelerometer allowed researchers to calculate the daily amount of participants' posture (sitting or lying, standing and stepping), total sedentary time, total sedentary breaks during waking time, prolonged bouts of sedentary breaks, and the average duration of those breaks.
The results revealed 56 percent of participants had a normal glucose metabolism; 15 percent had an impaired glucose metabolism; and 714 had type 2 diabetes. Participants with type 2 diabetes were more likely to be current smokers, though less likely to consume a lot of alcohol; more mobility limitation; and higher body mass index compared to those with impaired or normal glucose metabolism.
Diabetics accrued the most sedentary time, up to 26 more minutes per day than other participants. And researchers found diabetes risk increased by 22 percent for every extra hour spent sitting. More sedentary time was also associated with 1.13 times higher odds for one to two metabolic syndrome criteria and 1.39 times higher odds for three to five criteria of metablic syndrome, regardless of whether participants reported more high-intensity exercise activity.
The underlying suggestion of this study is that perhaps the larger focus on exercise may not be the way to prevent and treat diabetes. Instead, it may serve people better to learn more about the risks of increased sitting time. A study on heart disease patients recently arrived at a similar conclusion. That said, the researchers admit the study is limited.
"The pattern in which sedentary time was accumulated, as expressed by number of sedentary breaks, number of prolonged sedentary bouts and average sedentary bout duration, was only weakly associated with an increased risk for the metabolic syndrome," they wrote. "Future studies in participants with type 2 diabetes should be conducted to confirm our results, and to explore dose–response relationships and causality."
But, they added, the findings could still have important implications for public health, namely the role sedentary behavior may play in the development and prevention of type 2 diabetes.
Source: van der Berg J, et al. Associations of total amount and patterns of sedentary behaviour with type 2 diabetes and the metabolic syndrome: The Maastricht Study. Diabetologia. 2016.