Though our bodies may be built for the savannah, modern life can mean we spend more and more time tied to the computer, the TV and the car. And, as you might imagine, that's bad news for our health. According to a new study in the Netherlands, each extra hour of time we spend being sedentary could mean a significantly increased risk of developing Type 2 diabetes.
The study, conducted by Julianne van der Berg, a PhD candidate at Maastricht University, and her team, looked at the associations between patterns and duration of inactivity and the metabolism of glucose by the body. Participants wore a thigh-mounted accelerometer — a device that measures movement and records the length and frequency of sedentary periods by analyzing posture. This, the researchers say, has shown to be an accurate way of assessing inactivity. The team published their results in Diabetologia — the journal of the European Association for the Study of Diabetes.
The researchers looked at 2,497 participants — just more than half (52%) were men and, as a whole, the group had an average age of 60 years old. They were asked to wear their accelerometer 24 hours a day for 8 consecutive days and from this the authors calculated the complete amount of sedentary time, the number of sedentary breaks each day, the number of prolonged periods of physical inactivity (30 minutes or more) and the average duration of these periods. In addition, each participant underwent an oral glucose tolerance test to check their diabetes status.
Of those taking part, 1,395 (56%) had a normal glucose metabolism; 388 (15%) had impaired glucose metabolism — a condition associated with insulin resistance and pre-diabetes, which occurs when the body has difficulty turning sugar into energy; and 714 (29%) had Type 2 diabetes. The authors say their study was the largest one where this type of technology has been used to record posture — a study known as accelerometry — and to measure total duration and patterns of sedentary behavior in a group of people that included those with Type 2 diabetes, impaired glucose tolerance and normal glucose metabolism. Participants with Type 2 diabetes were found to be the most sedentary with up to 26 minutes per day more compared to those with an impaired or normal rate of glucose metabolism.
As a result, the scientists say, the risk of diabetes increases by as much as 22% for every additional hour of relative physical inactivity. They say no significant associations were seen for the number of sedentary breaks, the number of prolonged sedentary periods or average duration of these sedentary periods with diabetes status. "Future studies in participants with Type 2 diabetes should be conducted to confirm our results," the team says. "Nevertheless, our findings could have important implications for public health as they suggest that sedentary behavior may play a significant role in the development and prevention of Type 2 diabetes, independent of high-intensity physical activity. Consideration should be given to including strategies to reduce the amount of sedentary time in diabetes prevention programs."