Every extra hour a day spent sitting could increase the risk of developing diabetes by about a fifth, new study has warned.

The study by Julianne van der Berg of Maastricht University in the Netherlands and colleagues investigated cross-sectional associations of total duration and patterns of sedentary behaviour with glucose metabolism status and the metabolic syndrome.

Each extra hour of daily sedentary time (for example spent sitting at a computer) was associated with a 22 per cent increased risk of developing type 2 diabetes, researchers said.

The study participants used a thigh-worn accelerometer, which classifies sedentary behaviour using data on posture, as this has shown to be an accurate means of assessing sedentary behaviour.

The study included 2,497 participants (mean age 60 years, 52 per cent men) who were asked to wear their accelerometer 24 hours per day for 8 consecutive days.

Researchers calculated the daily amount of sedentary time, daily number of sedentary breaks, number of prolonged sedentary periods (of 30 minutes or more), and the average duration of these sedentary periods.

To determine diabetes status, participants underwent an oral glucose tolerance test.

Overall, 1,395 (56 per cent) participants had a normal glucose metabolism, 388 (15 per cent) had an impaired glucose metabolism and 714 (29 per cent) had type 2 diabetes.

Participants with type 2 diabetes spent the most time sedentary, up to 26 more minutes per day in comparison with participants with an impaired or normal glucose metabolism.

The increased risk of diabetes per additional hour of sedentary time was 22 per cent.

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.

The study is the largest in which this type of posture-identifying accelerometry has been used to objectively measure total duration and patterns of sedentary behaviour in a cohort of people with type 2 diabetes, impaired glucose tolerance, and normal glucose metabolism, researchers said.

"An extra hour of sedentary time was associated with a 22 per cent increased odds for type 2 diabetes," they said.

The study was published in the journal Diabetologia.