A new study has indicated that every hour spent watching television means increasing the risk of developing diabetes by 3.4%.
The research was conducted by Dr. Bonny Rockette-Wagner, lead author and Dr. Andrea Kriska, senior author from the University of Pittsburgh, and colleagues, with the aim to study the effects of sedentary or 'sitting' time on diabetes risk.
The study had enrolled 3,234 overweight US adults of at least 25 years of age with the goal of delaying or preventing type 2 diabetes in high risk individuals with either a metformin drug or lifestyle intervention. It was examined whether the DPP lifestyle intervention, which was shown to be effective at increasing physical activity, also decreased self-reported sitting time.
Prior to the intervention, total time spent watching TV was not found to be significantly different between the placebo, metformin, and lifestyle groups of DPP (around 140 minutes per day in all three groups).
For the lifestyle participants, a reduction in reported TV watching time throughout follow-up was observed for all participant subgroups including age, sex, work status, race, obesity status, or those achieving the weight or activity goal. Similarly, the lifestyle group had the greatest reduction in mean time spent in TV watching time plus time sitting at work during follow-up. The combined average reduction in TV watching and time sitting at work was 9, 6, and 37 min per day for the placebo, metformin and lifestyle groups respectively.
The authors also investigated the impact of sedentary behavior over time on diabetes incidence. For participants in all treatment arms, the risk of developing diabetes increased approximately 3.4% for each hour spent watching TV after adjustment for age, sex, treatment arm and time-dependent leisure physical activity. This association was reduced when time-dependent weight was added to the model suggesting that subsequent changes in body weight may account for some of the relationship between sitting behavior changes and diabetes development.
Dr. Kriska said that the findings were noteworthy because a decrease in sitting occurred despite the absence of program goals aimed at reducing sitting. He added it was likely that a lifestyle intervention program that incorporated a specific goal of decreasing sitting time, would result in greater changes in sitting.
The study is published in Diabetologial
, the journal of the European Association for the Study of Diabetes.