With the rise of type 2 diabetes in youth, it is critical to investigate factors such as physical activity (PA) and time spent sedentary that may be contributing to this public health problem. This article describes PA and sedentary time in a large cohort of youth with type 2 diabetes and compares these levels with other large-scale investigations.
The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) trial is a study in 699 youth, recruited from 15 US clinical centers, aged 10 to 17 years with <2 years of type 2 diabetes and a BMI ≥85th percentile.
In comparison with the subset of the NHANES cohort who were obese (BMI ≥95th percentile), TODAY youth spent significantly more time being sedentary (difference averaging 56 minutes per day; P < .001) as assessed by accelerometry. Although moderate to vigorous activity levels in both obese cohorts for all age groups were exceptionally low, younger TODAY boys were still significantly less active than similarly aged NHANES youth. Comparisons between the TODAY girls and other investigations suggest that the TODAY girls also had relatively lower PA and fitness levels.
Adolescents with type 2 diabetes from the large TODAY cohort appear to be less physically active and tend to spend more time being sedentary than similarly aged youth without diabetes identified from other large national investigations. Treatment efforts in adolescents with type 2 diabetes should include decreasing sitting along with efforts to increase PA levels.
Comments
Metformin alters cardiometabolic fitness and may alter propensity to exercise.
In the work by Kriska et al. (1) they find significant differences in several parameters between subjects recently diagnosed with type 2 diabetes and obese subjects from other large scale studies. Included in these differences are sedentary time as well as cardiorespiratory capacity. The TODAY study participants all had recently been diagnosed with type 2 diabetes. In addition all of the TODAY participants were on metformin, whereas it is likely that few, if any, of the participants in other studies were on metformin. In small trials metformin has been shown, fairly convincingly, to decrease aerobic capacity (2,3). This decrease may account for some or all of the difference in cardiorespiratory fitness. This effect of metformin on aerobic capacity is not widely discussed, however, some hypothesize that this decrease in capacity may also be associated with, or lead to a decrease in propensity to do physical activity. Thus, it is possible that the differences observed in the study by Kriska et al. may be due to metformin treatment rather than intrinsic to those recently diagnosed with type two diabetes.
1) Kriska A, et al. Sedentary Behavior and Physical Activity in Youth With Recent Onset of Type 2 Diabetes. PEDIATRICS. 2013 Mar 1;131(3):e850- 6. 2) Johnson ST, et al. Acute effect of metformin on exercise capacity in active males. Diabetes Obes Metab. 2008 Sep;10(9):747-54. 3) Braun B, et al. Impact of metformin on peak aerobic capacity. Appl Physiol Nutr Metab. 2008 Feb;33(1):61-7.
Conflict of Interest:
None declared