Sitting less elicits metabolic responses similar to exercise and enhances insulin sensitivity in postmenopausal women

Abstract

Aims/hypothesis In our current society sedentary behaviour predominates in most people and is associated with the risk of developing type 2 diabetes. It has been suggested that replacing sitting time by standing and walking could be beneficial for individuals with type 2 diabetes but the underlying mechanisms are unknown and direct comparisons with exercise are lacking. Our objective was to directly compare metabolic responses of either sitting less or exercising, relative to being sedentary. Methods We performed a randomised, crossover intervention study in 12 overweight women who performed three well-controlled 4 day activity regimens: (1) sitting regimen (sitting 14 h/day); (2) exercise regimen (sitting 13 h/day, exercise 1 h/day); and (3) sitting less regimen (sitting 9 h/day, standing 4 h/day and walking 3 h/day). The primary outcome was insulin sensitivity measured by a two-step hyperinsulinaemic–euglycaemic clamp. We additionally performed metabolomics on muscle biopsies taken before the clamp to identify changes at the molecular level. Results Replacing sitting time by standing and walking over 4 days resulted in improved peripheral insulin sensitivity, comparable with the improvement achieved by moderate-to-vigorous exercise. Specifically, we report a significant improvement in peripheral insulin sensitivity in the sitting less (~13%) and the exercise regimen (~20%), compared with the sitting regimen. Furthermore, sitting less shifted the underlying muscle metabolome towards that seen with moderate-to-vigorous exercise, compared with the sitting regimen. Conclusions/interpretations Replacing sitting time by standing and walking is an attractive alternative to moderate-to-vigorous exercise for improving metabolic health. Trial registration ClinicalTrials.gov NCT03912922. Graphical abstract

Managing weight and glycaemic targets in people with type 2 diabetes—How far have we come?

“…For the large proportion of people with T2D who are ageing, currently sedentary, overweight or obese, deconditioned or unable to embark upon structured exercise, ‘sitting less’ may prove an alternative behavioural strategy. In a recent experimental study in postmenopausal women, a significant improvement in peripheral insulin sensitivity in the sitting less (~13%) and the exercise regimen (~20%) has been reported, compared with the sitting regimen 91 . Encouragingly, these results confirmed earlier findings in which breaking sitting with standing and light‐intensity walking effectively improved 24 h glucose levels and insulin sensitivity in elderly people with T2D 92 .…”

“…In a recent experimental study in postmenopausal women, a significant improvement in peripheral insulin sensitivity in the sitting less (~13%) and the exercise regimen (~20%) has been reported, compared with the sitting regimen. 91 Encouragingly, these results confirmed earlier findings in which breaking sitting with standing and light-intensity walking effectively improved 24 h glucose levels and insulin sensitivity in elderly people with T2D. 92 Therefore, people should be encouraged to find some physical activity that they enjoy and are likely to sustain or to vary physical activities to have more tools to help maintain higher habitual activity levels.…”

Timing of physical activity in relation to liver fat content and insulin resistance

“…Several studies have demonstrated that short breaks in sedentary time are associated with an improved cardiometabolic profile, including reduced triacylglycerol and glucose concentrations [6,7]. Findings from observational studies are supported by (semi-)experimental studies showing that frequent interruptions of prolonged sitting with standing or light activities resulted in improved glycaemic responses [7][8][9][10][11] and triacylglycerol levels [9,12]. High fasting serum triacylglycerol concentrations may reflect high liver fat content [13], which is strongly associated with insulin resistance [14].…”

Reducing Sedentary Time and Whole-Body Insulin Sensitivity in Metabolic Syndrome: A 6-Month Randomized Controlled Trial

“…In the short term (i.e., in acute crossover trials or in interventions lasting for less than a week), breaking up sitting with short activity breaks decreases postprandial plasma glucose and insulin levels (20)(21)(22). Moreover, replacing 5 h of daily sitting with standing and walking improved peripheral insulin sensitivity measured by a two-phase HEC in a 4-d crossover trial (23). In addition, replacing 1-2 h of daily SB with standing may slightly decrease body fat as well as fasting plasma glucose and insulin (24).…”