Substituting sitting with standing and walking in free-living conditions improves daily glucose concentrations in South Asian adults living with overweight/obesity.

Background: Controlled laboratory studies have demonstrated that breaking up sitting can reduce postprandial glucose in South Asian adults. This study examined the effects of substituting sitting with standing and walking on interstitial glucose in South Asian individuals under free-living conditions.

Methods: South Asian adults (n = 14 [50% male]; body mass index 26.5 ± 0.8 kg·m) aged 41 ± 3 years completed two, 4-day regimens in a counter-balanced order: (1) SIT (restrict walking and standing to ≤ 1 h/day each) and (2) SITless (substitute ≥ 5 h/day of sitting with ≥ 3 h of standing and ≥ 2 h of walking, and interrupt sitting every 30 min). Interstitial glucose was measured using Flash glucose monitoring. Sitting and physical activity were measured with the activPAL3. Outcomes were compared between regimens using linear mixed models.

Results: Interstitial glucose net incremental area under the curve (iAUC) for waking hours was lower by - 9.2 mmol L·16 h (95% Confidence Interval [CI]: - 18.1, - 0.3) in SITless than SIT (p = 0.04), while lunch postprandial glucose iAUC was significantly lower by -1.0 mmol L2 h (95% CI - 1.8, 0.2) in SITless (p = 0.02). There were no significant differences in other 24 h or 16 h glucose metrics (p ≥ 0.06). Compared to SIT, sitting was lower by - 3.6 h/day (95% CI - 4.9, - 2.3) in SITless (p < 0.01). Standing and stepping time were higher by 1.9 h/day (95% CI 0.6, 3.2) and 1.6 h/day (95% CI 1.2, 2.1) in SITless (p ≤ 0.01).

Conclusions: Substituting sitting with standing and walking under free-living conditions can be used to effectively attenuate glycaemia during waking hours, but not across 24 h, in South Asian adults.

Clinical Trial Registration: NCT04645875..