Sports and Exercise Medicine Division, Department of Medicine, University of Padova, Padova, Italy,
Center for the Study and the Integrated Treatment of Obesity, Padova Hospital, Padova, Italy,
Obes Facts. 2021;14(4):415-424. doi: 10.1159/000517589. Epub 2021 Jul 30.
Metabolic adaptations to maximal physical exercise in people with obesity (PwO) are scarcely described. This cross-sectional study evaluates the metabolic response to exercise via the respiratory exchange ratio (RER) in PwO and different degrees of glycemic control.
Eighty-five PwO (body mass index 46.0 [39.0-54.0] kg/m2), that is, 32 normoglycemic (Ob-N), 25 prediabetic (Ob-preDM), and 28 diabetic (Ob-T2DM) subjects and 18 healthy subjects performed an incremental, maximal cardiopulmonary exercise test. The RER was measured at rest (RERrest) and at peak exercise (RERpeak).
RERpeak was significantly higher in healthy subjects than that in PwO. Among those, RERpeak was significantly higher in Ob-N than that in Ob-preDM and Ob-T2DM (1.20 [1.15-1.27] vs. 1.18 [1.10-1.22] p = 0.04 and vs. 1.14 [1.10-1.18] p < 0.001, respectively). Accordingly, ΔRER (RERpeak-RERrest) was lower in Ob-preDM and Ob-T2DM than that in Ob-N (0.32 [0.26-0.39] p = 0.04 and 0.29 [0.24-0.36] p < 0.001 vs. 0.38 [0.32-0.43], respectively), while no significant difference was found in ΔRER between Ob-preDM and Ob-T2DM and not even between Ob-N and healthy subjects. Moreover, ΔRER in PwO correlated with glucose area under curve (p = 0.002).
PwO demonstrate restricted metabolic response during maximal exercise. Particularly, those with prediabetes already show metabolic inflexibility during exercise, similarly to those with type 2 diabetes. These findings also suggest a potential role of cardiopulmonary exercise testing in detecting early metabolic alterations in PwO.
肥胖人群（PwO）在进行最大体力活动时的代谢适应情况鲜有描述。本横断面研究通过呼吸交换率（RER）评估了 PwO 以及不同血糖控制程度人群在运动时的代谢反应。
85 名 PwO（体重指数 46.0 [39.0-54.0] kg/m2），包括 32 名血糖正常（Ob-N）、25 名糖尿病前期（Ob-preDM）和 28 名 2 型糖尿病（Ob-T2DM）患者和 18 名健康对照者进行了递增式最大心肺运动试验。在静息时（RERrest）和运动峰值时（RERpeak）测量 RER。
健康受试者的 RERpeak 明显高于 PwO。在这些人群中，Ob-N 的 RERpeak 明显高于 Ob-preDM 和 Ob-T2DM（1.20 [1.15-1.27] vs. 1.18 [1.10-1.22]，p=0.04；vs. 1.14 [1.10-1.18]，p<0.001）。相应地，Ob-preDM 和 Ob-T2DM 的 ΔRER（RERpeak-RERrest）低于 Ob-N（0.32 [0.26-0.39]，p=0.04；0.29 [0.24-0.36]，p<0.001 vs. 0.38 [0.32-0.43]），但 Ob-preDM 和 Ob-T2DM 之间的 ΔRER 差异无统计学意义，Ob-N 和健康对照者之间亦无差异。此外，PwO 的 ΔRER 与血糖曲线下面积（AUC）呈正相关（p=0.002）。
PwO 在最大运动时表现出受限的代谢反应。特别是，那些患有糖尿病前期的患者在运动时已经表现出代谢灵活性降低，与 2 型糖尿病患者相似。这些发现还表明，心肺运动试验在检测肥胖人群早期代谢改变方面可能具有一定作用。
