Insulin resistance is a central mediating factor of the metabolic syndrome (MetS), with exercise training and metformin proven antidotes to insulin resistance. However, when the two therapies are combined there is conflicting data regarding whether metformin blunts or improves exercise training-induced adaptations. The volume of exercise (duration, intensity, and frequency) on the interaction of exercise training and metformin has yet to be investigated. The aim of this study is therefore to explore the impact of a combination of different exercise volumes and metformin on MetS severity. This is a secondary analysis of data from one of the sites of the ‘Exercise in Prevention of Metabolic Syndrome’ (EX-MET) study. Ninety-nine adults with MetS were randomized into a 16-week exercise program completing either: (i) moderate-intensity continuous training (MICT) at 60–70% of peak heart rate (HRpeak) for 30 min/session (n = 34, 150 min/week); (ii) high-volume high-intensity interval training (HIIT) consisting of 4 × 4 min bouts at 85–95% HRpeak, interspersed with 3 min of active recovery at 50–70% HRpeak (n = 34, 38 min/session, 114 min/week); or (iii) low volume HIIT, 1 × 4 min bout of HIIT at 85–95% HRpeak (n = 31, 17 min/session, 51 min/week). Metformin intake was monitored and recorded throughout the trial. MetS severity was calculated as z-scores derived from MetS risk factors assessed at pre- and post-intervention. Sixty-five participants had complete pre- and post-intervention data for MetS z-score, of which 18 participants (28%) were taking metformin. Over the 16-week intervention, a similar proportion of participants clinically improved MetS severity (Δ ≥ −0.87) with metformin (8/18, 44%) or without metformin (23/47, 49%) (p = 0.75). While there were no between-group differences (p = 0.24), in those who did not take metformin low-volume HIIT had more likely responders (10/15, 67%) compared to MICT (6/16, 38%) and high-volume HIIT (7/16, 44%). In those taking metformin, there was a lower proportion of participants who clinically improved MetS severity following high-volume HIIT (1/6, 17%) compared to MICT (2/4, 50%) and low-volume HIIT (5/8, 63%), but with no between-group difference (p = 0.23). Moreover, in those who performed high-volume HIIT, there was a statistically significantly higher proportion (p = 0.03) of likely non-responders with improved MetS severity in participants taking metformin (4/6, 67%) compared to those not taking metformin (3/16, 19%). In individuals with MetS, the effect of high volume HIIT on MetS severity may be blunted in those taking metformin. These findings need to be confirmed in a larger study.

中文翻译：

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优化运动量和二甲双胍的相互作用以诱导代谢综合征严重程度的临床显着降低：一项随机试验。

胰岛素抵抗是代谢综合症（MetS）的主要调节因子，运动训练和二甲双胍证明是胰岛素抵抗的解毒剂。但是，当两种疗法结合使用时，关于二甲双胍会变钝还是改善运动训练引起的适应性，存在相互矛盾的数据。关于运动训练与二甲双胍相互作用的运动量（持续时间，强度和频率）尚待研究。因此，本研究的目的是探讨不同运动量和二甲双胍联合使用对MetS严重程度的影响。这是对“预防代谢综合症锻炼”（EX-MET）研究之一的数据的二次分析。九十九名患有MetS的成年人被随机分为一个为期16周的运动计划，以完成以下一项任务：n = 34，150分钟/周）；（ii）高强度高强度间歇训练（HIIT），包括在HRpeak为85–95％时进行4×4分钟搏击，并在HRpeak为50–70％时进行3分钟的主动恢复（n = 34，38分钟/节，114分钟/周）；或（iii）小剂量HIIT，在HRpeak为85–95％时进行1×4分钟的HIIT（n= 31、17分钟/会话，51分钟/周）。在整个试验过程中监测并记录二甲双胍的摄入量。MetS严重程度的计算方法是根据干预前和干预后评估的MetS危险因素得出的z得分。65名参与者在MetS z评分的干预前后具有完整的数据，其中18名参与者（28％）正在服用二甲双胍。在16周的干预过程中，有类似比例的参与者在有二甲双胍（8/18，44％）或无二甲双胍（23/47，49％）的情况下临床改善了MetS严重程度（Δ≥-0.87）（p = 0.75）。组间无差异（p= 0.24），相比于MICT（6/16，38％）和大剂量HIIT（7/16，44％），在未服用二甲双胍的人群中，小剂量HIIT的应答者可能性更高（10/15，67％） ）。在服用二甲双胍的患者中，与大剂量ICT（2/4，50％）和小剂量HIIT（5/8）相比，大剂量HIIT（1/6，17％）后临床改善MetS严重程度的参与者比例较低（63％），但组间无差异（p = 0.23）。此外，在进行高强度HIIT的患者中，统计学上显着更高的比例（p与未服用二甲双胍的受试者（3/16，19％）相比，服用二甲双胍的受试者（4/6，67％）的MetS严重性改善的可能无反应者= 0.03）。在患有MetS的个体中，高剂量HIIT对MetS严重程度的影响在服用二甲双胍的患者中可能会减弱。这些发现需要在更大的研究中得到证实。