Introduction/background

Mitochondrial myopathy (MM) encompasses a clinical heterogenous group of patients that can be difficult to diagnose. The aim of this study was to investigate if changes in plasma lactate concentration during a 6-minute submaximal handgrip test (6MHGT) and a 20-minute post-exercise recovery period can be used as a diagnostic test for MM.

Methods

Twenty-nine patients with MM and nineteen healthy controls (HC) performed an intermittent handgrip exercise test at ½ Hz for 6 min at 50% of maximal voluntary contraction force. We calculated the area under the curve (AUC) of change in plasma lactate during exercise and recovery and compared AUC between groups (MM vs. HC, and between MM subgroups based on disease severity).

Results

The change in plasma lactate during exercise and recovery was similar in MM and HC (p = 0.65 and p = 0.57) and similar between MM subgroups (p ≥ 0.24).

Conclusion

Plasma lactate measured during and after a submaximal 6MHGT cannot be used as a diagnostic variable for MM.

中文翻译：

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次最大握力运动期间和之后的血浆乳酸反应对线粒体肌病的诊断没有帮助

简介/背景

线粒体肌病 (MM) 包括临床上异质的一组患者，这些患者可能难以诊断。本研究的目的是调查 6 分钟次最大握力试验 (6MHGT) 和 20 分钟运动后恢复期间血浆乳酸浓度的变化是否可用作 MM 的诊断试验。

方法

29 名 MM 患者和 19 名健康对照者 (HC) 在 50% 的最大自主收缩力下以 ½ Hz 进行了 6 分钟的间歇性握力运动测试。我们计算了运动和恢复期间血浆乳酸变化的曲线下面积 (AUC)，并比较了组间的 AUC（MM 与 HC，以及基于疾病严重程度的 MM 亚组之间）。

结果

运动和恢复期间血浆乳酸的变化在 MM 和 HC 中相似（p = 0.65 和 p = 0.57），并且在 MM 亚组之间相似（p ≥ 0.24）。

结论

在次最大 6MHGT 期间和之后测量的血浆乳酸不能用作 MM 的诊断变量。