Plasma lactate responses during and after submaximal handgrip exercise are not diagnostically helpful in mitochondrial myopathy
Nicoline Løkken, Sofie Vinther Skriver, Tahmina Khawajazada, Jesper Helbo Storgaard, John Vissing, Nicoline Løkken, Sofie Vinther Skriver, Tahmina Khawajazada, Jesper Helbo Storgaard, John Vissing
Abstract
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.
Trial registration: ClinicalTrials.gov NCT03513835.
Keywords: Diagnostic screening test; Handgrip test; Mitochondrial myopathy; Plasma lactate; Relative workload.
Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.
Source: PubMed