Effects of incremental exercise on plasma metabolite levels according to muscle MAD activity.

<p>Patients performed an incremental exercise testing (<i>inset</i>). Blood was sampled before (Rest), during exercise (50% of Predicted Maximal Power and Peak exercise), and after exercise (2, 5, 10 and 15 min recovery). Filled symbols correspond to glycogenoses, open symbols correspond to the absence of glycogenoses. (A) Ammonia. (B) Ammonia/rest. (C) Lactate. (D) Lactate/rest. (E) Lactate/Pyruvate ratio. Data are represented as means ± standard error of mean (error bars not included for ammonia values in the subgroup with glycogenose and normal MAD in panel A).*: Absent vs. Normal MAD staining, †: Decreased vs. Normal MAD staining (<i>P</i> < 0.05, Games-Howell <i>post-hoc</i> test).</p

Diagnostic performance of blood parameters to discriminate abnormal from normal MAD activity (A) and decreased from absent MAD activity (B).

<p>Diagnostic indices for predictors, with areas under receiver operating characteristic curves (AUC) ≥ 0.750 listed in the tables. The best AUC for each parameter is shown in the ROC space, with the corresponding 95% confidence interval. Circles denote cut-off points, corresponding to the highest concomitant sensitivity and specificity. (A) Performance of blood parameters to discriminate between Normal (n = 37) and Abnormal (n = 11) MAD activity. (B) Classifiers for the differentiation of Absent (n = 5) from Decreased (n = 6) MAD activity. 50% PMP: 50% from predicted maximal power (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#sec006" target="_blank">Methods</a>), R: Recovery from exercise, Se: Sensibility, Sp: Specificity, Acc: Accuracy, PPV: Positive predictive value, NPV: Negative predictive value, LR+: Positive likelihood ratio, LR-: Negative likelihood ratio, DOR: Diagnostic odds ratio, NC: Not calculable.</p

Flowchart of the study.

<p>Muscle biopsies were analysed using standard techniques including histoenzymology with Periodic acid-Schiff (PAS) and MAD staining (Fishbein’s method [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#pone.0132972.ref035" target="_blank">35</a>]).</p

Clinical features of exertional heat stroke, 2008–2010 cohort with questionnaire.

<p>Clinical features of exertional heat stroke, 2008–2010 cohort with questionnaire.</p

<i>In vitro</i> contracture test status, 2004–2010 cohort.

<p>Legend: MHN, malignant hyperthermia normal response; MHS, malignant hyperthermia susceptible.</p><p>^aIncluding MHS for caffeine and MHS for halothane patients.</p><p><i>In vitro</i> contracture test status, 2004–2010 cohort.</p

Histochemical MAD staining using <i>p</i>-nitro blue tetrazolium.

<p>(A) Relative <i>p</i>-NBT staining intensity was expressed as a percentage of the mean optical density in control muscle biopsies (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#sec006" target="_blank">Methods</a>). Horizontal bars represent the mean value of each group. *: Decreased vs. Normal MAD staining, †: Absent vs. Normal MAD staining, ‡: Absent vs. Decreased MAD staining (<i>P</i> < 0.05, Games-Howell <i>post-hoc</i> test). Representative serial cross sections of lateral vastus biopsies: (B) Normal, (C) Decreased, and (D) Absent MAD staining (original magnification: × 100).</p

Proposed algorithm for the diagnosis of glycogenoses, MAD deficiencies, and mitochondrial myopathies.

<p>The ROC curve to discriminate between the presence and absence of mitochondrial myopathy was determined according to the parametric methodology [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#pone.0132972.ref022" target="_blank">22</a>]. (A) For this purpose, we used the values (mean ± SD) published by Dandurand <i>et al</i>. in eight patients with mitochondrial myopathies [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#pone.0132972.ref051" target="_blank">51</a>]. The values in the disease control group from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#pone.0132972.ref051" target="_blank">51</a>] are in line with those from the group with no metabolic myopathy (n = 37) in the present study. (B) The cut-off corresponds to the highest value for the Youden index (Se = 72.5%, Sp = 73.5%). MAD: Myoadenylate deaminase.</p

Diagnostic algorithm for glycogenoses and MAD deficiencies.

<p>(A) The algorithm classifies subjects referred for metabolic exercise testing into four groups. The figure combines the optimal cut-off values reported in decision tree nodes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132972#pone.0132972.g004" target="_blank">Fig 4A and 4B</a>). L/P: lactate-to-pyruvate ratio, R: Recovery from exercise. (B) A contingency table was constructed on the basis of whether subjects have a metabolic myopathy or not, and corresponding common performance metrics with 95% confidence interval were calculated. TP: True positive, FP: False positive, FN: False negative, TN: True negative.</p

Anthropometric characteristics and maximal exercise test data.

<p>Data are means ± SD. MAD: Myoadenylate deaminase, f: Female, m: Male, BMI: Body Mass Index</p><p>*: Different from the Normal MAD activity group (<i>P</i> < 0.05, Games-Howell <i>post-hoc</i> test).</p><p>Anthropometric characteristics and maximal exercise test data.</p

Exertional heat stroke recurrence, 2008–2010 cohort with questionnaire.

<p>Legend: BMI, body mass index; EHS, exertional heat stroke; ICU, intensive care unit; Tco, body core temperature.</p><p>^aFor male subjects between 20 and 29 years of age, the results are ‘excellent’ for distances > 2800 m, ‘good’ for distances of 2400–2800 m, ‘average’ for distances between 2200 and 2400 m, ‘low’ for distances between 1600 and 2200 m and ‘weak’ for distances < 1600 m [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135496#pone.0135496.ref019" target="_blank">19</a>].</p><p>Exertional heat stroke recurrence, 2008–2010 cohort with questionnaire.</p