title: MiR-181a: a potential biomarker of acute muscle wasting following elective high-risk cardiothoracic surgery.
abstract: BACKGROUND
  Acute muscle wasting in the critically ill is common and associated with significant morbidity and mortality. Although some aetiological factors are recognised and muscle wasting can be detected early with ultrasound, it not possible currently to predict in advance of muscle loss those who will develop muscle wasting. The ability to stratify the risk of muscle wasting associated with critical illness prior to it becoming clinically apparent would provide the opportunity to predict prognosis more accurately and to intervene at an early stage. MicroRNAs are small non-coding RNAs that modulate post-transcriptional regulation of translation, some are tissue specific and can be detected and quantified in plasma. We hypothesised that certain plasma microRNAs could be biomarkers of ICU acquired muscle weakness.
  
  
  METHODS
  Plasma levels of selected microRNAs were measured in pre- and post-operative samples from a previously reported prospective observational study of 42 patients undergoing elective high-risk cardiothoracic surgery, 55% of whom developed muscle wasting.
  
  
  RESULTS
  The rise in miR-181a was significantly higher on the second post-operative day in those who developed muscle wasting at 1 week compared to those who did not (p = 0.03). A rise in miR-181a of greater than 1.7 times baseline had 91% specificity and 56% sensitivity for subsequent muscle wasting. Other microRNAs did not show significant differences between the groups.
  
  
  CONCLUSIONS
  Plasma miR-181a deserves further investigation as a potential biomarker of muscle wasting. Additionally, since mir-181a is involved in both regulation of inflammation and muscle regeneration and differentiation; our observation therefore also suggests directions for future research.
authors.affiliation: Molecular Medicine, National Heart and Lung Institute, Imperial College, SW7 2AZ, London, UK. Susannah.bloch@doctors.org.uk.|National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, SW3 6NP, London, UK. Susannah.bloch@doctors.org.uk.
authors.forename: Susannah A A
authors.initials: SA
authors.lastname: Bloch
authors.affiliation: National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, SW3 6NP, London, UK. annadonaldson@doctors.org.uk.
authors.forename: Anna V J
authors.initials: AV
authors.lastname: Donaldson
authors.affiliation: Molecular Medicine, National Heart and Lung Institute, Imperial College, SW7 2AZ, London, UK. a.lewis@qmul.ac.uk.
authors.forename: Amy
authors.initials: A
authors.lastname: Lewis
authors.affiliation: National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, SW3 6NP, London, UK. w.banya@rbht.nhs.uk.
authors.forename: Winston A S
authors.initials: WA
authors.lastname: Banya
authors.affiliation: National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, SW3 6NP, London, UK. m.polkey@rbht.nhs.uk.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.affiliation: National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, SW3 6NP, London, UK. m.griffiths@imperial.ac.uk.|Leukocyte Biology, National Heart and Lung Institute, Imperial College London, London, UK. m.griffiths@imperial.ac.uk.
authors.forename: Mark J D
authors.initials: MJ
authors.lastname: Griffiths
authors.affiliation: Molecular Medicine, National Heart and Lung Institute, Imperial College, SW7 2AZ, London, UK. p.kemp@imperial.ac.uk.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Kemp
mesh_terms: D000208:Acute Disease; D000368:Aged; D015415:Biomarkers / Q000097:blood; D013504:Cardiovascular Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D009133:Muscular Atrophy / Q000097:blood* / Q000209:etiology*; D011183:Postoperative Complications; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D019616:Thoracic Surgical Procedures
chemical_list: D015415:Biomarkers; C540193:MIrn181 microRNA, human; D035683:MicroRNAs