ICU Admission Muscle and Fat Mass, Survival, and Disability at Discharge

A Prospective Cohort Study
Published:October 27, 2018DOI:


      Skeletal muscle dysfunction occurring as a result of ICU admission associates with higher mortality. Although preadmission higher BMI correlates with better outcomes, the impact of baseline muscle and fat mass has not been defined. We therefore investigated the association of skeletal muscle and fat mass at ICU admission with survival and disability at hospital discharge.


      This single-center, prospective, observational cohort study included medical ICU (MICU) patients from an academic institution in the Unites States. A total of 401 patients were evaluated with pectoralis muscle area (PMA) and subcutaneous adipose tissue (SAT) determinations conducted by CT scanning at the time of ICU admission, which were later correlated with clinical outcomes accounting for potential confounders.


      Larger admission PMA was associated with better outcomes, including higher 6-month survival (OR, 1.03; 95% CI, 1.01-1.04; P < .001), lower hospital mortality (OR, 0.96; 95% CI, 0.93-0.98; P < .001), and more ICU-free days (slope, 0.044 ± 0.019; P = .021). SAT was not significantly associated with any of the measured outcomes. In multivariable analyses, PMA association persisted with 6 months and hospital survival and ICU-free days, whereas SAT remained unassociated with survival or other outcomes. PMA was not associated with regaining of independence at the time of hospital discharge (OR, 0.99; 95% CI, 0.98-1.01; P = .56).


      In this study cohort, ICU admission PMA was associated with survival during and following critical illness; it was unable to predict regaining an independent lifestyle following discharge. ICU admission SAT mass was not associated with survival or other measured outcomes.

      Key Words


      MICU ( medical ICU), mMRC ( modified Medical Research Council), PMA ( pectoralis muscle area), SAT ( subcutaneous adipose tissue)
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        • Puthucheary Z.A.
        • et al.
        Acute skeletal muscle wasting in critical illness.
        JAMA. 2013; 310: 1591-1600
        • Jaitovich A.
        • Barreiro E.
        Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD): what we know and can do for our patients.
        Am J Respir Crit Care Med. 2018; 198: 175-186
        • Ali N.A.
        • et al.
        Acquired weakness, handgrip strength, and mortality in critically ill patients.
        Am J Respir Crit Care Med. 2008; 178: 261-268
        • Sharshar T.
        • et al.
        Presence and severity of intensive care unit-acquired paresis at time of awakening are associated with increased intensive care unit and hospital mortality.
        Crit Care Med. 2009; 37: 3047-3053
        • De Jonghe B.
        • et al.
        Respiratory weakness is associated with limb weakness and delayed weaning in critical illness.
        Crit Care Med. 2007; 35: 2007-2015
        • Adler D.
        • Dupuis-Lozeron E.
        • Richard J.C.
        • Janssens J.P.
        • Brochard L.
        Does inspiratory muscle dysfunction predict readmission after intensive care unit discharge?.
        Am J Respir Crit Care Med. 2014; 190: 347-350
        • Dos Santos C.
        • et al.
        Mechanisms of chronic muscle wasting and dysfunction after an intensive care unit stay. A pilot study.
        Am J Respir Crit Care Med. 2016; 194: 821-830
        • Herridge M.S.
        • et al.
        Functional disability 5 years after acute respiratory distress syndrome.
        N Engl J Med. 2011; 364: 1293-1304
        • Chan K.S.
        • et al.
        Evaluating muscle mass in survivors of acute respiratory distress syndrome: a 1-year multicenter longitudinal study.
        Crit Care Med. 2018; 46: 1238-1246
        • Alberda C.
        • et al.
        The relationship between nutritional intake and clinical outcomes in critically ill patients: results of an international multicenter observational study.
        Intensive Care Med. 2009; 35: 1728-1737
        • Kelmenson D.A.
        • et al.
        Outcomes of ICU patients with a discharge diagnosis of critical illness polyneuromyopathy: a propensity-matched analysis.
        Crit Care Med. 2017; 45: 2055-2060
        • Goligher E.C.
        • et al.
        Mechanical ventilation-induced diaphragm atrophy strongly impacts clinical outcomes.
        Am J Respir Crit Care Med. 2018; 197: 204-213
        • Herridge M.S.
        • et al.
        The RECOVER program: disability risk groups and 1-year outcome after 7 or more days of mechanical ventilation.
        Am J Respir Crit Care Med. 2016; 194: 831-844
        • Looijaard W.G.
        • et al.
        Skeletal muscle quality as assessed by CT-derived skeletal muscle density is associated with 6-month mortality in mechanically ventilated critically ill patients.
        Crit Care. 2016; 20: 386
        • Weijs P.J.
        • et al.
        Low skeletal muscle area is a risk factor for mortality in mechanically ventilated critically ill patients.
        Crit Care. 2014; 18: R12
        • Ferrante L.E.
        • et al.
        Factors associated with functional recovery among older intensive care unit survivors.
        Am J Respir Crit Care Med. 2016; 194: 299-307
        • Jaitovich A.
        • et al.
        ICU admission skeletal muscle mass, in-hospital outcomes and 6-months mortality: a prospective study.
        Am J Respir Crit Care Med. 2017; 195: A2775
        • McDonald M.L.
        • et al.
        Quantitative computed tomography measures of pectoralis muscle area and disease severity in chronic obstructive pulmonary disease. A cross-sectional study.
        Ann Am Thorac Soc. 2014; 11: 326-334
        • Tong Y.
        • et al.
        Chest fat quantification via CT based on standardized anatomy space in adult lung transplant candidates.
        PLoS One. 2017; 12: e0168932
        • Young P.
        • et al.
        Acetaminophen for fever in critically ill patients with suspected infection.
        N Engl J Med. 2015; 373: 2215-2224
        • Fuchs G.
        • et al.
        Lumbar skeletal muscle index derived from routine computed tomography exams predict adverse post-extubation outcomes in critically ill patients.
        J Crit Care. 2018; 44: 117-123
        • Janssen I.
        • Heymsfield S.B.
        • Wang Z.M.
        • Ross R.
        Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr.
        J Appl Physiol (1985). 2000; 89: 81-88
        • Pai M.P.
        • Paloucek F.P.
        The origin of the “ideal” body weight equations.
        Ann Pharmacother. 2000; 34: 1066-1069
        • Casaer M.P.
        • Van den Berghe G.
        Nutrition in the acute phase of critical illness.
        N Engl J Med. 2014; 370: 1227-1236
        • Ferrante L.E.
        • et al.
        Functional trajectories among older persons before and after critical illness.
        JAMA Intern Med. 2015; 175: 523-529
        • Ferrante L.E.
        • et al.
        The association of frailty with post-ICU disability, nursing home admission, and mortality: a longitudinal study.
        Chest. 2018; 153: 1378-1386
        • Deasy B.M.
        • et al.
        A role for cell sex in stem cell-mediated skeletal muscle regeneration: female cells have higher muscle regeneration efficiency.
        J Cell Biol. 2007; 177: 73-86
        • Moisey L.L.
        • et al.
        Skeletal muscle predicts ventilator-free days, ICU-free days, and mortality in elderly ICU patients.
        Crit Care. 2013; 17: R206
        • Evans W.J.
        What is sarcopenia?.
        J Gerontol A Biol Sci Med Sci. 1995; 50: 5-8
        • Hepple R.T.
        Muscle atrophy is not always sarcopenia.
        J Appl Physiol (1985). 2012; 113: 677-679
        • Delbono O.
        Expression and regulation of excitation-contraction coupling proteins in aging skeletal muscle.
        Curr Aging Sci. 2011; 4: 248-259
        • Sandri M.
        • et al.
        Signalling pathways regulating muscle mass in ageing skeletal muscle: the role of the IGF1-Akt-mTOR-FoxO pathway.
        Biogerontology. 2013; 14: 303-323
        • O'Brien Jr., J.M.
        • et al.
        Body mass index is independently associated with hospital mortality in mechanically ventilated adults with acute lung injury.
        Crit Care Med. 2006; 34: 738-744
        • Martino J.L.
        • et al.
        Extreme obesity and outcomes in critically ill patients.
        Chest. 2011; 140: 1198-1206
        • Shashaty M.G.
        • Stapleton R.D.
        Physiological and management implications of obesity in critical illness.
        Ann Am Thorac Soc. 2014; 11: 1286-1297
        • Paolini J.B.
        • et al.
        Predictive value of abdominal obesity vs. body mass index for determining risk of intensive care unit mortality.
        Crit Care Med. 2010; 38: 1308-1314
        • Puthucheary Z.A.
        • et al.
        Rectus femoris cross-sectional area and muscle layer thickness: comparative markers of muscle wasting and weakness.
        Am J Respir Crit Care Med. 2017; 195: 136-138
        • Puthucheary Z.A.
        • et al.
        Qualitative ultrasound in acute critical illness muscle wasting.
        Crit Care Med. 2015; 43: 1603-1611
        • Files D.C.
        • et al.
        A critical role for muscle ring finger-1 in acute lung injury-associated skeletal muscle wasting.
        Am J Respir Crit Care Med. 2012; 185: 825-834
        • Jaitovich A.
        • et al.
        High CO2 levels cause skeletal muscle atrophy via AMP-activated kinase (AMPK), FoxO3a protein, and muscle-specific Ring finger protein 1 (MuRF1).
        J Biol Chem. 2015; 290: 9183-9194
        • Kim Y.S.
        • Kim E.Y.
        • Kang S.M.
        • Ahn H.K.
        • Kim H.S.
        Single cross-sectional area of pectoralis muscle by computed tomography—correlation with bioelectrical impedance based skeletal muscle mass in healthy subjects.
        Clin Physiol Funct Imaging. 2017; 37: 507-511
        • Gokhin D.S.
        • et al.
        Thin-filament length correlates with fiber type in human skeletal muscle.
        Am J Physiol Cell Physiol. 2012; 302: C555-C565
        • Ciciliot S.
        • Rossi A.C.
        • Dyar K.A.
        • Blaauw B.
        • Schiaffino S.
        Muscle type and fiber type specificity in muscle wasting.
        Int J Biochem Cell Biol. 2013; 45: 2191-2199
        • Fan E.
        • et al.
        An official American Thoracic Society Clinical Practice guideline: the diagnosis of intensive care unit-acquired weakness in adults.
        Am J Respir Crit Care Med. 2014; 190: 1437-1446
        • Kinsey C.M.
        • et al.
        Lower pectoralis muscle area is associated with a worse overall survival in non-small cell lung cancer.
        Cancer Epidemiol Biomarkers Prev. 2017; 26: 38-43
        • Detsky M.E.
        • et al.
        Discriminative accuracy of physician and nurse predictions for survival and functional outcomes 6 months after an ICU admission.
        JAMA. 2017; 317: 2187-2195
        • Mahler D.A.
        • Wells C.K.
        Evaluation of clinical methods for rating dyspnea.
        Chest. 1988; 93: 580-586
        • Hough C.L.
        • Lieu B.K.
        • Caldwell E.S.
        Manual muscle strength testing of critically ill patients: feasibility and interobserver agreement.
        Crit Care. 2011; 15: R43