Lean mass as a risk factor for intensive care unit admission: an observational study

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Purpose</jats:title> <jats:p>Intensive care unit (ICU) survivors have reduced physical function likely due to skeletal muscle wasting and weakness acquired during critical illness. However, the contribution of pre-morbid muscle mass has not been elucidated. We aimed to examine the association between pre-ICU muscle mass and ICU admission risk. Secondary outcomes include the relationship between muscle mass and ICU outcomes.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>ICU admissions between June 1, 1998, and February 1, 2019, were identified among participants of Geelong Osteoporosis Study (GOS), a population-based cohort study. Cox proportional hazard regression models estimated hazard ratios (HR) for ICU admission across T-score strata and continuous values of DXA-derived lean mass measures of skeletal mass index (SMI, lean mass/body mass %) and appendicular lean mass corrected for height (ALM/h<jats:sup>2</jats:sup>, kg/m<jats:sup>2</jats:sup>). Multivariable regression was used to determine the relationship between lean mass and ICU outcomes.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>One hundred and eighty-six of 3126 participants enrolled in GOS were admitted to the ICU during the follow-up period. In adjusted models, lean mass was not predictive of ICU admission (SMI: HR 0.99 95%CI 0.97–1.01, <jats:italic>p</jats:italic> = 0.32; ALM/h<jats:sup>2</jats:sup>: HR 1.11 95%CI 0.94–1.31, <jats:italic>p</jats:italic> = 0.23), while greater appendicular lean mass was related to reduced 28-day mortality (ALM/h<jats:sup>2</jats:sup> adjOR: 0.25, 95%CI 0.10–0.63, <jats:italic>p</jats:italic> = 0.003, SMI adjOR: 0.91, 95%CI 0.82–1.02, <jats:italic>p</jats:italic> = 0.09).</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>Lean mass was not associated with ICU