Low‐cost and fast‐performing indicators of muscle mass loss are good predictors of clinical outcomes in hospitalized patients: A longitudinal observational study

Abstract

Background: "Gold standard" methods for muscle mass (MM) assessment are expensive and difficult to use in clinical practice. The present study aimed to evaluate the association between easy-to-apply and low-cost indicators of MM and clinical outcomes in hospitalized patients. Methods: In this cohort study, calf circumference [CC], adductor pollicis muscle thickness [APMT], midarm muscle circumference [MAMC], and arm muscle area [AMA]were measured within 48 h of admission to detect MM loss, and it was also evaluated by physical examination. Patients were followed up until discharge for collection of inhospital death and length of hospital stay (LOS) data, and they were contacted by phone to assess hospital readmission and mortality at 6 months after discharge.

Absence of association between low calf circumference, adjusted or not for adiposity, and ICU mortality in critically ill adults: A secondary analysis of a cohort study

“…14 They observed that low unadjusted calf circumference at ICU admission increased the risk of ICU mortality by 2.63-fold in 249 patients with COVID-19. 14 However, their patient characteristics differed significantly from those in our sample, presenting higher severity with a mean SOFA score of 9.6 ± 3.5, median ICU stay of 14 days (range, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], and an ICU death rate of 48.6%. Notably, they examined unadjusted calf circumference in their analysis.…”

“…(3) a cohort study of 601 hospitalized patients observed that low calf circumference (<34 cm for men and <33 cm for women) was an independent predictor of in-hospital death and death at 6 months after discharge 22 ; (4) a cohort study involving 12,138 patients with cancer established that calf circumference values <32.8 cm for men and <30 cm for women were associated with higher mortality risk. 29 The review also excluded studies analyzing continuous calf circumference.…”

“…19,32 Its raw measurement requires interpretation in the context of an individual's body adiposity because it includes subcutaneous adipose tissue, leading to an overestimation of muscle mass. 16,33 However, most studies assessing calf circumference as a muscularity marker and its prognostic value in hospitalized patients 9,10,[12][13][14]22,27,28 and outpatients overlook BMI's impact on measurements and do not include BMI as a covariate in their multivariable analysis. [23][24][25] A further concern involves the values adopted to classify low calf circumference.…”

“…34 Many studies analyze calf circumference as a dichotomous independent variable in multiple regression. [9][10][11][12][13][14]22,24,25,27,28,35,36 However, this procedure leads to information loss, bias, and inefficiency because it ignores within-category variations, limits study comparability, and increases the misclassification risk. 37,38 Moreover, data distribution and outliers can influence calf circumference performance.…”

“…These results align with a meta-analysis showing 51.0% with low skeletal muscle mass at ICU admission, primarily by CT evaluation. 1 Prior studies have demonstrated the association between low calf circumference and adverse clinical outcomes in non-critically ill hospitalized patients [9][10][11][12][13]22 and outpatients. [23][24][25] A meta-analysis by Wei et al 26 comprising various settings showed that individuals with low calf circumference had a twofold higher mortality risk.…”