Low calf circumference adjusted for body mass index is associated with prolonged hospital stay

Background: Calf circumference (CC) is of emerging importance because of its practicality, high correlation with skeletal muscle, and potential pre-dictive value for adverse outcomes. However, the accuracy of CC is influenced by adiposity. CC adjusted for BMI (BMI-adjusted CC) has been proposed to counteract this problem. However, its accuracy to predict outcomes is unknown.Objectives: To evaluate the predictive validity of BMI-adjusted CC in hospital settings.Methods: A secondary analysis of a prospective cohort study in hospitalized adult patients was conducted. The CC was adjusted for BMI by reducing 3, 7, or 12 cm for BMI (in kg/m2) of 25-29.9, 30-39.9, and >= 40, respectively. Low CC was defined as <34 cm for males and <33 cm for females. Primary outcomes included length of hospital stay (LOS) and in-hospital death, and secondary outcomes were hospital readmissions and mortality within 6 mo after discharge.Results: We included 554 patients (55.2 +/- 14.9 y, 52.9% men). Among them, 25.3% presented with low CC, whereas 60.6% had BMI-adjusted low CC. In-hospital death occurred in 13 patients (2.3%), and median LOS was 10.0 (5.0-18.0) d. Within 6 mo from discharge, 43 patients (8.2%) died, and 178 (34.0%) were readmitted to the hospital. BMI-adjusted low CC was an independent predictor of LOS >= 10 d (odds ratio = 1.70; 95% confidence interval: 1.18, 2.43], but it was not associated with the other outcomes.Conclusions: BMI-adjusted low CC was identified in more than 60% of hospitalized patients and was an independent predictor of longer LOS.

Automated summary

Calf circumference (CC) is important for predicting adverse outcomes, but its accuracy is influenced by adiposity. BMI-adjusted CC has been proposed as a solution, but its predictive validity is unknown. This study evaluates the predictive validity of BMI-adjusted CC in hospital settings.