New Perspectives in the Association between Anthropometry and Mortality: The Role of Calf Circumference

Aims Considering the impact of sarcopenia on mortality, and the difficulty to assessment of body composition, the hypothesis of the study is that calf circumference (CC) is closely related to mortality in older patients. The aim of the study was to analyze the potential role of CC to predict mortality in old individuals at 3, 6 and 12 months after discharge from hospital. Methods Patients aged >65 years were recruited for this retrospective study from September 2021 to March 2022. Their physical and body composition characteristics (including Body Mass Index-BMI and Mini Nutritional Assessment-MNA) were measured; data on mortality at 3 (T3), 6 (T6) and 12 (T12) months after discharge were recorded. Sarcopenia was diagnosed according to the 2019 European Consensus criteria. Results Participants were 192 older adults (92 women), with a mean age of 82.8 +/- 7.0 years. Sarcopenic people were 41. The mortality rate was higher in sarcopenic people only at T3 and T6. CC had comparable validity in predicting mortality to that of MNA and ASMMI (Appendicular Skeletal Muscle Mass), and was better than BMI and serum albumin at each time point. Youden's index showed that the best cut-off for CC for predicting mortality was 30.6 cm both at T3 (sensitivity: 74%; specificity: 75%) and T6 (sensitivity: 75%; specificity: 67%). At the Cox regression model for mortality, high values of CC (HR 0.73, CI95% 0.60-0.89/p<0.001) and ADL scores (HR 0.72, CI95% 0.54-0.96/p=0.04) were protective factors at T6 and T12 respectively; at T12 high comorbidity rate was a risk factor (HR 1.28, IC95% 1.02-1.62/p=0.04). Conclusions CC has a validity comparable to MNA and ASMMI in predicting mortality at 3, 6 and 12 months after hospital discharge. Moreover, it can be considered an independent predictor of medium-term mortality in the hospitalized older population. CC can be an effective method for the prognostic stratification of these patients, due to its simplicity and immediacy.