Avaliação de risco de sarcopenia em pacientes idosos com câncer usando a ferramenta SARC-CALF: comparação entre a circunferência da panturilha bruta e ajustada pelo índice de massa corporal

Abstract

Introduction: Sarcopenia is a concerning condition in elderly cancer patients and can lead to adverse outcomes. In clinical practice, screening tools are considered one of the most accessible methods for healthcare professionals. The SARC-CalF is an available screening method that includes the Calf Circumference (CC) parameter as a marker of Muscle Mass (MM). However, in overweight patients, adiposity may lead to false negatives. In these cases, adjusting CC by Body Mass Index (BMI) could help identify patients with low CC who are at risk of sarcopenia. Although BMI-adjusted CC is already available, no study has explored its prognostic value in SARC-CalF among an elderly cancer population. Objectives: To evaluate and compare the frequencies of positive scores using the unadjusted SARC-CalF with scores derived from the SARC-CalF after adjusting Calf Circumference (CC) by Body Mass Index (BMI). The secondary objective was to evaluate the prognostic value of the SARC-CalF after BMI adjustment, including hospitalization time and mortality. Methods: This is a prospective cohort study (2019-2023) of elderly (≥60 years) outpatients and inpatients recruited from the Onofre Lopes University Hospital (HUOL) in Brazil. Sociodemographic and clinical data were collected, including the outcomes of length of stay and in-hospital mortality at 6 and 12 months. Weight, height and WC were measured. BMI was classified according to the World Health Organization (WHO) and patients who were overweight (≥ 25 Kg/m²) had their WC adjusted based on the adjustment proposed by Gonzales et. al, (2021). In these individuals, the values of 3 cm, 7 cm and 12 cm were subtracted, according to the BMI values: 25-29.9 Kg/m², 30- 39.9 Kg/m² and ≥ 40.0 Kg/m², respectively. The SARC-CalF was used to assess the risk of sarcopenia (score ≥11). The data was analyzed using the Statistical Package for the Social Sciences (SPSS) and MedCalc software. The normality of the continuous variables was assessed using the Shapiro-Wilk normality test. Sex-specific and SARCCalF comparisons were conducted using the following tests: independent Student's ttest, Mann-Whitney U-test, Pearson's χ² test or Fisher's exact test, as appropriate. The variance ratio of SARC-CalF scores was assessed using the F-test. Crude and adjusted Cox regression analyses were conducted to assess the association between unadjusted and BMI-adjusted SARC-CalF. Results: A total of 206 individuals were included in this analysis, with a mean age of 69 years and half being male (52.1%). Excess weight was present in 36.4% (n=75), and their Calf Circumference (CC) was adjusted by Body Mass Index (BMI). The prevalence of low CC increased from 65% (n=134) to 84% (n=173) after BMI adjustment. The risk of sarcopenia was identified in 51% (n=105) of the population before adjustment, and after adjustment, the frequency of positive SARC-CalF scores increased to 65.0% (n=134). The unadjusted SARC-CalF was independently associated with mortality at 12 months (adjusted HR 2.26 [95% CI 1.38-3.71]). After adjusting CC by BMI, SARC-CalF emerged as an independent predictor of prolonged hospitalization (adjusted HR: 1.26 [95% CI 1.03-1.53]), mortality at 6 months (adjusted HR 1.42 [95% CI 1.07-1.87]), and at 12 months (adjusted HR 1.99 [95% CI 1.03-1.53]). Conclusion: The BMI-adjusted SARC-CalF could be a practical strategy to better identify overweight elderly cancer patients at risk of sarcopenia, representing a potential prognostic tool, as it was independently associated with prolonged hospitalization and mortality.