Background: A nationwide, prospective, multicenter, cohort study (the Disease-Related caloric-protein malnutrition EChOgraphy (DRECO) study) was designed to assess the usefulness of ultrasound of the rectus femoris for detecting sarcopenia in hospitalized patients at risk of malnutrition and to define cut-off values of ultrasound measures. Methods: Patients at risk of malnutrition according to the Malnutrition Universal Screening Tool (MUST) underwent handgrip dynamometry, bioelectrical impedance analysis (BIA), a Timed Up and Go (TUG) test, and rectus femoris ultrasound studies. European Working Group on Sarcopenia in Older People (EWGSOP2) criteria were used to define categories of sarcopenia (at risk, probable, confirmed, severe). Receiver operating characteristic (ROC) and area under the curve (AUC) analyses were used to determine the optimal diagnostic sensitivity, specificity, and predictive values of cut-off points of the ultrasound measures for the detection of risk of sarcopenia and probable, confirmed, and severe sarcopenia. Results: A total of 1000 subjects were included and 991 of them (58.9% men, mean age 58.5 years) were evaluated. Risk of sarcopenia was detected in 9.6% patients, probable sarcopenia in 14%, confirmed sarcopenia in 9.7%, and severe sarcopenia in 3.9%, with significant differences in the distribution of groups between men and women (p < 0.0001). The cross-sectional area (CSA) of the rectus femoris showed a significantly positive correlation with body cell mass of BIA and handgrip strength, and a significant negative correlation with TUG. Cut-off values were similar within each category of sarcopenia, ranging between 2.40 cm² and 3.66 cm² for CSA, 32.57 mm and 40.21 mm for the X-axis, and 7.85 mm and 10.4 mm for the Y-axis. In general, these cut-off values showed high sensitivities, particularly for the categories of confirmed and severe sarcopenia, with male patients also showing better sensitivities than women. Conclusions: Sarcopenia in hospitalized patients at risk of malnutrition was high. Cut-off values for the better sensitivities and specificities of ultrasound measures of the rectus femoris are established. The use of ultrasound of the rectus femoris could be used for the prediction of sarcopenia and be useful to integrate nutritional study into real clinical practice.

Bariatric surgery is the most efficacious treatment for obesity, though it is not free from complications. Preoperative conditioning has proved beneficial in various clinical contexts, but the evidence is scarce on the role of prehabilitation in bariatric surgery. We describe the protocol and pilot study of a randomized (ratio 1:1), parallel, controlled trial assessing the effect of a physical conditioning and respiratory muscle training programme, added to a standard 8-week group intervention based on therapeutical education and cognitive-behavioural therapy, in patients awaiting bariatric surgery. The primary outcome is preoperative weight-loss. Secondary outcomes include associated comorbidity, eating behaviour, physical activity, quality of life, and short-term postoperative complications. A pilot sample of 15 participants has been randomized to the intervention or control groups and their baseline features and results are described. Only 5 patients completed the group programme and returned for assessment. Measures to improve adherence will be implemented and once the COVID-19 pandemic allows, the clinical trial will start. This is the first randomized, clinical trial assessing the effect of physical and respiratory prehabilitation, added to standard group education and cognitive-behavioural intervention in obese patients on the waiting list for bariatric surgery. Clinical Trial Registration: NCT0404636.