Prevalence and development of sarcopenia and malnutrition in neurological patients during inpatient rehabilitation: a prospective cohort with an embedded, cross-sectional concurrent validity study for regional sarcopenia measurements

Evidence indicates that neurological patients exhibit high levels of sarcopenia due to disease, inactivity and malnutrition, which itself often occurs due to feeding impairments. Knowledge about the evolution of these pathologies during inpatient rehabilitation is lacking. Additionally, current gold-standard measures assess whole-body sarcopenia although regional presentations may be common in neurological patients. The aims of this study are to investigate the prevalence and development of sarcopenia and malnutrition over six months during in-patient neurological rehabilitation using 1.) gold-standard measurements (EWGSOP2 Criteria) and 2.) regional measurements (segmental BIA) for sarcopenia, to evaluate the concurrent-validity. Patients admitted to a neurological rehabilitation clinic between April-June 2023 were assessed for eligibility and, if eligible, followed for six months. Those eligible were screened for malnutrition and sarcopenia risk at admission, three weeks, three months, and six months or three days prior to discharge, those screening positive underwent diagnostic testing. Sarcopenia was assessed using gold-standard and regional (index) tests. From 105 individuals admitted, 45 (48.9% male) were included and analyzed. Malnutrition: baseline prevalence was 31.1% (95% CI 18.2-46.6), which dropped to 0% (95% CI 0-28.5) after 6 months. Sarcopenia: baseline prevalence was 37.8% (95% CI 23.8-53.5), which dropped to 26.2% (95% CI 13.9-42) at 3 weeks and did not change again. The baseline prevalence of regional sarcopenia was higher (42.2%), but the trends were similar. Regional measurements demonstrated high sensitivity (100%), specificity (93-100%) and levels of agreement (k=0.91-1.0) compared to gold standard. Malnutrition and sarcopenia are common in neurological patients. Regional sarcopenia tests have similar validity to whole-body assessments and can find asymmetric sarcopenia, which makes it useful for targeted rehabilitation in neurological patients. Registered at ClinicalTrials.gov with the identifier 2022-01098.