Biomarkers for individualized nutritional therapy in disease-related malnutrition: a narrative review

Disease-related malnutrition in hospitalized adult medical patients is a syndrome associated with substantially higher morbidity, disability, both short- and long-term mortality, delayed recovery, and increased healthcare costs compared with individuals without malnutrition. Research on malnutrition has aimed to translate existing knowledge of its pathophysiology into improved diagnostic and therapeutic strategies. The aim of this narrative review is to summarize current evidence on the use of biomarkers to individualize nutritional therapy. There is particular interest in developing nutritional interventions to mitigate the adverse effects of disease-related malnutrition within hospital environments. Recent high-quality randomized controlled trials have demonstrated that nutritional therapy significantly reduces morbidity and other complications associated with malnutrition in selected patient populations. Additionally, there is growing evidence that phenotyping patients through assessing nutritional biomarkers or adapted risk screening scores may enhance our ability to characterize them in terms of prognosis and likelihood of treatment response. Currently, several promising biomarkers have been identified, including markers of inflammation (e.g. C-reactive protein and interleukin-6), indicators of chronic disease (e.g. creatinine, prealbumin, albumin, and red cell distribution width), measures of muscle health (e.g. hand grip strength and computed tomography scan results), endocrine and exocrine markers, estimates of catabolism as well as emerging metabolomic indicators. Although the clinical use of individual biomarkers requires careful assessment, machine learning and artificial intelligence show promise for improving the analysis and interpretation of existing data in the near future. It is crucial to use biomarkers to distinguish etiology at an individual level when implementing nutritional treatment interventions. The key challenge ahead is to determine the most effective way to incorporate these biomarkers into established assessment tools, optimizing personalized nutritional care for patients with malnutrition.