Unraveling the Link between Malnutrition and Adverse Clinical Outcomes: Association of Acute and Chronic Malnutrition Measures with Blood Biomarkers from Different Pathophysiological States

BACKGROUND AND AIMS: Malnutrition is associated with poor clinical outcomes. Whether there is a causal relationship or it merely mirrors a severe patient condition remains unclear. We examined the association of malnutrition with biomarkers characteristic of different pathophysiological states to better understand the underlying etiological mechanisms. METHODS: We prospectively followed consecutive adult medical inpatients. Multivariable regression models were used to investigate the associations between malnutrition - as assessed using the Nutritional Risk Screening (NRS 2002) - and biomarkers linked to inflammation, stress, renal dysfunction, nutritional status and hematologic function. RESULTS: A total of 529 patients were included. In a fully adjusted model, malnutrition was significantly associated with the inflammatory markers procalcitonin (0.20, 95% CI 0.03-0.37), proadrenomedullin (0.28, 95% CI 0.12-0.43) and albumin (-0.39, 95% CI -0.57 to -0.21), the stress marker copeptin (0.34, 95% CI 0.17-0.51), the renal function marker urea (0.23, 95% CI 0.07-0.38), the nutritional markers vitamin D25 (-0.22, 95% CI -0.41 to -0.02) and corrected calcium (0.29, 95% CI 0.10-0.49) and the hematological markers hemoglobin (-0.27, 95% CI -0.43 to -0.10) and red blood cell distribution width (0.26, 95% CI 0.07-0.44). Subgroup analysis suggested that acute malnutrition rather than chronic malnutrition was associated with elevated biomarker levels. CONCLUSION: Acute malnutrition was associated with a pronounced inflammatory response and an alteration in biomarkers associated with different pathophysiological states. Interventional trials are needed to prove causality.