Selected Biochemical, Hematological, and Immunological Blood Parameters for the Identification of Malnutrition in Polish Senile Inpatients: A Cross-Sectional Study

<b>Background/Objectives</b>: Malnutrition in senile patients leads to functional disability while reducing quality of life. Medical professionals should routinely assess their nutritional status during hospitalization. However, diagnosing malnutrition may be difficult, especially since obesity may mask malnourishment. Thus, it is essential to search for biomarkers that improve the identification of malnourished inpatients. <b>Methods</b>: In the present cross-sectional study, selected venous blood parameters were analyzed in 137 older inpatients at the age of 80.5 ± 7.78 admitted to the Geriatrics Clinic of the Antoni Jurasz University Hospital No. 1 in Bydgoszcz, Poland between 2017 and 2018, for a comprehensive geriatric assessment. The participants were grouped according to their nutritional risks based on the Mini Nutritional Assessment (MNA) and the Geriatric Nutrition Risk Index (GNRI). The Kruskal-Wallis test was utilized to evaluate the equality of variances for a variable calculated for two or more groups. The level of significance was set at <i>p</i> < 0.05. <b>Results</b>: For total protein, albumin, homocysteine, hemoglobin, hematocrit, total magnesium, total calcium, C-reactive protein (CRP), interleukin 6 (IL-6), and interferon γ-induced protein 10 (IP-10), statistically significant differences were found between groups of patients classified by the MNA. However, additional significant differences were also observed for creatinine, folic acid, and triglycerides, according to the GNRI compartmentalization. The results indicate that decreased levels of albumin (<3 g/dL) and hemoglobin (<11 g/dL), along with elevated homocysteine, CRP, IL-6 (>7.5 pg/mL), and IP-10 (>250 pg/mL), should alert medical professionals to potential malnutrition in hospitalized patients. <b>Conclusions</b>: Routine analysis of venous blood parameters can help rapidly identify malnutrition and the immediate implementation of a specialized diet.