Predictive value of bioelectrical impedance analysis for clinical outcomes in older adults at nutritional risk admitted to an intermediate care convalescent unit.

BACKGROUND: Bioelectrical impedance analysis (BIA) is a widely used technique in clinical practice, especially in the field of nutrition. Some of its parameters have been associated with an increased risk of malnutrition, sarcopenia, and mortality. AIM: To evaluate the prognostic value of BIA parameters in elderly people at risk of malnutrition admitted to a convalescent unit. METHODS: We conducted an observational and prospective study of older adults at nutritional risk admitted to a convalescent unit, followed from admission to hospital discharge. All of them underwent BIA within the first week of admission. The main outcome measures were in-hospital complications, in-hospital mortality, and length of stay. Nutritional status (GLIM criteria), sarcopenia (EWGSOP2 criteria), and frailty (Frail-VIG criteria) were assessed as well. RESULTS: 142 patients (62% men, mean age of 82.5 years (SD, 7.58) were recruited. A total of 57.7% exhibited complications during admission; the mean length of stay was 45.0 days (SD, 24.1), and the in-hospital mortality rate, 11.3%. In women, in-hospital complications and mortality were associated with a lower Phase Angle (PhA) and a higher total body water/fat free mass and extracellular water/intracellular water ratios. Survival was significantly lower when PhA on admission was <4.5 ° in men and <4.0 ° in women, as well as when the intracellular water/fat free mass ratio was <0.33 in both sexes. CONCLUSIONS: PhA and an imbalance between extracellular and intracellular water are indicators of poor prognosis in elderly patients admitted to a convalescent unit.