Population aging is accompanied by multimorbidities and several systemic changes, such as cardiovascular, functional and strength, which can result in recurrent hospitalizations. In it, functional alterations of pre-existing strength and independence are potentiated, increasing dependence, loss of function and prolonged hospitalization. Identify the profile of the elderly in terms of these variables allows directing effective interventions in search of major complications.

To evaluate cardiac autonomic control, functional capacity, peripheral muscle strength and independence for activities of daily living (ADL), and the relationship between these variables and the risk of mortality in hospitalized elderly.

Observational, cross-sectional study carried out in a university hospital. Elderly >60 years old, with preserved cognition and hemodynamically stable, were included. Lowered level of consciousness, acute respiratory failure, unstable vital signs, dyspnea on minimal exertion and sepsis were exclusion criteria. The Charlson Comorbidity Index was applied, and the following evaluations were performed: records of the R-R intervals for analysis of heart rate variability (HRV), Barthel index, handgrip strength (HGS) and the 5-time sit-to-stand test (STS5) (patients eligible for execution). Statistical analysis: Using the SPSS software, the Shapiro-Wilk, Wilcoxon and Spearman correlation tests were applied. Values presented as mean, standard deviation and p≤0.05.

20 elderly with a mean age of 70.4 ± 7.17 years (12 men (60%) and 8 women (40%)) participated until the moment of the study. The HRV indices showed no significant change in the change between the supine and sitting position (SDNN p=0.65; RMSSD p=0.57; PNN50 p=0.39; LF p=0.14; HF p=0, 15 and LF/HF p=0.19). The average Charlson score was 5.65 ± 2.90. Reduced HGS values were found in the dominant limb (24.22 ± 9.45 Kgf; 75.78% of predicted), STS5 (19.04 ± 6.10s; 57.93% of predicted) and Barthel (63.25 ± 29.57). The RMSSD index showed a negative correlation with the STS5 (rs=-0.90, p=0.03) and the Barthel index showed a positive correlation with the FPP (rs=0.62, p=0.01).

Hospitalized elderly did not show changes in HRV indices after postural change, which may indicate an altered autonomic response in this population. In addition, they showed a reduction in peripheral muscle strength and functional performance, and a moderate risk of mortality at one year. Higher RMSSD index values correlated with lower execution times in the STS5, as well as higher FPP correlated with lower dependency. We suggest that new studies like this one be carried out, characterizing, and correlating these variables with frailty and sarcopenia.

Given these results, even though the sample is small and partial, it is imperative to evaluate these variables at the time of hospitalization of the elderly, to guide multidisciplinary teams in decision-making for intervention and prevention of greater functional and strength losses in this population.