Phase angle from bioelectrical impedance analysis as a reliable marker for malnutrition detection in patients with...

Malnutrition is common among patients with heart failure (HF), yet accurate assessment of nutritional status in this population remains challenging. The phase angle (PhA) derived from bioelectrical impedance analysis (BIA) has been proposed as a marker of nutritional status at the cellular level; however, concerns persist regarding its dependence on hydration status.

This study aimed to assess the association between HF and nutritional status, with particular emphasis on phase angle (PhA) measured at 50 kHz, and to evaluate its diagnostic value in comparison with other indices, including the Nutritional Risk Screening 2002 (NRS 2002), body mass index (BMI), and selected laboratory parameters.

In this cross-sectional study, 270 patients with chronic coronary syndrome were evaluated using laboratory tests, anthropometric measurements, the NRS 2002, and BIA. Patients were stratified according to HF status. Statistical analyses included parametric and non-parametric tests, correlation analyses, multivariable logistic regression models, and receiver operating characteristic (ROC) curve analysis. Adjustments were made for age, sex, BMI, estimated glomerular filtration rate (eGFR), hemoglobin, and extracellular fluid percentage (ECF%).

Heart failure was present in 91 of 270 patients (33.7%). Patients with HF had significantly lower PhA (median 4.79 vs 5.22; p < 0.001), higher NRS 2002 scores (p = 0.010), and lower eGFR and hemoglobin levels. In multivariable logistic regression analysis, PhA remained independently associated with HF (odds ratio (OR) = 0.62; p = 0.016), whereas NRS 2002 and ECF% were not significant. Inclusion of ECF% did not improve model performance. In ROC analysis, PhA showed modestly higher discriminative ability for HF (area under the curve (AUC) = 0.636) compared with NRS 2002 (AUC = 0.594) and BMI (AUC = 0.598).

Heart failure is associated with impaired nutritional status. Phase angle appears to be a clinically relevant marker that remains independently associated with HF after adjustment for hydration status and may be considered as a complementary tool for routine nutritional screening in this high-risk population.