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Can phase angle determined by bioelectrical impedance analysis assess nutritional risk? A comparison between healthy
Ursula G Kyle1, Esther P Soundar, Laurence Genton
1Baylor College of Medicine/Texas Children's Hospital, Pediatric Critical Care Medicine, 6621 Fannin St WT6-006, Houston, TX 77030, USA. ukyle@bcm.edu
Insights
Low phase angle (PhA), a measure from bioelectrical impedance analysis (BIA), is a reliable indicator of nutritional risk in hospitalized patients. This study identified optimal PhA cut-off values, demonstrating its utility as a screening tool.
Area of Science:
- Clinical Nutrition
- Biomarkers
- Medical Diagnostics
Background:
- Low phase angle (PhA) measured by bioelectrical impedance analysis (BIA) is linked to increased morbidity and nutritional risk in patients.
- Establishing reliable cut-off values for PhA is crucial for accurate nutritional assessment.
Purpose of the Study:
- To determine optimal phase angle (PhA) cut-off values in male and female patients upon hospital admission.
- To compare the efficacy of PhA against established nutritional screening tools: Nutritional Risk Screening 2002 (NRS-2002) and Subjective Global Assessment (SGA).
- To evaluate the association between PhA and serum albumin levels.
Main Methods:
- Phase angle (PhA) was measured in 382 men and 267 women, alongside age-, sex-, and height-matched healthy controls.
- Sensitivity, specificity, and receiver operator characteristic area under the curve (ROC-AUC) were calculated for PhA against NRS-2002, SGA, and serum albumin.
- Cut-off values for PhA were determined using ROC-AUC analysis.
Main Results:
- Optimal PhA cut-off values were identified as 5.0° for men and 4.6° for women.
- PhA demonstrated good sensitivity and specificity when compared to NRS-2002 and SGA.
- Patients with serum albumin levels below 35 g/L had a 7.5-fold increased risk of having a low PhA.
Conclusions:
- The consistent performance of PhA compared to NRS-2002, SGA, and serum albumin validates its use in nutritional assessment.
- Phase angle (PhA) serves as a valuable and practical screening tool for identifying nutritional risk in hospitalized patients.
- PhA offers an advantage as it does not require weight or height measurements for assessment.
Background & Aims:
Low phase angle (PhA) by bioelectrical impedance analysis (BIA), is associated with increased morbidity and nutritional risk. This study determined the cut-off values for PhA compared to Nutritional Risk Screening (NRS-2002) and Subjective Global Assessment (SGA) in patients at hospital admission, and evaluated the association between PhA and serum albumin.
Methods:
PhA was determined in patients (Men (M)/Women (W)=382/267), and healthy age-, sex- and height-matched controls. Sensitivity and specificity were calculated for PhA compared to NRS-2002, SGA and serum albumin. The cut-off values were assessed by receiver operator characteristics area under the curve (ROC-AUC).
Results:
The best PhA cut-offs were 5.0° and 4.6° in M/W. The sensitivity for NRS-2002 was 70.0/58.1% (M/W); SGA: 73.3/64.5%; albumin: 58.8/23.5%; specificity for NRS-2002: 85.1/81.7% (M/W); SGA: 76.6/76.1% and albumin: 93.2/96.6%. The PhA showed a ROC-AUC for NRS-2002 of 0.85/0.80 (M/W); SGA: 0.83/0.80 and albumin: 0.85/0.91. Patients with albumin levels <35 g/L had a relative risk of 7.5 to have low PhA compared to patients with ≥35 g/L CONCLUSIONS: The consistent sensitivity and specificity between PhA and three screening tools strengthens the validity of our study. PhA appears to be a useful screening tool to assess nutritional risk without having to measure weight or height.
