Association between phase angle and the nutritional status in pediatric populations: a systematic review

Abstract

Background and aimsMalnutrition is prevalent in pediatric populations with any disease, and it is also related to changes in body composition. In addition, recent studies have documented relationships between these changes and phase angle (PhA), an important parameter of functional nutritional assessment. PhA could be a new marker of nutritional status. Many studies have generated information about the association between PhA and malnutrition in various pathologies, although the vast majority of this information is from adult populations. In this systematic review, we answered the following question: What is the association between PhA and the nutritional status in pediatric populations?MethodsWe performed a systematic search of the Medline/PubMed and Latin American and Caribbean Health Sciences Literature databases (LILACS) databases for studies published up to October 2022. The inclusion criteria were pediatric subjects, which reported the relationship between PhA and the nutritional status with any objective nutritional indicator, and PhA was measured by electric impedance and reported at 50 kHz. We synthesized data from the studies that reported cutoff analysis of PhA with receiver operating characteristic (ROC) curves, mean PhA values presented by nutritional status strata, and correlations between PhA and nutritional status indicators. We assessed the risk of bias by using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the Quality Assessment for Diagnostic Accuracy Studies.ResultsOf the 126 studies we identified, 15 met the inclusion criteria. The included studies reported the association between PhA and objective indicators of nutritional status, including weight-for-age z-score (WAZ) <-1 standard deviation (SD) for malnutrition, height-for-age z-score (HAZ) for malnutrition-stunting, body mass index (BMI) for the starvation state, body mass index z-score (BMIz) and BMI for malnutrition, mid-upper arm circumference (MUAC) <11 cm for severe acute malnutrition (SAM), and fat-free mass index z-score (FFMIz) <-2 z-score for moderate malnutrition, among others. The report of these associations between PhA and nutritional status was based on cutoff points generated with ROC curve analysis or comparison of mean PhA values, which were reported stratified by the presence or absence of malnutrition, and correlations between PhA and anthropometric indicators for the evaluation of the nutritional status in the pediatric population. It was difficult to compare the studies due to the heterogeneity of the bioelectrical impedance analysis models used, how PhA was reported (standardized, percentiles, or degrees), and the anthropometric indicators used to diagnose malnutrition.ConclusionThe early identification of malnutrition is relevant to establish the correct nutritional treatment; PhA appears to be a sensitive indicator of nutritional status and is easy to obtain. Although the results of this review are inadequate to establish PhA cutoff points associated with malnutrition in pediatric populations, in most of the studies, there was an association between PhA and objective indicators of nutritional status.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022362413, identifier: PROSPERO 2022 CRD42022362413.

High resting energy expenditure, less fat-free mass, and less muscle strength in HIV-infected children: a matched, cross-sectional study

“…Although the phase angle does not contribute to changes in REE, having higher REE and not being able to meet caloric requirements may be associated with a lower phase angle, reflected in reduced cellular health and worsened disease prognosis. Some studies have associated a lower phase angle with states of malnutrition ( 39 ); we did not see phase angle differences because the groups were matched by BMI-for-age. Furthermore, while biochemical parameters do not directly influence REE, they can serve as indirect indicators of disease.…”

The Impact of Nutritional Markers and Dietary Habits on the Bioimpedance Phase Angle in Older Individuals

“…The percentages of body fat mass and skeletal muscle mass were calculated as body fat mass and skeletal muscle mass, respectively, divided by the body weight. Whole-body raw values of R and Xc at 50 kHz were measured using InBody 720, and PhA values were obtained by calculating PhA (°) = [−arc tangent (Xc/R) × 180°/π] [ 2 , 3 ].…”

“…The phase angle (PhA) was calculated as follows: PhA (°) = [−arc tangent (Xc/R) × 180°/π] [ 2 ]. PhA represents the resistance of cell membranes, somatic cell volume [ 3 , 4 ], and intra- and extracellular fluid distribution [ 5 ]. A high PhA value typically indicates better cellular health and integrity, whereas a low PhA value reflects structural damage to cell membranes or reduced cell density, indicating compromised cellular function [ 6 ].…”