Body composition and phase angle as an indicator of nutritional status in children with juvenile idiopathic arthritis

The science of bioelectrical impedance-derived phase angle: insights from body composition in youth

Despite bioelectrical impedance analysis (BIA)-derived phase angle (PhA) being recognized as a global marker of health, reflecting both cellular integrity and fluid distribution, its biological determinants still need to be described in youth. This narrative review provides a comprehensive framework examining to what extent dielectric properties shaping PhA are influenced by qualitative and quantitative determinants at multiple levels of body composition in healthy and clinical pediatric populations. At the atomic-molecular level, water content, glycogen, lipids, and ionic concentrations are expected to influence PhA by affecting electrical conductivity and/or capacitance. While the increase in the absolute values of intracellular (ICW) and extracellular water (ECW) enhances electric conductivity, an increase in the relative portion of ECW is expected to reflect hydration imbalances with an impact on electrical pathways. At the cellular level, body cell mass is a key determinant of PhA, mainly due to the presence of skeletal muscle cells favoring conductive and capacitive properties. At the tissue level, skeletal muscle architecture and orientation strongly influence conductivity, while increases in skeletal muscle mass positively impact PhA by enhancing electric conductivity and capacitance. Beyond the theoretical insights presented in this review, careful interpretation of dielectric data remains crucial due to the lack of methodological standardization. Future research should prioritize validated reference methods, investigate longitudinal changes, integrate localized BIA, and explore additional BIA models to refine the interpretation of PhA.

Dynamic Nutrition Strategies for Anorexia Nervosa: Marker-Based Integration of Calories and Proteins

BACKGROUND/OBJECTIVES

Anorexia nervosa (AN) is a severe psychiatric disorder characterized by profound nutritional deficits and significant alterations in body composition, cellular integrity, and hydration. Nutritional rehabilitation is critical not only for weight restoration but also for improving body composition and metabolic functions. However, optimal strategies for integrating caloric and protein intake to achieve balanced recovery remain underexplored. This study aims to evaluate the interactions between caloric/protein intake and time on quantitative (weight and BMI) and qualitative (body composition and cellular health) outcomes, and to identify markers that predict recovery trajectories and guide personalized nutritional interventions.

METHODS

This retrospective observational study analyzed 79 patients with AN admitted to Villa Miralago for six months of nutritional rehabilitation. Anthropometric and body composition parameters-including body weight (BW), body mass index (BMI), fat mass (FM), fat-free mass (FFM), body cell mass (BCM), phase angle (PA), and hydration markers (TBW and ECW)-were assessed at baseline (T0), 3 months (T1), and 6 months (T2). Generalized Estimating Equations (GEEs) were used to evaluate the effects of caloric and protein intake over time.

RESULTS

Significant increases in BW (+6.54 kg, p < 0.0001) and BMI (+2.47 kg/m2, p < 0.0001) were observed, alongside improvements in FM, FFM, and BCM. PA increased significantly (+0.47°, p < 0.0001), indicating enhanced cellular health. TBW increased (+1.58 L, p < 0.0001), while ECW% decreased, reflecting improved fluid distribution. Caloric intake predominantly influenced early fat mass recovery, while protein intake was crucial for preserving lean tissues and promoting cellular regeneration. Interaction effects between caloric/protein intake and time revealed dynamic changes in body composition, underscoring the need for adaptive strategies.

CONCLUSIONS

This study highlights the importance of a dynamic, marker-based approach to nutritional rehabilitation in AN. Integrating caloric and protein intake with advanced body composition and hydration markers enables personalized interventions and balanced recovery, shifting AN treatment toward a focus on qualitative improvements overweight restoration alone.

Factors associated with sarcopenia among young adults with juvenile idiopathic arthritis: a cross-sectional study

BACKGROUND

Sarcopenia is a generalized loss of skeletal muscle mass, strength, and performance, and early identification is crucial to minimize adverse outcomes. While sarcopenia is well-studied in older populations, data on its prevalence and risk factors in young adults with juvenile idiopathic arthritis (JIA) remain limited.

OBJECTIVES

The study aimed to evaluate the prevalence of sarcopenia in young adults with JIA and to identify associated risk factors.

METHODS

A cross-sectional single-center study was conducted at the Rheumatology Department of Communal Noncommercial Institution "Oleksandrivska Clinical Hospital", Kyiv, Ukraine, involving 70 patients between November 2020 and November 2022. Initially, 84 patients were recruited; however, 14 were excluded due to joint replacement, diabetes, or refusal to participate. Sarcopenia was diagnosed using the Find-Assess-Confirm-Severity algorithm, assessing muscle strength with a dynamometer, confirming sarcopenia using dual-energy X-ray absorptiometry, and determining severity via gait speed tests. Univariable and multivariable logistic regression was used to identify factors associated with sarcopenia and reported as odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Low handgrip strength, sarcopenia, and severe sarcopenia were observed in 64% (45/70), 59% (41/70), and 34% (24/70) of the patients, respectively. Men were less likely to lose muscle mass than women were (OR 0.29, 95% CI 0.10-0.89; p = 0.03). Sarcopenia was significantly predicted by disease activity according to the Disease Activity Score 28 based on erythrocytes sedimentation rate (DAS28-ESR) and clinical Juvenile Arthritis Disease Activity Score (cJADAS27) (OR 2.08, 95% CI 1.15-3.76; p = 0.01; OR 1.15, 95% CI 1.04-1.27; p = 0.007, respectively), articular and extra-articular Juvenile Arthritis Damage Index (JADI) (JADI-A OR 2.29, 95% CI 1.23-4.25; p = 0.009; JADI-E OR 3.15, 95% CI 1.36-7.29; p = 0.008, respectively), and functional capacity according to the Health Assessment Questionnaire (OR 4.14, 95% CI 1.38-12.5; p = 0.01).

CONCLUSION

Sarcopenia in young adults with JIA was associated with disease activity (measured by DAS28-ESR and cJADAS27), articular and extra-articular damage (measured by JADI indices), and lower functional capacity.

Increased adiposity in juvenile idiopathic arthritis - A comparison of the bioelectrical impedance analysis and dual-energy X-ray absorptiometry for the assessment of body composition

AIM

Higher adiposity and increased risk of cardiovascular diseases have been reported in juvenile idiopathic arthritis (JIA), but body composition measurements have produced inconsistent results. This controlled cross-sectional study assessed body composition with two methods to evaluate adiposity in children with JIA.

METHODS

We measured body composition by dual- energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) from 79 JIA-patients in two Finish university hospitals in 2017-2019. Their age- and sex-matched controls (n = 79) were selected from the Physical Activity and Nutrition in Children- study and through National Registry.

RESULTS

Body fat percentage measured by BIA was higher (mean, SD) in patients compared to controls (23.1 ± 9.3% vs. 20.1 ± 7.5%, p = 0.047). Also, using DXA, there was a tendency of higher body fat percentage in patients (27.1 ± 9.1% vs. 24.6 ± 8.6, p = 0.106). BIA and DXA showed strong correlation (r from 0.810 to 0.977) in all body composition variables.

CONCLUSION

Increased adiposity was observed in patients with JIA. Evaluation of body composition should be included in the multidisciplinary care of JIA to reduce the possible risk of cardiovascular diseases in adulthood. BIA could be a useful tool for assessing body composition due to its clinical availability and safety.

Association between Physical Activity Level, Body Composition, and Phase Angle in University Students from Bioelectrical Impedance Analysis (BIA)

Background: The aim of this study is to determine the relationship between selected components of body composition and the phase angle specified by bioelectrical impedance analysis, depending on the level of physical activity among students. Materials and Methods: The study group consisted of 484 university students from Krosno. The diagnostic survey method (IPAQ-SF), measurements of highs, and analysis of body composition components (BIA) were used. The relationship between variables was determined using the χ2 test, the V-Kramer coefficient, and Spearman's rho coefficient. Results: University students in physical education demonstrated the highest level of physical activity and the lowest incidence of excessive body mass. Among the participants, 28.1% did not engage in any physical activity, or their level was insufficient. The PhA level was correlated with lean body mass and muscle mass. The correlation between higher levels of PA and PhA values was statistically significant, as was the relationship between self-assessment of physical fitness and the level of PA determined by IPAQ-SF. Conclusions: Preventive actions and educational programs, especially about spending leisure time in active ways, should be particularly targeted at students of disciplines with a significant amount of sedentary classes.

Lipid profiles in patients with juvenile idiopathic arthritis: a systematic literature review and meta-analysis

OBJECTIVE

The purpose of this study was to comprehensively evaluate the lipid profiles in patients with juvenile idiopathic arthritis (JIA).

METHODS

The literature and relevant reviews were searched for published clinical studies on the relationship between JIA and blood lipid levels. The Newcastle-Ottawa scale (NOS) was applied to evaluate the risk and methodological value of the included case‒control and cohort studies. Standardized mean differences (SMDs) and 95% confidence intervals were derived for all variables with adequate unprocessed data. This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines.

RESULTS

In total, 16 studies were incorporated through screening. The analysis findings revealed that the levels of very low-density lipoprotein cholesterol [SMD=-0.411, 95% CI (-0.774~-0.048), P = 0.026], high-density lipoprotein cholesterol [SMD=-0.528, 95% CI (-0.976~-0.079), P = 0.021], and apolipoprotein A1 [SMD=-1.050, 95% CI (-1.452~-0.647), P = 0.000] in JIA patients were statistically lower than those observed in healthy controls. The level of low-density lipoprotein cholesterol [SMD = 0.202, 95% CI (0.003 ~ 0.400), P = 0.046] was significantly higher in JIA patients than in healthy controls. In JIA patients, body mass index [SMD=-0.189, 95% CI (-0.690 ~ 0.311), P = 0.459], high-density lipoprotein [SMD =-1.235, 95% CI (-2.845 ~ 0.374), P = 0.133), low-density lipoprotein [SMD = 0.616, 95% CI (-0.813 ~ 2.046), P = 0.398), triglycerides (SMD = 0.278, 95% CI (-0.182 ~ 0.738), P = 0.236], total cholesterol [SMD=-0.073, 95% CI (-0.438 ~ 0.293), P = 0.696] and apolipoprotein B levels [SMD = 0.226, 95% CI (-0.133 ~ 0.585), P = 0.217] were not significantly different from those in healthy controls.

CONCLUSIONS

The outcomes of this meta-analysis suggest that dyslipidemia is common in JIA patients compared to healthy controls. Patients with JIA have a significantly increased risk of atherosclerosis and cardiovascular disease later in life.

Body Composition and Phase Angle: How to Improve Nutritional Evaluation in Juvenile Dermatomyositis Patients

(1) Background: This study aimed to assess body composition (BC) using bioelectrical impedance and food intake in juvenile dermatomyositis (JDM) patients. Associations between BC and physical activity, disease activity/cumulative damage and health-related quality of life parameters were also evaluated; (2) Methods: This was a cross-sectional study with 30 consecutive JDM patients (18 female and 12 male) and 24 healthy volunteers (14 female and 10 male) of both sexes followed at our pediatric rheumatology unit. The gathering of anthropometric and dietary data, and the performance of physical activity and bioelectrical impedance were undertaken in face-to-face meetings and through questionnaires. Clinical and therapeutic data were collected from medical records according to information from routine medical appointments; (3) Results: The frequency of high/very high body fat was significantly higher in controls compared with JDM patients (66.7% vs. 91.7%; p = 0.046). The median phase angle was significantly lower in patients compared with controls (5.2 ± 1.3 vs. 6.1 ± 1.0; p = 0.016). Body fat and lean mass were positively correlated with disease duration (rs = +0.629, p < 0.001 and rs = +0.716, p < 0.001, respectively) and phase angle (PhA) (rs = +0.400, p = 0.029 and rs = +0.619, p < 0.001, respectively). JDM patients with PhA ≥ 5.5 presented higher lean mass when compared with patients with PhA < 5.5 (p = 0.001); (4) Conclusions: Bioelectrical impedance can be a useful auxiliary exam in the medical and nutritional follow-up of JDM patients, because it seems to impact functional ability. These findings may assist professionals when advising JDM patients about the importance of physical activity and healthy eating in the preservation of lean mass.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

An Overview of Nutritional Aspects in Juvenile Idiopathic Arthritis

There is evidence that nutritional impairment can complicate juvenile idiopathic arthritis (JIA). It is also recognized that the JIA drug treatment may affect the nutritional aspects of patients. It is crucial to understand the impacts that nutritional aspects can have on a patient's treatment, health, and life. Therefore, this review explores how nutrition influences juvenile idiopathic arthritis. Dietary aspects play essential roles in JIA patients' growth, body mass index (BMI), bone mineral density (BMD), inflammation, and recovery. Suboptimal nutrition seems to adversely affect the long-term outcome of JIA patients. Nutritional deficiency potentially affects JIA patients' general wellbeing and disease control and contributes to growth, inflammation, BMI, and BMD disturbances. It was also possible to verify that the correct status of nutrients helps the body recover and reduce inflammation in JIA patients, since nutritional status and nutrients play an important role in regulating immune function. Studies are diverse, and most analyze the effects of a single nutrient on JIA. Moreover, the diet and nutrition impacts are difficult to interpret in the pediatric population due to family influence, dietary regulation, and data collection in children/adolescents. Despite the lack of standardization among studies, the potential benefits of a healthy diet on short- and long-term health and wellbeing in JIA patients are noteworthy.

The nutritional status of healthy children using bioelectrical impedance and anthropometric measurement

OBJECTIVE

Monitoring of healthy children should include precise assessment of their nutritional status to identify children and adolescents at risk of nutrition disorders. Therefore, the aim of this study was to assess the nutritional status of healthy children using different nutritional risk screening tools.

METHOD

The study sample consisted of 550 participants within the age range of 7-15 years. Anthropometric characteristics (body mass, height, body mass index) were collected using standard procedures. In addition, the following parameters were analyzed: fat mass, fat-free mass, body cell mass, and total body water.

RESULTS

The results revealed that variables such as children's age and sex significantly differentiated the values of selected components of the body composition.

CONCLUSIONS

This observation suggests that it is necessary to use different methods to evaluate nutritional status among healthy children.

Adiposity Is Related to Inflammatory Disease Activity in Juvenile Idiopathic Arthritis

OBJECTIVE

To identify factors associated with the higher proportion of fatty tissue and overweight/obesity observed in patients with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

We performed a cross-sectional study of 80 JIA patients aged 4-15 years with 80 age- and sex-matched healthy controls. Body composition was assessed using dual-energy x-ray absorptiometry. The 27-joint Juvenile Arthritis Disease Activity score (JADAS27) was calculated. Two multivariate models were constructed to identify factors associated with overweight/obesity and fat mass index (FMI).

RESULTS

No differences were found between cases and controls in body mass index (BMI) or body composition. However, compared with controls, patients with a high inflammatory activity (JADAS27 > 4.2 for oligoarticular JIA or >8.5 for polyarticular disease) had higher values for BMI (p = 0.006); total fat mass (p = 0.003); FMI (p = 0.001); and fat in the legs (p = 0.001), trunk (p = 0.001), and arms (p = 0.002). The factors associated with overweight/obesity in patients were the duration of therapy with biological drugs, measured in months (OR [95% CI] = 1.12 [1.02-1.04]; p = 0.037), and physical activity (OR [95% CI] = 0.214 [0.07-0.68]; p = 0.010), while the factors associated with FMI were age (β [95% CI] = 0.30 [0.17-1.41]; p = 0.014), JADAS27 (β [95% CI] = 0.45 [0.16-1.08]; p = 0.009), and physical activity (β [95% CI] = -0.22 [-5.76 to 0.29]; p = 0.031).

CONCLUSION

Our study revealed no differences between JIA patients with well-controlled disease and low disability and the healthy population in BMI or body composition. Furthermore, the association observed between inflammatory activity and adiposity could be responsible for poorer clinical course.

Assessment of nutritional status in paediatric outpatients using bioelectrical impedance analysis and anthropometric z-scores

AIM

To investigate paediatric outpatients' nutritional status using bioelectrical impedance analysis and anthropometric z-scores.

METHODS

A retrospective data analysis of tertiary paediatric hospital outpatients from 2017 to 2019 was conducted. Patients were categorised into three groups (non-illness, illness and simple obesity) according to clinical diagnoses. The nutritional status was evaluated using anthropometric and bioelectrical impedance analysis. In addition, body composition measurements of patients in three subgroups of the illness group and age- and gender-matched healthy controls were compared.

RESULTS

A total of 2015 paediatric outpatients were enrolled. According to body mass index z-scores, undernutrition prevalence among participants was 14.0% (non-illness group, 21.3%; illness group, 11.4%). Body composition measurements indicated that 41.6% of participants had a low fat-free mass index, and the proportions of participants with a low fat-free mass index in the non-illness, illness and simple obesity groups were 48.4, 47.0 and 10.7%, respectively. Compared with healthy controls, the haematology and oncology subgroup had a significantly lower fat-free mass index and fat mass index; the nephrology and rheumatology subgroup had significantly lower height-for-age z-scores but higher fat mass index; and the gastroenterology subgroups had lower fat mass index, fat-free mass index and body mass index z-scores.

CONCLUSIONS

The results suggested the low fat-free mass index prevalence was greater than the low body mass index z-score prevalence among paediatric outpatients, and body composition parameters varied across different illnesses. Body composition analysis is recommended in nutrition clinics for accurate paediatric outpatient nutritional assessment, thereby providing timely individualised nutritional interventions.

Body composition monitoring in children and adolescents: reproducibility and reference values

There is an increasing need for suitable tools to evaluate body composition in paediatrics. The Body Composition Monitor (BCM) shows promise as a method, but reference values in children are lacking. Twenty children were included and measured twice by 4 different raters to asses inter- and intra-rater reproducibility of the BCM. Reliability was assessed using the Bland-Altman method and by calculating intraclass correlation coefficients (ICCs). The intra-rater ICCs were high (≥ 0.97) for all parameters measured by BCM as were the inter-rater ICCs for all parameters (≥ 0.98) except for overhydration (0.76). Consequently, a study was set up in which BCM measurements were performed in 2058 healthy children aged 3-18.5 years. The age- and gender-specific percentile values and reference curves for body composition (BMI, waist circumference, fat mass and lean tissue mass) and fluid status (extracellular and intracellular water and total body water) relative to age were produced using the GAMLSS method for growth curves.Conclusion: A high reproducibility of BCM measurements was found for fat mass, lean tissue mass, extracellular water and total body water. Reference values for these BCM parameters were calculated in over 2000 children and adolescents aged 3 to 18 years. What is Known • The 4-compartment model is regarded as the 'gold standard' of body composition methods, but is inappropriate for regular follow-up or screening of large groups, because of associated limitations. • Body Composition Monitor® is an inexpensive field method that has the potential to be an adequate monitoring tool. What is New • Good reproducibility of BCM measurements in children provides evidence to use the device in longitudinal follow-up, multicentre and comparative studies. • Paediatric reference values relative to age and sex for the various compartments of the body are provided.

Body composition in children with chronic inflammatory diseases: A systematic review

BACKGROUND & AIMS

Aberrations in body composition are expected in children suffering from chronic inflammatory conditions. The objective is to examine whether children with inflammatory bowel disease (IBD: Crohn's disease and ulcerative colitis), coeliac disease, asthma and juvenile idiopathic arthritis (JIA) have an altered body composition as compared to healthy children.

METHODS

A systematic review, registered in Prospero (registration number: CRD42018107645), was conducted according to PRISMA guidelines. We conducted a search of three databases, Pubmed, Cochrane and Scopus. An assessment of the quality of the study was performed.

RESULTS

Data from 50 studies, 32 with IBD, 8 with coeliac disease, 2 with asthma and 8 with JIA, involving 2399 children were selected for review after applying the eligibility criteria. In all but 4 studies, children with Crohn's disease exhibited decreased amounts of fat mass and fat free mass. Reductions in fat mass were also evident in studies in children with coeliac disease. It is uncertain whether body composition is altered in children with asthma or JIA.

CONCLUSIONS

Children with Crohn's disease manifest with lowered adiposity and lean mass and therefore are likely to be at risk for suffering malnutrition-related clinical complications. Apart from Crohn's disease, data examining body composition in children with chronic inflammatory conditions are scarce and there is a paucity of reports examining the relationship between inflammation and body composition. Interpretation of the current study results is hampered by the low quality of the studies and due to the fact that the analyses have been habitually secondary outcomes.