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This protocol assesses alterations in hydration and body cell mass status using bioelectrical impedance vectorial analysis following a dynamic exercise program designed for patients with rheumatoid arthritis. The dynamic exercise program itself is detailed, highlighting its components focused on cardiovascular capacity, strength, and coordination. The protocol details steps, instruments, and limitations.
Rheumatoid arthritis (RA) is a debilitating disease that can result in complications such as rheumatoid cachexia. While physical exercise has shown benefits for RA patients, its impact on hydration and body cell mass remains uncertain. The presence of pain, inflammation, and joint changes often restrict activity and make traditional body composition assessments unreliable due to altered hydration levels. Bioelectrical impedance is a commonly used method for estimating body composition, but it has limitations since it was primarily developed for the general population and does not consider changes in body composition. On the other hand, bioelectrical impedance vectorial analysis (BIVA) offers a more comprehensive approach. BIVA involves graphically interpreting resistance (R) and reactance (Xc), adjusted for height, to provide valuable information about hydration status and the integrity of the cell mass.
Twelve women with RA were included in this study. At the beginning of the study, hydration and body cell mass measurements were obtained using the BIVA method. Subsequently, the patients participated in a six-month dynamic exercise program encompassing cardiovascular capacity, strength, and coordination training. To evaluate changes in hydration and body cell mass, the differences in the R and Xc parameters, adjusted for height, were compared using BIVA confidence software. The results showed notable changes: resistance decreased after the exercise program, while reactance increased. BIVA, as a classification method, can effectively categorize patients into dehydration, overhydration, normal, athlete, thin, cachectic, and obese categories. This makes it a valuable tool for assessing RA patients, as it provides information independent of body weight or prediction equations. Overall, the implementation of BIVA in this study shed light on the effects of the exercise program on hydration and body cell mass in RA patients. Its advantages lie in its ability to provide comprehensive information and overcome the limitations of traditional body composition assessment methods.
Rheumatoid arthritis (RA) is a disabling disease that affects patients' functionality and independence due to acute joint pain, reduced muscle strength, and impaired physical function, all of which are associated with the inflammatory process inherent to the disease1,2. In advanced stages, persistent inflammation causes structural alterations leading to deformity, joint dysfunction, and rheumatoid cachexia, which is a poor prognostic factor for these patients3,4.
Rheumatoid cachexia is characterized by alterations in body composition, such as muscle loss with stable weight and increased fat mass, which can significantly impact the quality of life for these patients3,5,6. Various techniques are available to assess body composition, with the most widely used being bioelectrical impedance analysis (BIA). However, when conventional BIA analysis is used in subjects with altered body compositions, the estimations may be limited as they are based on prediction equations formulated for a healthy or normally hydrated population7,8.
A different approach, called bioelectrical impedance vector analysis (BIVA), utilizes the impedance vector based on graphical RXc. It utilizes impedance, resistance (R), and reactance (Xc) data corrected for height, resulting in a vector that provides information about the hydration state and integrity of the cell mass. BIVA is capable of classifying patients into categories such as dehydration, overhydration, normal, athlete, lean, cachectic, and obese, making it a valuable tool for RA patients8,9,10. Vectors located above or below the main axis (the left or right halves of the ellipses) have been associated with higher and lower cell mass in soft tissues, respectively. Forward and backward displacements of vectors parallel to the major axis are linked to dehydration and fluid overload. Athletes are defined as individuals with higher cell mass, potentially accompanied by dehydration. The lean classification refers to those with lower cell mass, potentially accompanied by dehydration, and the obese classification applies to individuals with higher cell mass, which may be accompanied by fluid overload. The classification of cachexia by BIVA is determined by high resistance and low reactance values, represented by the movement of the vector to the right of the graph, indicating a decrease in cell mass, potentially accompanied by an alteration in hydration status11 (Figure 1).
Conventional pharmacological treatments for RA primarily focus on reducing pain, inflammation, and joint damage progression, with limited attention given to alterations in body composition12. Among the non-pharmacological therapies commonly used in this population, exercise-based interventions have shown positive outcomes in improving functionality, fatigue, pain, joint mobility, aerobic capacity, muscle strength, endurance, flexibility, and psychological well-being. Importantly, these interventions have been shown to achieve these benefits without exacerbating symptoms or causing joint damage in patients without extensive pre-existing damage13,14,15,16,17. However, there is limited knowledge on implementing and evaluating changes in hydration and body cell mass status following exercise interventions in this population. These patients often experience pain, inflammation, and structural joint changes, limiting the types of activities they can engage in and further complicating body composition assessments using traditional approaches. This protocol aims to demonstrate how to evaluate changes in hydration and body cell mass status using bioelectrical impedance vectorial analysis after implementing a dynamic exercise program for patients with rheumatoid arthritis. Additionally, the protocol provides details of the dynamic exercise program, including cardiovascular capacity, strength, and coordination components, as well as the steps, instruments, limitations, and general considerations.
The present protocol was approved by and followed the Human Research and Ethics Committee guidelines of the National Institute of Medical Sciences and Nutrition Salvador Zubirán (Ref.: 1347). Informed consent was obtained from the human participants before participation in this study. Only patients in functional class I to III without total or partial arthroplasties18,19 and who were not candidates for prostheses were included in this study. Exclusion criteria included patients with cardiovascular disease, cancer, chronic kidney disease, pregnancy, or other autoimmune diseases that overlap with RA.
1. Recruitment of participants
2. Participant pre-test
NOTE: Pre-tests were performed 1 week before beginning the dynamic exercise program. Multifrequency bioelectrical impedance analysis equipment (see Table of Materials) was used, and measurements were performed with patients fasting for 4 to 5 h.
3. Dynamic exercise program
NOTE: The program was applied and supervised by a physiotherapist. An intervention duration of 48 sessions per patient was estimated. The exercise sessions were carried out in a mechanotherapy gym within a physiotherapy area belonging to the Rheumatology and Immunology department of the "INCMNSZ" with a duration of 90 min, twice a week.
4. Post-test evaluation
NOTE: The post-test assessment must be scheduled during the week after the last exercise session.
Results are presented for six female patients with RA who participated in a 48 session dynamic exercise program. The mean age of the patients was 52.7 ± 13.1 years, and their BMI was 26.8 ± 4.6. The average disease duration was 15.5 ± 6.1 years, and the disease activity, measured by Disease Activity Score 28, was classified as low activity with an average of 1.9 ± 1. Regarding disability, the Health Assessment Questionnaire Disability yielded an average score of 0.5 ± 0.3. For the six participant...
In rheumatoid arthritis, the vicious circle of the disease has been described, which refers to the structural changes in joints caused by inflammation mechanisms; these changes, together with the chronic inflammatory state, lead to patients going through stages of great pain and inflammation, with structural changes in joints and as a consequence functional disability, that increase the risk of developing metabolic and cardiovascular diseases and alterations in body composition such as rheumatoid cachexia
The authors have nothing to disclose.
The authors would like to thank professors Piccoli and Pastori of the Department of Medical and Surgical Sciences, University of Padova, Italy, for providing the BIVA software. Also, to Dr. Luis Llorente and Dra. Andrea Hinojosa-Azaola from the Department of Immunology and Rheumatology at the INCMNSZ for rheumatological assessment of patients. This work was supported by the CONACyT which sponsored the scholarship CVU 777701 for Mariel Lozada Mellado during his Ph.D. course study and through the Research Project Grant 000000000261652. The sponsor did not have any role in the study design or in the collection, analysis, or interpretation of data, nor in the writing of the report and in the decision to submit the paper for publication.
Name | Company | Catalog Number | Comments |
Alcohol 70% swabs | NA | NA | Any brand can be used |
bicycle ergometer | NA | NA | Any brand can be used |
BIVA tolerance software 2002 | NA | NA | Is a sofware created for academic use, can be download in http://www.renalgate.it/formule_calcolatori/bioimpedenza.htm in "LE FORMULE DEL Prof. Piccoli" section |
BIVA confidence software | NA | NA | Is a sofware created for academic use, can be download in http://www.renalgate.it/formule_calcolatori/bioimpedenza.htm in "LE FORMULE DEL Prof. Piccoli" section |
Chair | NA | NA | Any brand can be used |
Chlorhexidine | NA | NA | Any brand can be used, 0.05% |
Examination table | NA | NA | Any brand can be used |
Leadwires square socket | BodyStat | SQ-WIRES | |
Long Bodystat 0525 electrodes | BodyStat | BS-EL4000 | |
Plastic ball | NA | NA | Any brand can be used, 30 cm |
Pulse oximeter | NA | NA | Any brand can be used |
Quadscan 4000 equipment | BodyStat | BS-4000 | Impedance measuring range: 20 - 1300 Ω ohms Test Current: 620 μA Frequency: 5, 50, 100, 200 kHz Accuracy: Impedance 5 kHz: +/- 2 Ω Impedance 50 kHz: +/- 2 Ω Impedance 100 kHz: +/- 3 Ω Impedance 200 kHz: +/- 3 Ω Resistance 50 kHz: +/- 2 Ω Reactance 50 kHz: +/- 1 Ω Phase Angle 50 kHz: +/- 0.2° Calibration: A resistor is supplied for independent verification from time to time. The impedance value should read between 496 and 503 Ω. |
Resistence bands | NA | NA | Any brand can be used, with resistence of 0.5 kg to 3.2 kg |
Stationary bicycle | NA | NA | Any brand can be used |
Treadmill | NA | NA | Any brand can be used |
Wooden stick | NA | NA | Any brand can be used, 1.5m in large and <1kg |
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