Chest wall volumes, diaphragmatic mobility, and functional capacity in patients with mucopolysaccharidoses

Abstract

Purpose

We investigated respiratory muscle strength, diaphragm mobility, lung function, functional capacity, quality of life, body composition, breathing pattern, and chest wall (V_T,CW) and compartmental volumes of Mucopolysaccharidosis (MPS) patients and compared these variables with matched healthy individuals.

Methods

A cross-sectional study with data analyzed separately according to age group. A total of 68 individuals (34 MPS and 34 matched-healthy subjects) were included. Six-minute walking test assessed functional capacity and ultrasound assessed diaphragm mobility during quiet spontaneous breathing (QB). Optoelectronic plethysmography assessed V_T,CW and breathing pattern during QB in two different positions: seated and supine (45° trunk inclination).

Results

Body composition, lung function, respiratory muscle strength, and functional capacity were reduced in MPS (all p < 0.01). Diaphragm mobility was only reduced in adolescents (p = 0.01) and correlated with body composition and breathing pattern. Upper chest wall compartmental volumes were significantly lower in MPS, while abdominal volume only differed significantly in adolescents. Percentage contribution (%) of upper ribcage compartments to tidal volume was reduced in MPS children, whereas %AB was significantly increased compared with healthy subjects.

Conclusion

Lung function, respiratory muscle strength, functional capacity, diaphragm mobility, and quality of life are reduced in MPS compared with matched healthy subjects. V_T,CW was mainly reduced due to pulmonary and abdominal ribcage impairment.

Implications for Rehabilitation

• Reduction in respiratory muscle strength, functional capacity, diaphragm excursion and low lung volumes were found in individuals with Mucopolysaccharidoses (MPS).

• Chest wall volumes and the upper chest wall compartmental volumes during quiet spontaneous breathing are reduced in MPS.

• Assessment and monitoring of the respiratory system for individuals with MPS should be performed periodically through standardized assessments to enable identification of changes and early intervention by rehabilitation protocols.

• This study may provide the necessary basis for carrying out respiratoty rehabilitation protocols that can improving chest wall mechanics with breathing exercise in this group.

Keywords:

• Optoelectronic plethysmography
• ultrasound
• six-minute walking test
• respiratory muscles
• diaphragm
• disability evaluation

Acknowledgements

The authors are very grateful to the participants and their families, to the Breno Bloise Institute (IBB) and to the Physiotherapy Department.

Author contributions

BBF and HF collected the data; BBF and JF analyzed the data; BBF and AS wrote the first version of the manuscript; CR, AS, AD contributed with the conception and design of study, as well, supervised the project and critically revised the manuscript.

Disclosure statement

The authors declare that there are no conflicts of interest associated with this study.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by CNPq – Brazil – Edital Universal 421756/2021-7, PQ 313163/202, FACEPE APQ 0801-4.08/21, and was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) Finance Code 001.