Determinants of diaphragm ultrasound and its diagnostic performance for predicting respiratory status in myotonic dystrophy type 1 - 26/05/26

Doi : 10.1016/j.resmer.2026.101283

Abdallah FAYSSOIL, MDPhD ^1,^2,^⁎ , Marie DE ANTONIO, PhD ³, Helene PRIGENT, MDPhD ², Anthony BEHIN, MD ¹, Tanya STOJKOVIC, MD ¹, Pascal LAFORET, MDPhD ², Karim WAHBI, MDPhD ⁴, Frederic LOFASO, MDPhD ², David ORLIKOWSKI, MDPhD ², Bertrand FONTAINE, MDPhD ¹, Guillaume BASSEZ, MDPhD ^1,⁵

¹ Service de Neuro-myologie, Institut de Myologie, CHU Pitié Salpetrière, Paris, France

² CHU Raymond Poincaré, APHP, Université de Versailles Saint Quentin en Yvelines, Garches, France

³ Unité de Bio statistiques, Direction de la Recherche Clinique et de l'Innovation, Centre Hospitalier Universitaire de Clermont-Ferrand, Université Clermont Auvergne, Clermont-Ferrand, France

⁴ Service de Cardiologie, CHU Cochin, APHP, Paris, France

⁵ Centre de Recherche en Myologie-UMR 974, Service de Neuro-Myologie, Institut de Myologie, Hôpital Universitaire Pitié-Salpêtrière, Sorbonne-Université, INSERM, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France

^⁎ Corresponding Author: Abdallah FAYSSOIL, MD PhD, CHU Raymond Poincaré, APHP, Université de Versailles Saint Quentin en Yvelines, Garches, France CHU Raymond Poincaré APHP Université de Versailles Saint Quentin en Yvelines Garches France

Sous presse. Manuscrit accepté. Disponible en ligne depuis le Tuesday 26 May 2026

HIGHLIGHTS

•	Measurement of right diaphragm is representative of the whole diaphragm mechanic in DM1
•	Diaphragm mechanics are different in male in comparison with female in DM1
•	Diaphragm ultrasound mechanics are correlated with respiratory function in DM1
•	Diaphragm ultrasound can predict respiratory status in DM1 with high diagnostic performance.

Le texte complet de cet article est disponible en PDF.

ABSTRACT

Background

Respiratory failure is a leading cause of mortality in patients with myotonic dystrophy type 1 (DM1). Monitoring of respiratory status is recommended in this disease. Ultrasound can be used to assess diaphragm function. We aimed to assess the performance diagnostic of diaphragm ultrasound for predicting respiratory involvement in DM1.

Materials and methods

Diaphragm ultrasound and spirometry were performed in DM1 patients in a Parisian neuromuscular center from 2015 to 2019.

Results

The study included 330 DM1 patients with a median age at 42.8 years (12.8). The mean pulmonary vital capacity (VC) was at 77.1% [ 22 ] of predicted value. The right and the left diaphragm ultrasound were significantly correlated [r 0.62, p < 0.001 for the diaphragm inspiratory motion (DIM)]. The VC was significantly associated with DIM (r 0.68, p < 0.0001) and sniff peak tissue Doppler diaphragm velocity (r= 0.43, p < 0.0001). A deep DIM < 57mm can predict a VC < 80% (AUC 0.83). A deep DIM < 34 mm can predict a VC < 50% (AUC 0.92). The DIM was significantly associated with gender (p=0.001), BMI < 25 kg/m² (p < 0.001), CTG repeat length (p < 0.001), Walton score ≥3 (p < 0.001), VC (p < 0.001), delta VC (p 0.05), PO2 (p < 0.001) and PCO2 (p < 0.001). In multivariate analysis, female gender (p < 0.001), Walton score ≥3 (p 0.006), CTG repeat length (p 0.026) and VC (p < 0.001) were significantly associated with DIM.