Clinical Profile and Pulmonary Function of Pediatric Patients with Duchenne Muscular Dystrophy at a Tertiary Government Hospital

Abstract

Objective: Our study aimed to determine the clinical profile and pulmonary function of pediatric patients with Duchenne Muscular Dystrophy (DMD). We also characterized the stages of progression of the disease and determined their potential association with spirometry variables.

Methods: In this cross-sectional study, we used data obtained from a review of medical records of all pediatric patients (0-18 years old) with DMD seen in a multidisciplinary neuromuscular clinic of a tertiary government hospital from August 2018 until March 2020.

Results: Included were 30 patients subdivided into groups according to the stage of disease progression. Overweight (26.7%), obesity (20%), and scoliosis (26.7%) were common among non-ambulatory patients. Only one late ambulatory patient had evidence of ineffective airway clearance. Symptoms of sleep-disordered breathing, particularly snoring (66.7%) and apnea (6.7%), were common across all disease stages. All patients had normal peripheral oxygen saturation on room air. The mean peak expiratory flow rate was 215.6 (±84) L/min. The mean Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), and FEV1/FVC were 66.2% (±23.7), 67.7% (±23.8), and 97.5 (±3.2), respectively. Among patients with polysomnography results, the average apnea-hypopnea index (AHI) per hour was 3 (±1.6). When patients were compared according to their stage disease progression, however, no significant differences exist.

Conclusion: This is the first study on the pulmonary function of Filipino pediatric patients with DMD. Spirometry patterns characteristic of restrictive lung disease were observed. Prospective studies may help identify respiratory variables that significantly correlate with pulmonary function.

Keywords: Duchenne muscular dystrophy; children; cross-sectional; pulmonary function.

Figure 1

Distribution of pulmonary function tests for across stages I-V of disease progression in Duchenne muscular dystrophy patient. The data are shown as box plots. (A) SpO₂, (B) Peak expiratory flow rate (L/min), (C) FVC (% predicted), (D) FEV1 (% predicted), and (E) FEV1 / FVC.