Early Detection of Respiratory Impairment in Pompe Disease: The Role of SNIP

The objective of this study was to evaluate whether sniff nasal inspiratory pressure (SNIP) is able to detect early diaphragmatic weakness more effectively than the standard conventional pulmonary function test: forced vital capacity (FVC). We conducted a prospective observational study of 15 patients with late onset Pompe disease (LOPD) followed up every 6 months during 5 consecutive years. Mean age of the cohort was 49.9 ± 11.6 years and 67% were male. Mechanical ventilation was required in 47% of cases, and 80% were receiving enzyme replacement therapy (ERT). During follow-up, FVC declined at a mean rate of 1.05% per visit (p = 0.01), whereas SNIP decreased by 2.53 cmH₂O per visit (p = 0.003). The divergence between FVC and SNIP trajectories reached statistical significance from the first year of follow-up (p = 0.032). Patients on ERT exhibited SNIP values 15.41 cmH₂O higher than untreated patients, a difference that was also statistically significant (p = 0.003). In this cohort, SNIP proved to be a more sensitive biomarker than FVC for the early detection of respiratory failure in LOPD, which could determine the indication of ERT. Furthermore, patients treated with ERT demonstrated significantly better preservation of inspiratory muscle strength, as reflected by higher SNIP values.