Assessment of diaphragmatic function by ultrasonography in patients with systemic sclerosis and its relation to clinical parameters : A case-control study.

BACKGROUND

Diaphragmatic function can be affected in many diseases and disorders. Although systemic sclerosis (SSc) is a serious connective tissue disease that affects not only the skin but also the pulmonary and musculoskeletal systems, there is insufficient information about diaphragm function.

AIMS: To compare the diaphragmatic parameters by ultrasonography (USG) in patients with SSc and healthy individuals and examine the relationship between these parameters and clinical features in patients with SSc.

METHODS

This study included 13 patients with SSc and 15 healthy individuals. Muscle thickness (in deep inspiration Tins and at the end of calm expiration Texp), changes in thickness (∆T), and thickening fraction at deep breathing were evaluated by USG. Skin thickness, pulmonary function tests, respiratory muscle strength, and the perception of dyspnea were measured as clinical features.

RESULTS

The results of Texp, Tins, and ∆T were similar in both groups (p > 0.05), albeit patients in the SSc group had less thickening fraction compared to the control group (79.9 ± 36.7 cm and 103.8 ± 20.6 cm, respectively, p < 0.05). The Tins, ∆T, and thickening fraction of the diaphragm were associated with skin thickness, pulmonary function test parameters, and respiratory muscle strength (p < 0.05). Besides, there was significant correlation between muscle thickening fraction and perception of dyspnea (p < 0.05).

CONCLUSION

These results confirm that diaphragm thickness and contractility can be affected in patients with SSc. Therefore, ultrasonographic evaluation of the diaphragm can play a complementary role to pulmonary function test and respiratory muscle strength measurement in the diagnosis and follow-up of patients with SSc.