Functional assessment of patients with systemic sclerosis by the use of 'Six-minutes-walking-test'

Systemic Sclerosis (SS) is a chronic inflammatory disease of the connective tissues, characterised by alterations in the functions and structures of the small blood vessels (capillaries and arterioles) and by modifications associated with the disposition of collagen in the tissues. One of the most frequent complication of the SS is the pulmonary arterial hypertension (PAH). Aim of this study was to assess the various pathophysiological relationships betweens SS and PAH in order to establish whether the presence of this systemic disease can represent a risk factor.

Ten patients affected by SS (9 women and 1 man, with a mean age of 55.7 +/- 11.4 years) were enrolled in our study, as inpatients at Dept. of Internal Medicine and Rheumatology Unit of Perugia University School of Medicine in the "Santa Maria" General Hospital in Terni, Italy. A control group of 10 clinically healthy subjects (CHS, 9 women and 1 man, ranging in age from 35 to 55 years) was also recruited in order to obtain normal clinical data of reference In subjects recruited, we have conducted a functional evaluation, based on physical tests (6-minute-walking-test, 6MWT), equipment and laboratory, on subjects suffering from SS with suspected PAH, in order to calculate the degree of cardio-pulmonary compromission brought on by this disease, taking into consideration important variables such as age and gender.

The 6 MWT showed that the mean value at rest of the O2 saturation (%) was 97.1 +/- 1.20, heart rate (hr/min) 76 +/- 8.8, and respiratory rate (rr/min) 20.4 +/- 2.8. HS had 98.6 +/- 0.52, 75.7 +/- 6.86, and 16.8 +/- 1.61, respectively. After the the test, the results showed that the patients had O2 saturation 93.8 +/- 3.42, hr 113 +/- 20.27, and rr 31 +/- 2.86. HS had 97.6 +/- 0.69, 90.7 +/- 5.67, and 20.1 +/- 1.59, respectively.

Our study has confirmed the high involvement of PAH and other cardio-respiratory disturbances in patients with SS. In fact, we have verified PAP to be above the normal range in 3 out of 10 patients, while the other 3 patients presented borderline values. Because it is a simple method to conduct at low cost, in addition to being non-invasive, reproducible and well accepted, we must affirm that the 6MWT should be more utilized and exploited, especially during the fi rst phases of diagnosis. This in turn can help us to assess the patients and to determine a course of treatment which is more complex and onerous, as in therapeutic monitoring for verifying efficacy.