Reduction of carotid baroreceptor sensitivity in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterised by diffuse vasculopathy and fibrosis of skin and visceral organs. Moreover, autonomic dysfunction is also suggested as an important step during the multifactorial SSc pathogenesis. Baroreceptors are responsible for maintaining blood pressure by means of autonomic system modulation. Considering that autonomic dysfunction and arteriosclerosis can both reduce baroreceptor sensitivity (BRS), in this cross-sectional study we investigated BRS in SSc patients.

Twenty-one SSc patients (mean age 55±10 years, 18 females) and 147 age/sex-matched healthy controls were recruited for the study. BRS (ms/mmHg) was measured by a Finapres® Midi device (Finapres Medical Systems, Amsterdam, The Netherlands). Other parameters were measured: blood pressure, heart rate, heart rate variability triangular index (HRVI), intima-media thickness (IMT), carotid distensibility and pulse wave velocity (PWV).

BRS was significantly lower in SSc patients compared to controls (6.3±3.3 vs. 10.7±6.8 ms/mmHg; p=0.004). IMT was comparable between SSc and controls, whereas carotid distensibility was lower in SSc (20.1±7.6 vs. 26.6±13.3 KPa-1·10-3; p=0.02) and PWV higher in SSc (8.4±1.3 vs. 7.1±1.1 m/sec; p=0.01). Furthermore, HRVI was lower in SSc (4.5±2.1 vs. 7.5±2.8; p<0.001). BRS impairment was independent from age and carotid distensibility in SSc patients, suggesting that BRS dysfunction could be only partially a consequence of SSc vasculopathy.

BRS was reduced in SSc patients compared with healthy controls. This finding could represent a SSc-related alteration involving the autonomic system, besides being the mere consequence of sclerodermic vasculopathy.