Vitamin D deficiency is associated with digital ulcer but not with atherosclerosis or arterial stiffness in patients with systemic sclerosis: a pilot study

The objective of this study was to investigate the association of vitamin D deficiency with digital ulcers (DUs) that result from microvasculopathy, carotid intima-media thickness (CIMT) as surrogate markers of atherosclerosis, and brachial-ankle pulse wave velocity (baPWV) representing arterial stiffness in patients with systemic sclerosis (SSc). In this cross-sectional study, 40 female SSc patients and 80 healthy controls matched for sex, age, and blood sampling season were recruited. Vitamin D deficiency was defined as serum 25-OHD levels <30 ng/mL. “DUs ever” included active and healed DUs. CIMT and carotid plaque were examined using high-resolution ultrasonography, and baPWV was measured using an automatic waveform analyzer. Vitamin D deficiency was more prevalent in SSc patients than in controls (30 vs. 11.3%). Regarding SSc patients, 9 (22.5%) had DUs ever, and the mean CIMT and baPWV were 0.68 mm and 1561.1 cm/s, respectively; carotid plaque was detected in 13 (34.2%) patients. The frequency of DUs ever was significantly higher for SSc patients with vitamin D deficiency than those without this feature (50 vs. 10.7%, p = 0.012), but the median CIMT and baPWV and the frequency of carotid plaque did not differ according to the presence of vitamin D deficiency. Multivariable logistic regression analysis showed that vitamin D deficiency was an independent risk factor for DUs ever (OR = 7.72, p = 0.024). Vitamin D deficiency was associated with DUs, but not with atherosclerosis or arterial stiffness, potentially indicating that vitamin D may have different effects on the microvascular and macrovascular involvement in SSc pathophysiology.