The aim of the present study was to analyze the association among systemic sclerosis (SSc), periodontitis (PT); we also evaluated the impact of PT and SSc on vitamin D levels. Moreover, we tested the association with potential confounders. A total of 38 patients with SSc, 40 subjects with PT, 41 subjects with both PT and SSc, and 41 healthy controls were included in the study. The median vitamin D levels in PT subject were 19.1 (17.6-26.8) ng/mL, while SSc + PT group had vitamin d levels of 15.9 (14.7-16.9) ng/mL, significantly lower with respect to SSc patients (21.1 (15.4-22.9) ng/mL) and to healthy subjects (30.5 (28.8-32.3) ng/mL) (p < 0.001). In all subjects, vitamin D was negatively associated with c-reactive protein (CRP) (p < 0.001) and with probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque score (PI) (p < 0.001 for all parameters) and positively related to the number of teeth (p < 0.001). Moreover, univariate regression analysis demonstrated an association among high low-density lipoproteins (LDL) cholesterol (p = 0.021), CRP (p = 0.014), and PT (p < 0.001) and reduced levels of vitamin D. The multivariate regression analysis showed that PT (p = 0.011) and CRP (p = 0.031) were both predictors of vitamin D levels. Subjects with PT and SSc plus PT had significant lower vitamin D values with respect to SSc and to healthy subjects. In addition, PT seems negatively associated with levels of vitamin D in all analyzed patients.
Keywords: C-reactive protein; clinical trial; diet; periodontal disease; systemic sclerosis; vitamin D.