- Serum levels of vitamin B12, folate, ferritin, hemoglobin in OLP patients and healthy controls
Compared with healthy controls, OLP patients had significantly lower serum levels of vitamin B12 and folate (both P < 0.001, Table 1). For both males and females, the levels of ferritin and hemoglobin were not significantly different between the two groups (Table 1).
- Hematinic deficiencies in OLP patients compared with healthy controls
Here, the frequency of overall hematinic deficiencies means the frequency of the subjects with at least one deficiency in serum folate, ferritin and vitamin B12. The frequency of overall hematinic deficiencies was 43.64% (103/236) in the OLP patients vs 12.39% (28/226) in the healthy controls. There was a statistically significant difference between the two groups (P < 0.001, Table 2). Similarly, the frequencies of serum ferritin deficiency and serum vitamin B12 deficiency in OLP patients were both significantly higher than those of the healthy controls (both P < 0.001, Table 2). However, no statistically significant difference was found in the frequency of serum folate deficiency between the OLP patients and healthy controls (4.24% vs1.33%, P = 0.059). Compared with the health controls, anemia was much more common in OLP patients (9.75% vs 3.98%, P = 0.015).
- Hematinic deficiencies in OLP patients according to gender and age
Compared with the male OLP patients, the female OLP patients had a significantly higher frequency of serum ferritin deficiency (4.88% vs 24.62%, P = 0.005, Table 3). On the contrary, serum folate deficiency was more common in male OLP patients (P < 0.001). No significant differences in serum vitamin B12 deficiency or anemia were found between male and female OLP patients (P = 0.511 and P = 0.148, respectively).
The frequencies of hematinic deficiencies were also compared among age subgroups of the OLP patients. Significant differences in serum ferritin deficiency and anemia were revealed among age subgroups of OLP patients (P < 0.001, P = 0.029, respectively, Table 3). However, there was no significant difference among age subgroups in either serum folate or vitamin B12 deficiency (P = 0.220 and P = 0.367, respectively).
- The correlation between two factors (age and gender) and presence of hematinic deficiencies in OLP patients
Both age and gender were significantly correlated with the presence of serum ferritin deficiency in the OLP patients (Table 4). However, neither age nor gender was significantly correlated with serum vitamin B12 deficiency in the OLP patients (P = 0.413 and P = 0.623, respectively, Table 4). Gender was significantly associated with serum folate deficiency in OLP patients (P < 0.001). Such significant correlation was also observed between age and anemia (P = 0.021, Table 4). For comparison, the same logistic regression analysis was conducted in the healthy controls and no significant correlation was found between the two factors and the presence of hematinic deficiencies (Table 4).
- Analysis of disease duration in OLP patients
In this study, 63.56% of OLP patients (150/236) had not experienced oral symptoms more than 6 months. Among these patients, serum folate deficiency was detected in six patients, serum vitamin B12 deficiency in 44 patients and serum ferritin deficiency in 23 patients. A shorter duration, 1 month or less, was found in 30 OLP patients. Among these, seven patients, five patients and no patient had serum vitamin B12 deficiency, serum ferritin deficiency or serum folate deficiency, respectively.
- Comparison of REU scores between OLP patients with and without hematinic deficiencies
The REU score (median ± IQR) of the OLP patients with one or more (two or three) deficiencies in serum folate, ferritin and vitamin B12 was 5 ± 3. For OLP patients without any deficiency, the REU score was 5 ± 3.75. The rank sum test revealed no significant difference between them (P = 0.824, Table 5). Separate analysis also showed that no significant difference existed between OLP patients with and without serum ferritin deficiency (P = 0.783), folate deficiency (P = 0.173), vitamin B12 deficiency (P = 0.493) or anemia (P = 0.723, Table 5).
- Statistical analysis of the association between hematinic deficiencies and OLP.
Spearman’s correlation coefficient revealed that both serum ferritin deficiency and serum vitamin B12 deficiency were significantly correlated with OLP (R = − 0.189, P < 0.001; R = − 0.262, P < 0.001, respectively). A borderline, but not statistically significant correlation was observed between serum folate deficiency and OLP (R = − 0.088, P = 0.059). Moreover, anemia was not significantly associated with OLP (R = − 0.05, P = 0.284).