br In the present study there was a
In the present study, there was a statistically significant increase in the mean salivary ET-1 levels among the OSCC and OPMDs group when compared to normal healthy controls. Similar to our study, Pickering et al. (2007)  analysed the salivary ET-1 levels in patients with OSCC prior to the treatment, in comparison to healthy patients. They found a significant increase in the SCH-772984 of salivary ET-1 levels in OSCC group. Similarly Cheng et al in 2012  stated in their study that salivary ET-1 levels in OSCC patients (P > 0.05) before treatment were significantly higher than the levels found in normal controls (P = 0.004). Tahereh et al. in 2017  reported that the mean of salivary endothelin-1 in patients with OSCC was 163.98 pg/mL and was significantly more than the level of endothelin-1 in control group, which was in accordance with our study. The study also found pair-wise correlation of salivary levels of ET-1; the present study also assessed for the pair- wise correlation among the groups which showed a significant difference between OSCC and SMF (P < 0.001), OSCC and leukoplakia (P < 0.001), OSCC and controls (P < 0.001), SMF and controls (P < 0.001) and Leukoplakia and controls (P < 0.001). The difference between OSMF and leukopla-kia (P = 0.016) was not statistically significant. Pritam et al. 2015
 compared the mean big ET-1 concentrations of the OSCC and control group, the study revealed a significantly higher big ET-1
concentration in OSCC cases when compared to controls (P < 0.0001, t = 11.37).Furthermore, intragroup comparison of the mean levels of serum big ET-1 also revealed statistically significant difference among all OSCC stages. In the present study, we assessed for the intragroup comparison among the histopath-ological staging of OSCC patients. We also correlated the ET-1 levels with the histopathological staging of SMF and leukoplakia. The mean levels were higher in the advanced stages both in OPMDs and OSCC, which made a meaningful conclusion that salivary ET-1 can be a potential diagnostic marker and it can help us to assess the disease progression. However, the levels were not statistically significant amongst different groups which could be attributed to the small sample size.
Group Mean Std. deviation Std. error 95% confidence interval for mean
Lower bound Upper bound
ANOVA Sum of Squares Mean Square F Sig.
Please cite this article in press as: Ankita K, et al. Assessment of salivary endothelin-1 in patients with leukoplakia, submucous fibrosis, oral cancer and healthy individuals – a comparative study. J Stomatol Oral Maxillofac Surg (2019), https://doi.org/10.1016/ j.jormas.2019.02.024
Fig. 1. Mean salivary ET-1 levels in OSCC, SMF, OL and CONTROLS.
Pair-wise comparison salivary Endothelin-1 level in study groups.
Group Comparison Mean Difference Std. Error Sig.
Correlation of salivary ET-1 levels with habit history was done among the study groups.
Salivary ET-1 level
Leukoplakia Biserial (rbi) P-value
Hoffman et al in his study in 2012  did not find any significant difference between controls and OSCC patients. They stated that several different factors might be related to that discrepancy, including the sample size. Additionally, other factors might be pointed out to explain the differences between their results and that from literature data, such as the presence of periodontal disease, traumatic lesions, dietary factors and the tumor stage. However, different from the data described by Hoffman et al, we had found statistically significant results between the means of salivary ET-1 levels among the study group.
Few studies have assessed for the salivary or serum ET-1 levels among the different age groups and gender. It has been well described that ET-1 level is vastly implicated in vascular related
Correlation of salivary ET-1 with age, clinical and histopathological staging of patient’s with leukoplakia, SMF, OSCC.
Salivary ET-1 level
Leukoplakia Spearman’s P P-value
Histological staging 0.52
P = 0.51) among OSCC and SMF groups respectively; but the results could not be generalised because of the small sample size included in the study. Concluding that impact of age and gender on salivary ET-1 levels is statistically insignificant.
4.2. Endothelin-1 and systemic diseases
In various studies, it has been shown that ET-1 plays a role in the pathogenesis of acute renal failure after renal ischaemia. Also, ET-1 causes potent vasoconstriction and prolonged elevation of blood pressure in experimental models. It has also been noted that plasma endothelin levels are increased in patients with CHF (congestive heart failure). Increased plasma endothelin levels correlate closely with the degree of haemodynamic and functional impairment in patients. In primary pulmonary hypertension there is proliferation of pulmonary arterial smooth muscle and endothelial injury. It has been observed that, endothelin isopepti-des can cause either pulmonary vasodilatation or vasoconstriction. Lam et al. in 2004  showed an increase of salivary IR-ET levels