Relationship of salivary RANKL and OPG with periodontal disease in type 1 diabetic patients

The alterations of the RANKL/OPG system and the relationship between diabetes and periodontitis have been implicated in several studies. This study aimed to evaluate the relationship between salivary RANKL and OPG concentration and periodontitis in patients with type 1 diabetes. Upon obtaining un-stimulated whole saliva samples from 50 volunteers including 27 type 1 diabetic patients, of whom 12 had periodontitis and 23 systemically healthy subjects, of whom 12 had periodontitis, clinical periodontal measurements were recorded. Statistical analysis was performed using Kruskal-Wallis, Mann-Whitney U test and Spearman correlations. Although lowest RANKL and OPG concentration and their relative ratio were observed in diabetic patients without periodontitis, there was no significant difference in RANKL and OPG concentration and RANKL/OPG ratio between the four groups of the study, but OPG concentration and RANKL/OPG ratio correlated positively with the duration of diabetes (p<0.05). In comparison of the two groups of diabetic patients (with or without periodontitis), there was a significant difference in OPG concentration (p<0.05). There was also a positive correlation between CAL and RANKL concentration (p<0.01) and RANKL/OPG ratio (p<0.05) in diabetic patients with periodontitis. Based on the limitation of the study, it seems that OPG level and OPG/RANKL ratio may serve as indicators of periodontal destruction in type 1 diabetes.