ObjectiveOsteoporosis (OP) and periodontal disease (PD) are two common health issues that threaten the older population and potentially connected each other in the context of type 2 diabetes mellitus (T2DM). Dysregulated expression of microRNAs (miRNAs) may contribute to the development and progression of both OP and PD among elderly T2DM patients. The present study aimed to evaluate the accuracy of miR-25-3p expression for the detection of OP and PD when compared to a mixed group of patients with T2DM.MethodsThe study recruited 45 T2DM patients with normal bone mineral density (BMD) and healthy periodontium, 40 type 2 diabetic osteoporosis patients coexistent with PD, 50 type 2 diabetic osteoporosis patients with healthy periodontium, and 52 periodontally healthy individuals. miRNA expression measurements in the saliva were determined by real-time PCR.ResultsThe salivary expression of miR-25-3p was higher in type 2 diabetic osteoporosis patients than patients with T2DM only and healthy individuals (P< 0.05). Among type 2 diabetic osteoporosis patients, those with PD exhibited a higher salivary expression of miR-25-3p than those with healthy periodontium (P< 0.05). Among type 2 diabetic patients with healthy periodontium, a higher salivary expression of miR-25-3p was noted in those with OP than those without (P< 0.05). We also found a higher salivary expression of miR-25-3p in T2DM patients than healthy individuals (P< 0.05). It was revealed that the salivary expression of miR-25-3p was increased as the T scores of BMD of patients were lowered, the PPD and CAL values of patients were enhanced. The salivary expression of miR-25-3p used as a test to predict a diagnosis of PD among type 2 diabetic osteoporosis patients, a diagnosis of OP among type 2 diabetic patients, and a diagnosis of T2DM among healthy individuals produced AUC of 0.859. 0.824, and 0.886, respectively.ConclusionThe findings obtained from the study support salivary miR-25-3p confers non-invasive diagnostic potential for PD and OP among a cohort of elderly T2DM patients.