The association between arterial stiffness and tongue manifestations of blood stasis in patients with type 2 diabetes

Background: Diabetes mellitus (DM) is a hypercoagulable state and is associated with highly increased risk of vascular complications. In the theory of traditional Chinese medicine (TCM), these vascular complications are classified as blood stasis. Diagnosis of the tongue plays an important role in TCM; a bluish tongue, petechiae, and engorged sublingual collateral vessels are manifestations of blood stasis. This study aimed to characterize the tongue manifestations of blood stasis and derive a relationship between blood stasis and vascular disorders in patients with type 2 DM. Method: We conducted a cross-sectional study of 140 patients with type 2 DM, and compared demography, laboratory, physical examination, ankle brachial index(ABI), brachial-ankle pulse wave velocity (ba-PWV), and tongue manifestation datas. An automatic tongue diagnosis system was used to capture tongue images and characterize clinical tongue manifestations. Results: A bluish or petechiae tongue was assoicated with a significant decrease in high-density lipoprotein level, and bluish tongue was associated with significant increase in blood triglyceride in patients with type 2 DM. On assessing arterial stiffness, patients with a petechiae tongue had a higher ba-PWV for both sides (L:1938.41 +/- 469. 54 cm/sec v.s. 1723.99 +/- 302.16, p = 0.02; R:1937.28 +/- 405.55 v.s. 1741.99 +/- 325.82, p = 0.03). Conclusion: Blood stasis, particularly a tongue with petechiae, may be associated with arterial stiffness in patients with type 2 DM. Furthermore, tongue diagnosis could detect blood stasis relevant to DM and could serve as a feasible predictor for DM.