[Revealing characteristics and rules of acupoint sensitization phenomena: based on knee osteoarthritis]

To explore the characteristics and rules of acupoint sensitization phenomena based on knee osteoarthritis (KOA), one of the clinical dominant diseases of acupuncture-moxibustion.

In combination with literature and expert experiences, the acupoints with the highest use frequency in treatment of KOA were screened, e.g. Heding (EX-LE 2), Liangqiu (ST 34), Mingmen (GV 4), Neixiyan (EX-LE 4), Ququan (LR 8) and Dubi (ST 35). In 814 patients with KOA and 217 healthy subjects, the acupoint temperature, mechanic pain threshold and pressure pain threshold were detected separately. Using machine learning method, the sensitization was judged at each acupoint.

Compared with healthy subjects, the acupoint temperature was increased and the mechanic pain threshold and pressure pain threshold were reduced in KOA patients (P<0.05). Besides, the cut-off value was presented to distinguish whether the acupoint was sensitized or not. The results of machine learning showed that the highest prediction accuracy of acupoint sensitization was 86.7% (Shenshu [BL 23]) and the lowest one was 73.9% (Heding [EX LE 2]). The prediction accuracy at the third clinical stage trial was higher, the highest was 93.3% (Ququan [LR 8]) in KOA patients.

It is confirmed that the acupoint sensitization reflects the characteristics of disease and is correlative with the conditions of illness, which may provide the reference for the auxiliary diagnosis and condition assessment of KOA.