Dynamic Change of Pain Sensitisation at Acupoints in Patients with Knee Osteoarthritis and Disease Severity: A Multilevel Analysis of a Longitudinal Study

Abstract

Background and aim: Acupuncture alleviates pain and improves physical function in knee osteoarthritis (KOA). The therapeutic effect of acupuncture may depend on acupoint selection. This longitudinal study aimed to observe dynamic change of acupoint sensitization in knee osteoarthritis (KOA) patients, and to investigate the relationship between acupoint PPTs and disease severity. Methods: Two-hundred-and-forty-six KOA patients were enrolled in this longitudinal study from 5 clinical centers.; data from 216 samples were analyzed. All participants underwent PPT assessment of 19 acupoints once weekly for 4 weeks. Multilevel analysis of repeated measurement data was performed. Results: The PPTs at each acupoint decreased across the four timepoints, as the 19 acupoints became more pain-sensitive over time. Single-factor multilevel analysis showed a greater decrease in acupoint PPT at clinical stage ≥III than clinical stage I (p<0.05); PPTs at Xuehai (SP-10), Heding (EX-LE2), Ququan (LR-8), Yingu (KI-10), Xiguan (LR-7) and Qiuxu (GB-40) decreased more in imaging classification II than imaging classification I (p<0.05); PPT at Yaoyangguan (DU-3) decreased more in imaging classification ≥III than imaging classification I (p<0.05). Multi-factor multilevel analysis showed that the PPTs of Heding (EX-LE2), Liangqiu (ST-34), Ququan (LR-8), Dubi (ST-35), Weiyang (BL-39), Yinglingquan (SP-9), Xiguan (LR-7), Zusanli (ST-36), Yanglingquan (GB-34), Qiuxu (GB-40), and Weizhong (BL-40) decreased more with the progression of clinical stages (p<0.05); PPTs at Xuehai (SP-10), Heding (EX-LE2), Ququan (LR-8), Yingu (KI-10), Xiguan (LR-7), and Qiuxu (GB-40) decreased more in imaging classification II than imaging classification I (p<0.05); PPT at Qiuxu (GB-40) decreased more in imaging classification ≥III than imaging classification I (p<0.05).Conclusion: The correlated acupoints became more pain-sensitive over time, and the acupoint PPTs were in accordance with disease severity. Liangqiu (ST-34), Dubi (ST-35), Weiyang (BL-39), Yinglingquan (SP-9), Xiguan (LR-7), Zusanli (ST-36), Yanglingquan (GB-34), and Qiuxu (GB-40) were most related to disease severity, they should be recommended clinically.Trial registration: ChiCTR, ChiCTR1800014616. Registered 24 January 2018 - Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=24037