Acupuncture for Reduction of Inflammation in Thyroid and Parathyroid Surgery: Randomized, Prospective Double Blind Pilot Clinical Trial

Acupuncture has traditionally been used in Asia and is increasingly popular in Western countries to treat a variety of conditions (1). In recent years, acupuncture is widely used to assist in improving pain and inflammatory diseases (2). However, the mechanisms associated with these treatments that influence the immune system are not yet understood.

Cytokines like interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) are proposed to be proximal mediators in the early stages of inflammation. They modulate many of the early inflammatory response that is induced by tissue injury, infection, or an immune stimulus (3, 4). Although the response is a critical first line of defense against pathogens, when the inflammatory reaction is uncontrolled, it can cause more damage to the host than the initial stimulus. TNF-α is a pro-inflammatory cytokine that is very effective in local and systemic inflammations (5). In addition, TNF-α increases the production of other inflammatory cytokines such as IL-1β, IL-6, and interleukin-18 (IL-18) during the inflammatory process. Therefore, it initially brings infections under control, produces coagulation in the damaged tissue, and stimulates tissue improvement. An excessive increase of TNF-α level causes an extreme immune reaction and contributes to the development of atherosclerosis, shock, endotoxemia, and chronic inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis, and inflammatory bowel disease (5-7). Yim and colleagues reported a decrease in increased serum TNF-α, IL-6, and interferon gamma levels by arthritis as a result of electroacupuncture treatment (9). In a rat model for ulcerative colitis, acupuncture inhibited the expression of IL-1β and IL-6 (10). It has been reported that acupuncture significantly reduces complete Freund's adjuvant-induced hind paw edema and mouse air pouch inflammation (11, 12). Acupuncture could also improve immune dysfunction after surgical stress both in human and animals (13, 14).

Some cytokines are pro-inflammatory, but others are anti-inflammatory (3). The anti-inflammatory interleukins comprise interleukine-4 (IL-4) and interleukine-10 (IL-10) and these are considered as mediating the down-regulation of immune-inflammatory conditions. Acupuncture for treatment of the ulcerative colitis rats is possibly related with the decrease of IL-1β, a pro-inflammatory cytokine, and the increase of IL-4, an anti-inflammatory cytokine (15).

Therefore, it is reasonable to expect that the protective action of acupuncture is exerted by the modulation of pro- and anti-inflammatory cytokines. The restoration of balance between pro- and anti-inflammatory cytokines by acupuncture gives into the mechanisms underlying the immune-modulation effect of acupuncture.

Inflammation is associated with pain hypersensitivity that is produced by the release of inflammatory mediators. The pro-inflammatory cytokines play an essential role in pain sensitization (16). The peripheral effects of these cytokines on sensitizing nociceptors have been well documented (16). Post-operative surgical pain can cause significant physiologic and psychologic distress for patients. An increase in pain duration and intensity after surgery can contribute to a variety of complications, including delayed ambulation, pulmonary and thromboembolic complications, increased length of hospital stay, and generalized distress and anxiety. Effective post-surgical pain relief requires a multidisciplinary effort and influences patients' satisfaction with care and successful outcomes (17). Acupuncture has been used for a long time for the reduction of pain. In light of these factors, the use of acupuncture that may allow a reduction in the dosage of conventional analgesics is highly valuable because it can lower the incidence of possible adverse effects. Several trials have demonstrated that patients receiving acupuncture prior to surgery have a lower level of pain, reduced opioid requirement, a lower incidence of post-operative nausea and vomiting, and lower sympatho-adrenal responses (18). The local release of β-endorphin could be responsible for the analgesic effect. β-endorphin may be interacting with cytokines to reduce pain and acupuncture may amplify the interaction between β-endorphin and cytokines.