Background: The incidence of thyroid carcinoma is on the rise all the world. Some studies have suggested that the change of adipokines can even induce thyroid carcinoma. However, other studies have come to the opposite conclusion. Therefore, we studied the relationship between adipokines and thyroid carcinoma.
Methods: Databases—PubMed, Cochrane Library, SinoMed, CNKI, Wanfang, and clinical trial registries were searched. A meta-analysis was performed with sufficiently homogeneous studies. Twenty-nine articles were finally included for analysis.
Results: The level of serum tumor necrosis factor-alpha (TNF-α) [standardized mean difference (SMD) =1.31, 95% confidence interval (95% CI): 0.35 to 2.28, I 2 =98%, P =0.008] and positive rate of tissue’s TNF-α [odds ratios (OR) =11.80, 95% CI: 5.88 to 23.66, I 2 =0%, P <0.00001] in thyroid carcinoma are significantly higher than those in control. The serum interleukin-6 (IL-6) in patients with thyroid carcinoma is higher than that in control (SMD=1.04, 95% CI: 0.40 to 1.67, I 2 =96%, P =0.001). No significant difference of the positive rate of IL-6 in tissues between carcinoma and control is found (OR=1.23, 95% CI: 0.62 to 2.43, I 2 =86%, P =0.55). The positive ratio of leptin in tissue is significantly associated with the risk of thyroid carcinoma (OR=12.21, 95% CI: 3.36 to 44.40, I 2 =85%, P <0.00001). However, after analyzing three studies on the expression of adiponectin, no significant difference is found in serum adiponectin level between thyroid carcinoma and the control ( P =0.81).
Conclusions: Adipokines play an important role in the occurrence and development of thyroid carcinoma, especially TNF-α, IL-6 and leptin. However, the effect of adiponectin on thyroid carcinoma needs further research.