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Circulating leptin levels in thyroid dysfunction: a systematic review and meta-analysis

Shanshan Liu, Jun Ma, Leyuan Zhang, Yanlong Yang, Ziqi Han, Limin Tian

BMC Endocrine Disorders, 2025

4,295 participants · 6 citations

Abstract

Leptin is an important regulator of energy homeostasis, analogous to thyroid hormone (TH). The purpose of this study was to investigate circulating leptin levels in thyroid dysfunction (TD) patients and the role of TH levels. The electronic databases PubMed, Embase, Cochrane Library, and Web of Science were independently searched by two researchers, from inception until February 3, 2024, and updated on February 15, 2025. Pooled standardized mean difference (SMD) with a 95% confidence interval (CI) was calculated by the random effects model. Thirty-eight studies reported circulating leptin levels in TD and control with euthyroidism, 4295 subjects were included in total, of which 1277 were hypothyroidism, 540 were hyperthyroidism, and 2478 were control. Compared to euthyroidism, leptin levels were significantly higher in hypothyroidism, and not significantly altered in hyperthyroidism (SMD [95%CI] = 0.71 [0.38, 1.04] and -0.03 [-0.57, 0.51], respectively). The subgroup analysis indicated that, compared to euthyroidism, leptin levels were significantly higher in subjects regardless of overt and subclinical hypothyroidism (SMD [95%CI] = 0.76 [0.25, 1.26] and 0.41 [0.11, 0.70], respectively), and not significantly different in overt hyperthyroidism (SMD [95%CI] = -0.14 [-0.74, 0.45]). Furthermore, when compared to age-, gender-, and body mass index (BMI)-matched euthyroidism, leptin levels were significantly higher in hypothyroidism and had no significant difference in…

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Evidence Hub reads this as a meta-analysis. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 4,295 participants or records.

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