Song Y M, Sheu W H, Lee W J, Wu C J, Kao C H
Department of Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China.
Kaohsiung J Med Sci. 1999 Mar;15(3):119-26.
Leptin, a newly defined protein synthesized and secreted from fat cells in both animals and humans, has gained wide attention. Many studies have been conducted on its roles in the regulation of body fat storage, energy expenditure and body weight changes. Thyroid dysfunction is known to have influences on the above changes in humans and these changes may in turn lead to a variation in circulating leptin levels. In addition, a sex dimorphism of plasma leptin levels has been a constant finding in many studies. However, the relationship between body fat mass and gender to plasma leptin levels in patients with various thyroid dysfunction has been rarely discussed together. A total of 134 patients with various thyroid function status were included in this study (hyperthyroidism: n = 50, hypothyroidism: n = 24, and euthyroidism: n = 60). Plasma leptin concentrations were compared between different thyroid function groups, and compared with body fat mass and body mass index (kg/m2) to check if these two parameters affect the circulating leptin levels. There were no significant differences between plasma leptin concentrations in the different thyroid function groups (Mean +/- SD: hyperthyroidism: 8.5 +/- 5.4 ng/ml, range: 1.5-25.8; hypothyroidism: 8.4 +/- 4.7 ng/ml, range: 1.8-20.1, and euthyroidism: 7.3 +/- 4.5 ng/ml, range: 0.6-20.9). Rather, a significant gender difference was found, with female subjects having two-fold higher levels than males when all study subjects were encompassed (female: 8.8 +/- 4.9 ng/ml, range: 11.7-25.8 vs male: 4.1 +/- 2.1 ng/ml, range 0.6-8.1, p < 0.001) or when thyroid function status was analyzed separately (hyperthyroidism: female: 9.7 +/- 5.5 ng/ml vs male: 4.3 +/- 2.1 ng/ml, p < 0.001; hypothyroidism: female: 9.7 +/- 4.6 ng/ml vs male: 4.4 +/- 2.4 ng/ml, p = 0.015; and euthyroidism: female: 7.9 +/- 4.5 ng/ml vs male: 3.6 +/- 1.9 ng/ml, p = 0.013). Plasma leptin concentrations had strong correlation with body fat mass in both females (r = 0.47, p < 0.001) and males (r = 0.71, p < 0.001). Good correlation was also observed between plasma leptin concentrations and body mass index in females (r = 0.51, p < 0.001) and males (r = 0.78, p < 0.001). Plasma leptin concentrations were not different in thyroid dysfunction. A significant gender difference existed and a positive correlation between body fat mass and BMI to plasma leptin was observed.
瘦素是一种新定义的由动物和人类脂肪细胞合成并分泌的蛋白质，已受到广泛关注。关于其在调节体脂储存、能量消耗和体重变化方面的作用，已经开展了许多研究。已知甲状腺功能障碍会影响人类上述变化，而这些变化反过来可能导致循环瘦素水平的改变。此外，血浆瘦素水平的性别差异在许多研究中一直存在。然而，各种甲状腺功能障碍患者的体脂量和性别与血浆瘦素水平之间的关系很少被同时讨论。本研究共纳入134例不同甲状腺功能状态的患者（甲亢：n = 50，甲减：n = 24，甲功正常：n = 60）。比较了不同甲状腺功能组之间的血浆瘦素浓度，并与体脂量和体重指数（kg/m²）进行比较，以检查这两个参数是否影响循环瘦素水平。不同甲状腺功能组之间的血浆瘦素浓度无显著差异（均值±标准差：甲亢：8.5±5.4 ng/ml，范围：1.5 - 25.8；甲减：8.4±4.7 ng/ml，范围：1.8 - 20.1，甲功正常：7.3±4.5 ng/ml，范围：0.6 - 20.9）。相反，发现了显著的性别差异，当纳入所有研究对象时，女性受试者的水平是男性的两倍（女性：8.8±4.9 ng/ml，范围：11.7 - 25.8，男性：4.1±2.1 ng/ml，范围0.6 - 8.1，p < 0.001），或者在分别分析甲状腺功能状态时也是如此（甲亢：女性：9.7±5.5 ng/ml，男性：4.3±2.1 ng/ml，p < 0.001；甲减：女性：9.7±4.6 ng/ml，男性：4.4±2.4 ng/ml，p = 0.015；甲功正常：女性：7.9±4.5 ng/ml，男性：3.6±1.9 ng/ml，p = 0.013）。血浆瘦素浓度在女性（r = 0.47，p < 0.001）和男性（r = 0.71，p < 0.001）中均与体脂量密切相关。在女性（r = 0.51，p < 0.001）和男性（r = 0.78，p < 0.001）中，血浆瘦素浓度与体重指数之间也观察到良好的相关性。甲状腺功能障碍患者的血浆瘦素浓度无差异。存在显著的性别差异，并且观察到体脂量和体重指数与血浆瘦素呈正相关。
