Földes J, Lakatos P, Zsadányi J, Horváth C
First Department of Medicine, Semmelweis University, Budapest, Hungary.
Eur J Endocrinol. 1997 Mar;136(3):277-81. doi: 10.1530/eje.0.1360277.
Postmenopausal women with endogenous subclinical hyperthyroidism seem to have reduced bone mass, which does not correlate with serum thyroid hormone levels. Relative insufficiencies of IGF-I and dehydroepiandrosterone sulphate (DHEAS) might be additional risk factors for low bone density in these patients. We measured IGF-I, IGF-binding protein-3 (IGFBP-3) and DHEAS levels together with bone mineral density (BMD) of the femoral neck and lumbar spine in women with an autonomously functioning thyroid nodule. Sixty-three women were classified as subclinical hyperthyroid (31 pre- and 32 postmenopausal) and 39 as overt hyperthyroid (16 pre- and 23 postmenopausal) and results were compared with data obtained from 41 age-matched euthyroid healthy women. In premenopausal women BMD was reduced only in the overt hyperthyroid group, and only in the spine, to 92% (P < 0.05). Serum IGF-I as well as IGFBP-3 were increased in the manifest hyperthyroid group, to 157% (P < 0.001) and 129% (P < 0.05) respectively, whereas DHEAS levels did not change in either premenopausal patient group. In postmenopausal women BMD was significantly reduced both in the subclinical hyperthyroid group (spine to 90% and femoral neck to 88%; P < 0.05), as well as in the hyperthyroid group (spine to 78% and femoral neck to 86%; P < 0.01). In contrast to premenopausal women, serum IGF-I and IGFBP-3 did not change in the two groups who were postmenopausal and serum DHEAS levels were reduced to 58% (P < 0.001) in both postmenopausal groups with subclinical as well as overt hyperthyroidism. In the same two groups of patients, serum IGF-I and DHEAS levels correlated with BMD (femoral neck; both r = 0.50, P < 0.05). In conclusion, women with a solitary autonomous thyroid nodule with subclinical hyperthyroidism have reduced BMD only if they are postmenopausal. This is probably due to the effect of subtle increases in thyroid hormone production together with lack of oestrogen protection of the skeleton. But additional risk factors for the development of enhanced bone loss might be a state of relative IGF-I and DHEAS insufficiency in these patients as well as in postmenopausal women with overt hyperthyroidism.
患有内源性亚临床甲状腺功能亢进的绝经后女性似乎骨量减少，且这与血清甲状腺激素水平无关。胰岛素样生长因子-I（IGF-I）和硫酸脱氢表雄酮（DHEAS）相对不足可能是这些患者骨密度降低的额外危险因素。我们测量了患有自主功能性甲状腺结节的女性的IGF-I、IGF结合蛋白-3（IGFBP-3）和DHEAS水平以及股骨颈和腰椎的骨密度（BMD）。63名女性被分类为亚临床甲状腺功能亢进（31名绝经前和32名绝经后），39名被分类为显性甲状腺功能亢进（16名绝经前和23名绝经后），并将结果与从41名年龄匹配的甲状腺功能正常的健康女性获得的数据进行比较。在绝经前女性中，仅在显性甲状腺功能亢进组且仅在脊柱处骨密度降低至92%（P<0.05）。显性甲状腺功能亢进组血清IGF-I以及IGFBP-3分别升高至157%（P<0.001）和129%（P<0.05），而绝经前患者组中DHEAS水平均未改变。在绝经后女性中，亚临床甲状腺功能亢进组（脊柱至90%，股骨颈至88%；P<0.05）以及甲状腺功能亢进组（脊柱至78%，股骨颈至86%；P<0.01）骨密度均显著降低。与绝经前女性不同，绝经后两组血清IGF-I和IGFBP-3均未改变，且亚临床和显性甲状腺功能亢进的绝经后两组血清DHEAS水平均降低至58%（P<0.001）。在同一两组患者中，血清IGF-I和DHEAS水平与骨密度（股骨颈；两者r = 0.50，P<0.05）相关。总之，患有孤立性自主甲状腺结节且亚临床甲状腺功能亢进的女性仅在绝经后骨密度降低。这可能是由于甲状腺激素产生的细微增加以及骨骼缺乏雌激素保护的作用。但这些患者以及患有显性甲状腺功能亢进的绝经后女性中，骨量增加丢失的额外危险因素可能是相对IGF-I和DHEAS不足的状态。
