甲状腺功能正常的绝经后2 型糖尿病患者 甲状腺功能与骨密度的相关性

Relationship between thyroid function and bone mineral density in postmenopausal T2DM women with normal thyroid function

摘要:

目的 探讨甲状腺功能正常的绝经后2 型糖尿病（T2DM）患者其甲状腺功能与骨密度（BMD） 的相关性。方法 回顾性分析甲状腺功能正常的绝经后T2DM 患者354 例，采用双能X 射线骨密度仪检查脊 柱L1 ～ 4 和左侧股骨BMD，分别将促甲状腺激素（TSH）、游离甲状腺素（FT4）、游离三碘甲腺原氨酸（FT3） 按三分位数由低至高进行分组，即A、B、C 组，比较各组脊柱L1 ～ 4 和左侧股骨BMD，并分析脊柱L1 ～ 4、左 侧股骨BMD 与TSH、FT4、FT3 及其他临床指标的相关性。结果 ① TSH A 组患者的脊柱L1 ～ 4 BMD 低于 C 组（P <0.05）；TSH A 组与C 组的左侧股骨BMD 比较，差异无统计学意义（P >0.05）；FT4、FT3 3 组患 者的脊柱L1 ～ 4 和左侧股骨BMD 比较，差异无统计学意义（P >0.05）。② Pearson 相关分析显示，脊柱L1 ～ 4 BMD 与TSH、体重指数（BMI）呈正相关（P <0.05），与年龄、血碱性磷酸酶（AKP）呈负相关（P <0.05）， 与FT4、FT3 无相关性（P >0.05）；左侧股骨BMD 与BMI、血三酰甘油（TG）呈正相关（P <0.05），与年龄、 AKP 呈负相关（P <0.05），与TSH、FT4、FT3 无相关性（P >0.05）。③多元线性回归分析显示，TSH、BMI 是脊柱L1 ～ 4 BMD 的独立保护因素（P <0.05），年龄是其独立危险因素（P <0.05）；BMI是左侧股骨BMD 的 独立保护因素（P <0.05），年龄、AKP 是其独立危险因素（P <0.05）。结论 在甲状腺功能正常的绝经后2 型 糖尿病患者中，TSH 是腰椎BMD 的独立保护因素，而与股骨BMD 无关；FT4、FT3 与腰椎和股骨BMD 无关。

Abstract:

Objective To investigate the relationship between thyroid function and bone mineral density (BMD) in postmenopausal women with type 2 diabetes (T2DM) and normal thyroid function. Methods A total 354 postmenopausal females with T2DM and normal thyroid function were analyzed retrospectively, and BMD of the lumbar spines L1-L4 and the left femur was measured using dual-energy X-ray absorptiometry. All subjects were divided into the group A (1st tertile), the group B (2nd tertile) and the group C (3rd tertile) depending on tertiles of serum TSH, FT4 and FT3 levels separately, then BMD of the lumbar spines L1-L4 and the left femur was compared among the groups; furthermore the relationships of the BMD with TSH, FT4, FT3 and other clinical indicators were analyzed. Results The BMD of the lumbar spines L1-L4 in the TSH group A was significantly lower than that in the TSH group C (P < 0.05), but there was no significant difference in the BMD of the left femur between the TSH groups A and C (P > 0.05). There was no significant difference in the BMD of the lumbar spines L1-L4 and the left femur among the three groups depending on tertiles of serum FT4 or FT3 separately (P > 0.05). Pearson correlation analysis showed that the BMD of the lumbar spines L1-L4 was positively correlated with TSH and body mass index (BMI) (P < 0.05), negatively correlated with age and alkaline phosphatase (AKP) (P < 0.05), not correlated with FT3 or FT4 (P > 0.05). The BMD of the left femur was positively correlated with BMI and triglyceride (P < 0.05), negatively correlated with age and AKP (P < 0.05), not correlated with TSH, FT4 or FT3 (P > 0.05). Multivariate linear regression analysis showed that TSH and BMI were the independent protective factors (P < 0.05), and age was the independent risk factor (P < 0.05) for BMD of the lumbar spines L1-L4. BMI was the independent protective factor (P < 0.05), and age and AKP were the independent risk factors (P < 0.05) for BMD of the left femur (P < 0.05). Conclusions In the postmenopausal women with type 2 diabetes and normal thyroid function, TSH is an independent protective factor for BMD of the lumbar spines, but not correlated with the BMD of the femur. FT4 and FT3 are not correlated with either the BMD of the lumbar spines or the BMD of the femur.