Effect Of Thyroid Stimulating Hormone On Bone Mineral Density And Fracture Risk In Postmenopausal Women With Normal Reference Range

Objective: To investigate the effect of thyroid stimulating hormone(TSH) on bone mineral density, osteoporosis and fracture risk in the normal range of postmenopausal women with normal thyroid function. Method: The data set used in this paper is based on the research of the Guiyang metabolic epidemiological investigationin in 2009. 1512 subjects ranging from 20 years old to 79 years old who by the inclusion and exclusion criteria screening after menopause in 234 euthyroid women enrolled in this study. According to the level of TSH, to the three percentile they were divided into 3 groups, T1 group(0.73-2.67 m U/L), T2 group(2.67-3.83 m U/L), T3 group(3.83-6.14 m U/ L), all subjects were conducted a questionnaire survey, physical examination, and detection of TSH. The serum level of 25 hydroxyvitamin D [25(OH) D], parathyroid hormone(i PTH), serum calcium, serum phosphorus, using dual energy X-ray absorptiometry, left femoral neck were measured, lumbar(L1-L4), total hip, trochanter, ward triangle bone density. The differences between the general situation, biochemical indexes and bone mineral density were compared between the groups, and the changes of normal TSH level and bone mineral density were analyzed, and their effects on fracture risk were analyzed. Results:(1) Compared with the T1 group, T2 group had lower bone mineral density(P<0.05), T1 group and T3 group compared with wards group, the bone mineral density of femoral neck was significantly lower(P<0.05).(2) TSH level and femoral neck, total hip, ward triangle area of bone mineral density was weak positive correlation(r = 0.17, 0.14, 0.16; P<0.05) and multiple linear regression analysis showed that TSH level is a predictor of BMD at the femoral neck, wards triangle bone mineral density independent effects of factors(β =0.134,0.125, P<0.05); TSH and lumbar spine(L1-L4), of the greater trochanter bone mineral density (BMD) no significant correlation(P>0.05). 3)To observe the positive rate of osteopenia, osteoporosis and fracture different TSH levels in tertiles. The positive rate of osteopenia in the femoral neck was T1 group(53.8%), T2 group(52.6%), and group T3(33.3%), The difference was statistically significant(P<0.05), In the lumbar(L1-L4) T1 group(44.9%) was higher than that in the T2 group(28.2%),The difference was statistically significant(P<0.05). Osteoporosis prevalence among the groups in the femoral neck and lumbar spine(L1-L4) were not seen significant difference. Among the three groups of fracture positive rate had no significant difference.(4). Logistics regression analysis showed that different levels of TSH groups were not significantly related with fracture of lumbar(P>0.05),(L1-L4) T value have obvious influence on fracture(OR=0.588, P<0.05). Conclusion: The physiological variation of thyroid stimulating hormone in normal thyroid function may have a certain effect on bone mineral density in postmenopausal women, but there is no direct correlation between the risk of bone fracture and fracture risk.