The Relationship Between Subclinical Hypothyroidism And Bone Metabolism In Residents In Taiyuan

Objective:By measuring the thyroid function,thyroid antibody,Total N-terminal peptides of collagen type Ⅰ,lumbar spine,and left hip joint inhabitants in some urban districts of Taiyuan,Shanxi Province,the past history and medication history were investigated to observe the patients with subclinical hypothyroidism.Density and changes in bone metabolism indicators,to explore the correlation between thyroid function and bone density and bone metabolism.Methods:From the residents of some urban areas in Taiyuan,Shanxi Province,529 randomly selected subjects were investigated.Based on the completeness of the survey data and inclusion criteria,97 patients(subclinical hypothyroidism group)that met the diagnostic criteria of subclinical hypothyroidism were included.The bone mineral density(BMD)was measured using a dual energy X-ray detector(DEXA)and the serum total type Ⅰ collagen N-terminal prolonged peptide(PINP)was detected.The serum levels were classified according to sex and menopause,and their age and gender were included.111 matched patients with normal thyroid function(control group)were compared.Bone mineral density and bone metabolic markers were compared between the two groups.Results:1.The reduction of bone mass and osteoporosis(OP)in the male lumbar vertebrae in the subclinical hypothyroidism group was significantly higher than that in the control group.There was no significant difference in the decrease of lumbar BMD between premenopausal and postmenopausal women compared with the control group.2.The ratio of BMD reduction in the left hip joint of male and premenopausal women in the subclinical hypothyroidism group was higher than that of the control group,and the difference was statistically significant(P<0.05).There was no significant difference in the composition of BMD reduction in the left hip of postmenopausal women compared with the control group(P>0.05).3.There was no significant difference between the total N-terminal prolongation peptideof type Ⅰ collagen in the subclinical hypothyroidism group and the control group.4.Logistic regression analysis showed that elevated levels of thyroid stimulating hormone(TSH)may be a risk factor for osteoporosis and osteopenia in the lumbar spine and left hip(OR=4.481,95% confidence interval,2.345 to 8.561;OR= 3.151,95%confidence interval is 1.248 to 7.955).The increase in age may be a risk factor for decreased BMD in the left hip(OR = 3.774,95% confidence interval 1.941 ~ 7.335).Increased BMI may be a protective factor for decreased BMD(OR = 0.290,95%confidence interval 0.142 to 0.591).Patients with a history of subclinical hypothyroidism have a high prevalence of osteoporosis.Conclusion:1.Subclinical hypothyroidism,to some extent,exists in the reduction of BMD and even the occurrence of osteoporosis in the lumbar spine and left hip joint.2.Raising the level of thyroid stimulating hormone within a certain range may be a risk factor for osteoporosis.There was no significant abnormality in the subclinical hypothyroidism PINP levels.