The Analysis Of Bone Metabolism In Patients With Graves’ Disease And The Changes After¹³¹I Therapy

ObjectiveAs is known to all, thyroid hormones can accommodate the metabolism of bone. In this study, we observe the bone turnover biochemical markers and bone mineral density in patients with Graves’disease, in order to analyze the morbidity of osteopenia and osteoporosis in patients with Graves’ disease and the characteristics of bone metabolism in these people. Also, we develop prospective observation in patients treated by131I, to observe of changes in thyroid hormones, bone turnover markers and bone mineral density, in order to reveal the therapeutic effect of131I therapy and the reversibility of bone loss in Graves’ disease.Materials and MethodsIn this study, we collected367patients admitted in Endocrinology department of Zhongshan Hospital affiliated to Fudan University from May2010to March2012. According to our exclusion criteria,52patients were eliminated and the residual315patients entered our analysis. At the same time, we collected177patients who were treated by131I more than6months in the outpatient department of Endocrinology, examined the thyroid hormones in these patients. Also, we collected43patients who accepted131I therapy6to12months ago, to detect bone turnover markers and bone mineral density in these patients.1. We observed the morbidity of osteopenia and osteoporosis in patients with Graves’ disease.2. By analyzing the relationship between thyroid hormones and bone turnover biochemical markers and the relationship between thyroid hormones and bone mineral density in patients with Graves’ disease, try to reveal the influence of thyroid hormones to bone metabolism.3. By observing the changes in thyroid hormones in patients who accepted131I therapy more than6months, evaluate the therapeutic effect of131I therapy.4. By observing the changes in bone turnover markers and bone mineral density in patients who accepted131I therapy6to12months ago, to research the reversibility of bone loss in patients with Graves’disease.Results1. In the overall315patients, osteopenia patients account for47.6%, while osteoporosis account for14.6%. In112male patients, osteopenia account for56.3%, osteoporosis account for20.5%. In203female patients, osteopenia account for43.4%, osteoporosis account for10.8%. The morbidity of abnormal BMD in men is higher than in women.2. In patients with Graves’ disease, the level of FT3as well as FT4is positively related to serum calcium and phosphorus, negatively related to PTH, positively related to OCN、β-cTX、PINP、urine Ca++/Cr, P value are al<0.01; FT3and FT4has no linear relationship with serum ALP and serum25(OH)D.3. In patients with Graves’disease, FT3、FT4has a negative relationship to Total hip BMD Z-score but no linear relationship with Lumbar spine BMD Z-score and Neck BMD Z-score.4. Along with the rise of FT3and FT4, lumbar spine、neck and hip BMD Z-score become lower than reference; Along with the rise of TRAb, hip BMD Z-score become lower than reference; Along with the rise of TGAb, lumbar neck and hip BMD Z-score become higher than reference.5. In the177patients who accepted the follow-up visit of thyroid function more than6months from131I therapy,114patients were evaluated as hypothyroidism,13patients were evaluated as healing,41patients were evaluated as improvement, and9patients were evaluated as invalid. The success rate of131I therapy was71.7%, while in male the success rate is72.1%and in female it is71.6%. There is no significant difference between male and female in success rate of131I therapy.6. In the43patients who accepted the follow-up visit of bone metabolism, there are24persons who were successfully treated by131I therapy and other19persons whose treatment is unsuccessful. In the successfully treated group, PTH is higher than baseline, ALP、OCN、β-cTX、Pinp、urine Ca++/Cr is lower than baseline, P value were all <0.01, serum calcium and25(OH)D had no significant change compared to baseline; Neck and Total hip BMD Z-score were higher than baseline, while Lumbar spine BMD Z-score has no change compared to baseline. In the unsuccessfully treated group, PTH is also higher than baseline, β-cTX is also lower than baseline, P value all<0.05, while serum calcium、ALP、OC、PINP、25(OH)D and urine Ca++/Cr had no significant change compared to baseline; Lumbar spine、Neck and Total hip BMD Z-score had a weak ascending trend compared to baseline, but all not up to statistical significance.Conclusion1. In Graves’ disease patients, as along with the rise of thyroid hormones, bone turnover becomes more and more quick, BMD becomes lower than normal people with the same gender and age.2. In patients accepted131I therapy in our hospital, the success rate of treatment is71.7%. There is no significant difference between the success rate in men and in women (72.1%for men and71.6%for women). After the131I therapy, along with the improvement of thyrotoxicosis, the high bone turnover can be suppressed, BMD can partly recover.