Analysis Of Body Composition And Bone Mineral Density In Patients With Hyperthroidism Before And After ¹³¹Ⅰ Therapy

【Objective】Based on the precision of the measurements of body composition and bone mineral density (BMD) by dual-energy X-ray absorptiometry(DXA),we analyzed the changes of body composition and BMD in patients with hyperthyroidism before and after ¹³¹I therapy to investigate the effect of ¹³¹ I therapy for hyperthyroidism on fat mass,lean mass and bone metabolism.【Methods】The short-term precision of body composition and BMD were measured by DXA(GE Lunar Prodigy).105 untreated hyperthyroid patients were divided into three groups:the effective group(60 cases),invalid group(13 cases) and hypothyroidism group(32 cases) according to the curative effect after ¹³¹I therapy.Total body and regional body composition[fat mass,lean mass and bone mineral content(BMC)]and BMD of total body,lumbar spine(L2-L4),femur were determined by DXA in patients with hyperthyroidism before and after 3 months ¹³¹I therapy, respectively.【Results】Total body and regional BMC precision was 0.7%-2.6%,fat mass was 1.5%-3.9%,lean mass was 0.7%-2.9%,BMD was 0.7%-2.1%.Underweight occurred in 40%,abnormal BMC occurred in 47.6%of the untreated hyperthyroid patients,fat mass,lean mass,BMC and BMD in patients with hyperthyroidism were lower than that in the control group significantly (p＜0.05).Compared with patients before ¹³¹I treatment,weight and lean mass in effective group after 3 months treatments increased significantly(p＜0.05),but BMC and fat mass did not change significantly(p＞0.05);In invalid group,lean mass increased(p＜0.05),weight,BMC and fat mass did not change significantly(p＞0.05);In hypothyroidism group,weight,fat mass and lean mass increased significantly(p＞0.05),and the BMC did not change significantly(p＞0.05).BMD in all 3 groups patients showed no changes significantly(p＞0.05). 【Conclusion】Fat mass,lean mass,BMC and BMD in patients with hyperthyroidism were decrease.The weight increased in effective patients with hyperthyroidism received ¹³¹I therapy after 3 months, mainly because their lean mass increased,while fat mass and bone mass did not change significantly.The weight in patients with hypothyroidism also increased,mainly because their lean mass and fat mass increased,while bone mass did not change significantly.However,there were no significant difference between the BMD in the patients treated after 3 months and that of the untreated patients.