The Effect Of Prednisone And Thyroid Tablet On The Incidence Of Hypothyroidism After ～(131)Ⅰ Treatment In GD Patients

PrefaceHyperthyroidism is one of the most common endocrine diseases. Its mechanism is very complicate,Graves' hyperthyroidism accounts for 80% of all hyperthyroidism patients,especially . Therapeutic methods of Graves' hyperthyroidism include anti-thyroid drug(ATD), surgery, radioactive iodine-131( ¹³¹I) therapy. Because ¹³¹I therapy has many advantages,such as,simple, safe, convenient, economic, effective, fewer side effect, it has been accepted by more and more patients and doctors. In fact, ¹³¹I therapy has become an ideal method. However, since its curative effect is influenced by many factors, like age, course, serum thyroid hormones level, ¹³¹I dosage and individual sensitivity, there was difficulties to some extent in ciincal practice.Hypothyroidism is a recognised major undesirable side effect of ¹³¹I therapy for hyperthyroidism, and its cumulative incidence was 20% at 1 year and increased 3% yearly. So the apply of ¹³¹I therapy is influenced by its major side effect in China and Europe. Regarding the decrease of hypothyroidism, many studies have been done and some achievements have been made. But the influence of treatment with prednisone and thyroid tablet on the incidence of hypothyroidism is not evaluated earlier.To investigate the effects of prednisone and thyroid tablet given in due time on the incidence of developing hypothyroidism after ¹³¹I treatment in patients with Graves disease(GD).Materials and MethodsNinety-two GD patients (20-65 years,23 male patients,69 female patients) were first treated with ¹³¹I therapy. They all stopped eating these foods(sea weed, laver, iodine rotula, iodine salt,ect)for at least two weeks and taking drugs (tapazole, propythiouracil, liquor iodi compostus,propantheline,ect) which can influence thyroid ¹³¹I uptake.According to ¹³¹I therapeutical procedure, the followings are carried out: serological examination, routine medical examination, thyroid weight estimation , ¹³¹I therapeutical dosage determination, taking the determined ¹³¹I by patients, follow-up arrangement, appraising ¹³¹I curative effectiveness.These patients were of two groups: Group 1 (Treatment group with prednisone and thyroid tablet) was devided into three subgroups:â‘ Thyroid auto-antibody positive(one or the two antibodies TgAb, TPOAb): Twenty patients were given prednisone after 13II treatment, 15mg one day for the first month, 10mg one day for the second month, 5mg one day for the third month, regularly persued, when the function of thyroid was in the normal lower limit within the first 6 months,they were given thyroid tablet treatment at a dose of 20mg/day for 3 months;â‘¡Thyroid auto-antibody positive.Twenty patients were not given prednisone after ¹³¹I treatment, regularly persued, when the function of thyroid was in the normal lower limit within the first 6 months,they were given thyroid tablet treatment at a dose of 20mg/day for 3 months;â‘¢Thyroid auto-antibody negative: Twenty patients were not given prednisone after ¹³¹I treatment, regularly persued, when the function of thyroid was in the normal lower limit within the first 6 months,they were given thyroid tablet treatment at a dose of 20mg/day for 3 months; Group 2(Control group): 20 patients, including 10 patients with positive thyroid auto-antibody, 10 patients with negative thyroid auto-antibody,they were not given any treatment(only thyroid tablet in case of hypothyroidism).These patients were followed for one year, then x² test was applied to the positive group with prednisone and the positive group without prednisone. the treatment group with thyroid tablet and without thyroid tablet when the function of thyroid was in the normal lower limit, thyroid auto-antibody positive group and thyroid auto-antibody negative group in order to see the impact of prednisone and thyroid tablet and thyroid auto-antibody on the incidence of hypothyroidism.The difference in the incidence of hypothyroidism between subgroups was compared using x² test and using SPSS statistical package(version 11.0). A P value of <0.05 was considered significant.ResultsThe incidence of hypothyroidism was 10% in the positive group with prednisone, 15% in the positive group without prednisone, the difference in the incidence of hypothyroidism between them was not significant(P>0.05 ). But when the function of thyroid was in the normal lower limit, these patients of treatment group were given 20mg thyroid tablet for three months, but these patients of control group were not given 20mg thyroid tablet(only thyroid tablet in case of hypothyroidism) . The incidence of hypothyroidism was 0% in treatment group, 33.3% in control group , the difference between them was significant (P <0.05 ). The incidence of hypothyroidism was 15% in the positive group, 10% in the negative group, the difference between them was not significant (P>0.05) .ConclusionIf GD patients after ¹³¹I treatment were given 20mg thyroid tablet when the function of thyroid was the normal lower limit, the incidence of developing hypothyroidism would be reduced; There was depressing tendency in the incidence of hypothyroidism under the treatment of prednisone, but the difference between the positive group with prednisone and without prednisone was not significant; There was increasing tendency in the incidence of hypothyroidism patients in GD patients with positive thyroid auto-antibody, but the difference between the positive group and the negative group was not significant.