Effect of different doses of TSH on the postoperative related indicators in patients with differentiated thyroid cancer

Objective:To investigate the effect of different doses of thyroid stimulating hormone(TSH) on the postoperative related indicators in patients with differentiated thyroid cancer.Methods:Fifty differentiated thyroid cancer patients scheduled by operation were investigated.After 30 days of operation,the patients were treated with removing remnant thyroid residual tissue using ¹³¹I combined with TSH therapy.Patients were divided into the conventional dose group and inhibitive dose group according to the different dose of TSH(25 cases each group).The conventional dose group was treated with 2.0 μg/kg L-thyroxine sodium tablet,and the inhibitive dose group was treated with 2.5 μg/kg L-thyroxine sodium tablet.The levels of free triiodothyronine(FT3),serum free thyroxine(FT4),TSH,the serum levels of calcium,phosphorus and alkaline phosphatase (ALP),and the bone mineral density in L_2-4 vertebral body,ward triangle,femoral large rotor and femoral shaft between before and after treatment in two groups were compared.Results:The differences of the levels of FT3,FT4 and TSH between two groups were not statistically significant before treatment(P>0.05).Compared with before treatment,the levels of FT3 and FT4 in two groups significantly increased(P<0.01),the TSH levels in two groups significantly decreased(P<0.01),the levels of FT3 and FT4 in inhibitive dose group were significantly higher than those in conventional dose group(P<0.01),and the levels of TSH in inhibitive dose group were significantly lower than that in conventional dose group after 12 months of treatment(P<0.01).The differences of the levels of calcium,phosphorus and ALP and bone mineral density in L_2-4 vertebral body,ward triangle,femoral large rotor and femoral shaft in two groups between before and after treatment were not statistically significant(P>0.05).Conclusions:The conventional dose of L-thyroxine can ensure the normal physiological needs of patients with differentiated thyroid cancer,and the inhibitive dose can keep thyroid function in subclinical hyperthyroidism.The effect of different doses of L-thyroxine on bone metabolism and bone mineral density is small.The dose is selected on the basis of the actual situation of patients.