| Objective:To study the relationship between short-term rapid hypothyroidism and blood lipid levels in patients with differentiated thyroid cancer.Methods:DTC patients(50 females and 25 males)who had undergone total thyroidectomy or partial thyroidectomy were enrolled.We measured thyroid hormone levels and serum lipid levels at two time points:while the patients were euthyroid before thyroidectomy,and the patients were hypothyroid(off LT4).We collected TSH,FT3,FT4 and TC,TG,LDL-C,HDLC and other parameters of DTC patients.We assessed the relationships between thyroid function and lipids in different genders.All participants were divided into 3 subgroups according to TSH levels(30-50μIU/mL,50-70μIU/mL,and>70μIU/mL).We evaluated the incidence of dyslipidemia in different subgroups and different genders.We make a statistical analysis of the data collected.All tests were two-sided,and p<0.05 was considered statistically significant.Result:1.Significant changes could be observed in thyroid hormones and serum lipid concentrations in all DTC patients(P<0.001).2.With the gradual increase of serum TSH concentration,the proportion of hypercholesteremia in men also increased.The incidence of hypercholesteremia in females was higher than that in males.By contrast,the prevalences of hypertriglyceridemia and low HDLC were significantly higher in males compared with females.As the serum TSH level increased,the prevalences of hypercholesteremia increased.3.The number of patients with hypercholesterolemia,high LDL-C and hypertriglyceridemia in hypothyroidism was at least 2 times higher than that in euthyroidism.The prevalences of hypercholesterolemia and hypertriglyceridemia in hypothyroidism were higher than those in euthyroidism(χ2=21.55,P<0.001).In addition,a significant negative correlation between FT3 and HDL-C,and a significant positive correlation between TSH and HDL-C were identified in females,which were not observed in males.4.In male patients with euthyroidism,a significant positive correlation between TSH and TG,a positive correlation between FT3 and LDL-C,and a positive correlation between FT4 and HDL-C.The correlation between thyroid hormones and lipids were not observed in females.In female patients with hypothyroidism,FT3 was negatively correlated with TC,FT4 was negatively correlated with TG,TC and LDL-C,but TSH was not correlated with lipids.The correlation between thyroid hormones and lipids were not observed in males with hypothyroidism5.Adjusted for age and body mass index,there was no correlation between TSH,FT3,FT4 and the changes of lipids from euthyroidism to hypothyroidism in males.In females,a significant negative correlation between FT4 and HDL-C from euthyroidism to hypothyroidism,FT3 and TG from euthyroidism to hypothyroidism,TC and HDL-C from euthyroidism to hypothyroidism.There was no correlation between TSH and the changes of lipids from euthyroidism to hypothyroidism.Conclusion:The level of serum lipids in DTC patients with hypothyroidism caused by withdrawal of thyroid hormone is significantly higher than that in euthyroidism.The incidence of hypercholesteremia in females was higher than that in males.By contrast,the prevalences of hypertriglyceridemia and low HDL-C were significantly higher in males compared with females.The changes of blood lipids in DTC patients with abnormal preoperative blood lipid levels during the withdrawal of thyroxine were greater than those in patients with normal preoperative blood lipid levels.Such patients should strengthen the management of blood lipids during the withdrawal of thyroxine in order to reduce the adverse effects of further abnormal blood lipids on patients. |
