[Research of relationship between thyroid-stimulating hormone level after surgery and hypercholesterolemia in female...

Objective:To evaluate changes of postoperative thyroid-stimulating hormone（TSH） and total cholesterol（TC） levels in serum, and to analyze the risk of hypercholesterolemia in female patients with differentiated thyroid cancer（DTC） receiving levothyroxine after total thyroidectomy. Method:Female patients with DTC in the first affiliated hospital of hebei north university, who underwent total thyroidectomy, were analyzed retrospectively. All patients were divided into four groups according to follow-up TSH levels:<0.03 mIU/L, 0.03-0.29 mIU/L, 0.30-4.20 mIU/L and>4.20 mIU/L. Changes in TC levels before and after surgery were compared and the occurrence of hypercholesterolemia was analyzed. Result:The lower postoperative TSH level groups had higher preoperative TC levels than the higher TSH level groups. Compared with preoperative level, the TC levels remained unchanged in 0.03-0.29 mIU/L group, but decreased in <0.03 mIU/L group, and markedly increased in greater than 0.3 mIU/Lgroups with TSH levels after surgery. The preoperative-to-follow-up change in TC levels had positive correlation with follow-up TSH level. Compared with those with TSH levels of 0.03-0.29 mIU/L, the risk of TC marginal elevation and hypercholesterolemia in the patients with TSH of 0.30-4.20 mIU/L was found to be 1.16 times and 1.91 times higher, respectively. For patients with TSH levels of >4.2 mIU/L, the risk of TC marginal elevation and hypercholesterolemia was 1.29 times and 3 times, respectively. The increase in TSH was consistent with the increase in the incidence of hypercholesterolemia （P for trend=0.003）. Conclusion:Women with DTC who are using levothyroxine to maintain TSH after surgery should be aware of the risk of hypercholesterolemia due to inadequate replacement.