Do we treat hypothyroidism properly? A survey of 2488 patients from University Hospital Center, Zagreb, Croatia.

OBJECTIVES

The objective was to examine the effectiveness of levothyroxine treatment in hypothyroid patients in achieving normal thyroid stimulating hormone (TSH), T4 and T3.

MATERIAL AND METHODS

Results of the treatment of 2448 hypothyroid patients treated with LT4 for at least 12 months between 2006 and 2011 (1920 with spontaneous hypothyroidism and 528 with hypothyroidism following surgery or 131I) are presented. Serum TSH, T4 and T3 were analyzed and referred as normal, increased or decreased.

RESULTS

Normal TSH was found in 75 and 68% of patients respectively. In subgroups with increased TSH, 15% and 14% of patients showed borderline or only mildly increased TSH (4.1-5.5 mIU/L). T4 (94 and 86%) and T3 (93 and 90% respectively) were normal in the majority of patients from both groups. LT4 over-treatment is observed in only 4 and 6% of patients respectively.

CONCLUSION

The results are less favorable for the group with hypothyroidism following surgery or (131)I than in spontaneous hypothyroidism, but in about 90% of patients with spontaneous hypothyroidism and 82% with hypothyroidism following surgery or (131)I, the LT4 dose could remain unchanged. It is discussed whether standard LT4 replacement could render normal TSH and thyroid hormone patterns in all hypothyroid patients.