Levothyroxine versus Levothyroxine with Iodine in Reduction of Thyroid Nodule Volume: A Double-Blind Randomized Controlled Trial

Abstract

Objective: To compare levothyroxine alone and in combination with iodine on thyroid nodule volume reduction.
 Methods: 
           Design:           Double-Blind Randomized Controlled Trial
           Setting:           Tertiary Government Hospital
           Participants: Nineteen (19) euthyroid patients age 19­-54 with at least 1 cytologically benign thyroid nodule were randomized to receive either levothyroxine + iodine or levothyroxine + placebo, taken once a day for 6 months with ultrasound and thyroid stimulating hormone monitoring on the 3rd and 6th month of intervention.
 Results: Main outcome measures included thyroid nodule volume reduction after six months of intervention. The mean change in volume from baseline to six months of levothyroxine + iodine group showed no statistically significant difference in nodule volume across time between  levothyroxine + placebo group, -0.010 ± 1.250 (CI -0.521 - 0.501) versus 0.507 ± 1.128 (CI 0.025 - 0.990), p=.158.  There were also new nodules (4 nodules) in the placebo group and none in the iodine group. No major adverse events were noted during the study.
 Conclusion: The two groups did not significantly differ in terms of nodule volume reduction.
 Keywords: thyroid nodule, prevention and control; drug therapy; iodine compounds, therapeutic use; levothyroxine, therapeutic use