Endocrine Abstracts

Introduction

There are very limited number of clinical studies and data on the effect of thyroid dysfunction in hypothyroidism on connective tissue. Tendinitis can be the first complaint in hypothyroidism and symptomatic relief can be provided with the appropriate treatment of primary thyroid deficiency. There are studies, showed softening in Achilles tendon with age, in patients with intermittent claudication, diabetes patients, and chronic kidney failure patients. To our knowledge, there are no studies in the literature on ARFI elastography findings of the Achilles tendon in hypothyroidism patients. The aim of our study was to investigate the effect of thyroid dysfunction on tendons and the contribution of Acoustic Radiation Force Impulse (ARFI) elastography to the diagnosis of tendinopathy.

Methods

Eighty Achilles tendons of 40 patients under levothyroxine treatment, who had previously known hypothyroidism but high serum TSH levels, and 80 Achilles tendons of 40 healthy individuals were evaluated with ARFI (Virtual Touch Quantification®). 19 of 40 of the patients with hypotiroidism’ Achilles tendons were re-evaluated after thyroid stimulating hormone levels reached to normal limits following the adjustments in thyroid hormone replacement therapy. The middle portion of the each Achilles tendon was chosen for the examination. Every examination consisted of three to five independent measurements (shear wave velocity – meters per second). The mean shear wave velocity value was calculated for each tendon, and used for statistical analysis.

Results

The stiffness values of both left and right Achilles tendons, represented as shear wave velocity, were similar in patients with hypothyroidism and control group (Right achilles 5.07 ± 1.14 vs 5.36 ± 1.11, P = 0.245; left achilles 5.09 ± 1.16 vs 5.21 ± 1.11; P = 0.662). There was no significant difference between the Achilles tendon shear wave velocity measurements of 19 of 40 hypothyroidism patients who were re-evaluated after the adjustments in thyroid hormone replacement therapy ( right achilles 5.14 ± 1.45 vs 4.7 ± 1.37, P = 0.269; left achilles 5.34 ± 1.36 vs 4.7 ± 1.17, P = 0.097)

Conclusions

The lack of significant difference in Achilles tendon stiffness between non-naive hypothyroid patients and the control group may be explained as a positive clinical effect of thyroid hormone replacement therapy. This study is important in terms of being a pilot study on a subject that can be considered new for the literature. Further prospective studies with larger sample size, which also include naive hypothyroidism patients, are needed to identify the causal relationship between the sonoeleastographic changes in Achilles tendon and hypothyroidism.