Indian Journal of Clinical Anatomy and Physiology

Page: 63-65

Background: Primary hypothyroidism with deranged TSH levels affects skeletal muscle strength, indicative of metabolic or neuromuscular dysfunction. The dysfunction may reverse when a euthyroid level is achieved with levothyroxine supplementation. Our study investigated whether skeletal myopathy exists even after achieving and maintaining an euthyroid state. The isometric hand grip test is a validated method to test for skeletal muscle strength. Our study aims to assess skeletal muscle strength in euthyroid hypothyroidism by employing it.

Materials and Methods:  Forty subjects diagnosed with primary hypothyroidism and rendered euthyroid for more than six months (levothyroxine supplementation) were assessed for muscle strength using the isometric hand grip test and compared with an equal number of age-matched healthy euthyroid controls.

Results: Preliminary results indicated that individuals with euthyroid hypothyroidism demonstrated significantly lower grip strength compared to controls, even though thyroid hormone levels remained within normal range. The data suggests that muscle weakness in euthyroid hypothyroidism may be influenced by other factors related to metabolism and neuromuscular function.

Conclusion: Muscle strength weakness is present in primary hypothyroidism even though the patients maintain euthyroid state with levothyroxine supplementation. This needs to be further evaluated so that proper timely measures are taken for further deterioration of muscle weakness that could impair the quality of life in such patients.

Keywords: Primary hypothyroidism, Levothyroxine supplementation, Grip strength