Related Experiment Videos
Skeletal muscle function and body composition of patients with hyperthyroidism
A C Da Nóbrega1, M Vaisman, C G De Araújo
1Cardiology Section, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil. mflacin@vm.uff.br
Medicine and Science in Sports and Exercise
|February 1, 1997
Summary
Treatment for hyperthyroidism improves muscle performance by increasing both muscle mass and intrinsic muscle function. This study demonstrates that enhanced muscle strength and endurance are key outcomes of managing thyroid disorders.
Area of Science:
- Endocrinology
- Muscle Physiology
- Clinical Medicine
Background:
- Hyperthyroidism is associated with muscle dysfunction.
- Previous research suggests muscle mass changes contribute to performance deficits.
- The specific impact on intrinsic muscle contractile function remains less understood.
Purpose of the Study:
- To investigate whether improved muscle performance post-hyperthyroidism treatment is due to increased muscle mass or enhanced intrinsic muscle function.
- To quantify changes in maximal voluntary contraction (MAX) and endurance (END) in patients with Graves' disease.
Main Methods:
- Nine patients with Graves' disease were assessed at diagnosis, after 1 week of propranolol, and upon achieving euthyroidism.
- Measurements included anthropometrics and skeletal muscle function tests (hip flexion, ankle dorsiflexion, handgrip).
- Maximal static voluntary contraction (MAX) and endurance (END) were recorded, with endurance defined as time to maintain 30% of MAX.
Main Results:
- Body weight and limb circumferences significantly increased post-treatment.
- MAX and END significantly improved for hip flexion, ankle dorsiflexion, and handgrip.
- Improvements in muscle function were observed even after adjusting for changes in muscle mass.
Conclusions:
- Treatment of hyperthyroidism leads to enhanced intrinsic muscle function.
- Improved muscle performance is a result of both increased muscle mass and better intrinsic muscle contractile properties.
- These findings highlight the multifaceted recovery of muscle function after managing hyperthyroidism.