Structural Pathology in the Muscles of Subclinical Hypothyroid Patients – Dr John Lowe
A study report we published in Thyroid Science this past week is well worth announcing. It stirs a hope in usthat the report will motivate more clinicians to provide subclinical hypothyroid patients with early thyroid hormone treatment. Early treatment is likely to relieve the patients suffering, enable them to maintain normal function, and reduce their overall costs for health care services.
In addition, early treatment willif assertively engaged inhalt incipient functional and structural abnormalities, or reverse the frank pathology that has already developed, such as the muscle abnormalities reported by the authors of the report we published this week.
Four of the researchers and authors of the report
(Drs. Michael Dunn, Arthur Cosmas, Linda Lamont, and Thomas Manfredi) are from the Department of Kinesiology, University of Rhode Island. The fourth (Dr. James Hennessey) is from the Division of Endocrinology, Rhode Island Hospital, Brown University School of Medicine.
To qualify a patient to enter their study, Dunn et al. used the conventional criteria for the diagnosis of subclinical hypothyroidism, the mildest form of hypothyroidism. The criteria included an above-range TSH level and an in-range free T4 level.
Their study shows that among subclinical hypothyroid patients, muscle symptoms may be underlain by objectively verifiable structural muscle abnormalities. The study is the first to document with light and electron microscopy, pathological structural changes in the skeletal muscles of subclinical hypothyroid patients. The researchers note that their findings indicate a progression of such changes from subclinical to overt hypothyroidism.
The structural muscle pathology that Dunn et al. report is consistent with other researchers reports of other muscle-related abnormalities in subclinical hypothyroid patients. (To read the specific findings of Dunn et al., detailed on pages 4 through 6 of their paper,[1,pp.4-6] must be compelling to clinicians who are committed to the well-being of their patients.)
Hekimsoy and Oktem, for example, reported elevated creatine kinase levels in subclinical patients.
The patients levels were not significantly elevated. Overall, however, the TSH and creatine kinase levels were positively correlated; that is, the higher the TSH levels, the higher the creatine kinase levels. Conversely, creatine kinase levels and free T3 and free T4 levels were inversely correlated; higher creatine kinase levels were associated with lower free T3 and free T4 levels. Monzani et al. reported