Natural course of 'subclinical' hypothyroidism in childhood and adolescence
D. C. Moore
Department of Clinical Investigation, Madigan Army Medical Center, Tacoma, Wash. USA.
OBJECTIVES: To describe the natural course of "subclinical" hypothyroidism
due to autoimmune thyroiditis in children and adolescents, and to determine
whether, like euthyroid childhood autoimmune thyroiditis, it would also run
a more benign course in this age group than in adults. DESIGN: Case series.
SETTING: Pediatric endocrine clinic in a tertiary medical center. PATIENTS:
Eighteen patients (age range, 5 to 19 years) with juvenile autoimmune
thyroiditis and an initially elevated serum thyrotropin
(thyroid-stimulating hormone) concentration were followed up from
documentation of the elevated serum thyrotropin concentration for a mean of
5.8 years. Eleven patients never received treatment, and seven were
followed up after discontinuation of therapy. MAIN OUTCOME MEASURES:
Changes in the serum thyrotropin and thyroxine concentrations and thyroid
gland size, as well as signs and symptoms of hypothyroidism, were monitored
throughout the observation period. RESULTS: The mean duration of
observation during which the patients did not receive any therapy was 47.3
months. At the end of the observation period, seven patients were
euthyroid, 10 continued to have an elevated serum thyrotropin concentration
with a normal serum thyroxine concentration, and one became hypothyroid.
CONCLUSIONS: "Subclinical" juvenile hypothyroidism may be a benign and
remitting process in many older children and adolescents. In view of the
undefined risks of levothyroxine sodium therapy, it may be possible to
follow up expectantly selected younger patients with a minimally elevated
serum thyrotropin concentration, rather than to treat them empirically.
