Triiodothyronine is an indicator of nutritional status in adolescent girls with eating disorders.
OBJECTIVE
Circulating thyroid hormone concentrations are influenced by nonthyroidal disease and changes in nutritional status. We studied thyroid hormones as possible indicators of nutrition in adolescent girls with eating disorders.


METHODS
Blood samples for analyses of thyroid hormones were obtained at 360 assessments of 298 patients and biweekly during 42 treatment periods in 36 patients.


RESULTS
At assessment, when most of the girls were on a weight losing course, serum triiodothyronine (T3) concentrations were low. Great weight loss and rapid rate of weight loss were the most important predictors of low T3 concentrations. Serum free thyroxine concentrations were in the lower normal range. In premenarcheal girls, weight loss was the most important predictor of free thyroxine but this relationship was weaker in postmenarcheal girls. Serum TSH concentrations were within the normal range and only weakly related to weight changes. During treatment, T3 increased in parallel with weight but was also influenced by the short-term weight trend.


CONCLUSIONS
Serum T3 concentration is an indicator of nutritional status in adolescent girls with eating disorders. It is sensitive to short-term weight changes and could be used to monitor progress throughout nutritional rehabilitation.
Swenne
Ingemar
I
Department of Women's and Children's Health, Uppsala University Children's Hospital, Uppsala SE-751 85, Sweden. ingemar.swenne@akademiska.se
Stridsberg
Mats
M
Thurfjell
Barbro
B
Rosling
Agneta
A