The prevalence of elevated serum thyroid-stimulating hormone in childhood/adolescent obesity and of autoimmune thyroid diseases in a subgroup.
OBJECTIVE
1) To ascertain the frequency of elevated thyroid-stimulating hormone (TSH) level in obese children and adolescents and 2) to determine the prevalence of positive thyroid antibodies in the subgroup of obese children with elevated serum TSH concentration.


METHODS
Retrospective chart review and prospective observation of 308 children, ages 6-17 years, with nonorganic, nonsyndromic obesity with BMI > 97th percentile. The control population consisted of 286 nonobese, otherwise-healthy children of the same age range. Thyroid function tests (free T4 or T4 with TSH) were obtained on all patients in both groups. Thyroid antibodies (thyroid peroxidase and thyroglobulin) were determined among those with elevated TSH levels.


RESULTS
Elevated TSH levels of > 4 uIU/ml (reference interval 0.4-4) were noted in 36 patients within the obese group (11.7%) but only two in the control group (< 0.7%). Five out of the 36 in the obese subgroup with elevated TSH levels had positive thyroid antibodies (14%). All five subjects in the obese subgroup with positive thyroid antibodies had TSH levels >7.4 uIU/ml, with an average of 9.8 uIU/ml. Thirty-one children in the obese subgroup with negative thyroid antibodies had TSH levels < 6.7 uIU/ml (average 5.33 uIU/ml).


CONCLUSIONS
A higher prevalence of TSH elevation was observed in the obese group (11.7%) than in the control group (0.7%). Positive thyroid peroxidase and thyroglobulin antibodies were observed in higher frequency in the obese subgroup with an elevated TSH level. The obese subgroup with positive thyroid antibodies also had higher TSH levels. Therefore, some instances of high TSH, especially those associated with antibodies, are likely due, at least in part, to thyroid disease, and others (possibly a majority) may be due to obesity, not its cause. It remains to be seen whether any children with mild TSH elevation benefit from thyroid hormone treatment.
Division of Endocrine and Metabolic Disease, University of South Alabama College of Medicine, 2451 Fillingim St., Suite 212, Mobile, AL 36617-2293, USA. sbhowmick@usouthal.edu
Samar K
SK
Bhowmick
Gayathri
G
Dasari
Kara L
KL
Levens
Kenneth R
KR
Rettig
D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000503:physiopathology*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013967:Thyroiditis, Autoimmune / Q000453:epidemiology* / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood*; D014481:United States / Q000453:epidemiology
D013972:Thyrotropin