Subclinical hypothyroidism in childhood obesity and its correlation with lipoproteins.

BACKGROUND/OBJECTIVE: There is an ongoing debate regarding the influence of subclinical hypothyroidism on body mass index. The objectives of the study were (i) to determine whether levels of thyroid stimulating hormone (TSH) are elevated in obese children, (ii) to compare the serum levels of triiodothyronine (T3) and thyroxine (T4) in obese with non-obese and (iii) to examine the association of subclinical hypothyroidism with lipoproteins and body mass index. METHODS: Fifty six obese children/adolescent girls aged 10.5 +/- 4.3 years, BMI 31.2 +/- 2.2 kg/m2 and apparently healthy children aged 11.2 +/- 5.2 years, BMI 21.0 +/- 2.1 kg/m2 were evaluated. Serum T3, T4 and TSH were measured using ELECSYS 1010 autoanalyzer while serum triglyceride, total cholesterol, LDL cholesterol, HDL cholesterol and glucose were measured using enzyme catalyzed colorimetric techniques. RESULTS: Subclinical hypothyroidism was observed in 10.7% of obese subjects. Significantly increase levels of T3 (p < 0.02), TSH (p < 0.01) and all lipoprotein fractions (p < 0.001) except HDL cholesterol which was lower (p < 0.001) were observed in obese than control subjects. TSH and triglyceride correlated positively with body mass index. CONCLUSION: Subclinical hypothyroidism was present in 10.7% of obese children. TSH and triglyceride correlated positively with body mass index in childhood/adolescent obesity. There is need for this group ofsubjects to be evaluated for thyroid hormones so that those requiring therapy can be diagnosed and treated.