Changes in lifestyle improve body composition, thyroid function, and structure in obese children

Background: Alterations in thyroid function and structure have been reported in obesity. Function reverses to normal after weight loss, but nothing is known about structure. Aim: To evaluate the effect of weight loss on thyroid function and structure in obese children. Subjects and methods: The study was conducted in 72 overweight and obese children. Measurement of free T-3 (fT(3)), free T-4 (fT(4)), TSH, antithyroid-antibodies and a thyroid ultrasound was performed at the beginning (phase 1) and after a period of 1.8 +/- 1.0 yr of lifestyle intervention (phase 2). Results: Height SD score (SOS), body mass index SDS, total fat mass did not change from phase 1 to phase 2. Percentage of fat free mass decreased significantly (p<0.05). Waist/height ratio decreased (0.6 +/- 0.1 vs 0.5 +/- 0.1; p<0.05) as well as waist/hip ratio (0.9 +/- 0.1 vs 0.8 +/- 0.1; p<0.05). In phase 1, TSH was 2.8 +/- 1.7 mU/l; in phase 2, it was 2.2 +/- 0.9 mU/l (p<0.05); 17.2% of children showed a TSH level above the normal range (3.6 mU/l) in phase 1, and 6.2% in phase 2 (p<0.05). fT(4) was 10.8 +/- 2.2 pg/ml in phase 1 and 10.7 +/- 1.9 pg/ml in phase 2. fT(3) was 4.4 +/- 1.3 pg/ml (phase 1) and 3.9 +/- 1.1 pg/ml (phase 2) (p<0.05). Thyroid volume was -0.5 +/- 0.8 SDS (phase 1) and -0.5 +/- 1 SDS (phase 2). A non-significant improvement in thyroid structure was observed. Conclusions: In conclusion, healthier lifestyle improves body composition, thyroid function, and structure. (J. Endocrinol. Invest. 35: 281-285, 2012) (C)2012, Editrice Kurtis