Thyroid function derangement and childhood obesity: an Italian experience

Abstract

BackgroundIn recent years, there has been an increasing attention to thyroid function in paediatric obese patients. In the present study we aimed 1) to determine the prevalence of abnormally elevated thyroid-stimulating hormone (TSH) levels in Italian obese children and adolescents 2) to investigate whether hyperthyrotropinemia in obese children cardiovascular and metabolic risk factors 3) to verify if TSH elevation is reversible after weight loss.MethodsWe examined 938 obese children and adolescents (450 females). Anthropometric, metabolic and hormonal variables were determined at baseline and, in a subgroup of children with hyperthyrotropinemia, after a six month weight loss program.ResultsHyperthyrotropinemia (TSH ≥4.2 μUI/ml) was diagnosed in 120 patients (12,8%). Body mass index (BMI) z-score (p = 0.02) and free T3 (fT3) levels (p = 0.03) were higher in patients with elevated TSH compared to the group with normal TSH. There were not significant differences in other metabolic parameters between the two groups.A positive correlation between baseline TSH and BMI z-score (p = 0.0045) and between Ft3 and BMI z-score (p = 0.0034) was observed, while there was no correlation between TSH and lipids. Twenty-three patients among those with hyperthyrotropinemia who participated to weight reduction intervention (64 patients), presented substantial weight loss and concomitantly a significant decrease in TSH and in fT3.ConclusionsThese results suggest that: (1) a moderate elevation of TSH concentrations, is frequently found in obese children; (2) in obese children increase of TSH is not associated to metabolic risk factors, (3) hyperthyrotropinemia is reversible after weight loss and these data suggest that it should not be treated.

Childhood obesity, thyroid function, and insulin resistance – is there a link? A longitudinal study

“…Contrasting results were reported by other authors who did not detect any association between TSH levels and HOMA-IR (5,14).…”

“…Taking into account previous studies where improvements in the metabolic profile only occurred in the presence of significant weight loss (i.e., a decrease > 0.5 in BMI-SDS) (4,5,23), the sample was divided into three groups according to the degree of weight loss: increase in BMI-SDS; decrease in BMI-SDS between 0 and 0.5; and decrease in BMI-SDS > 0.5.…”

“…Some studies report that obese children with high TSH levels have more severe insulin resistance than obese children with normal TSH levels, with HOMA-IR positively correlating with TSH levels (5,16). Some authors attribute this relationship to weight variation and not to thyroid function (1,14).…”

“…The growing prevalence of overweight and obesity is becoming an increasingly important health problem throughout the world, as obese children have greater likelihood than normal weight children to develop dyslipidemia, high blood pressure, and impaired glucose metabolism, which significantly increase their risk for cardiovascular and metabolic diseases (1)(2)(3)(4)(5)(6)(7)(8)(9).…”

Thyroid hormones and BMI in obese children: One year follow up results

“…These results were compatible with the results of several other studies. Grandone et al found high TSH levels (>4.2mIU/ ml) in 12.8% of 938 obese children aged between 4.5-16 years [9]. In Bhowmick et al's study high TSH (>4 mIU/ml) rate was 11.7% in 308 obese children aged 6-17 years [10].…”