Subclinical Hypothyroidism in Danish Lean and Obese Children and Adolescents.
OBJECTIVE
Thyroid abnormalities are common in obese children. The aim of the present study was to examine the prevalence of subclinical hypothyroidism (SH) and to determine how circulating thyroid hormone concentrations correlate with anthropometrics in Danish lean and obese children and adolescents.


METHODS
In this cross-sectional study, we included 3006 children and adolescents, aged 6-18 years, from the Registry of the Danish Childhood Obesity Biobank. The overweight/obese group (n=1796) consisted of study participants with a body mass index (BMI) standard deviation score (SDS) ≥1.28. The control group (n=1210) comprised lean children with a BMI SDS <1.28. All participants were characterized by anthropometrics (weight, height, and waist circumference) and fasting serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine, and free thyroxine (fT4) at baseline.


RESULTS
The prevalence of SH was higher among overweight/obese compared to lean study participants (10.4% vs. 6.4%, p=0.0001). In the overweight/obese group, fasting serum TSH concentrations were associated positively with BMI SDS (p<0.0001) and waist-height ratio (WHtR) (p<0.0001) independent of age, sex, and pubertal developmental stage, whereas fasting serum fT4 concentrations were associated positively only with WHtR. The odds ratio of exhibiting SH was 1.8 when being overweight/obese compared with lean (p=0.0007) and 1.8 when presenting with a WHtR >0.5 (p=0.0003).


CONCLUSIONS
The prevalence of SH was higher among overweight/obese study participants. The positive correlations of circulating TSH and fT4 with WHtR suggest that central obesity, independent of the overall degree of obesity, augments the risk of concurrent thyroid abnormalities in children and adolescents with obesity.
Maria
M
Dahl
Johanne Dam
JD
Ohrt
Cilius Esmann
CE
Fonvig
Julie Tonsgaard
JT
Kloppenborg
Oluf
O
Pedersen
Torben
T
Hansen
Copenhagen University Hospital Holbæk, The Children's Obesity Clinic, Department of Pediatrics, Holbæk, Denmark Phone: +45 59484200 E-mail: jhom@regionsjaelland.dk.
Jens Christian
JC
Holm
D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000097:blood* / Q000503:physiopathology; D050177:Overweight / Q000097:blood* / Q000503:physiopathology; D015995:Prevalence; D012042:Registries / Q000706:statistics & numerical data; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D055105:Waist Circumference
D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine