Background: Childhood obesity is a worldwide health problem and its prevalence is increasing steadily and dramatically all over the world. Obese and overweight children and adolescents have a much greater likelihood than normal-weight children and adolescents of acquiring dyslipidemia, elevated blood pressure, impaired glucose metabolism, and hormonal disturbances which significantly increase their risk of cardiovascular and metabolic diseases. Of the various hormonal disturbances observed in childhood overweight and obesity, subclinical hypothyroidism (SH), defined as serum levels of thyroid-stimulating hormone (TSH) above the upper limit with normal concentrations of free T4 (FT4), is the most common and is often regarded as an adaptive response to reduce body weight by increasing the metabolic rate.
Objective: this study was designed to evaluate thyroid function among overweight and obese Egyptian children and adolescents for prevalence of subclinical hypothyroidism.
Patients and Methods: This is a cross-sectional study that was conducted on 100 Egyptian children and adolescents aged 2 to 18 years. It was carried out on 40 overweight, 40 obese and 20 normal weight children and adolescents as a control group. They were selected from pediatric endocrinology clinic and outpatient pediatric clinic at Al Hussein University Hospital from January, 1st 2021 to June, 1st 2021. they were selected by simple random method. Each included child was submitted to medical history taking, complete clinical examination and laboratory investigations in the form of CBC, serum TSH, FT4, cholesterol, triglyceride, HDL and LDL.
Results: Prevalence of subclinical hypothyroidism is increased in higher BMI groups. 12.5 and 27.5% of overweight and obese had subclinical hypothyroidism respectively. Total cholesterol and triglyceride levels were higher in groups with subclinical hypothyroidism than normal children. Body mass index (BMI) was positively correlated with serum concentrations of the TSH and negatively correlated with serum concentrations of FT4 after adjusting for age. The concentrations of total cholesterol and triglyceride were positively correlated with the TSH concentrations following adjustment for age and BMI standard deviation scores. The FT4 concentrations were negatively linked with total cholesterol after adjusting for age and BMI standard deviation scores.
Conclusion: Subclinical hypothyroidism was common in the obese and overweight groups, and the concentrations of TSH were linked with the lipid profile. Subclinical hypothyroidism in obese and overweight children or adolescents should be closely monitored while also evaluating metabolic risk factors.
Keywords: Childhood obesity, Subclinical hypothyroidism, body mass index, thyroid-stimulating hormone, cholesterol.