Objectives: We investigated the relationship between insulin resistance reflected by homeostasis model assessment (HOMA-IR) index and serum HbA1c levels of obese children. Material and Methods: This study included 70 obese and 60 normal weight healthy children between the ages of 3 and 15. Anthropometric measures and biochemical tests (fasting glucose, fasting insulin, HbA1c) were performed on all subjects. Plasma glucose levels were measured by the glucose oxidase method. Plasma insulin concentrations were measured by radioimmunoassay (RIA). HOMA-IR index was used to estimate insulin resistance. A cut-off HOMA-IR level of ≥2.5 was accepted. The HbA1c analysis was performed using high-pressure liquid chromatography. The statistical analysis was performed using SPSS 5. Student's unpaired t-test and the Mann-Whitney U test were used to determine statistical significance. Results: Gender distribution did not reveal significant difference among the obese (F: 48.6%, M: 51.4%) and the non-obese (F: 46.7%, M: 53.3%) groups. The mean age value was significantly higher in the obese group (10.09± 3.09) (p>0.005) than the non-obese group (8.31±3.14) (p<0.05). The mean value of body mass index (BMI) was 25.55±4.3 in the obese group and 16.63±2.3 in the non-obese group. The mean HOMA-IR values of obese group (2.84±1.77) was significantly higher than the non-obese group (1.50±0.95) (p<0.005). Insulin resistance was significantly higher in the obese group. Subjects with HOMA-IR ≥2.5 levels in the obese group had significantly higher HbA1c values than those with HOMA-IR <2.5 levels. Conclusions: High HbA1c levels in obese children can be used as a screening tool to detect insulin sensitivity and resistance at an early stage.

We observed that obese children had higher carotis intima media thicknesses. Carotis intima media thickness related to obesity can play an important role in future pre-atherosclerotic changes. Large population based studies are required to confirm this associaton.

Background. The frequency of subclinical hypothyroidism (SH) in patients with obesity is increased compared with the normal population. However, data on the risk of cardiovascular disease (CVD) in patients with SH are still scarce. Lipid parameters are strong predictors of early CVD. We aimed to investigate the role of lipid indices in predicting CVD risk compared to conventional lipid components.Methods. A total of 220 euthyroid obese children (EU) and 90 obese children with SH were included in the study. All data were collected from hospital files. Lipid indices were evaluated. Atherogenic index of plasma (AIP), cardiac risk ratio (CRR) and atherogenic coefficient (AC) were calculated. AIP>0.24, CRR>5 ve AC>3 were considered as cardiovascular risk criteria.Results. The presence of SH increased the risk of higher AIP and the risk of CRR, compared to euthyroid obese children. Conclusion.Subclinical hypothyroidism in obese children may cause dislipidemia carrying a high cardiovascular disease risk.

Context. The links between obesity and thyroid function or thyroid volume in children are still controversial with limited available data.Objective. This study aimed to examine thyroid function and volume in obese Turkish school-age children in comparison to normal-weight children.Design. Cross-sectional study. Subjects and Methods. One hundred obese children (47 boys, 53 girls; mean age 10.34±2.79 years) with a body mass index (BMI) above 95th percentile, and 100 normal-weight children (42 boys, 58 girls; 10.34±2.79 years) were included. The study parameters were BMI z score (Z-BMI), body surface area (BSA), thyroid volume, free thyroxine (fT4) and thyroid stimulating hormone (TSH) levels.Results. The mean TSH and fT4 levels did not show a significant difference between obese and normal-weight children (p>0.05). The mean thyroid volume was higher in obese children (6.46±5.84 and 4.64±1.44, respectively; p=0.043). fT4 correlated negatively with Z-BMI in both normal-weight and obese children (r=-0.285, p=0.004 and r=-0.289, p=0.004, respectively). Thyroid volume, on the other hand, correlated positively with Z-BMI, again in both normal-weight and obese children (r=0.657, p<0.001 and r=0.444, p<0.001, respectively). Similar associations were found for BSA.Conclusions. Thyroid volume correlated positively and fT4 correlated negatively with Z-BMI and BSA, in both obese and normal-weight school-age children, whereas TSH appears to be independent of these parameters.

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