Plasma Total Homocysteine Levels in Childhood Obesity

The objective was to investigate total plasma homocyst(e)ine (tHcy) in childhood obesity and in a control group and the contribution of insulin to tHcy values in childhood obesity. A total of 18 subjects with exogenous obesity and 20 subjects of an age- and sexmatched control group were recruited. Fasting samples for tHcy, vitamin B12, folate, glucose, insulin, lipid profile and creatinine were measured in both groups. Moreover, oral glucose tolerance test (OGTT) were performed in 18 obese subjects to better assess their insulin resistant state and the subjects were divided in two groups according to peak serum insulin concentrations during OGTT (> 150 µU/ml or hyperinsulinemic group and < 150 µU/ml or normoinsulinemic group). Obese subjects had higher tHcy levels compared with controls (6.1 ± 1.8 vs. 4.6 ± 1.1 µmol/l; p= 0.005). There were significant differences in the body mass index, waist/hip ratio, and insulin levels between the groups but not in systolic blood pressure, diastolic blood pressure, lipid profile, vitamin B12, folate and creatinine levels. After making statistical corrections for risk factors, obese subjects had also higher tHcy levels than controls. Fasting tHcy negatively correlated with folate (r= -0.67, p= 0.003) in obese subjects. In a multivariate regression model for all subjects, the independent correlates for tHcy were obese state (p=0.001) and folate (p=0.002). In a multivariate regression model for tHcy in obese subjects, the independent correlate for tHcy was only folate (p< 0.001). tHcy levels were not significantly different between hyperinsulinemic and normoinsulinemic obese subjects. These results suggest that higher tHcy levels are present in the childhood obesity and that tHcy could play a role in the higher risk of cardiovascular disease in obesity. Furthermore, our study demonstrates that obese state and folate but not insulin are a main correlate of tHcy in childhood obesity and suggests that decreased folate may contribute to impairment of tHcy metabolism in childhood obesity.