Association of telomere length with IL-6 levels during an obesity treatment in adolescents: interaction with the-174G/C polymorphism in the IL-6gene

BACKGROUND

Shorter telomeres have been associated with elevated risk for age-related diseases. However, little is known about the biomarker role of telomere length (TL) for predicting inflammation and glucose alterations.

OBJECTIVE

The objective of this research is to evaluate the association between TL, inflammatory markers and glucose levels after a 2-month weight-loss programme in obese adolescents.

METHODS

Telomere length was measured using a quantitative polymerase chain reaction in 66 obese adolescents aged 12-17 years (51% men) from the EVASYON programme. The adolescents were genotyped for the polymorphism -174G/C (rs1800795) in the IL-6gene, and anthropometric and biochemical markers as well as inflammatory cytokines were analysed.

RESULTS

Multiple-adjusted models showed that longer telomeres at baseline were associated with a higher reduction in glucose (B = -4.08, 95% confidence interval: -6.66 to -1.50) and IL-6 (B = -1.03, 95% confidence interval: -2.01 to -0.05) serum levels after 2 months of the weight-loss treatment. The -174G/C polymorphism modulated the association between basal TL and changes in IL-6 (P interaction = 0.029). Thus, subjects with the GG + GC genotype and with longer telomeres showed a higher decrease in IL-6 levels than CC homozygotes.

CONCLUSION

Longer telomeres are associated with an improvement in glucose tolerance and inflammation after a weight-loss programme in obese adolescents. Moreover, the -174G/C polymorphism may influence the relationship between TL and IL-6 changes.

Total antioxidant capacity and oxidative stress after a 10-week dietary intervention program in obese children

Dietary and serum total antioxidant capacity (TAC) are considered appropriate tools for investigating the potential health effects of dietary antioxidants consumed in mixed diets. The aim was to analyze the impact of a dietary intervention on macronutrient intakes and to evaluate the improvement on oxidative status after weight loss (WL) by measuring dietary and serum TAC, and urinary F2-isoprostane levels as markers of oxidative stress. Forty-four overweight/obese children (mean age 11.5 years) were enrolled to undergo a 10-week WL program. They were dichotomized at the median of body mass index-standard deviation score (BMI-SDS) change, as high (HR) and low responders (LR) after intervention. Subjects were prescribed with a fixed full-day meal diet, calculated according to their basal metabolic rate and physical activity levels. A validated food-frequency questionnaire was used to retrospectively calculate TAC and daily nutrient intake. The HR subjects were able to reduce anthropometric indices and to improve lipid and glucose profile. They also significantly diminished fat intake (p = 0.013). Moreover, baseline serum TAC values did significantly predict the reduction in urinary F2 isoprostane (B = -0.236 (-0.393 to -0.078); p = 0.014) in the HR group after the WL program. Notably, changes in dietary TAC after the treatment were associated with a decrease in body weight after the 10-week intervention (B = -2.815 (-5.313 to -0.318), p = 0.029) in the HR group. The -ΔSerumTAC/ΔDietaryTAC and the -ΔF2Isoprostane/ΔDietaryTAC ratios revealed that the relationships between oxidative markers and antioxidants dietary intake were more favorable in the HR than in the LR group.

CONCLUSION

Our study showed that a 10-week WL program was able to reduce adiposity indices in obese children. Moreover, after the intervention changes in dietary TAC and WL were significantly associated. Our result suggests that specific food with a high TAC content (such as fruits, vegetables, and legumes) could be recommended to improve WL.

Decreased cardiotrophin-1 levels are associated with a lower risk of developing the metabolic syndrome in overweight/obese children after a weight loss program

OBJECTIVE

Cardiotrophin-1 (CT-1) shares some similarities with other cytokines, and participates in the control of energy metabolism. Higher circulating levels are observed in obese humans, but little information is gathered in weight loss (WL) programs. Therefore, we aimed to investigate the association of serum CT-1 levels with metabolic variables and the risk of developing metabolic syndrome (MetS) after a WL program in overweight/obese children.

SUBJECTS AND METHODS

Forty-four overweight/obese children (mean age 11.5 y; 50% males) undergoing a 10-week WL program were enrolled. Subjects were dichotomized at the median of Body Mass Index-Standard Deviation Score (BMI-SDS) change, as high and low responders after intervention.

RESULTS

CT-1 levels were significantly reduced (-48 fmol/mL, p=0.043) in the high responder group after the WL program. They had significantly lower body weight (-3.7 kg, p<0.001), body fat mass (-8%, p<0.001), BMI-SDS (-0.78, p<0.001) and waist circumference (-5.4 cm, p<0.001), and a significant improvement in lipid and glucose profiles (p<0.05). Interestingly, decreased CT-1 levels significantly predicted changes in total cholesterol (41%) and LDL-cholesterol (28%). Moreover, in our participants the lower the CT-1 levels, the higher the reduction in MetS risk components, after the 10-week intervention, (p-ANCOVA=0.040, p-trend=0.024).

CONCLUSION

We showed, for the first time, a reduction in serum CT-1 levels after a WL program and this decrease in CT-1 was strongly associated with a reduction in cholesterol levels and in MetS risk factors in overweight/obese children. Our findings may suggest that CT-1 could be an indirect marker for the diagnosis of MetS in this population.