Myokine-adipokine cross-talk: potential mechanisms for the association between plasma irisin and adipokines and cardiometabolic risk factors in Mexican children with obesity and the metabolic syndrome.

BACKGROUND

Adipokines and the myokine irisin, involved in mechanisms associated with obesity and metabolic syndrome (MS), are understudied in the pediatric population.

OBJECTIVE

To investigate the relationship between irisin, and leptin, resistin, adiponectin, adipsin, anthropometric and cardiovascular risk factors in Mexican children.

METHODS

A cross-sample of 126 Mexican children aged 6-12 years old were classified as normal weight (n = 46), obese (n = 40), and MS (n = 40) according to CDC's and Cook's age-modified criteria for obesity and MS. Anthropometric parameters and blood pressure were determined and percentiles calculated for age and gender. Irisin, leptin, adiponectin, adipsin, resistin, triglycerides, glucose, high-density lipoprotein cholesterol (HDL-c) levels, and physical activity were determined. Statistical tests for differences between groups, correlation, and multiple regression analyses were performed.

RESULTS

Irisin plasma levels were significantly lower in the obese (6.08 [4.68-6.65]) and MS groups (6.46 [5.74-7.02]) compared with the normal-weight group (8.05 [7.24-8.94]) (p < 0.001). Irisin levels were not influenced by age or gender, but significant dispersion was observed in obese girls (95% CI median [2.29-6.30]). Leptin, resistin, and adipsin levels were significantly increased in the obese and MS groups. Lean-fat ratio was significantly higher in the NW group. Irisin correlated negatively with leptin (- 0.310), resistin (- 0.389), adipsin (- 0.362), BMI% (-0.472), WC% (- 0.453), BMI z-score (- 0.496), fat free mass (- 0.257), fat percentage (- 0.532), fat mass (- 0.515), triglycerides (- 0.291), the number of cardiometabolic risk factors (- 0.443) (p < 0.001); positively with lean-fat ratio (0.489) and HDL-c (0.328) (p < 0.001) and none with physical activity (< 0.001). Following stepwise multiple linear regression analysis, the lean-fat ratio was the only determinant of irisin levels (B = 1.168, p < 0.001).

CONCLUSIONS

Lean-fat ratio, more than the absolute amount of muscle or fat mass, as well as potential myokine-adipokine cross-talk mechanisms may explain the lower irisin levels in children with obesity and MS, through blunted compensatory responses interfering with tissue-dependent irisin secretion, contributing to a continuous deleterious effect cycle.