The state of the melatonin-associated hormonal system in children with overweight

Abstract

Background. Overweight (OW) may be the first step to obesity. The mechanisms underlying the pathogenesis of obesity and chronic diseases associated with it are being studied to combat this global pandemic. In this context, dysfunction of adipose tissue is considered, which manifests itself in the form of changes in the profile of adipokines, the secretion of some of them is under circadian control. This regulation may, at least, be partially mediated by melatonin. Objective: to study the state of the melatonin-associated hormonal system in children with OW and normal weight (NW). Materials and methods. A one-time epidemiological survey of the children population aged 7–18 years was conducted during preventive examinations in schools in Chernivtsi and Chernivtsi region (936 people). Primary screening included questioning, anthropometry, and assessment of physical development. A total of 60 people with OW were selected from 936 individuals for a detailed study. The comparison group included 55 healthy subjects with NW. Diagnosis of OW was established if body mass index was greater than 85th percentile, but less than 95th percentile according to age-sex nomograms. NW was diagnosed with body mass index values ranging from 5th to 84th percentiles. For evaluation of serum concentrations of melatonin, adiponectin, leptin, resistin, and omentin-1, commercially available immunoassay kits for the Model 680 Microplate Reader were used. Statistical data analysis was performed using the Statistica 10.0 application package. Results. Among those with OW, boys were dominant — 32 (53.3 %). OW was most often registered among boys over 17 years of age (59.4 %) and girls aged 15–16 years (64.2 %, pφ < 0.05). According to the study, children with OW have significantly lower melatonin levels and imbalance of melatonin-associated hormones. Leptin and resistin indices were within the reference values in both groups and in all age groups, the level of adiponectin was statistically significantly lower in patients with OW, and the level of omentin-1 tended to decrease. Hormonal imbalance deepens with increasing body mass. Conclusions. It has been established that children with оverweight have significantly lower melatonin levels and imbalance of melatonin-associated hormones.