Decreased Circulating Levels of Spexin in Obese Children.

Abstract

Spexin is a novel peptide that is implicated in obesity and related energy homeostasis in animals and adult humans. Little is known about its role in children. The aim of the current study was to determine the potential role of Spexin in obese children and explore its relationships with various cardiometabolic risk factors. This was a cross-sectional study composed of 69 children (51 obese and 18 normal weight; age 15.3 ± 0.26 y). Spexin was measured using a specific enzyme-linked immunosorbent assay. Leptin, total and high-molecular-weight adiponectin, IL-6, high-sensitivity C-reactive protein, glucose, and insulin were also measured. Mann-Whitney U test, Pearson and Spearman rank correlations, logistic regression, and cluster analysis were used for the analysis and interpretation of the data. Spexin levels were significantly lower in obese vs normal-weight children, median(IQR) (0.33 ng/mL [0.27-0.44] vs 0.42 ng/mL [0.33-0.55]; P = .024), but did not correlate with other adipokines and/or insulin and glucose levels. Ordinal categorical variables of Spexin showed a strictly reverse association of obesity with the level of Spexin. Cluster analysis of Spexin and body mass index z score resulted in splitting the participants into normal-weight and obese-weight groups with high accuracy. Lower circulating levels of Spexin in obese children compared with their normal-weight counterparts and the ability to discriminate obese and normal-weight groups based on Spexin concentration enabled us to suggest a potential role for this novel peptide in childhood obesity. The clinical significance of these findings needs additional investigation.