Circulating Spexin Decreased and Negatively Correlated with Systemic Insulin Sensitivity and Pancreatic β Cell Function in Obese Children

Abstract

Objectives: Spexin (SPX) is a novel peptide that has recently emerged as an important regulatory adipokine of obesity and related metabolic disease. Little is known about its role in children. The aim of the current study was to determine the potential role of SPX in obese children and explore its relationships with obesity-related markers, insulin sensitivity and pancreatic β cell function. Method: We studied the levels of serum SPX in 40 obese and 32 normal weight pre-puberty children (mean age was 8.59 ± 1.82 and 8.15 ± 2.03 years in obesity and control groups respectively). We investigated the levels of body mass index, blood pressure, lipids, glucose, insulin, Homeostasis model assessment for insulin-resistant (HOMA-IR, HOMA for β-cell function [HOMA-β]), insulinogenic index and C-peptide index and analyzed their correlations with SPX levels. Results: SPX levels were significantly decreased in obese children compared to controls. Moreover, serum SPX levels were lower in IR obese subjects in contrast with the non-IR obese subjects. Serum SPX concentrations correlated negatively and significantly with triglycerides, systolic blood pressure, diastolic blood pressure, fasting insulin level, HOMA-IR, insulinogenic index, and HOMA-β levels in obese children. Conclusions: In summary, serum SPX levels significantly decreased in obese children and negatively correlated with insulin resistance and pancreatic β cell function indicators. Therefore, SPX may play a protective role in the process of glucose homeostasis and is closely related to β cell function in obese children.

Serum Spexin is Correlated with Lipoprotein(a) and Androgens in Female Adolescents

“…Kumar et al [7] observed a reverse association between body mass index (BMI) and serum spexin levels, with obese children having significantly lower circulating spexin than normal-weight children. Similarly, in the study of Chen et al [8], serum spexin levels were significantly decreased in obese prepubertal children compared to controls and were negatively correlated with fasting insulin and the homeostatic model assessment for insulin resistance (HOMA-IR).…”

“…Lin et al [11] reported that spexin levels were significantly correlated with TG. Serum spexin concentrations correlated negatively with TG in obese children in the study of Chen et al [8].…”

Emerging Roles of NPQ/Spexin in Physiology and Pathology

“…Moreover, the serum spexin was markedly negative correlation with leptin in the obese patients (Walewski and Berk, 2013; Walewski et al., 2014). In children, the circulating serum spexin level in obese people was lower than that of the normal weight person (Kumar et al., 2016; Chen et al., 2019), indicating a potential role of spexin in childhood obesity. The circulating spexin level was inversely correlated with leptin in adolescents with obesity (Kumar et al., 2017).…”

“…show that the level of spexin in serum had a modestly relationship with glucose and insulin sensitivity in pregnant women but had no influence on GDM and obesity (Al-Daghri et al., 2018a). In obese children, spexin was negatively correlated with insulin resistance and pancreatic β-cell function indicators (Chen et al., 2019). Recently, Sassek et al.…”

Evolution of Structural and Functional Diversity of Spexin in Mammalian and Non-mammalian Vertebrate Species

“…In obese patients a significant down-regulation of SPX gene expression is observed in omental and subcutaneous fat (5). Also, circulating SPX levels are significantly lower in obese children (40, 41) and patients with metabolic syndrome (39) or remain unchanged in obese adolescents (42). In addition, Kumar and colleagues reported low level of SPX and high level of leptin in the blood of obese adolescent, together with high level of high sensitivity-C reactive protein (hs-CRP).…”