Children and adolescents with obesity have lower levels of serum catestatin — an endogenous peptide found to be negatively associated with blood pressure level and insulin resistance — compared with children and adolescents with normal weight, according to findings published in Pediatric Diabetes.
Several studies in adults have described a correlation between hypertension and catestatin levels, with research suggesting that catestatin influences BP through other mechanisms, such as the stimulation of histamine release from mast cells and subsequent vasodilation, Marko Simunovic, MD, of the department of pediatrics at University Hospital of Split, Croatia, and colleagues wrote in the study background.
“Although the roles of catestatin in the onset and progression of obesity and [metabolic syndrome] have not yet been completely elucidated, catestatin may plausibly regulate fat cell function through catecholamines and decreasing leptin levels,” Simunovic and colleagues wrote. “Furthermore, catestatin may additionally exert an effect on the absorption of nutrients in the small intestine as a competitive leptin receptor antagonist, resulting in decreased leptin activity and a subsequent reduction in hyperglycemia.”
In a cross-sectional study, Simunovic and colleagues analyzed data from 92 participants aged 10 to 18 years with a BMI z score greater than 2 who were referred to a pediatric endocrinology clinic for an obesity assessment, along with 39 healthy, normal-weight participants matched by age, sex and pubertal status. All participants underwent a physical examination and provided fasting blood samples. Researchers assessed levels of serum insulin, insulin-like growth factor I, HbA1c, glucose and lipid profile, and serum catestatin level. Pearson correlation coefficients were calculated to examine the correlations between serum catestatin level and cardiometabolic risk factors.
Among participants with obesity, 31 met criteria for metabolic syndrome.
The researchers observed lower serum catestatin concentrations in participants with obesity vs. controls (mean, 10.03 ng/L vs. 13.13 ng/mL; P = .004). When participants with obesity were stratified by metabolic syndrome status, researchers found that those with metabolic syndrome had the lowest catestatin levels (mean, 9.02 ng/mL; P = .008). There were no between-sex differences when assessing catestatin levels in participants with obesity and controls (P = .918), and pubertal status did not influence catestatin level (P = .287), according to researchers.
Researchers also found that serum catestatin was negatively associated with diastolic BP (P = .014), insulin resistance as measured by homeostatic model assessment of insulin resistance (P = .037) and high-sensitivity C-reactive protein (P = .044) in participants with obesity and those with normal weight.
The researchers noted that additional studies are needed to clarify the effects of catestatin on the onset and progression of metabolic syndrome in children and adolescents with obesity, as well as to determine the exact clinical significance of catestatin levels in the early detection of cardiovascular risk factors.
“Catestatin possibly represents as an independent predictor of [insulin resistance] and low-grade inflammation,” the researchers wrote. “Based on our findings, catestatin is a potential new link in the complex pathophysiological mechanism of [metabolic syndrome] in obese children and adolescents.” – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.