Alarin as a potential biomarker in childhood obesity: Evidence from a case-control study

Studies on Alarin, a newly identified orexigenic adipokine, have mainly focused on adults, while research investigating Alarin levels and its association with obesity in children remains limited. The aim of this study was to measure Alarin levels in children and adolescents with obesity and investigate their relationship with various metabolic parameters, as well as explore how these associations may differ by age group and gender. This prospective case-control study included 30 children with obesity (body mass index [BMI] standard deviation score [SDS] > +2) and 49 age- and gender-matched controls (BMI SDS between -1.9 and +1.9). Participants were recruited at the pediatric endocrinology outpatient clinic between April 2022 and April 2023. Clinical data, including chronological age, physical examination findings, and laboratory test results (alanine transaminase [ALT], aspartate transaminase [AST], total cholesterol, triglycerides, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], fasting blood glucose, and insulin levels), were collected from the hospital's information management system. The presence and severity of hepatosteatosis were assessed by abdominal ultrasound. Insulin resistance (IR) was determined using the HOMA-IR index, with a cutoff value of 2.5 for prepubertal patients and 3.16 for pubertal patients. The mean age of the participants was 11.6 ± 3.5 years (range: 4.5-17.7 years), with 58.2% (n = 46) being female. Serum Alarin, LDL-C, γ-glutamyl transferase (GGT), insulin, and HOMA-IR levels were significantly higher in the obesity group (P < .05). In the obese group, Alarin levels showed positive correlations with age, BMI SDS, fasting glucose, and presence of hepatic steatosis (P < .05). No significant correlations were found in the control group. The study found elevated Alarin levels in children and adolescents with obesity, similar to previous findings in adults. This suggests that Alarin may play a role in energy homeostasis and insulin resistance in childhood obesity. The results contribute to a deeper understanding of obesity's molecular mechanisms of obesity and may help to identify new therapeutic targets for preventing obesity-related complications and metabolic diseases.