ESPE Abstracts

Introduction: The role of gamma-glutamyl transferase (GGT) enzyme as a marker of insulin resistance (IR) in pediatric obesity is well known. Recent evidence, mainly in the adult population, has identified GGT/High-Density Lipoprotein (HDL) ratio as a risk index for hepatic steatosis. The study has the purpose of examining the relationship between GGT, GGT/HDL ratio and the clinical/laboratory data of a group of obese Italian children living in the province of Salerno, Campania.

Materials and Methods: A retrospective study was conducted on 82 children (42M, 40F, age 5-16 years) with obesity (BMI z-score 2.86 ± 0.27) assessed at the pediatric endocrinology service of the Pediatric Unit - PO di Battipaglia - ASL Salerno from January 2016 to January 2020. All of them practiced: weight, height, BMI z-score, waist circumference (WC), neck circumference (NC) and blood pressure measurement; glucose, insulin (for calculating HOMA index), c-peptide, ALT, AST, gammaGT, total cholesterol, HDl, LDl, triglycerides (TG), ESR, PCR blood dosages. They also followed the oral glucose tolerance test (OGTT). The correlation coefficient was calculated between GGT, GGT/HDL ratio and clinical/laboratory identified values.

Results: GGT progressively increases with weight (r=0.33093 P=0.00861), BMI (r=0.48214 P=0.00019), NC (r=0.34778 P=0.02230), WC (r=0.41622 P=0.00401) and also has a significant correlation with insulin function and in particular with c-peptide (r=0.43309 P=0.00188), basal insulin (r=0.46427 P=0.00001), HOMA index (r=0.39320 P=0.00026), insulin levels at 120 minutes during OGTT (r=0.72239 P=0.00106) and TG (r = 0.29235 P=0.00769). GGT/HDL ratio correlates with an even stronger statistical significance than GGT with TG (r=0.44958 P=0.00003), anthropometric parameters such as weight (r=0.51733 P=0.00003), BMI (r=0.59392 P=0.00000), CC (r=0.51164 P=0.00063), CV (r=0.59944 P=0.00002) and with insulin function indicators such as c-peptide (r=0.59105 P=0.00001), basal insulin (r=0.48467 P=0.00000), HOMA index (r=0.42632 P=0.00009) and insulin levels at 120 minutes during OGTT (r = 0.89387 P=0.00009). Finally, GGT/HDL ratio decreases with higher Vitamin D levels (r=-0.22923 P=0.04351) and also statistically correlates with TSH levels (r = 0.26460 P=0.01630).

Conclusion: GGT/HDL ratio shows a significant and stronger statistical association than GGT with anthropometric and laboratory parameters of IR in our obese children population. These data require studies on a larger pediatric population and could be influenced by Vitamin D levels and thyroid disfunction.