The Association Between Gamma-Glutamyl Transferase and Metabolic Syndrome and Its Components Among Adolescents Applying International Diabetes Federation (IDF) and Cook's Criteria.

INTRODUCTION

The prevalence of metabolic syndrome (MetS), a cluster of metabolic abnormalities, is rising globally, particularly in the Middle East and North Africa. Gamma-glutamyl transferase (GGT) is gaining attention as a biomarker for liver function and its association with MetS and its components.

METHODS

This cross-sectional study is part of the Tehran Lipid and Glucose Study (TLGS). We included 696 adolescents (347 males) aged 10-19 from the seventh examination survey (2018-2021). MetS was defined using both the International Diabetes Federation (IDF) and Cook's criteria. Serum GGT was measured, and its association as a continuous and categorical variable was assessed with MetS and its components using logistic regression, adjusting for a large set of covariates.

RESULTS

MetS prevalence was 15.66% and 9.19% according to Cook's and IDF criteria, respectively. Higher GGT levels were significantly associated with increased MetS risk by both definitions (odds ratio [95% confidence interval] = 1.28 [1.12-1.46] and 1.30 [1.14-1.49] per 5 U/L increase, respectively) after adjusting for age, sex, smoking and family history of type 2 diabetes mellitus. This association was attenuated upon adjusting for ALT levels. GGT levels were robustly associated with high waist circumference, with odds ratios of 1.98 [1.59-2.46] and 1.71 [1.38-2.11] per 5 U/L increase, respectively, even after adjusting for alanine aminotransferase (ALT). Associations with high blood pressure (21% and 17% increased risk by IDF and Cook's criteria) and triglycerides (13% and 16% increased risk by IDF and Cook's criteria) were significant but attenuated after ALT adjustment. No significant associations were found between GGT levels and high fasting plasma glucose or low high-density lipoprotein cholesterol.

CONCLUSIONS

Elevated serum GGT is strongly associated with a higher risk of MetS and its components, particularly central obesity, in adolescents. These findings suggest that GGT is a valuable biomarker for early MetS detection.