Supplementary Material for: Association between serum gamma-glutamyl transferase levels and polyvascular atherosclerotic plaques and stenosis: A cross-sectional study

Introduction
Serum gamma-glutamyl transferase (GGT) was associated with cardiovascular disease. However, limited research has explored the relationship between GGT and polyvascular atherosclerosis.
Methods
This study is based on the baselines cross-sectional survey of the PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events study, a population-based cohort study. Serum GGT levels were categorized into quartiles. Atherosclerotic plaques and stenosis were evaluated using magnetic resonance imaging and computed tomography angiography. The extent of atherosclerotic plaques and stenosis was assessed based on the number of these 8 vascular sites (e.g., intracranial, extracranial, coronary, subclavian, aortic, renal, iliofemoral, and peripheral arteries) and was classified as affected vascular sites as zero, one, two-three, or four-eight extensive atherosclerotic sites. The correlation of GGT with the presence and extent of plaques and stenosis was assessed by binary logistic and ordinal logistic regression models.
Results
A total of 3046 participants were included with a mean age of 61.2±6.7 years. GGT levels were associated with the presence (Q4 vs. Q1, odds ratio (OR),2.14; 95% confidence interval (CI) 1.35-3.39) and the extent (common odds ratio (cOR),2.08; 95%CI 1.68-2.57) of atherosclerotic plaques, and the presence (OR, 1.57; 95%CI, 1.24-2.00) and extent (cOR, 1.64; 95%CI, 1.30-2.06) of atherosclerotic stenosis after adjusting for age, sex, smoking, and alcohol consumption. However, associations were not significant after further adjusting for body mass index, low-density lipoprotein cholesterol, hypertension, diabetes mellitus, dyslipidemia, and medication history.
Conclusion
GGT levels were associated with the presence and burden of atherosclerotic plaques and stenosis, but not after adjusting some metabolism-related factors.