Associations between γ-glutamyltransferase (GGT) and biomarkers of atherosclerosis: The multi-ethnic study of atherosclerosis (MESA)

•This investigation occurred in the MESA cohort.•We tested for associations between GGT and biomarkers of atherosclerosis.•GGT activity was associated with oxLDL, IL-6, CRP and sICAM-1, in adjusted models.•Associations were evident in ethnic subgroups.•Associations were largely attenuated with adjustment for metabolic status.

ObjectiveTo evaluate associations between total serum γ-glutamyltransferase activity (GGT) and biomarkers of arteriosclerosis in the Multi-Ethnic Study of Atherosclerosis (MESA), including 6783 participants from four ethnic subgroups, i.e., White, Chinese, Black and Hispanic.MethodsAssociations between fasting total serum GGT activity and oxidized low-density lipoproteins (oxLDL), interleukin-6 (IL-6), C-reactive protein (CRP), and soluble intercellular adhesion molecule-1 (sICAM-1) were assessed. Following evaluation of linear trends between GGT and biomarkers of interest, multivariable linear regression models were serially adjusted for age, gender, site, ethnicity (M1); M1 + lifestyle variables (M2); M2 + traditional cardiovascular risk factors plus medications (M3); and M3 + metabolic status (M4). Interactions were evaluated between GGT and age and ethnicity in all models.ResultsLinear trends were positive and significant between GGT and oxLDL, IL-6, CRP and sICAM-1 in crude models, and trends remained significant in all ethnic subgroups for CRP (p < 0.0001) and sICAM-1 (p < 0.001), and for IL-6 except in the Chinese. Trends between GGT and oxLDL were significant in the entire cohort and the White subgroup (p < 0.0001), but not in other ethnic subgroups. Multivariable models demonstrated continuous strong, positive associations between GGT and CRP, IL-6 and sICAM-1. Associations between GGT and oxLDL were attenuated upon adjustment for LDL-C and other traditional risk factors. All models were attenuated with adjustment for metabolic status. No age interactions were evident.ConclusionsOur findings support the hypothesis that total serum GGT activity represents the impact of metabolic disease on vascular injury and atherosclerosis.