“…However, there have not been many studies evaluating the relationship of GGT levels with former smoking. 10,11 Many studies have shown that serum GGT is a biomarker of increased alcohol consumption, however, GGT is known to be affected beside previous condition, such as smoking, obesity, and hepatic steatosis. 12 Data is gathering that higher serum GGT levels may be associated with an increased incidence of cardiovascular events, metabolic syndrome and diabetes; therefore, more attention has been paid recently to this liver enzyme.…”