Increase in GGT values are found in:
Alcoholic liver disease
Drug-induced liver disease
Bile stasis
Alcohol and drug intoxication (barbiturates, antiepileptics, carbamazepine, cimetidine, methotrexate)
Acute and chronic liver diseases
Biliary obstruction
Pancreatic disease (chronic pancreatitis, pancreatic cancer)
Heart attack
Nephropathies of various kinds
Chronic obstructive pulmonary disease
Diabetes mellitus
Liver cancer (both primary and secondary)
Benign transient hyperphosphatasemia