Which condition is indicated by high levels of gamma-glutamyl transferase?

High levels of gamma-glutamyl transferase (GGT) are most commonly associated with alcohol abuse. GGT is an enzyme found in various tissues throughout the body, with particularly high concentrations in the liver. When the liver is exposed to excessive alcohol, it can lead to an increase in GGT levels as the liver cells become damaged or stressed.

Alcohol consumption can stimulate the production of GGT, and chronic alcohol abuse is often reflected in significantly elevated GGT levels in blood tests. While other liver conditions like hepatitis can also elevate GGT, the specific link between GGT and alcohol is strong enough that it is often utilized clinically to assess alcohol-related liver disease or to monitor alcohol abstinence in recovering patients.

The other options do not typically correlate with high GGT levels to the same degree. Hepatitis and liver disease in general can also raise GGT levels, but the association with alcohol is more pronounced. Diabetes does not directly affect GGT levels, and heart disease is not relevant to GGT measurement. Thus, the elevation of GGT is most indicative of alcohol abuse among the choices provided.