What is the normal Gamma-Glutamyltransferase (GGT) level in relation to blood pressure?

From the Guidelines

GGT is not a blood pressure measurement, but rather a liver enzyme called gamma-glutamyl transferase, and it has no direct relationship to blood pressure levels. GGT is commonly tested as part of liver function tests to detect liver disease, bile duct problems, or alcohol abuse. Normal GGT levels typically range from 8 to 61 units per liter for men and 5 to 36 units per liter for women, though reference ranges may vary between laboratories. Elevated GGT levels can indicate liver damage, excessive alcohol consumption, certain medications, or other conditions affecting the biliary tract.

Key Points to Consider

• If you're concerned about blood pressure, the standard measurements are systolic (top number) and diastolic (bottom number) pressures, measured in millimeters of mercury (mmHg), with normal adult blood pressure being below 120/80 mmHg, as indicated in the 2007 guidelines for the management of arterial hypertension 1.
• Blood pressure and GGT are entirely different health parameters that require separate testing methods.
• The classification of hypertension is based on cutoff values, with optimal blood pressure being less than 120/80 mmHg, and grades of hypertension ranging from mild to severe, as outlined in the European Society of Hypertension and European Society of Cardiology guidelines 1.
• The management of blood pressure and GGT levels should be based on individual risk factors and medical history, with consideration of lifestyle changes and medical treatment as needed.

Relevant Guidelines and Recommendations

• The 2007 guidelines for the management of arterial hypertension recommend a flexible approach to blood pressure management, taking into account individual cardiovascular risk factors 1.
• The American Journal of Kidney Diseases guidelines for diabetes and chronic kidney disease recommend a lower blood pressure goal for patients with persistent high-level macroalbuminuria, with a systolic blood pressure goal of less than 130 mmHg 1.

From the Research

GGT and Blood Pressure

• The relationship between GGT levels and blood pressure is complex, with studies suggesting that higher GGT levels are associated with higher blood pressure 2, 3.
• A study found that drinkers with higher serum GGT levels tend to have higher blood pressure, independent of the volume of alcohol consumed 2.
• Another study found that serum GGT levels within the normal range were positively associated with fasting blood glucose, triglyceride, and uric acid, which are all risk factors for cardiovascular disease 4.
• A meta-analysis found that GGT level is positively associated with the development of hypertension, with a 23% increase in risk per 1 SD logGGT increment 3.

GGT Levels and Hypertension

• A study found that subjects with prehypertension had higher GGT levels than those with normal blood pressure, and that those who developed hypertension during a 3-year follow-up period had higher GGT levels than those who did not 5.
• Another study found that GGT levels were positively associated with carotid artery luminal diameter and aortic stiffness, which are indicators of arterial remodeling and stiffness 5.
• The association between GGT levels and hypertension is thought to be related to the role of oxidative stress in subclinical arterial damage and prehypertension 5.

Clinical Implications

• The findings of these studies suggest that GGT has important clinical implications as a marker of cardiovascular risk, beyond its traditional use as a marker of alcohol consumption and hepatobiliary disease 4, 3, 5.
• Elevated GGT levels may be an indicator of increased risk of hypertension and cardiovascular disease, even in individuals without conventional diagnostic criteria for acute liver injury 6.
• Further studies are needed to confirm these findings and to elucidate the exact mechanisms by which GGT levels are associated with hypertension and cardiovascular disease 3, 5.