Researchers studied nearly 3,800 women to see if a simple blood test could help identify who might develop endometriosis, a painful condition where tissue grows outside the uterus. They looked at two measurements from routine blood work: GGT (a liver enzyme) and HDL (the “good” cholesterol). Women with higher ratios of these two markers were more likely to have endometriosis. While this finding is promising, doctors would need more research before using this blood test to screen for the condition in everyday practice.

The Quick Take

  • What they studied: Whether a simple ratio from routine blood work (comparing a liver enzyme called GGT to good cholesterol called HDL) could help predict who has endometriosis
  • Who participated: 3,815 women from a large national health survey conducted between 1999 and 2006; 307 of them had been diagnosed with endometriosis
  • Key finding: Women with higher GGT/HDL ratios were 22% more likely to have endometriosis. This means for every small increase in this ratio, the risk went up noticeably
  • What it means for you: This blood test combination might one day help doctors identify women who could be at higher risk for endometriosis, but it’s too early to use it for screening. More research is needed first

The Research Details

This study used information collected by the U.S. government’s National Health and Nutrition Examination Survey (NHANES), which regularly checks the health of Americans. Researchers looked at data from 1999 to 2006 and examined blood test results alongside health questionnaires. They specifically looked at two measurements from standard blood work: GGT (an enzyme that shows liver activity) and HDL cholesterol (the protective type of cholesterol). They calculated the ratio between these two numbers and then used statistical methods to see if women with higher ratios were more likely to have endometriosis.

The researchers used a statistical technique called logistic regression, which helps determine whether one thing (the blood ratio) is connected to another thing (endometriosis). They also ran additional tests to make sure their findings were solid and not affected by other health conditions like heart disease or liver problems.

This approach matters because endometriosis is difficult to diagnose—currently, the only way to confirm it is through surgery. If doctors could identify at-risk women with a simple blood test, it could lead to earlier detection and treatment. The study used real-world data from thousands of Americans rather than a controlled lab setting, which makes the findings more relevant to everyday life

The study’s strengths include its large sample size (nearly 3,800 people) and use of actual national health data. However, there are some limitations: endometriosis was diagnosed based on what women reported rather than confirmed through surgery, which could mean some diagnoses were missed or incorrect. The data is also from 1999-2006, so it’s somewhat dated. The study shows an association between the blood ratio and endometriosis, but doesn’t prove that one causes the other

What the Results Show

Among the 3,815 women studied, 307 had endometriosis (about 8%). When researchers looked at the GGT/HDL ratio, they found a clear pattern: women with higher ratios were more likely to have endometriosis. Specifically, for each unit increase in the ratio, a woman’s likelihood of having endometriosis increased by 22%. To put this in perspective, if a woman’s ratio went from 1.0 to 1.1, her risk would increase by about 22%.

The researchers also performed several additional analyses to make sure this finding was reliable. They tested the data different ways—using the original numbers instead of transformed ones, adjusting for more health factors, and excluding women with heart or liver disease. Every time they tested it, the relationship between the GGT/HDL ratio and endometriosis remained statistically significant, meaning it wasn’t likely due to chance.

The study confirmed that the association was robust across different analytical approaches. When researchers excluded women with existing cardiovascular disease or liver disease, the relationship remained strong. This suggests the connection between the GGT/HDL ratio and endometriosis isn’t simply explained by other health conditions that might affect these blood markers

This is one of the first studies to examine the GGT/HDL ratio specifically in relation to endometriosis. The GGT/HDL ratio has recently been studied as a marker for metabolic problems and liver disease, but its connection to endometriosis is relatively new. Previous research has shown that endometriosis involves inflammation and metabolic changes, so finding a blood marker that reflects these changes is a logical next step

The biggest limitation is that endometriosis diagnoses came from what women reported, not from medical records or surgery. This means some women might have thought they had endometriosis when they didn’t, or vice versa. The data is also from 1999-2006, which is 15-20+ years old, and health patterns may have changed. Additionally, this study shows a connection between the blood ratio and endometriosis, but it doesn’t prove that the ratio causes endometriosis or that changing the ratio would prevent or treat the condition. The study also can’t explain why this particular blood ratio is connected to endometriosis

The Bottom Line

Based on this single study, doctors should not yet use the GGT/HDL ratio as a screening tool for endometriosis. However, the finding is interesting enough to warrant further research. If you have symptoms of endometriosis (severe period pain, pain during intercourse, or heavy bleeding), discuss them with your doctor regardless of blood test results. Confidence level: Low to Moderate—this is preliminary evidence that needs confirmation

Women with endometriosis or symptoms suggestive of endometriosis should be aware of this research. Healthcare providers interested in early detection methods should follow this line of research. Women without symptoms don’t need to worry about this blood ratio right now. This research is not yet ready for clinical use

If this finding leads to a useful screening tool, it would likely take 5-10 years of additional research before it could be used in regular medical practice. Any benefits would depend on whether the blood ratio can reliably predict endometriosis and whether early detection leads to better treatment outcomes

Want to Apply This Research?

  • If you have endometriosis or suspect you might, track your GGT and HDL cholesterol levels from routine blood work every 6-12 months and note any changes in symptoms. Record the dates and values in a health tracking app to share with your doctor
  • Request that your doctor include GGT and HDL measurements in your routine blood work if they aren’t already included. Calculate your GGT/HDL ratio and discuss the results with your healthcare provider, especially if you have endometriosis symptoms
  • Maintain a health log that includes: (1) dates of blood work and GGT/HDL ratio values, (2) endometriosis symptoms and their severity, (3) any treatments or lifestyle changes, and (4) notes from doctor visits. This long-term tracking will help you and your doctor identify patterns and assess whether the blood ratio correlates with your symptoms

This research is preliminary and should not be used for self-diagnosis or to replace professional medical advice. The GGT/HDL ratio is not currently recommended by medical organizations as a screening tool for endometriosis. If you suspect you have endometriosis, consult with a qualified healthcare provider for proper evaluation and diagnosis. This study shows an association but does not prove causation. Always discuss any health concerns and blood test results with your doctor before making medical decisions.