Researchers in Ethiopia studied a hormone called prolactin in men with type 2 diabetes and compared it to healthy men. They found that men with diabetes had higher prolactin levels than healthy men. About 9 out of every 100 men with diabetes had unusually high prolactin levels, compared to 6 out of every 100 healthy men. The study suggests that eating a variety of foods and having higher blood sugar levels were connected to these elevated hormone levels. While these findings are interesting, doctors say more research is needed before making major changes to how diabetes is treated.

The Quick Take

  • What they studied: Whether men with type 2 diabetes have different levels of a hormone called prolactin compared to healthy men, and what factors might cause these differences.
  • Who participated: 330 men total: 165 men diagnosed with type 2 diabetes and 165 healthy men without diabetes, all from a hospital in Ethiopia. Researchers collected information about their diet, lifestyle, and health during June and August 2024.
  • Key finding: Men with type 2 diabetes had higher prolactin levels on average (7.79 compared to 6.81 in healthy men). Additionally, about 9% of men with diabetes had abnormally high prolactin levels, compared to 6% of healthy men.
  • What it means for you: This research suggests doctors might want to check prolactin levels in men with type 2 diabetes as part of routine care. However, it’s unclear yet whether high prolactin causes problems or just happens alongside diabetes. Talk to your doctor before making any changes based on this study.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time by comparing two groups of men at the same moment. They selected 330 men using a systematic method to ensure fairness: 165 men with type 2 diabetes and 165 healthy men without diabetes. All participants answered questions about their diet, exercise, smoking, and other lifestyle habits. Researchers then took blood samples from everyone and measured prolactin levels using a special laboratory test called chemiluminescent immunoassay, which is very accurate at detecting hormone amounts.

The researchers also measured other important health markers like fasting blood sugar (how much sugar is in your blood after not eating) and cholesterol levels. They used statistical tests to compare the two groups and figure out which factors were most strongly connected to high prolactin levels.

This study design is useful for finding connections between diabetes and prolactin levels, but it can’t prove that one causes the other. Cross-sectional studies are like taking a photograph—they show what’s happening at one moment but don’t show how things change over time. This approach is good for identifying patterns that doctors should investigate further with longer-term studies.

The study was conducted at a major hospital with proper laboratory equipment and trained staff, which increases reliability. The researchers used standard, validated methods for measuring hormones and blood sugar. However, the study only included men from one hospital in Ethiopia, so results might not apply to women or people from different regions. The sample size of 330 participants is reasonable for this type of research. The study was published in Scientific Reports, a well-respected scientific journal, which means other experts reviewed the work before publication.

What the Results Show

Men with type 2 diabetes had significantly higher prolactin levels than healthy men. On average, men with diabetes had prolactin levels of 7.79 units compared to 6.81 units in healthy men—a difference that was statistically significant (p-value = 0.004, meaning there’s less than a 1% chance this difference happened by random chance).

When researchers looked at how many men had abnormally high prolactin levels (a condition called hyperprolactinemia), they found it was more common in the diabetes group. About 9.1% of men with type 2 diabetes had high prolactin, compared to only 6.1% of healthy men. This means diabetes patients were about 1.5 times more likely to have this hormone imbalance.

The study identified two main factors connected to high prolactin levels. First, men who ate a more diverse diet (eating many different types of foods) were more likely to have high prolactin. Second, for every 1 mg/dL increase in fasting blood sugar, the risk of high prolactin increased slightly. This suggests that blood sugar control might be connected to prolactin levels.

The research showed that dietary diversity was surprisingly associated with higher prolactin levels, which was unexpected. Men with more varied diets were about 3.2 times more likely to have high prolactin. This finding was unexpected because researchers usually think diverse diets are healthier. The connection between blood sugar and prolactin was also notable—even small increases in fasting blood sugar were linked to higher prolactin risk, suggesting these hormones may be closely connected in the body.

Previous research has shown that prolactin plays a role in metabolism and can affect blood sugar control, but most studies focused on women or didn’t specifically look at type 2 diabetes. This study adds to our understanding by showing that men with diabetes consistently have higher prolactin levels. The finding that dietary diversity is connected to prolactin is new and contradicts some earlier assumptions about diet and hormones, suggesting that the relationship between food and hormones is more complex than previously thought.

This study has several important limitations. First, it only included men, so we don’t know if the same patterns apply to women with diabetes. Second, it only studied people from one hospital in Ethiopia, so results might be different in other countries or populations. Third, because this is a cross-sectional study (a snapshot in time), researchers can’t prove that diabetes causes high prolactin—they can only show that the two occur together. Fourth, the study didn’t measure all the factors that might affect prolactin, such as medications men were taking or stress levels. Finally, the unexpected finding about dietary diversity needs more investigation to understand why eating more variety was connected to higher prolactin.

The Bottom Line

Based on this research, doctors may want to consider checking prolactin levels in men newly diagnosed with type 2 diabetes as part of routine screening (moderate confidence level). Men with diabetes should focus on maintaining good blood sugar control through diet and exercise, as this may help keep prolactin levels normal (high confidence level based on existing diabetes research). However, this single study isn’t strong enough to recommend major treatment changes yet—more research is needed (low to moderate confidence level).

Men with type 2 diabetes should be aware of this research and discuss it with their doctor, especially if they experience symptoms like unusual breast tissue growth or sexual dysfunction, which can be signs of high prolactin. Healthcare providers treating men with diabetes should consider this research when deciding what tests to order. Women with diabetes don’t need to worry about this specific study since it only included men, though they should discuss prolactin screening with their doctors separately. People without diabetes don’t need to take action based on this research.

If prolactin levels are high, it typically takes several weeks to months of improved blood sugar control to see changes in hormone levels. Don’t expect immediate results—give any dietary or lifestyle changes at least 3 months before checking prolactin levels again with your doctor.

Want to Apply This Research?

  • Track fasting blood sugar levels daily (before eating breakfast) and record them in the app. Also note the variety of food groups eaten each day (vegetables, fruits, grains, proteins, dairy) to monitor dietary diversity patterns and their connection to blood sugar control.
  • Use the app to set a goal of eating foods from at least 5 different food groups daily while maintaining target blood sugar levels. Create reminders for fasting blood sugar checks and log results to identify patterns between diet variety, blood sugar, and overall health metrics.
  • Review weekly trends in fasting blood sugar and dietary diversity in the app. Share monthly reports with your doctor to track whether improved blood sugar control correlates with any changes in how you feel. If your doctor orders prolactin testing, record the results in the app and compare them to your blood sugar and diet logs over time.

This research is informational only and should not replace medical advice from your doctor. The study was conducted on men in Ethiopia and may not apply to all populations. If you have type 2 diabetes or concerns about hormone levels, discuss this research with your healthcare provider before making any changes to your treatment plan. Do not start, stop, or change any diabetes medications based on this study. Anyone experiencing symptoms like unusual breast tissue growth, sexual dysfunction, or irregular periods should contact their doctor immediately, as these may indicate hormonal imbalances requiring medical attention.