Researchers studied over 2,000 American adults without high blood pressure to see if even slightly elevated blood pressure numbers could affect liver health. They found that nearly 4 out of 10 people had a condition called fatty liver disease, even when their blood pressure seemed normal. The study discovered that as blood pressure numbers went up—even in the “normal” range—the risk of developing this liver condition increased. This suggests that keeping blood pressure as low as possible, even before it becomes officially “high,” might help protect your liver from developing fat buildup.

The Quick Take

  • What they studied: Whether people without high blood pressure diagnosis could still develop fatty liver disease if their blood pressure numbers were even slightly elevated
  • Who participated: 2,017 American adults from 2017-2018 who did not have a diagnosis of high blood pressure, representing a mix of ages, races, and backgrounds from across the United States
  • Key finding: Nearly 39% of people without high blood pressure had fatty liver disease. For every 10-point increase in the top blood pressure number (systolic), the risk of fatty liver disease increased by about 59% in the normal-to-elevated range
  • What it means for you: Even if your doctor hasn’t diagnosed you with high blood pressure, keeping your blood pressure numbers as low as possible within the normal range may help protect your liver. However, this is one study and more research is needed before making major lifestyle changes based solely on this finding

The Research Details

This was a cross-sectional study, which means researchers took a snapshot of people at one point in time rather than following them over years. They used data from the National Health and Nutrition Examination Survey (NHANES), a large government study that regularly checks the health of Americans. Researchers looked at blood pressure measurements and liver health information collected in 2017-2018 from over 2,000 adults who did not have a high blood pressure diagnosis.

The researchers measured two blood pressure numbers: systolic (the top number, which measures pressure when your heart beats) and diastolic (the bottom number, which measures pressure when your heart rests). They also checked for a condition called metabolic dysfunction-associated fatty liver disease (MAFLD), which is when fat builds up in your liver due to metabolic problems like obesity or blood sugar issues.

The team used statistical methods to look for connections between blood pressure levels and fatty liver disease, while accounting for other factors that might affect liver health, such as age, weight, and blood sugar levels.

This approach is important because it shows real-world patterns in a large, representative group of Americans rather than just laboratory findings. By looking at people without a high blood pressure diagnosis, the researchers could see if there’s a “gray zone” where blood pressure is technically normal but still affects liver health. This helps doctors understand whether they should pay attention to blood pressure numbers even when they’re not in the high range.

The study used data from a well-respected national health survey that carefully collects information from diverse Americans, which makes the results more likely to apply to the general population. However, because this is a cross-sectional study (a snapshot in time), it can only show that blood pressure and fatty liver disease are connected—it cannot prove that one causes the other. The study was published in BMJ Open, a peer-reviewed medical journal, meaning other experts reviewed it before publication.

What the Results Show

The researchers found that fatty liver disease was surprisingly common, affecting nearly 4 out of 10 people in the study who didn’t have high blood pressure. This was an important finding because many people might assume that if they don’t have high blood pressure, their liver is safe.

When looking at the top blood pressure number (systolic), there was a clear pattern: as the number went up, the risk of fatty liver disease went up too. Specifically, for every 10-point increase in systolic blood pressure in the normal-to-elevated range (90-129 mm Hg), the risk of having fatty liver disease increased by about 59%. This means someone with a systolic reading of 120 had more liver disease risk than someone with 110, even though both numbers are considered “normal.”

The bottom blood pressure number (diastolic) showed a similar trend, but the relationship was weaker and not as clearly significant. This suggests that the top number might be more important for liver health than the bottom number.

These patterns held true even after researchers adjusted for other factors that affect liver health, such as weight, age, and blood sugar control, suggesting the blood pressure connection is real and not just due to other health factors.

The researchers performed additional analyses to make sure their findings were reliable. These “sensitivity analyses” confirmed the main results, showing that the connection between systolic blood pressure and fatty liver disease was consistent across different ways of analyzing the data. The study also showed that this relationship existed across different age groups and body types, suggesting it’s a widespread pattern rather than something that only affects certain people.

Previous research has shown that high blood pressure is connected to fatty liver disease, but most studies focused on people who already had a high blood pressure diagnosis. This study adds new information by showing that even in people without a high blood pressure diagnosis, the relationship exists. It suggests that the connection between blood pressure and liver health may start earlier than doctors previously thought, even in the “normal” range. This aligns with recent thinking in medicine that lower blood pressure numbers may be healthier than previously believed.

This study has several important limitations. First, because it’s a snapshot in time, we can’t know if high blood pressure actually causes fatty liver disease or if they just happen to occur together. Second, the study only included data from 2017-2018, so it may not reflect current patterns. Third, the study relied on a single blood pressure measurement, while doctors usually take multiple readings to diagnose high blood pressure. Fourth, the researchers couldn’t account for all possible factors that might affect liver health, such as alcohol consumption or certain medications. Finally, the study included mostly people who participated in a health survey, which might not perfectly represent all Americans.

The Bottom Line

Based on this research, maintaining blood pressure in the lower part of the normal range (below 120 mm Hg systolic) appears to be beneficial for liver health. This can be done through regular exercise, a healthy diet low in salt and processed foods, maintaining a healthy weight, limiting alcohol, and managing stress. However, this is one study, so these recommendations should be considered alongside advice from your doctor. (Confidence level: Moderate—the findings are interesting but need confirmation from additional studies)

This research is most relevant for adults without a high blood pressure diagnosis who want to protect their liver health. It’s particularly important for people who are overweight, have blood sugar problems, or have a family history of liver disease. People who already have high blood pressure should focus on their doctor’s treatment plan. This research is less relevant for children or people with certain medical conditions that affect blood pressure.

If you make lifestyle changes to lower blood pressure, you might see improvements in blood pressure readings within weeks to months. However, changes in liver health typically take longer to develop and improve—usually several months to a year or more. It’s important to be patient and consistent with healthy habits.

Want to Apply This Research?

  • Track your systolic blood pressure (top number) weekly at the same time of day, aiming to keep it below 120 mm Hg. Record the date, time, and reading to identify trends over time.
  • Set a goal to check your blood pressure regularly (weekly or monthly) using a home blood pressure monitor. Pair this with one lifestyle change: either adding 30 minutes of walking most days, reducing salt intake, or losing 5-10% of body weight if overweight.
  • Create a dashboard showing your blood pressure trend over 3-6 months alongside lifestyle factors like exercise minutes, salt intake, and weight. Use this data to identify which changes have the biggest impact on your blood pressure numbers.

This research describes an association between blood pressure and fatty liver disease but does not prove that one causes the other. The findings apply to adults without a high blood pressure diagnosis and may not apply to everyone. This information is educational and should not replace advice from your healthcare provider. Before making changes to your diet, exercise routine, or any health decisions, consult with your doctor, especially if you have existing health conditions or take medications. If you have been diagnosed with high blood pressure or fatty liver disease, follow your doctor’s treatment plan.