Researchers studied how a type of diabetes medication called SGLT2 inhibitors affects how our bodies handle salt. They compared 14 people taking this medication with 12 people not taking it, and had both groups eat different amounts of salt for a week at a time. The people taking the medication had much smaller increases in blood pressure when eating salty food compared to those not taking it. The medication seemed to help their bodies get rid of extra salt and water more efficiently after meals. This discovery could explain why this medication is so good at protecting people’s hearts.

The Quick Take

  • What they studied: Whether a diabetes medication called SGLT2 inhibitors makes people’s blood pressure less sensitive to eating salty foods
  • Who participated: 26 adults with type 2 diabetes: 14 taking SGLT2 inhibitor medication and 12 not taking it
  • Key finding: People taking SGLT2 inhibitors had almost no blood pressure increase when eating salty food (only a 1.2 point increase), while those not taking it had a 5.6 point increase. This difference was statistically significant and suggests the medication protects against salt’s effects on blood pressure.
  • What it means for you: If you have type 2 diabetes and take SGLT2 inhibitors, this medication may help protect your blood pressure from being affected by salty foods. However, this is still early research with a small group, so talk to your doctor before making any changes to your diet or medication.

The Research Details

This was a small research study where scientists compared two groups of people with type 2 diabetes. One group was already taking SGLT2 inhibitor medication, and the other group wasn’t taking it. Both groups followed the same eating plan for two weeks. For the first week, they ate a very low-salt diet plus extra salt (like eating 4,800 mg of salt daily—about 2 teaspoons). For the second week, they ate the same low-salt diet but with much less added salt (about 1,200 mg daily). The researchers measured their blood pressure, checked how much salt and water their bodies got rid of, and looked at hormone levels that control salt balance.

The study was “open-label,” which means both the participants and researchers knew who was taking the medication and who wasn’t. This is different from a “blind” study where people don’t know what they’re taking. The researchers used 24-hour blood pressure monitors that people wore continuously to get accurate readings throughout the day and night.

The study was relatively small with only 26 people total, which is important to keep in mind when thinking about how much we can trust the results.

This research design allowed scientists to see how the same people’s bodies responded to different amounts of salt. By measuring blood pressure continuously over 24 hours instead of just taking a quick reading in a doctor’s office, they got a much more accurate picture of how salt affects blood pressure. Looking at how much salt and water people’s bodies got rid of helped explain why the medication worked.

This study has some strengths: it used continuous blood pressure monitoring which is more accurate than single readings, and it carefully controlled what people ate. However, there are important limitations: it’s very small (only 26 people), it wasn’t randomized (meaning people weren’t randomly assigned to groups), and it wasn’t blinded (everyone knew who was taking the medication). These factors mean the results are interesting but need to be confirmed with larger, more rigorous studies before we can be very confident.

What the Results Show

The main finding was that people taking SGLT2 inhibitors had much smaller blood pressure increases when eating salty food compared to those not taking the medication. When the non-medication group ate the high-salt diet, their systolic blood pressure (the top number) went up by about 5.6 points on average. In contrast, the SGLT2 inhibitor group’s systolic blood pressure actually stayed about the same or went down slightly by 1.2 points. The difference between groups was statistically significant, meaning it’s unlikely to have happened by chance.

The diastolic blood pressure (bottom number) showed a similar pattern. The control group’s diastolic pressure increased by about 4.6 points with high salt, while the SGLT2 inhibitor group’s actually decreased slightly by 1.2 points. This suggests the medication provides protection against salt’s effects on both numbers that make up a blood pressure reading.

The researchers discovered that people taking SGLT2 inhibitors got rid of more salt and water through their urine after meals compared to the control group. This happened both when eating high-salt and low-salt diets. This enhanced salt and water excretion appears to be the main mechanism explaining why their blood pressure didn’t increase with salty food.

Interestingly, the medication group showed less activation of their body’s salt-regulating hormones (renin and aldosterone) when eating low-salt food. This suggests the medication changes how the body’s natural salt-balancing systems work.

The study found that hydration levels (how much water was in people’s bodies) and glycosuria (sugar in the urine) didn’t change in ways that explained the blood pressure differences. This tells us the medication’s blood pressure benefits come from its effects on salt handling, not from changes in hydration or blood sugar control. The enhanced salt excretion after meals was particularly important—this is when the body normally absorbs salt from food, but the medication seemed to help people get rid of it instead.

Previous animal studies had suggested that SGLT2 inhibitors might reduce salt sensitivity, but this is one of the first human studies to confirm this effect. The findings align with what we know about how these medications work in the kidneys and help explain why they’re so effective at lowering blood pressure and protecting the heart in people with diabetes. This research bridges the gap between animal studies and real-world effects in humans.

This study is small with only 26 participants, which limits how much we can generalize the findings to all people with diabetes. It wasn’t a randomized controlled trial, meaning people weren’t randomly assigned to take or not take the medication—they were already taking it or not. This makes it harder to be certain the medication caused the differences rather than other factors. The study was also open-label, so everyone knew who was taking the medication, which could potentially influence results. Additionally, the study only lasted two weeks, so we don’t know if these effects continue long-term. Finally, all participants had type 2 diabetes, so we don’t know if these results apply to people without diabetes or those with type 1 diabetes.

The Bottom Line

Based on this research, SGLT2 inhibitors appear to help protect blood pressure from the effects of salty foods in people with type 2 diabetes. However, this is early-stage research, so the evidence is moderate rather than strong. If you have type 2 diabetes and your doctor has prescribed an SGLT2 inhibitor, this research provides additional support for taking it as prescribed. You shouldn’t change your salt intake based solely on this study—continue following your doctor’s dietary recommendations. More research with larger groups of people is needed before we can make stronger claims.

This research is most relevant to people with type 2 diabetes, especially those concerned about blood pressure or heart health. People already taking SGLT2 inhibitors may find this reassuring as it explains one way the medication helps protect their heart. People with type 2 diabetes not yet on medication should discuss with their doctor whether this medication might be appropriate for them. This research is less directly relevant to people without diabetes, though it may eventually inform how we treat high blood pressure in the general population.

The blood pressure benefits from SGLT2 inhibitors typically appear within weeks to a few months of starting the medication, though this study only measured effects over two weeks. The salt-handling improvements shown here happened during the study period, suggesting relatively quick effects. However, the long-term cardiovascular protection these medications provide develops over months to years of consistent use.

Want to Apply This Research?

  • Track daily sodium intake (in milligrams) and 24-hour average blood pressure readings if you have a home monitor. Record these weekly to see if your blood pressure remains stable even when sodium intake varies, which would indicate the medication is working as this research suggests.
  • If you take an SGLT2 inhibitor, use the app to log your medication adherence daily and track blood pressure readings 2-3 times per week. This helps you see whether consistent medication use correlates with stable blood pressure despite dietary salt variations. Set reminders to take your medication at the same time each day.
  • Create a weekly summary view showing average blood pressure alongside average daily sodium intake over the past month. Look for trends showing whether blood pressure stays relatively stable even when sodium intake increases. Share these trends with your doctor at regular checkups to confirm the medication is working effectively for you.

This research is preliminary and comes from a small study. It should not be used to make decisions about starting, stopping, or changing any diabetes or blood pressure medication. Always consult with your healthcare provider before making changes to your treatment plan or diet. While SGLT2 inhibitors have been shown to have cardiovascular benefits, they may not be appropriate for everyone and can have side effects. Your doctor can help determine if this medication is right for your individual situation. This article is for educational purposes and is not a substitute for professional medical advice.