Researchers studied 202 people hospitalized with heart failure and discovered something surprising: those with smaller calf muscles had higher levels of a protein that indicates their hearts were working harder. About 75% of the heart failure patients in the study had smaller-than-normal calf muscles. The study suggests that measuring calf size could be a simple, quick way for doctors to spot patients who aren’t getting enough nutrition and whose hearts are under extra stress. This finding could help hospitals identify which heart failure patients need extra nutritional support to feel better.

The Quick Take

  • What they studied: Whether the size of a person’s calf muscles is connected to how much stress their heart is experiencing in heart failure patients
  • Who participated: 202 people who were in the hospital being treated for heart failure. The group included people with different types of heart failure.
  • Key finding: Patients with smaller calf muscles (adjusted for their body weight) had more than double the heart stress markers compared to those with normal-sized calves (11,970 versus 5,621 units, which is a very significant difference). About 3 out of 4 patients had smaller-than-normal calf muscles.
  • What it means for you: If you have heart failure, your doctor might want to measure your calf size as part of checking your nutrition and overall health. This simple measurement could help identify if you need extra nutritional support. However, this is one study, so talk to your doctor before making any changes to your care plan.

The Research Details

This was a retrospective cross-sectional study, which means researchers looked back at medical records from 202 heart failure patients who were already in the hospital. They collected information about each patient’s height, weight, calf size, and blood test results. They then analyzed whether there was a connection between calf size and a blood marker called NT-proBNP, which shows how hard the heart is working.

The researchers adjusted the calf measurements based on each person’s body weight, since taller or heavier people naturally have larger calves. This adjustment helped them compare patients fairly, regardless of their overall size. They used statistical methods to look for patterns and connections between calf size and heart stress markers, while accounting for other factors that might affect the results.

This research approach is important because it uses a simple, free measurement (calf circumference) that hospitals already have the tools to do. Unlike expensive imaging tests, measuring a calf takes seconds and costs nothing. If this measurement can reliably identify patients with poor nutrition and high heart stress, hospitals could use it as a quick screening tool. This could help doctors catch malnourished heart failure patients earlier and give them the help they need.

This study has some strengths: it included a decent-sized group of 202 patients, it looked at real hospital data, and the findings were statistically significant (very unlikely to be due to chance). However, because it’s a cross-sectional study (a snapshot in time), it can only show that calf size and heart stress are connected—it can’t prove that one causes the other. The study was done in one hospital or healthcare system, so results might be different in other populations. The researchers did adjust for other factors that might affect the results, which strengthens the findings.

What the Results Show

The main finding was striking: 74.8% of the hospitalized heart failure patients had smaller-than-normal calf muscles (when adjusted for their body weight). This is a very high percentage and shows that muscle loss is extremely common in heart failure patients.

Patients with smaller calves had significantly higher NT-proBNP levels (a marker of heart stress) compared to those with normal-sized calves. The difference was dramatic: 11,970 units versus 5,621 units—more than double. This difference was highly statistically significant, meaning it’s very unlikely to have happened by chance.

When researchers used statistical analysis to account for other factors that might affect heart stress (like age, other medical conditions, and medications), the connection between calf size and heart stress remained strong and significant. For every unit decrease in adjusted calf circumference, NT-proBNP increased by about 927 units. This shows that the relationship between muscle loss and heart stress is real and independent of other factors.

The study included patients with different types of heart failure (those with reduced ejection fraction and those with preserved ejection fraction), and the pattern of muscle loss and elevated heart stress markers appeared across all these groups. This suggests the finding is relevant to heart failure patients broadly, not just one specific type. The high prevalence of muscle loss (nearly 75% of patients) highlights that malnutrition and muscle wasting are major, underrecognized problems in hospitalized heart failure patients.

Previous research has shown that heart failure patients often develop malnutrition and lose muscle mass, and that muscle loss is linked to worse outcomes. This study adds to that knowledge by showing that a simple, practical measurement (calf circumference) can identify these at-risk patients. The study also confirms what other research has suggested: that muscle loss and heart stress are connected. However, most hospitals don’t routinely measure calf circumference as part of standard nutrition screening, even though international guidelines recommend it.

This study looked at patients at one point in time, so we can’t know if the muscle loss caused the heart stress or if the heart stress caused the muscle loss—or if both are caused by something else. The study was done in one hospital or healthcare system, so the results might be different in other places or in different populations. The study didn’t include information about patients’ diets, exercise, or other lifestyle factors that might affect muscle mass. We don’t know if improving calf muscle size would actually reduce heart stress or improve outcomes—the study only shows they’re connected. Finally, the study is relatively small (202 patients), so larger studies would help confirm these findings.

The Bottom Line

For heart failure patients: Ask your doctor about measuring your calf circumference as part of your nutrition assessment. If your calf size is smaller than normal, discuss with your doctor or a dietitian about whether you need extra protein, nutrition support, or physical therapy. The evidence is moderate—this is one study showing a connection, so it’s not definitive yet. For healthcare providers: Consider adding calf circumference measurement to your standard nutrition screening for hospitalized heart failure patients, especially since it’s quick and free. This could help identify patients who need nutritional intervention.

This research is most relevant to people with heart failure who are hospitalized or at risk for malnutrition. It’s also important for cardiologists, heart failure specialists, and dietitians who care for these patients. If you have heart failure, this suggests you should pay attention to maintaining muscle mass through adequate nutrition and appropriate exercise. If you’re a healthcare provider, this suggests you should screen for muscle loss in your heart failure patients. This research is less directly relevant to people without heart failure, though maintaining muscle mass is important for everyone’s health.

If you’re a heart failure patient and your doctor recommends nutrition support or increased protein intake based on low calf measurements, you might start to feel benefits within weeks to a few months. However, building muscle takes time—usually several weeks to months of consistent good nutrition and appropriate activity. Improvements in heart stress markers might take longer to show up in blood tests. Talk to your doctor about realistic timelines for your specific situation.

Want to Apply This Research?

  • Measure and track your calf circumference monthly (at the widest part of your calf, with a soft measuring tape). Record the measurement in your health app along with your weight. This simple tracking can help you and your doctor monitor whether your muscle mass is stable, improving, or declining.
  • If you have heart failure and your calf measurements are low, use your app to track your daily protein intake (aim for the amount your doctor recommends) and log any physical activity you do. Set a daily reminder to eat a protein-rich snack or meal. Share your calf circumference measurements and nutrition logs with your healthcare team during appointments.
  • Create a monthly check-in reminder to measure your calf circumference and record it in your app. Track trends over 3-6 months. If measurements are declining, alert your healthcare provider. Also monitor any changes in how you feel (energy levels, shortness of breath, exercise tolerance) and correlate these with your calf measurements and nutrition intake. This long-term tracking helps you and your doctor see the bigger picture of your health.

This research shows an association between calf muscle size and heart stress in heart failure patients, but it does not prove that one causes the other. This study should not replace professional medical advice. If you have heart failure or are concerned about muscle loss, please consult with your cardiologist or healthcare provider before making any changes to your diet, exercise routine, or treatment plan. The findings are from one study of 202 patients and should be confirmed by larger research before being widely adopted in clinical practice. Always work with your healthcare team to develop a personalized nutrition and exercise plan appropriate for your specific condition.