Cystic fibrosis is a genetic disease that affects the lungs and digestion. As people with CF live longer thanks to new treatments, doctors are noticing they’re developing other health problems, including diabetes and weak bones. This study looked at 81 young people with CF (ages 10-21) to see if problems with blood sugar control were connected to weaker bones. The researchers found that those with blood sugar problems had lower bone density than those with normal blood sugar. This suggests that managing blood sugar might be just as important as managing lungs in CF care.

The Quick Take

  • What they studied: Whether problems with blood sugar control in young people with cystic fibrosis are connected to weaker bones
  • Who participated: 81 young people with cystic fibrosis between ages 10 and 21 years old who received routine health screenings between 2019 and 2024
  • Key finding: Young people with CF who had blood sugar problems (either early-stage glucose problems or CF-related diabetes) had significantly weaker bones compared to those with normal blood sugar. Those with higher blood sugar levels had the weakest bones.
  • What it means for you: If you have cystic fibrosis, keeping your blood sugar under control may help protect your bones from becoming weak. Talk to your CF care team about regular blood sugar and bone health screening, especially starting at age 10.

The Research Details

This was a cross-sectional study, which means researchers looked at a group of people at one point in time rather than following them over years. The team reviewed medical records from 81 young people with cystic fibrosis who had routine screening tests between 2019 and 2024. They collected information about each person’s genetics, blood sugar control (using a special glucose tolerance test), bone health markers (like calcium and vitamin D levels), and bone density measurements of the lower spine. The researchers then compared bone density between groups: those with normal blood sugar, those with early blood sugar problems, those with impaired glucose tolerance, and those with CF-related diabetes.

This research approach is important because it shows real-world patterns in CF care. By looking at actual patient data, researchers can identify which health problems tend to happen together. This helps doctors understand that blood sugar control might affect bone health, which could change how CF patients are monitored and treated.

This study has some strengths: it used objective medical tests (not just patient reports), included a reasonable number of participants, and looked at a specific age group where CF complications are emerging. However, because it’s a snapshot in time rather than following people over years, we can’t be completely sure that blood sugar problems cause weak bones—they might just happen together. The study also didn’t find that newer CF medications affected these results, possibly because patients hadn’t been on them long enough.

What the Results Show

Among the 81 young people studied, most (about 68%) had normal blood sugar control. However, about 32% had some kind of blood sugar problem: 11% had early glucose problems, 11% had impaired glucose tolerance (a pre-diabetes state), and 10% had CF-related diabetes. The key finding was that those with any blood sugar problem had significantly weaker bones than those with normal blood sugar. Specifically, young people with impaired glucose tolerance and those with CF-related diabetes had lower bone density scores and lower body weight compared to the normal group. The relationship between blood sugar and bone weakness was clear: the higher someone’s blood sugar levels (measured by HbA1c, a three-month average), the weaker their bones tended to be.

The study also found that young people with blood sugar problems had lower lung function scores, which makes sense because CF affects both the lungs and digestion. Interestingly, the newer CF medications (called HEMTs) didn’t show a significant impact on either blood sugar or bone health in this study, though researchers think this might be because patients hadn’t been using them long enough to see benefits.

Previous research has shown that people with type 1 and type 2 diabetes have weaker bones, but there hasn’t been much research on this connection in children with cystic fibrosis specifically. This study fills that gap by showing that even early blood sugar problems—not just full-blown diabetes—are connected to weaker bones in CF patients. This is important because it suggests doctors should pay attention to blood sugar control even before diabetes develops.

This study has several limitations to keep in mind. First, it’s a snapshot of one moment in time, so we can’t prove that blood sugar problems cause weak bones—they might just happen together. Second, the study is relatively small (81 people), so the findings might not apply to all CF patients. Third, the study only looked at the lower spine bones, not the whole skeleton. Finally, the study couldn’t fully evaluate the effects of newer CF medications because patients hadn’t been on them long enough.

The Bottom Line

Young people with cystic fibrosis should have routine screening for both blood sugar problems and bone health starting at age 10, as current guidelines recommend. If blood sugar problems are found, working with your CF care team to manage blood sugar through diet, exercise, and possibly medication may help protect bone health. This should be part of a comprehensive CF care plan that addresses lungs, digestion, and overall health. (Confidence level: Moderate—this is one study, but it supports existing guidelines.)

This research is most relevant to: young people with cystic fibrosis and their families, CF care teams and doctors, and anyone involved in CF health management. It’s less relevant to people without CF, though the general principle that blood sugar affects bone health may apply more broadly.

Blood sugar problems develop gradually, and bone weakness also develops over time. You won’t see dramatic changes in weeks, but consistent management of blood sugar over months and years should help protect bone health. Regular screening (typically yearly) will help track progress.

Want to Apply This Research?

  • Track blood sugar readings (if you have a glucose monitor) and bone health markers (calcium, vitamin D, phosphorus levels from lab work) monthly. Create a simple chart showing HbA1c levels over time alongside bone density scores to visualize the connection.
  • Set reminders for: (1) taking CF medications as prescribed, (2) eating calcium and vitamin D-rich foods daily, (3) doing weight-bearing exercise like walking or dancing for 30 minutes most days, and (4) attending scheduled blood sugar and bone health screening appointments.
  • Use the app to log: annual HbA1c test results, bone density scan results (typically every 1-2 years), vitamin D and calcium levels, exercise minutes per week, and any symptoms of weak bones (like fractures or back pain). Set up alerts for upcoming screening appointments and medication refills.

This research is informational only and should not replace professional medical advice. If you or a family member has cystic fibrosis, consult with your CF care team about screening for blood sugar and bone problems, and discuss any concerns about these findings. The study shows an association between blood sugar problems and weaker bones, but doesn’t prove that one causes the other. Individual results may vary, and treatment decisions should be made with your healthcare provider based on your specific situation.