Researchers studied how a bone-strengthening medication called teriparatide (PTH 1-34) affects blood sugar levels in postmenopausal women with severe osteoporosis. They tracked 26 women for one month and found that about half experienced lower blood sugar levels while taking the drug. Interestingly, the women whose blood sugar decreased also showed signs of stronger bone building. This suggests the medication might have an unexpected benefit beyond just strengthening bones, though more research is needed to understand why this happens and whether it matters for long-term health.

The Quick Take

  • What they studied: Whether teriparatide, a medication that helps rebuild bone, affects blood sugar levels in postmenopausal women with weak bones.
  • Who participated: 26 postmenopausal women with severe osteoporosis who were starting teriparatide treatment. The study excluded women who already had high blood sugar or diabetes.
  • Key finding: After one month, about half the women had lower blood sugar (7% decrease on average), while the other half had higher blood sugar (8% increase on average). The women with lower blood sugar also showed better signs of bone building.
  • What it means for you: If you’re a postmenopausal woman taking teriparatide for bone health, your blood sugar might change—but this early finding suggests it could actually improve if your bones are building well. However, this is preliminary research, and you should continue monitoring your blood sugar as your doctor recommends.

The Research Details

This was a small observational study where researchers followed 26 postmenopausal women starting teriparatide treatment for one month. At the beginning and after one month, they measured multiple things: fasting blood sugar, calcium levels, kidney function, vitamin D, and special markers that show whether bones are being built or broken down. They also asked women about their diet and exercise habits. After one month, researchers divided the women into two groups based on whether their blood sugar went up or down, then compared everything between the groups to see what was different.

The researchers were careful to exclude women who already had high blood sugar or diabetes at the start, so they could see the medication’s direct effect. They also checked that both groups were similar at the beginning in terms of weight, previous treatments, diet, and exercise, which helps ensure any differences found were related to how the medication worked, not other factors.

This type of study is useful for spotting unexpected effects of medications and generating ideas for future research, but it’s smaller and less controlled than a randomized trial where some people get the real drug and others get a placebo.

Understanding how bone-building medications affect blood sugar is important because many postmenopausal women are at risk for both weak bones and diabetes. If teriparatide can help with both conditions, it could be especially valuable for these women. This research also helps doctors understand the full effects of medications, not just their main purpose.

This study has several strengths: it carefully measured multiple markers of bone and sugar metabolism, excluded women with existing high blood sugar to see the medication’s direct effect, and confirmed that both groups were similar at the start. However, it’s a small study with only 26 women, so the findings might not apply to everyone. It’s also short-term (only one month), so we don’t know if these changes continue or matter over longer periods. The study doesn’t have a comparison group of women not taking the medication, which would help confirm the drug caused the changes.

What the Results Show

After one month of teriparatide treatment, the women split into two roughly equal groups: those whose blood sugar decreased (group B) and those whose blood sugar increased (group A). The decrease in group B averaged 7%, while the increase in group A averaged 8%—a statistically significant difference, meaning this wasn’t likely due to chance.

The most interesting finding was that women in group B (lower blood sugar) showed a much larger increase in BALP, a marker of bone building, compared to group A. BALP increased by an average of 19% in group B but actually slightly decreased in group A. This suggests that when the medication successfully stimulates bone building, blood sugar tends to decrease.

Other markers changed similarly in both groups: vitamin D levels increased, and PTH and RANKL (a bone breakdown marker) decreased. These changes were expected from the medication and didn’t differ between the groups. The researchers found no differences between groups in diet, exercise, weight, or previous bone treatments, suggesting the blood sugar changes weren’t due to lifestyle differences.

Both groups showed improvements in bone metabolism markers, indicating the medication was working to build bone in both groups. Vitamin D levels increased in both groups, which is important because vitamin D helps with both bone health and blood sugar control. The decrease in RANKL (a marker of bone breakdown) in both groups confirmed the medication was reducing bone loss. These consistent changes across both groups show the medication was effective overall, but only some women experienced the blood sugar benefit.

Previous research has suggested that PTH (parathyroid hormone) might affect blood sugar, but most studies focused on the hormone’s bone effects. This research adds to a growing body of evidence that bone-building hormones may have broader metabolic effects. The finding that bone building and blood sugar improvement go together is new and suggests these processes might be connected in ways scientists don’t fully understand yet.

The main limitation is the small sample size of 26 women, which means results might not apply to larger populations. The study lasted only one month, so we don’t know if blood sugar changes continue, reverse, or become clinically important over time. There’s no control group of women not taking the medication, so we can’t be completely certain the drug caused the changes rather than natural variation. The study excluded women with existing high blood sugar or diabetes, so findings may not apply to women with these conditions. Finally, the study doesn’t explain why some women’s blood sugar decreased while others’ increased, which limits our ability to predict who will benefit.

The Bottom Line

If you’re a postmenopausal woman with severe osteoporosis starting teriparatide, continue monitoring your blood sugar as your doctor recommends. This research suggests your blood sugar might improve, especially if your bones are building well, but it’s too early to change diabetes management based on this finding alone. Discuss these preliminary findings with your doctor—they may want to monitor your blood sugar more closely during the first month of treatment. (Confidence: Low—this is preliminary research in a small group.)

Postmenopausal women with osteoporosis considering or starting teriparatide should know about this potential benefit. Women with both osteoporosis and prediabetes or diabetes should especially discuss this with their doctors. Healthcare providers treating osteoporosis should be aware of this possible effect. This research is less relevant for men, premenopausal women, or people with normal bone density.

Blood sugar changes appeared within one month of starting treatment, suggesting any effect happens relatively quickly. However, we don’t know if these changes are temporary or permanent, or if they become clinically meaningful over months or years. Most benefits would likely be assessed over 3-6 months of treatment.

Want to Apply This Research?

  • If you’re starting teriparatide, track your fasting blood sugar (measured first thing in the morning before eating) weekly for the first month, then monthly. Record the date, time, and value. Note any changes in diet or exercise. This creates a clear picture of whether your blood sugar is trending up, down, or staying stable.
  • Use the app to set a reminder for fasting blood sugar checks at the same time each morning (ideally 8-10 hours after your last meal). Log results immediately. If you notice a downward trend, celebrate it as a potential bonus benefit of your bone medication—but don’t change any diabetes medications without consulting your doctor.
  • Create a dashboard showing your blood sugar trend over time alongside your teriparatide treatment timeline. Set monthly check-ins to review the trend with your healthcare provider. If you’re also tracking bone health markers (like BALP through blood tests), correlate improvements in bone building with blood sugar changes to see if the pattern from this study applies to you.

This research is preliminary and based on a small study of only 26 women followed for one month. The findings suggest teriparatide may affect blood sugar levels, but more research is needed before this becomes standard medical guidance. If you take teriparatide or are considering it, discuss these findings with your doctor before making any changes to your treatment plan. Do not adjust diabetes medications or stop any current treatments based on this research alone. Blood sugar monitoring should continue as recommended by your healthcare provider. This information is educational and not a substitute for professional medical advice.