People taking GLP-1s were somewhat more likely to develop these problems over five years than people not taking the drugs. The increases were relatively small, but researchers say they highlight the need for physicians to closely monitor patients on GLP-1s and suggest interventions when necessary — and for patients to make lifestyle changes that can boost bone and joint health.
“These medications should be a jump start toward a healthy lifestyle with diet and exercise, not a substitute,” says the lead author, John Gabriel Horneff III, MD, an associate professor of orthopedic surgery at the University of Pennsylvania in Philadelphia.
People on GLP-1s Had a 30 Percent Higher Osteoporosis Risk
To explore possible links between GLP-1 drugs and bone health, researchers analyzed five years of medical records from more than 146,000 adults with both type 2 diabetes and obesity.
The study compared patients who were taking GLP-1 medications with an equal number of matched patients who were not using the drugs. The GLP-1 group included people taking medications such as semaglutide (Ozempic, Wegovy) and liraglutide (Victoza, Saxenda), though the records did not specify exactly which drug each person used.
Over five years, the researchers found:
- Osteoporosis developed in about 4.1 percent of GLP-1 users, compared with 3.2 percent of nonusers — a roughly 29 percent higher relative risk.
- Gout occurred in 7.4 percent of GLP-1 users, compared with 6.6 percent of those not taking the drugs — about a 12 percent increase.
- Osteomalacia, a condition involving the softening of bones due to impaired mineralization, was rare but occurred about twice as often in the GLP-1 group.
How GLP-1s Could Affect Bone Health
Researchers say there are several possible reasons GLP-1 medications might affect bone health, though the exact mechanisms remain unclear.
Nutrition changes could be a culprit. “One theory is that the curbed appetite simply decreases the intake of important nutrients and vitamins for bone health, such as calcium and vitamin D,” says Dr. Horneff.
Rapid weight loss may also play a role. “We know from bariatric surgery data that significant weight loss and altered nutrition absorption can be associated with lower bone density and osteoporosis,” says Marilyn Tan, MD, an associate professor of medicine and endocrinologist at Stanford Health Care in California, who was not involved in the study.
GLP-1 medications are often used specifically to promote weight loss, and the metabolic changes accompanying that process can affect bone turnover and lower bone density, says Dr. Tan.
Why Gout Risk Might Rise With GLP-1 Use
Gout is an acute form of arthritis caused by a buildup of uric acid in the blood. The most common symptom is pain and swelling in the big toe, but it can also affect other joints in the foot, ankle, and knee.
Tan says the 12 percent increase in gout risk reported in the study is a “significant increase.” It’s possible GLP-1s could lead to temporary changes in uric acid level because of shifting fat-muscle ratios, she says.
When the body breaks down tissue during weight loss, it enters what scientists call a catabolic state, Horneff explains.
Uric acid is a by-product of that process, which can lead to increased levels in the bloodstream. Elevated uric acid can trigger gout attacks in susceptible individuals, says Horneff.
The researchers did not analyze whether patients had a prior history of gout, which could also influence risk.
The Study Doesn’t Prove GLP-1s Cause Osteoporosis or Gout
Because the study was observational, it cannot determine whether GLP-1 medications directly caused the increased rates of bone issues or gout.
The medical records also did not include several factors that strongly influence bone health, such as what people ate or drank, physical activity levels, or if they took vitamin D supplements.
Additionally, the research focused specifically on adults with both obesity and type 2 diabetes, so the findings may not apply to people using GLP-1 drugs solely for weight loss.
Bottom Line: People on GLP-1s Should Be Monitored for Health Changes
Experts say the findings should not discourage appropriate use of GLP-1 medications, which provide significant benefits for many people with diabetes and obesity, including improvements in heart health, kidney function, and liver disease.
But the results do reinforce why it’s important that healthcare providers keep tabs on patients, including on their nutrition and bone health, while using the medications.
It’s “100 percent important” that healthcare providers monitor people taking GLP-1s, says Horneff. “They should be having blood draws for comprehensive metabolic profiles beyond just looking at labs for diabetes,” he says.
Other steps to protect bone health, Tan says, should include: