A new study has shown that nitroglycerin ointment, that is used for chest pain or angina can be beneficial in postmenopausal women in improving their bone density. In this group of women, the bone becomes increasingly weak and brittle and leads to easy fractures. The study showed that postmenopausal women who used it for 2 years showed a modest increase in bone mineral density and decrease in bone resorption (loss). The study was published in the February 23 issue of JAMA.
The authors write, “The number of osteoporotic fractures is increasing worldwide as populations age. An inexpensive and widely available treatment may help limit this increase… Nitroglycerin stimulates bone formation and inhibits bone resorption, is inexpensive, and is widely available. Its effects on bone density, bone structure, and bone strength are unknown.”
Sophie A. Jamal of the Women's College Research Institute and University of Toronto, Canada, and colleagues tested the efficacy of once-daily nitroglycerin ointment to increase bone mineral density (BMD) at the spine, thigh bone, neck and hip. The team involved 243 postmenopausal women from November 2005 to March 2010. The participants were randomized to nitroglycerin ointment (15 mg/d; 126 women) or placebo or dummy (117 women), applied at bedtime to the upper arm for 2 years.
Results showed that compared with placebo, women randomized to the nitroglycerin group had significant increases in BMD. Density rose by 6.7 percent over the spine, 6.2 percent over hip, 7.0 percent over the thigh bone or femur at end of 24 months. Nitroglycerin users also had increases in certain measures of BMD and bone strength of the arm bones and leg bones. Additionally, compared with placebo, treatment with nitroglycerin was significantly associated with an increase in bone-specific alkaline phosphatase, a marker of bone formation; and a decrease in urine N-telopeptide, a marker of bone resorption or loss. Both groups did not suffer from any major side effects. Headaches were reported by 40 (35 percent) in nitroglycerin and 6 (5.4 percent) in placebo groups during the first month, decreasing substantially after 12 months.
Authors conclude, “In conclusion, daily administration of nitroglycerin ointment increases bone formation and decreases bone resorption; thereby, substantially improving BMD, bone structure, and indices of bone strength at least as much as existing treatments. Together, these findings suggest that daily nitroglycerin may reduce the risk of vertebral and non-vertebral fractures. Furthermore, nitrates have a potential advantage of easy administration as an ointment, patch, or pill and wide availability of generic preparations. The efficacy of nitrates for reducing risk of fracture should be tested in a larger randomized controlled trial.”
In an accompanying editorial to the article, Sundeep Khosla of Mayo Clinic, Rochester, Minn., writes that although this study was small, it should set the stage for an adequately powered, larger study using nitroglycerin ointment with fracture as an outcome. He writes, “If such a study demonstrates efficacy for reducing fractures, clinicians would have a novel and inexpensive therapy for osteoporosis. The findings of the current study also should prompt development of additional nitric oxide donors with greater skeletal efficacy and a better adverse effect profile, particularly with regard to headaches.”
The study was funded by the Canadian Institute of Health Research and the Physicians’ Services Incorporated.