Transdermal nitroglycerin therapy may not prevent early postmenopausal bone loss

Area of Science:

• Bone biology and osteoporosis research.
• Pharmacological interventions for bone health.

Background:

• Osteoporosis is a significant health concern for postmenopausal women.
• Nitric oxide (NO) donors have shown potential in preliminary studies to mitigate bone mineral density (BMD) loss.

Purpose of the Study:

• To investigate the efficacy of the nitric oxide (NO) donor, nitroglycerin, in preventing bone loss among postmenopausal women.
• To evaluate nitroglycerin's effect on bone mineral density (BMD) in a clinical trial setting.

Main Methods:

• A 3-year, randomized, double-blind, placebo-controlled clinical trial involving 186 postmenopausal women (aged 40-65) with baseline BMD T-scores between 0 and -2.5.
• Participants received either nitroglycerin ointment (22.5 mg daily) or a placebo, alongside daily calcium and vitamin D supplements.
• Bone mineral density (BMD) was assessed annually using dual-energy x-ray absorptiometry, with percent change in lumbar vertebrae BMD as the primary outcome.

Main Results:

• No significant difference in lumbar spine BMD change was observed between the nitroglycerin group (-2.1%) and the placebo group (-2.5%) after 36 months (P = 0.59).
• Secondary outcomes, including hip BMD and total body bone mineral content, also showed no significant differences between groups.
• The nitroglycerin group reported a higher incidence of headaches (57% vs. 14%, P < 0.001) compared to the placebo group.

Conclusions:

• The tested dose of transdermal nitroglycerin (approximately 16 mg/d after compliance adjustment) was ineffective in preventing bone loss in postmenopausal women.
• The study suggests that the administered dose of nitroglycerin was sub-therapeutic for preventing postmenopausal bone loss.
• Further research may be needed to determine optimal dosing or alternative NO-donating strategies for bone health.