INTERMITTENT USE OF NITRATES INCREASES BONE-MINERAL DENSITY - THE STUDY OF OSTEOPOROTIC FRACTURES

Nitric oxide slows bone remodeling and bone loss in animals, Because n itroglycerin and other nitrates increase nitric oxide levels, we hypot hesized that nitrate use may be associated with greater bone mineral d ensity (BMD) and decreased risk of fracture in humans, Further, interm ittent nitrate use may be associated with greater benefits than daily nitrate use, which results in tachyphylaxis. We tested this hypothesis using data from the Study of Osteoporotic Fractures, We prospectively studied 6201 elderly women of whom 317 took nitrates on a daily basis and 74 used them intermittently. We measured BMD at the hip and the h eel and adjusted all comparisons for multiple potential confounders. W e found that women taking daily nitrates had slightly greater hip BMD (difference, 1.3%; 95% confidence interval [CI], 0.14-4.1%) but the sa me heel BMD (difference, 0%; 95% CI -2.6-2.6%) as nonusers. By contras t, women using nitrates intermittently had substantially greater hip ( difference, 2.6%; 95% CI, 0.4-6.8%) and heel BMD (difference, 5.3%; 95 % CI, 2.6-11%) than nonusers. This study suggests that the intermitten t administration of nitrates may enhance BMD.