The diagnosis of osteoporosis in men is controversial, although most studies demonstrate similar fracture rates for men and women with the same level of hip bone mineral density (BMD). Whether this applies to the lumbar spine is currently uncertain and has important implications with respect to choice of reference population for T-score calculation and osteoporosis diagnosis. This question was specifically addressed in the population-based Canadian Multicentre Osteoporosis Study cohort of 4745 women and 1887 men ages 50+ yr at the time of baseline lumbar spine dual energy x-ray absorptiometry. In up to 10 yr of observation, incident clinical major osteoporotic fractures occurred in 110 men (5.8%) vs 543 women (11.4%) (p < 0.001). Mean lumbar spine BMD in men was greater than in women, both among those with and those without incident major osteoporotic fracture (p < 0.001). Men were at slightly lower risk for incident major osteoporotic fracture than women for an equivalent lumbar spine BMD (age- and BMD-adjusted rate ratio 0.75, 95% confidence interval 0.60-0.93, p = 0.008) with similar findings after adjustment for the World Health Organization fracture risk assessment clinical risk factors or competing mortality. No significant sex difference in the BMD relationship was seen for vertebral fractures (clinical or radiographic) or for all fractures. In summary, this large population-based longitudinal cohort study found similar or lower fracture risk for men vs women after adjustment for absolute lumbar spine BMD and additional covariates. The least complicated model for describing fracture risk is therefore to use the same reference lumbar spine data for generating T-scores in men and women.
Bibliographical noteFunding Information:
We thank all those participants in CaMos whose careful responses and attendance made this analysis possible. The Canadian Multicentre Osteoporosis Study is supported by Canadian Institutes of Health Research (CIHR), Amgen Canada Inc, Dairy Farmers of Canada, Merck Canada Eli Lilly Canada, and Novartis Canada. Disclosures: William D. Leslie: Speaker bureau: Amgen, Eli Lilly, Novartis. Research grants: Novartis, Amgen, Genzyme. David Goltzman serves as a consultant for Eli Lily, Novartis, Merck, Proctor & Gamble, and Amgen. Christopher S. Kovacs has received honoraria for advisory boards, consultancies, or speaker's fees from Amgen, Danone, Eli Lilly, Merck, and Novartis. Robert Josse serves as a consultant for Amgen, Eli Lilly, GlaxoSmithKline, Merck, Novartis, Warner Chilcott, sanofi-aventis, Servier. Wojciech P. Olszynski has received honoraria, speaker fees and consulted for Amgen, Bristol Meyers Squibb, Hoffman-LaRoche, Novartis, Pfizer, and Warner Chilcott. David A. Hanley serves as an advisory board member and/or has received grants and honoraria from Amgen, Eli Lilly, Merck, Novartis, NPS Pharmaceuticals, and Warner-Chilcott. K. Shawn Davison has served as advisory board member/received honoraria from Amgen, Merck, Proctor & Gamble, sanofi-aventis, and Servier. Tassos Anastassiades has received honoraria from Merck, Proctor & Gamble, Schering Plow, and Servier. Tanveer Towheed has received grant support from Abbott Laboratories and sanofi-aventis and honoraria from Bristol-Myers Squibb, Novartis, and sanofi-aventis. Stephanie Kaiser has served as advisory board member/received honoraria from Amgen, Eli Lilly, Novartis, and Warner-Chilcott. Eli Lilly, Novartis, Proctor & Gamble, sanofi-aventis, Servier, and Wyeth-Ayerst. The remaining authors do not have any financial disclosures.
- Bone mineral density
- Dual energy x-ray absorptiometry
- Lumbar spine