Treatment implications for men when switching from male to female bone mineral density reference data: the Manitoba Bone Density Program.

Since 2001, the International Society for Clinical Densitometry Official Position has been to use a young female normative database in women and a young male normative in men for T-scores. Several prospective studies have shown that men and women with identical hip bone mineral density (BMD) have the same fracture rates, and so there has been reconsideration of whether female reference data should be adopted for men. We studied 4691 men age 50 yr and older with baseline dual-energy X-ray absorptiometry assessments to explore how a change in BMD reference data from male to female would affect the number of men meeting National Osteoporosis Foundation (NOF) intervention criteria. We found that use of male vs female BMD reference data for T-score calculation did affect individual eligibility criteria for treatment under the NOF guidelines, but that overall differences in treatment rates were small when eligibility for treatment considered any of the NOF intervention criteria. Specifically, the majority of men who no longer qualified for treatment based upon T-scores calculated from female as opposed to male reference data would still qualify for treatment based upon other NOF intervention criteria. In addition, men only eligible for treatment under NOF criteria when using male reference data were at low fracture risk. We conclude that choice of male or female reference data for T-score calculation in men has little effect on overall treatment eligibility rates under NOF guidelines.