Some patients experience reduced bone mineral density (BMD) despite bisphosphonate therapy. We performed a retrospective chart review study to detect factors associated with decreased BMD in men prescribed alendronate.

Two investigators reviewed eligible medical records and used a standardized form to record potential characteristics predicting men’s response to alendronate. We analyzed patient characteristics associated with annualized change in hip and spine BMD (D-BMD).

Among 115 eligible men, 19 (17%) experienced significantly decreased BMD at the hip or spine, defined as a change exceeding precision error. Eleven men (10%) fractured during therapy. Spine D-BMD was positively associated with adherence to alendronate (R = 0.23, p=0.02) and inversely associated with baseline body weight (R = −0.21, p=0.03). Hip D-BMD was positively associated with annualized weight change (R = 0.19, p=0.0498) and negatively associated with patient age and number of concomitant medications (R = −0.21, p=0.03; R = −0.20, p = 0.03, respectively). In stepwise linear models, spine D-BMD was positively associated with alendronate adherence and multivitamin use, and negatively with baseline body weight. Hip D-BMD was negatively associated with age. Fracture during treatment was associated with fracture prior to therapy (p=0.03)

In this small study of men prescribed alendronate, BMD response showed a positive association with adherence to therapy, weight gain, and use of a multivitamin. By contrast, older age, higher baseline body weight, and higher number of medications were each associated with a decrease in BMD. Larger studies are needed to confirm and extend these findings.