Modifiable predictors of bone loss in older men: a prospective study.

BACKGROUND: The determinants of change in bone mineral density (BMD) have been well characterized in women but not in men. This prospective study describes the patterns of BMD change at the hip and spine, incidence of osteoporosis, and modifiable predictors of bone loss in 507 ambulatory community-dwelling men aged 45 to 92 years.
METHODS: Bone mineral density was assessed at the hip and lumbar spine by dual-energy x-ray absorptiometry (DEXA) between 1988 and 1992 and again 4 years later. BMD change was examined both as a continuous and a dichotomous (BMD loss vs no change/gain) variable. Incidence of osteoporosis was evaluated based on t -scores. Data were analyzed in 2002.
RESULTS: Annual BMD loss averaged 0.47% at the total hip and 0.34% at the femoral neck with an annual average of 0.22% gain at the spine. The rate of BMD loss at the hip and incidence of osteoporosis increased significantly with age. The main predictors of BMD loss were age >/=75 years, baseline BMI <24 kg/m(2), 4-year weight loss of >/=5%, current smoking, and physical inactivity. Moderate alcohol consumption showed some bone-sparing effect. Diuretic and calcium supplement use were not associated with bone loss.
CONCLUSIONS: Relatively healthy community-dwelling men lose bone with age, and men aged >/=75 years are particularly vulnerable. Potentially modifiable characteristics such as low body mass, weight loss, smoking, and physical inactivity were important predictors of bone loss and should be considered for the prevention of osteoporosis in men.