Determinants of mortality were studied in a prospective study of 677 women and men with primary or secondary osteoporosis. Prevalent vertebral fractures were associated with increased mortality, but other known predictors of mortality explain a significant proportion of the excess risk.
Introduction: In population studies, prevalent vertebral fractures are associated with increased mortality. It is unknown whether this excess mortality is related to low bone mineral density or its determinants or whether there is an additional component associated with fracture itself.
Methods: We studied 677 women and men with osteoporosis, 28-88 years old, of whom 352 had morphometrically determined vertebral fracture, to examine the risk and causes of mortality in patients with osteoporosis (defined densitometrically as a spine bone mineral density T-score < -2.5 and -3.0 for women and men, respectively, and/or one or more prevalent vertebral fractures without a history of significant trauma). The participants had enrolled in a double-blind placebo-controlled study in osteoporosis and were comprised of 483 women with postmenopausal osteoporosis, 110 women with secondary osteoporosis, and 84 men with osteoporosis of any cause. Demographics, medical history, and other measures of skeletal and nonskeletal health status were assessed at entry.
Results: During a median follow-up of 3.2 years, 37 (5.5%) participants died, with 31 of these deaths occurring in those with prevalent vertebral fractures. Compared with participants who did not have a prevalent vertebral fracture, those with one or more fractures had a 4.4-fold higher (95% CI, 1.85, 10.6) mortality rate. After adjustment for predictors for poor health--including number of medications, number of diseases, use of oral corticosteroids, alcohol intake, serum albumin and erythrocyte sedimentation rate (ESR), renal function, height, weight, gender, and age--the point estimate of risk remained elevated but was no longer statistically significant (hazard ratio, 2.4; 95% CI, 0.93, 6.23).
Conclusions: Prevalent vertebral fractures in osteoporotic patients are associated with increased mortality. Other known predictors of mortality can explain a significant proportion of the excess risk.