The association between low bone mass at the menopause and cardiovascular mortality

Low bone mineral density in late postmenopausal women has been associated with increased nontrauma mortality. We investigated whether bone mass in women soon after menopause was also associated with the risk of mortality in later life.

Between 1977 and 1988, two samples of healthy women were enrolled; one group soon after the menopause (age 50 +/- 2 years [mean +/- SD], n = 309) and another later after menopause (age 70 +/- 2 years, n = 754). The baseline visit included a medical examination and a measurement of bone mineral content in the distal forearm. In 1994, vital status was checked. All causes of death were registered, excluding those that were due to trauma or suicide. Multivariate relative risks (RR) and 95% confidence intervals (CI) were determined.

In the early postmenopausal group, each decrease of one SD (0.4 g/cm) in bone mineral content was associated with a 43% increase in mortality (RR = 1.4; 95% CI 1.0 to 2.0; P < 0.05). When only cardiovascular death was considered, the relative risk of dying within 17 years of the menopause was increased 2.3-fold (95% CI 1.0 to 5.3; P < 0.05). Correspondingly, a 70-year-old woman with a bone mineral content 1 SD below the mean for her age had a 1.8-fold increased risk of dying from cardiovascular disease (95% CI 1.0 to 3.2; P = 0.06). Expressed as quartiles, women with bone mass in the lowest quartile had twice the risk of cardiovascular death compared with those in the highest quartile. A prevalent vertebral compression fracture in the late postmenopausal group was independently associated with cardiovascular death (RR = 2.0; 95% CI 1.4 to 3.3; P = 0.004).

Low bone mineral content at the menopause is a risk factor for increased mortality in later life, especially from cardiovascular disease.