Age changes in the bone mineral of the lumbar spine in normal women.

The bone mineral content (BMC) and the bone mineral areal content (BMAC) were determined with dual-photon absorptiometry in the third lumbar vertebra in a random sample of 214 women between 35 and 80 years of age in the city of Göteborg, Sweden. A continuous aging decrease (1%/year) of both the BMC and the BMAC was noted after age 35. The rate at which bone loss occurred was similar for all age groups when analyzed by 5 year intervals. No clear acceleration of bone loss was noted around the usual time of the menopause.