Risk for developing osteoporosis in untreated premature menopause.

The bone mineral density (BMD) of the lumbar spine and proximal femur was determined by dual photon absorptiometry in 32 women with untreated premature menopause (cessation of menses before 45 years of age). The BMD of the spine and proximal femur in four obese patients was not different from the BMD of the age-matched controls. On the contrary, the BMD of the nonobese females with premature menopause was significantly lower with respect to the average values found in healthy young women, in age-matched and menopause-matched controls. The BMD deficit was greater over the lumbar spine than in the proximal femur. Forty three percent of nonobese patients were already under the vertebral fracture threshold and 25% of nonobese patients were below the hip fracture threshold. The BMD deficit in the lumbar spine was correlated to the loss observed in the femoral neck (r = 0.59, P less than 0.001), in the trochanter (r = 0.65, P less than 0.001) and in the Ward's triangle (r = 0.73, P less than 0.001). A negative correlation was observed between years of menopause and the BMD of the lumbar spine (r = -0.39, P less than 0.05). The results indicate the high individual risk for osteoporotic fractures in nonobese females with untreated premature menopause. The BMD loss was greater over the skeletal areas that are predominantly composed of trabecular bone compared with cortical bone.