ABSTRACT
Osteoporosis is a metabolic disease characterized by a disturbance in the quantity of bone tissue. In osteoporosis, in contrast with other metabolic disorders such as rickets and osteomalacia, the ratio of inorganic (hydroxyapatite crystals) to organic substance (matrix and collagen) is kept constant. Cancellous bone is affected to a greater extent compared to cortical bone, and this is due to the fact that 80% of the bone metabolism occurs in the cancellous bone, while the remaining 20% occurs in the cortical bone. In young adults and in premenopausal women, the formation and absorption of bone occur at the same rate, resulting in the maintenance of bone mass over time. Bone loss is a chronic process that starts after the fourth decade of life (1). The deficiency of estrogen and progesterone observed in menopause causes an increased rate of bone remodeling in which bone resorption predominates formation. Therefore, this negative balance results in bone mass loss and leads to postmenopausal osteoporosis (2,3). Particularly, an intensification in the loss of bone mass is observed the first 5–10 years after menopause (3–5).
