Bone diseases
Author: Ann Brown
By their nature, bone, and connective tissue support rigid and soft tissues of the body, is subject to risk factors that may condition its stability and functional capacity.
1. The origin of the pathologies
There are metabolic disorders which affect bone health throughout our lives, most of which are caused by the increased number and activity of osteoclasts (bone tissue removed), which exceeds the capacity to compensate for the osteoblasts (bone forming cells).
Shares of many of the diseases that affect adults, such as osteoporosis and rheumatoid arthritis, are either a result of abnormal metabolism and bone remodeling, or the result of a chronic inflammatory process affecting the structure and function of bone.
Recent studies suggest that the onset and severity of these pathologies may be delayed or lessened if bone modeling is optimized during the early phases of life or if diets are supplemented adequately with certain nutrients that reduce the concentration of factors that alter skeletal health .
2. Osteoporosis
Osteoporosis is most common bone disease, manifested in 40% of Spanish women and 11% of men over 70 years. It is characterized by loss of bone mass, microarchitectural deterioration of bone tissue and increased fracture risk.
The relative impact of environmental and genetic factors in osteoporosis is not well defined: Epidemiological studies suggest that environmental factor is the most decisive, while studies on bone mass among brothers (twins) validate the role of genetic factors . With the rapid advancement of the Human Genome Project and biotechnology, will be possible to evaluate new genes involved in osteoporosis and fracture risk calculated for each individual in the context of environmental influences.
In postmenopausal women, lower estrogen concentrations in blood (from the cessation of ovarian activity) is accompanied by a negative balance in bone remodeling with bone loss. However, the amount of bone formed during each cycle of bone turnover decreases with age, regardless of gender. For men, the risk factors are steroidal anti-inflammatory treatment, the snuff, drinking excessive alcohol and hypogonadism.
There are other manifestations of osteoporosis, such as the glucocorticoid-induced (the type of secondary osteoporosis more common), juvenile idiopathic (characterized by fractures of long bones and vertebrae in prepubertal boys and girls), osteoporosis in rheumatic diseases, diabetes, hyperthyroidism, cancer …
3. Rickets and osteomalacia
Vitamin D deficiency is the leading cause of rickets in children and osteomalacia in adults. The defects in bone mineralization, vitamin D deficiency associated with secondary hyperparathyroidism, increased mobilization of bone matrix and the risk of osteoporosis.
Rickets is caused by a failure to deposit bone mineral substance in the osteoid (uncalcified young bone) and epiphyseal cartilage during the first years of life.
Osteomalacia is a rare bone disease characterized by a generalized disorder of bone mineralization, which leads to unmineralized bone matrix in the skeleton (bone “soft”). In children with rickets is accompanied by widening of the epiphysis (ends of long bones) and abnormal bone growth.