musculoskeletal and connective tissue disorders
Osteoporosis
Risk Factors for Osteoporosis
Because mechanical stress, including weight bearing, is necessary for bone growth, immobilization or extended sedentary periods result in bone loss. A low body mass index predisposes to decreased bone mass. Insufficient dietary intake of calcium, phosphorus, magnesium, andvitamin Dpredisposes to bone loss, as does endogenous acidosis. Tobacco and alcohol use also adversely affect bone mass. A family history of osteoporosis, particularly a parental history of hip fracture, also increases risk. Patients who have had one fragility fracture are at increased risk of having other clinical (symptomatic) fractures and clinically asymptomatic vertebral compression fractures. Certain populations, including White and Asian people, have been thought to have a higher risk of osteoporosis than other groups. However, these purported population differences are coming into question because of newly understood difficulties in sorting individuals into population groups. 