WHAT IS OSTEOPOROSIS
The currently accepted definition of osteoporosis is “systemic skeletal disease characterized by low bone mass and micro architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture risk”.
Bone mineral can be measured with reasonable accuracy and precision. These tests form the basis for diagnosis of osteoporosis and the prediction of fracture risk.
Bone mass refers to the amount of bone tissue contained in the skeleton. Bone mass can be expressed in terms of bone mineral content (the total grams of bone mineral within a given area of bone) or in terms of bone mineral density (the bone mineral content normalized for the projected area).
Normally bone density peaks between the ages of 30 to 40 and in subsequent years the bone density decreases. If the decrease is significant enough, the so called “fracture threshold” is reached.
At this level of bone density the patient is at significant risk of fracture. These thresholds are reached at different ages and the extend of bone loss varies depending on the peak bone mass and generic and environmental factors, including activity level and diet.
The decrease of bone density in post-menopausal women is significantly greater than in pre-menopausal women or men. The average annual bone loss in post-menopausal women is 1% – 2% and in men 0.2% – 0.5%.
Although the rate of bone loss in women is the highest in the years after the menopause, it continues in many patients for many years and increases again after the age of 70. Annual losses can even reach 3% -5% during the first years following the menopause. In women the major cause of bone loss and osteoporosis is estrogen withdrawal, most commonly associated with the menopause and declining ovarian function, but any cause of estrogen deficiency can cause bone loss.
In men, androgen might play a role in causing osteoporosis. Here progressive loss of bone starts around the third decade and continues during life. There are many conditions other then estrogen or androgen deficiency that cause bone loss, including malignancies, metabolic abnormalities, gastrointestinal diseases and exposure to certain drugs. Also smoking and excessive use of alcohol may contribute to bone loss.
A study group of the World Health Organization (WHO) has proposed diagnostic guidelines for interpretation of bone mass measurement in Caucasian women.
Bone density values in individuals are expressed in relation to a reference in Standard Deviation (SD) units.
This reduces the problems associated with differences between the various measuring instruments; it does however require defined “normal” ranges.
If bone mineral density (BMD) is below 1 SD but not below 2.5 SD of the mean value of peak bone mass in young normal women, than there is a low bone mass (Osteopenia). If this value is greater than 2.5 SD below this value the patient has Osteoporosis.
This definition is definitely not perfect but reasonable well for diagnostic and therapeutic considerations. Osteoporosis is a-symptomatic until a fracture occurs.
The risk of fracture is inversely related to bone mass. As bone mass decreases, the risk of fracture increases. Even relatively small alterations in bone mass can lead to significant changes in the risk of fractures. The most common sites of fracture in osteoporotic patients are the vertebrae, the hip, and the forearm.
Osteoporotic fractures are associated with significant morbidity and mortality. The most important complaint of patients with osteoporosis is acute or intermittent back pain following normal activity. The pain usually lasts a few days or weeks and then subsides. Such episodes recur and may result in chronic backache. The episodes are due to crush fractures of vertebrae. As the disease progresses, loss of height, spinal deformity and fracture occur.
Hip fractures, in particular, frequently have grim prognosis. The mortality rate of osteoporotic hip fractures is between 15 % and 20 %, primarily due to pulmonary emboli, pneumonia, and other complications of surgery and prolonged hospitalization. The lifetime risk of hip fractures in white women is as great as the risk of breast, endometrial and ovarian cancer combined. One half of patients who survive a hip fracture are unable to walk unassisted and 25 % are confined to nursing homes. In up to 20 % of hip fractures the patient dies within 6 months.
A GROWING HEALTH PROBLEM
Osteoporosis is a major and growing health problem worldwide. It affects an estimated 75 million people in the United States, Europe and Japan, including a large amount of men. One-third of women over 65 will have vertebral fractures and 90 % of women over the age of 75 have an evidence of osteoporosis.
The enormity of this health problem when considering the increasing population of elderly people in the world is contrasted by the present therapeutic difficulties in significantly adding bone and improving bone strength once it has been lost. Osteoporosis will become an even more serious public health problem. Osteoporosis related fractures can be expected to double during the next 5 decades. It is also expected that the occurrence of osteoporosis in men will increase.
ELECTRO-MAGNETIC FIELD TREATMENT
Selected low-energy time-varying electromagnetic fields have been used during the past 15 years to treat un-united fractures (non-unions). More than 100,000 patients, mainly in the USA, have been treated. Retrospective studies have substantiated their biological effectiveness in large numbers. Bone is responsive to the mechanical demands placed on it. When loading diminishes, as it does during bed rest, immobilization and weightlessness, bone mass is lost. On the other hand when loading is increased correctly, bone mass increases.
Results of bio-mechanical and histologic investigations prove that electromagnetic fields not only prevent bone loss, but also restore bone mass, once lost. A program was set up at McGill University of Montreal, where was found that electro-magnetic fields damp bone resorption activity. Furthermore prove was found that selected electro-magnetic fields increase bone formation. The resorption of bone is lowest and formation of new bone greatest, when energy of the imposed fields is concentrated in the lower frequency components.
These results are consistent with other studies showing, that cells respond to a broad spectrum of frequencies. They appear to be most sensitive to frequencies in the range of those produced endogenously, that is in the range of 1000 Hz or less. Tissue dosimetry studies show that the frequency response of cortical bone over a range of 100 Hz to 20 kHz shows a steep roll off between 100 and 200 Hz.
Electro-magnetic fields at specific frequencies have shown to produce osteogenic effects in a turkey ulna model. Furthermore low-amplitude signals decrease bone resorption in a canine fibular model.
Lifestyle factors like malnutrition, smoking, excessive use of alcohol and a sedentary lifestyle contribute to, and worsen, osteoporosis. It is not known whether this response derives from decreased osteoblastic activity, increased osteoclastic resorption, or both.
Elderly persons can heal fractures in normal intervals, showing that osteoblasts can be activated by appropriate stimuli.
A pilot study at the Pacific Health Research Institute in Honolulu was designed to provide concrete data on the restoration of bone mass in postmenopausal females. A total of 20 subjects between 57 and 75 years, all with decreased bone mineral density as defined by a bone densitometer, were treated during a period of 12 weeks. After a period of 6 weeks the bone density rose in those patients with an average of 5.6%.
Electromagnetic fields do modify biological behavior by inducing electrical changes around and within the cell. The key to rational use of electro-magnetic fields lies in the ability to define the specific treatment parameters (amplitude, frequency, orientation and timing).
Various studies have clearly shown that bone density does increase in Osteoporosis-prone patients exposed to specific pulsed electromagnetic Fields. Properly applied pulsed electromagnetic fields, if scaled for whole body use, have clear clinical benefits for treatment of osteoporosis.
WHAT IS OSTEOPOROSIS