Osteoporosis has become an increasingly important health problem in the United States affecting 24 million Americans-mainly women-after age 45. It is responsible for more than 1.5 million fractures annually with 500,000 vertebral fractures, 300,000 hip fractures, 200,000 wrist fractures and 300,000 fractures at other sites.

Approximately 37,500 people die of complications related to osteoporosis and hip fractures. The direct medical cost associated with hip fractures is estimated to be between $5.4 billion and 7.4 billion. Costs are escalating incrementally as more people live longer lives, leading to a projected rate of 840,000 fractures by the year 2040.¹

Starting Prevention

In the United States, roughly one in four women and one in eight men more than 50 years of age have osteoporosis. Postmenopausal osteoporosis in 20 percent of women is directly related to estrogen deficiency with peak incidence in their 60s and 70s. Women can lose around 35 percent of their bone in the first five years after menopause, and nearly 50 percent of their trabecular bone and 35 percent of their cortical bone throughout their lifetime. Men lose about 25 percent of both types of bone.

The two major factors that impact the development of osteoporosis are peak bone mass and rate of bone loss. Peak bone mass is achieved between 18 and 25 years of age.²Prevention needs to begin early in life, with teenagers being taught the importance of weight-bearing physical exercise and a diet rich in calcium. Adequate intake of vitamin D is also an important element of good bone health. Menopausal women need to be aware of their risk factors, get a screening test, and start supplementation and increased physical exercise to avoid the major consequences of osteoporosis later in life.

Bonjour et al studied peak bone mass during puberty and found that there was a significant sex-related difference in the bone mineral density (BMD) at both the lumbar and femoral diaphyses, becoming apparent in pubertal maturation.³There is asynchrony in structural height gain and bone mass production. This transient phase may create a slight increase in fractures in adolescence.

Baroncelli and Saggese also confirmed that puberty is one of the main factors influencing lumbar bone content and BMD accumulation. There may be a period of reduced BMD, creating a higher incidence of fractures during this period.⁴

The Exercise Effect

Pettersson et al studied the effect of high-impact activity on bone mass and size in adolescent females.⁵They took three different groups of adolescent girls 17.8 +/-0.8 years and had one group doing competitive rope-jumping for six to seven hours per week, the second group playing soccer for six to eight hours per week and a third control group doing physical activity from 0.9 to 1.1 hours per week.

They found that the jump-rope group had the highest BMD, better bone geometry and greater muscle strength. Weight-bearing activities were therefore concluded to be a major determinant of the quality and quantity of bone mass development.

Katoo, Yamashita et al recently looked at whether adolescent exercise had any effect on the BMD of middle-aged menopausal women.⁶They did a cross-sectional comparison of women over age 60, dividing them into two groups. Group one included women who had done some sport participation or engaged in high-impact physical activity during their growth between ages 12 and 18, and a second group of low-impact or non-weight-bearing sports (such as swimming) or had no participation at all. Measurement via DXA (bone density) and MRI showed that adolescent weight-bearing exercise exerted a preservation effect even after 40 years.

Douchi and Yamamoto et al looked at the effects of physical exercise on body fat distribution and BMD in post-menopausal women.⁷They compared one group of 60+ women who had exercised regularly for at least two years with a group who was sedentary. Their results showed that exercise had a beneficial effect, both in reduction of upper-body fat and increase in BMD.

Nutrition Factors

Pinheiro et al, in their BRAZOS (The Brazilian Osteoporosis Study) in 2009, found that inadequate nutrients were related to osteoporotic fractures in men and women.⁸They surveyed 2,420 individuals for more than 40 years and examined the association between their nutrient intake (especially phosphorus, calcium and magnesium) and presence of fracture. Their study demonstrated that for every 100 mg increase of phosphorus, the risk of fracture was increased by 9 percent. Phosphorus intake is related to a higher consumption of cola/sodas.

Cranney and Horsley et al looked at the effectiveness of vitamin D in relation to bone health.⁹They reviewed the literature for specific associations between circulating levels of 25 (OH) vitamin D concentration and bone-health outcomes in children, women of reproductive age, post-menopausal women and elderly men. They found a fair amount of evidence linking the association of rickets in children with low levels of vitamin D. In adolescents, there was a fair association with BMD and low levels of circulated concentration of vitamin D. In older adults, there was fair evidence that vitamin D levels were inversely associated with the number of falls, and a positive association with BMD. The combination of calcium supplementation with vitamin D showed a beneficial effect on the BMD of post-menopausal women.

Sacco et al looked at the effect of bone health with a combination of low-dose estrogen therapy and flaxseed.¹⁰Their aim was to determine the effects of 10 percent flaxseed, low-dose estrogen therapy and its combination on bone density in a model of ovariectomized rats to simulate post-menopausal women. They found that the greatest protection of lumbar bone density came from a combination of low-dose estrogen therapy combined with the lignans and alpha linoleic acids of flaxseed.

Hormone Therapy

Curran et al looked at estradiol and norgestimate as hormone replacement therapy in post menopausal women.¹¹They found that BMD increased significantly and the rate of bone turnover was reduced in post-menopausal women, with the administration of continuous estradiol plus intermittent oral progesterone (Norgestimate). This may be an effective option for hormone replacement therapy in post-menopausal women.

A University of Arizona study states that nine out of 10 teenage girls and seven out of 10 teenage boys do not get the recommended daily allowance of 1,300 mgm of calcium in their diets.¹²In addition, guzzling carbonated soft drinks that contain bone-damaging phosphates, poor nutritional choices and sedentary lifestyles set them up for higher risk in their later years for the development of osteoporosis.

Between 1995 and 2001, the University of Arizona conducted the Bone Estrogen Strength Training Study (BEST) following post-menopausal women with an average age of 55.6 years. Two hundred sixty-six healthy, non-smoking participants were put on a specific resistance exercise protocol and 800 mg of a daily calcium supplement. These women were followed up with regular bone-density measurements and their compliance with the calcium supplement.

This study showed that weight-bearing and? resistance exercises, combined with the calcium supplementation, significantly improved bone density at the skeletal sites that were at highest risk for fracture.¹³In light of these findings, it makes sense to target women at two crucial stages of their lives-the teenage years to ensure they are getting the maximum out of their peak bone mass development, and the menopause years to avoid loss of bone at this stage.

References are available at www.advanceweb.com/pt or on request.

Asha Bajaj has more than 30 years of experience in a variety of settings including the management and operation of an outpatient private practice in Walnut Creek, CA, from 1985-2004. She has served in Bhutan and India with Health Volunteers Overseas. Currently, she is involved with acute care in a hospital setting and an outpatient clinic.