Peak Bone Mineral Density Research Articles

Bone mineral density in French Canadian women.

This cross-sectional study investigated bone mineral density (BMD) at the lumbar spine (L2-4) and femoral neck in French Canadian women residing in the Quebec city area. Data collection was initiated in 1988 and completed in 1994. A total of 747 French Canadian Caucasian women (16-79 years of age) with no metabolic bone disease were evaluated. BMD measurements were obtained using dual-photon absorptiometry (DPA) or dual-energy X-ray absorptiometry (DXA). Anthropometric measures such as weight, height and body mass index (BMI) were recorded. Medical files provided information on demographic characteristics, hormonal profile and lifestyle habits. Results show a curvilinear trend of BMD with aging. Furthermore, the peak BMD at the lumbar spine (L2-4) was reached at 29 years followed by a stable phase until 35 years, after which BMD started to decrease. The pattern of bone evolution at the femoral neck was different, peak BMD being achieved earlier, at 21 years, while after age 26 years a significant decrease was already observed. Women older than 60 years showed the lowest BMD. Regression analysis showed that age, weight and height are determinants of BMD at the lumbar spine and explained 33.9% of inter-individual variation. At the femoral neck, 29.1% of variation was explained by age and height only. In conclusion, our data suggest that French Canadian women have a different pattern of bone loss at the femoral neck compared with the lumbar spine, according to their mean BMD values.

Assessment of Primary and Salvage Lateral Mass Screw Insertion Torque in a Cadaveric Model

This study was performed to determine the insertion torques of three types of lateral mass screws and to explore their relationship to bone mineral density (BMD). The peak insertion torque of primary articular screws was measured, and the holes were then stripped by overtightening. Larger diameter salvage screws were placed in the stripped holes, and peak insertion torque was measured. Peak primary screw insertion torque and BMD were positively correlated (r = 0.48, p = 0.00001). The ratio of salvage to primary screw insertion torque varied significantly among the systems (p = 0.0003). The positive correlation between BMD and primary screw peak insertion torque confirms the importance of bone density for satisfactory screw purchase. The large variation in the ratio of salvage to primary screw insertion torque among systems may be due to differences in primary and salvage screw design.

Assessment of Primary and Salvage Lateral Mass Screw Insertion Torque in a Cadaveric Model

This study was performed to determine the insertion torques of three types of lateral mass screws and to explore their relationship to bone mineral density (BMD). The peak insertion torque of primary articular screws was measured, and the holes were then stripped by overtightening. Larger diameter "salvage" screws were placed in the stripped holes, and peak insertion torque was measured. Peak primary screw insertion torque and BMD were positively correlated (r = 0.48, p = 0.00001). The ratio of salvage to primary screw insertion torque varied significantly among the systems (p = 0.0003). The positive correlation between BMD and primary screw peak insertion torque confirms the importance of bone density for satisfactory screw purchase. The large variation in the ratio of salvage to primary screw insertion torque among systems may be due to differences in primary and salvage screw design.

Bone Mineral Density in Normal Chinese Men and Women in Singapore

169 men and 267 women aged 20 to 69 years had bone mineral density measured in the lumbar spine and femoral neck by dual energy X-ray absorptiometry (DXA). The male subjects were significantly taller and heavier than the female subjects. However, there was no significant difference in body mass indexes of males and females. In males, the regression of age on lumbar spine and femoral neck BMD was linear, with peak BMD attained in the 20–29 age group. In females, peak BMD occurred in the age group 30–39 years. The regression of BMD with age in females was best fit by a cubic regression curve. There was no difference in peak spine BMD (1.176 ± 0.121 g/cm2 for males versus 1.221 ± 0.129 g/cm2 for females; p < 0.01). However, males were found to have significantly higher peak BMD in the femoral neck (1.052 ± 0.119 g/cm2 for males versus 0.949 ± 0.108 g/cm2 for females; p < 0.01). When our data was compared to the reference database from the American and Japanese populations, it was found that Chinese women in Singapore and American women had similar BMD values and both groups had significantly higher BMD than the Japanese in both the lumbar spine and femoral neck.

9 Osteoporosis in men

Hip fractures in men account for one third of all hip fractures and have a higher mortality than in women. The public health burden will increase as the increase in the numbers of elderly men in the community increases. In addition, the age-specific incidence of hip fractures may be increasing in some, but not all, countries. Vertebral fractures may be a public health problem as recent studies suggest that the prevalence in the community is 20-30%, similar to that reported in women. Forearm fractures should probably not be regarded as a public health problem. Peak bone mass is higher in men than women because men have bigger bones. Peak bone mineral density is the same. The amount of trabecular bone lost at the spine and iliac crest during ageing is similar in men and women. Cortical bone loss is less in men because endocortical resorption is less and periosteal formation is greater. Bone loss accelerates in elderly men because endocortical resorption and increasing cortical porosity increase the surface available for resorption. Bone fragility is less in men than women because: (a) the cross-sectional surface of the bone is larger; (b) trabecular bone loss is less as a percentage of the higher peak bone mass; (c) trabecular bone loss occurs by thinning rather than perforation; and (d) periosteal appositional growth compensates for endocortical resorption by maintaining the bending strength of bone. Reduced BMD in men with fractures may be due to reduced peak bone size and mass, and bone loss. Bone loss occurs by reduced bone formation. Whether men with fractures have increased bone fragility due to reduced periosteal appositional growth during ageing is unknown. The age-related decline in testosterone, adrenal androgens, growth hormone, and insulin-like growth factor 1 may contribute to reduced bone formation and bone loss. Men with vertebral fractures often have hypogonadism or illnesses with few clinical features that should be considered with a high index of suspicion (alcoholism, myeloma, malabsorption, primary hyperparathyroidism, haemochromatosis, Cushing's disease). Secondary hyperparathyroidism may contribute to bone loss by activating bone turnover and so increasing the number of bone remodelling units with impaired bone formation in each. There is no proven treatment for osteoporosis in men because there have been no trials using anti-fracture efficacy as an end point. Testosterone replacement should be considered in men with proven hypogonadism and vitamin D deficiency should be corrected if present. Calcium supplements and bisphosphonates are reasonable options given the lack of information.

Normal data for lumbar spine bone mineral content in healthy Chinese men.

The aim of this study was to evaluate the influence of age on bone mineral density (BMD) of teh lumbar spine for health Chinese men. In 430 healthy Chinese men (ages 20-92 years) living on Taiwan, BMD at the level of the 2nd to 4th lumbar vertebraes (L2-L4) was determined with a commercial dual-energy X-ray absorptiometer (DXA). Our study found that the peak BMD value of lumbar spines of healthy Chinese men was 1.056 +/- 0.127 g/cm2 which occurs from age 20 to 29. The results show that a linear correlation between the age and BMD of lumbar vertebraes for healthy Chinese is notable. Only slight decreases of BMD values in the different age groups are found. In comparison with the normal data of white men and Asian men from Japan and Korea, the mean BMD values of lumbar spines of Chinese men seem to be lower than those of the white, Japanese, and Korean men of the same ages. Our findings indicate that the influence of age and ethnicity may exist in the BMD values for healthy Chinese males.

Current and potential future drug treatments for osteoporosis.

There has been a major interest in the drug treatment of osteoporosis and an increase in the number of drugs available in most countries. The ideal drug (one which increases or restores bone density and trabecular connectivity) is still not available. However, in patients with relatively preserved trabecular connectivity and moderately reduced bone density, several agents have shown substantial clinical benefit. Oestrogens are still the mainstay of drug treatment, but the risks of breast cancer versus the cardiovascular and skeletal benefits with long term use have to be assessed in the individual. Newer tissue specific oestrogens show some promise in this respect. The bisphosphonates and possibly fluoride are likely to be the major alternatives to oestrogens in the medium term. The newer bisphosphonates, alendronate and in the future risedronate, are likely to supersede etidronate. Calcitriol probably has a limited role, confined to those patients in whom HRT or bisphosphonates are not appropriate. Calcium supplementation, or an increase in dietary intake if deficient, irrespective of which agent is used, is also of benefit. In older patients there is considerable support for using a combination of calcium and vitamin D. Whether combination treatment, for example oestrogens, bisphosphonates, and calcium together, will result in greater efficacy remains to be conclusively shown, but may be an attractive option in younger patients with higher bone turnover. Apart from fluoride, bone formation stimulators are unlikely to have a major role until the next century, although it may be possible to use growth factors as part of an ADFR regimen (A = activate remodelling, D = depress resorption, F = free formation, and R = repeat). This is still an important theoretical approach and needs further work with newer agents to see if increased efficacy can be found. In addition sequential treatment may be necessary in view of the limited time periods over which particular agents, such as intermittent fluoride (four years), have been examined, and this will have to be individually tailored. Other approaches include trying to increase peak bone mineral density, although influencing the young to prevent a disease that may not manifest itself for half a century is daunting.

It pays to look after your bones!

Osteoporosis, defined as abnormally low bone density, results in increased risk of fractures with consequent increase in morbidity and mortality. An important determinant of age‐related fractures is low bone density. Current public health strategies aim to maximize bone mass in elderly people, yet the bone mass obtained in the first three decades of life is a major determinant of bone mass later. Up to half the variation in peak adult bone mass among women is non‐genetic and is influenced by lifestyle factors such as physical activity, calcium nutrition and sex hormone status. These factors were studied in surveys of a school age population of girls in Bournemouth. Using a seven‐day dietary diary, the mean daily calcium intake of 11‐12 year olds was calculated as 692.9mg (SD 209.91mg). Of the total population surveyed, 14.6 per cent had calcium intakes below the UK dietary reference values. Up to 1,500mg calcium per day in adolescence has been recommended to increase peak bone mineral density. Weight bearing activity accounted for approximately 16 per cent of daily activities. Additional information was collected on perception of body weight and dieting habits. An osteoporosis prevention health education package was produced for local teenage school children with the message that “It Pays to Look after Your Bones!” by promoting calcium nutrition and exercise.

Prevalence of osteopenia and osteoporosis in a control female puerto rican population

The World Health Organization criteria for the diagnosis of Osteopenia and Osteopoposis was applied to a control group of 33 females ages 50 to 59 years and 24 females ages 60 to 69 years. The general exclusion criteria for the selection of subjects included early menopause and diseases, use of drugs and toxic habits such as smoking and alcoholism, known to affect bone and mineral metabolism. Bone mineral densities were measured with a DEXA Hologic, model 1000. In the reference population mean peak bone mineral density expressed in g/cm2 was 1.051 (SD = 0.119) for the lumbar spine at age 30 to 39 years and for the femoral neck 0.861 (SD = 0.098) at age 20 to 29 years. Bone densities below 1 to 2.5 SD from mean peak bone mass ranged from 0.932 to 0.754 g/cm2 in the lumbar spine and 0.763 to 0.616 g/cm2 for the femoral neck. The mean age of the pooled group was 58.4 years. The prevalence of osteopenia in the pooled group was 42 % for the lumbar spine and 56% for the femoral neck and of osteoporosis, 12% for the lumbar spine and 8.7% for the femoral neck. A similar prevalence has been found by other investigators in hispanic populations. Such a high percentage of females with osteopenia implicates that bone densitometry must be done in the perimenopausal years and in young individuals at risk so as to proceed with early medical intervention to prevent osteoporosis.

Bone Mineral Density in Adolescents

Bone densitometry is becoming more widely available and is no longer limited to studying the elderly. Rapid, safe, and accurate methods of measuring BMD now allow serial determination of this important factor in fracture risk and will undoubtedly become even more accessible in the future. Likewise, our knowledge about the mechanisms and genetics of bone resorption and bone formation is rapidly expanding. Therefore, efforts to prevent osteoporosis in later life by maximizing peak BMD during adolescence and young adulthood must be directed at identifying young people who are at risk because of low body weight, inactivity, inadequate calcium intake, sex hormone deficiency, or because of disease or treatments associated with reduction of BMD. If BMD is found to be low, efforts to enhance bone formation (eg, weight gain, weightbearing exercise, increased calcium intake, and effective treatment of the underlying illness) should be encouraged. Antiresorptive agents, such as sex hormones, should be used cautiously, since they can have significant side effects and may not produce the expected results. Pediatricians must keep in mind the axiom: osteoporosis ... the only cure is prevention.

Peak bone mass in young women.

Increasing peak bone mineral density (BMD) or content (BMC) in young women may help to reduce the incidence of osteoporosis. Identifying the age when peak bone content or density is attained is essential to develop strategies aimed at optimizing peak BMD and BMC. Total body bone mineral density (TBBMD) and content (TBBMC) were measured by a dual X-ray absorptiometer in healthy females (n = 247, aged 11-32 years). TBBMD and TBBMC were modeled separately as a nonlinear function of age. By age 22.1 +/- 2.5 years, 99% of peak BMD is attained, and by age 26.2 +/- 3.7 years, 99% of peak BMC is attained. Nonlinear relationships between weight and TBBMD or TBBMC were also modeled. In this model, the influence of several parameters, including age, weight, and height, on BMC and BMD were simultaneously assessed. A model with age and weight described the best fit for TBBMD, whereas age, weight, and height described the best fit for total body TBBMC.

Bone mineral density of total body, spine, and femoral neck in children and young adults: A cross-sectional and longitudinal study

Bone mineral density (BMD) of total body (TBMD), lumbar spine (L2-4), and femoral neck was measured in 266 normal subjects (136 males) aged 4-27 years (mean 13 years) using dual-energy x-ray absorptiometry (DXA). BMD of all sites increased significantly with age until 17.5 years in males and 15.8 years in females, except for femoral neck BMD in females, which peaked at age 14.1 years. Males had higher peak TBMD, which was attributed to greater weight and lean tissue mass. In contrast, despite a later timing, peak L2-4 BMD in males was not different from that in females. Before peak BMD, weight was the best predictor of TBMD and L2-4 BMD in both sexes (r2 ranged from 0.77 to 0.88), whereas femoral neck BMD was predicted equally by height and weight. Longitudinal information collected from 53 (25 boys) of these children, aged 4-16.9 years, showed that the average annualized gain in TBMD was 0.047 g/cm2 for boys and 0.039 g/cm2 for girls. No significant difference in the association between age and BMD (slopes) was found between cross-sectional and longitudinal data for either sex. We conclude that the timing for peak BMD was consistent for total body, lumbar spine, and femoral neck for each sex. The earlier peak BMD in females is most likely related to earlier puberty. The cross-sectional normative data of this study are useful in serving as a standard for serial assessment in health and disease states.

A study of bone mineral density versus age in Omani women and a comparison with normal British women

Dual photon absorptiometry (DPA) of the lumbar spine (2nd, 3rd and 4th lumbar vertebrae) was carried out using a Norland 2600 bone densitometer on 194 Omani women (OW). The exclusion criteria were (1) any medical treatment known to affect calcium metabolism or bone mass, (2) osteomalacia or secondary osteoporosis, (3) the presence of osteophytes or compression fractures of the lumbar vertebrae and (4) the presence of aortic calcifications. The bone mineral density (BMD) results showed a peak value occurring in the 30-35 year old age range (mean 1.1 g cm-2, standard deviation 0.1). The data were compared with a group of 165 normal British women (BW) with a similar age distribution whose peak BMD (obtained with dual X-ray absorptiometry) occurred in the 40-45 year old age range. The two groups were compared in each 10 year age range and the BMD of the OW group was found to be significantly lower in the 40-49 year old age range (P < 0.01) as well as the 50-59 and 60-69 year old age ranges (P < 0.001).

Peak Bone Mineral Density in Young Women

<h3>To the Editor.</h3> —Lloyd et al¹showed that increasing daily calcium intakes from 80% of the recommended daily allowance to 110% via supplementation with calcium citrate malate resulted in significant increases in total body and spinal bone density in adolescent girls. This is an important addition to the growing body of evidence showing that greater peak skeletal mass can be achieved by consciously increasing calcium intakes above those usually chosen by females during growth and development. Lloyd et al cite our article,²"Bone Gain in Young Adult Women," but misrepresent our work by

Peak bone mineral density in young women

Peak bone mineral density in young women

Peak Bone Mineral Density in Young Women-Reply

In Reply. —The comments by Drs Recker and Heaney call to attention our incomplete understanding of the dynamics and probable variation in the peak bone mass concept. From the three recent cross-sectional studies 1-3 of bone density among a total of 197 young women, aged 9 to 21 years, peak lumbar spine and peak femoral neck bone density were observed for between 15 and 18 years. From the two large cross-sectional studies 4,5 using a total of 694 women, aged 20 to 40 years, no peak was observed for lumbar spine or femoral neck bone density after age 20 years. From their longitudinal study of 98 young women aged 9 to 19 years, Theintz and coworkers 6 observed cessation of lumbar spine and femoral neck bone gain by age 18 years. In contrast, Recker and Heaney reported that cessation of total body and spinal bone mineral gain occurred at about age

Apparent velocity of ultrasound (AVU) at the patella in comparison to bone mineral density at the lumbar spine in normal males and females

It has been reported that apparent velocity of ultrasound (AVU) at the patella discriminates as well between osteoporotic and normal subjects as measurement of bone mineral density (BMD) using dual photon absorptiometry. To investigate the relationship between AVU and peak bone mass, we compared AVU (Signet™, Osteo-Technology, Framingham, MA) at the patella and BMD (QDR 1000™, Hologic, Waltham, MA) at the lumbar spine in a large sample of healthy males and females. The study population consisted of 153 males (aged 20–60 years) and 129 premenopausal females (aged 20–52 years). Vertebral BMD showed no significant difference between males and females (1.03 ± 0.16 g/cm 2 for males vs. 1.07 ± 0.14 g/cm 2 for females, NS), while AVU values were significantly higher in males compared with females (1967 ± 64 m/s vs. 1938 ± 76 m/s, P < 0.05). In men there was a significant decrease in BMD with aging ( r = −0.27, P < 0.05), in premenopausal females we found no age-related change in BMD. Similarly in males AVU decreased significantly with age ( r = −0.2, P < 0.05), whereas in females AVU values showed relative stability over the age range. There was a significant correlation between AVU and BMD ( r = 0.36 for males, r = 0.34 for females, P < 0.05). Our study demonstrates only a weak correlation between AVU at that patella and BMD at the lumbar spine, supporting the view that AVU not only reflects bone quantity but possibly also qualitative properties of bone structure. The sex difference in AVU but not in BMD suggests that the trabecular bone at the patella differs significantly from axial trabecular bone. The identical peak BMD at the lumbar spine for young males and females underscores the importance of the menopause for later manifestation of vertebral fractures.

Epidemiology of bone mass in premenopausal women.

The belief that optimal bone mass counters considerable bone loss during the perimenopausal period has led to much research to depict premenopausal bone mass and to identify factors which optimize it. Research consistently shows that genetics play a strong role in peak bone mineral density. In fact familiality explains 10% to more than 50% of premenopausal bone mass. Studies of bone density levels in ovariectomized and amenorrheic women indicate that estrogen is needed to maintain premenopausal bone mass. The link between reproduction and estrogens role is not yet clear however. Strenuous exercise in amenorrheic women is related to bone loss. On the other hand moderate physical exercise in women with normal menstruation patterns optimizes premenopausal bone density within each womans genetic potential. A possible intervention to reduce bone loss is through the diet especially calcium intake. Yet the levels of nutrients and the timing of dietary intervention are not clear. Current recommended levels of nutrients have not been disproved however. Longitudinal studies are needed to determine what happens to premenopausal bone mass levels during the perimenopausal period. These studies would be especially useful if they could identify characteristics of women who lose bone rapidly and of those who lose it slowly. Future research needs to identify the time for and length of maximum mineralization of bone. Knowing this would help prevention programs increase their effectiveness. Future research also needs to determine what factors are related to differences in premenopausal bone density. Research activities that determine the contribution of nutrition exercise and reproductive events (pregnancy nulliparity parity lactation) must continue. They should also examine possible interactions between these factors. They must consider sample size and selection of controls.

Osteopenia in Men with a History of Delayed Puberty

The effect of delayed puberty on peak bone mineral density in men is unknown. To determine whether such a delay reduces normal peak bone density and leads to osteopenia during adulthood, we measured radial bone mineral density by single-photon absorptiometry and spinal bone mineral density by dual-energy x-ray absorptiometry in 23 men who had a history of constitutionally delayed puberty and 21 men who underwent normal puberty. Their mean ages were 26 and 24 years, respectively. The groups were matched for other factors known to affect bone mass. The mean (+/- SD) radial bone mineral density was significantly lower in the men with a history of delayed puberty than in the normal men (0.73 +/- 0.07 vs. 0.80 +/- 0.05 g per square centimeter; P less than 0.0002). Spinal bone mineral density was also significantly lower in the men with delayed puberty than in the normal men (1.03 +/- 0.10 vs. 1.13 +/- 0.11 g per square centimeter; P less than 0.003). Radial bone density was at least 1 SD below the mean value for the normal men in 15 of the 23 men with a history of delayed puberty, and spinal bone density was similarly decreased in 10 of the 23. Adult men with a history of constitutionally delayed puberty have decreased radial and spinal bone mineral density. These findings suggest that the timing of puberty is an important determinant of peak bone density in men. Because the peak bone mineral density achieved during young adulthood is a major determinant of bone density in later life, men in whom puberty was delayed may be at increased risk for osteoporotic fractures when they are older.

Hip mineral density in females with a recent hip fracture.

To evaluate the role of local bone mineral density (BMD) in the etiology of hip fractures, we measured the hip BMD using dual photon absorptiometry in 29 females who had recently suffered a hip fracture associated with minimal or moderate, but not major, trauma and compared their BMD to those of 14 young normal females, 58 early postmenopausal normal females, 13 age-matched normal females, and 114 spinal osteoporotic females without a hip fracture. Hip-fractured patients had a BMD significantly lower (P less than 0.001) than that of all other studied groups, suggesting that a low hip BMD is associated with hip fracture risk. A femoral neck BMD below 0.75 g/cm2 suggests an increased likelihood for developing a hip fracture. Peak BMD was measured at 1.03 g/cm2, a value comparable to published normative data. Thus, a loss in hip BMD of approximately 30% from peak mineral density appears necessary before a hip fracture may occur after moderate trauma.