Hormone replacement therapy and bone mineral density: a co-twin approach

OBJECTIVE: Our objective was to estimate the difference in bone mass at clinically relevant sites within female twin pairs who were discordant for use of hormone replacement therapy (HRT). METHODS: We studied 46 female twin pairs who were discordant for HRT use. Bone mineral content and density were measured at the lumbar spine, total hip, femoral neck, 13 total forearm, and the total body. HRT use, calcium intake, physical activity, alcohol intake, and lifetime smoking were determined by questionnaire. RESULTS: Within a pair, lumbar spine bone mineral density was significantly greater in past and current HRT users compared with nonusers (6.2% +/- 2.0%; P = 0.006). In those pairs who were currently using HRT, the within-pair difference in lumbar spine bone density was 7.8% +/- 2.1% (P = 0.002), and a significant within-pair difference in forearm bone density (5.1 +/- 2.1%; P = 0.02) was apparent. A significant difference (4.6%; P = 0.03) was observed in total body bone mineral content when an adjustment was made for age, lean mass, fat mass, and height. CONCLUSIONS: In keeping with randomized clinical trial findings, these results indicate that HRT in routine clinical use protects significantly against menopausal bone loss at the lumbar spine and the forearm. Our results also quantify the magnitude of the benefit of HRT on bone density that might be anticipated in clinical practice.     

Peripheral and axial bone mass in Austrian free climbers

Summary The present investigation was carried out in healthy white adult males to determine the effects of exercise, in the form of free climbing, on peripheral and axial bone mass.13 men who have been regularly engaging in alpine free climbing for a mean period of nine years and, for training purposes, have been performing additional muscle building exercises (4.5 h±1 SEM per week) and 12 age matched controls were included in the study. Bone mineral content of the non-dominant distal forearm was measured by single-photon absorptiometry, and bone mineral density of the lumbar spine was determined by quantitative computed tomography.It was found that consistent exercise in the form of alpine free climbing was associated with increased bone mass of the lumbar spine (162.4 ±4.4 vs 184.8 ±7.9 mg/ml, p< 0.025). Peripheral bone mineral content of the distal forearm was slightly but not significantly increased in the free climbers (55.4 ±9.0 vs 61.1±7.4 Units, p<0.09 N.S.).The study provides additional evidence that exercise in the form of alpine climbing, is associated with increased lumbar bone mass.Abbreviations BMC bone mineral content - SPA single-photon absorptiometry - BMD bone mineral density - QCT quantitative computed tomography     

Peripheral quantitative computed tomography (pQCT) is useful for monitoring bone mineral density of the patients who receive hormone replacement therapy

OBJECTIVE: A forearm fracture (Colles' fracture) is often the first sign of osteoporosis and should alert the patient and physician to the possibility of underlying skeletal fragility. Therefore, the establishment of a more accurate and reliable method for the measurement of bone mineral density (BMD) at the distal radius would be beneficial for the patients who suffer from osteoporosis. The objective of the present study was to evaluate the usefulness of peripheral quantitative computed tomography (pQCT) to assess the change of BMD at the distal radius in early postmenopausal women who receive hormone replacement therapy (HRT). METHODS: Twenty healthy early postmenopausal women who were diagnosed as osteoporosis or osteopenia were randomized to either HRT or placebo treatment. We analyzed BMD of the distal radius by pQCT, lumbar spine by dual-energy X-ray absorptiometry (DXA) and the biochemical markers of bone turn over (osteocalcin, deoxypyridinoline) every 6 months. RESULTS: The placebo group showed a significant decrease from the baseline in the trabecular BMD of the radius at 12 months (7.4+/-2.5%) (p<0.05), whereas the HRT group showed a slight increase (0.7+/-2.2%). The changes in the trabecular BMD of the radius between the HRT and placebo groups were statistically different at 12 months (p<0.05). On the other hand, in the cortical BMD of the radius, no significant differences were seen between the changes of bone densities in the HRT and control groups after 1 year of treatment. pQCT could detect a significant loss of BMD of the radius in early postmenopausal women after 1 year and HRT prevented its loss. CONCLUSION: Our preliminary clinical trial showed that pQCT might be useful for the early detection of bone loss in early postmenopausal women and for the monitoring BMD of the patients who receive HRT.     

Estrogen receptor alpha and beta polymorphisms: is there an association with bone mineral density, plasma lipids, and response to postmenopausal hormone therapy?

OBJECTIVE AND DESIGN: A cross-sectional segregation analysis of polymorphisms in the estrogen receptor (ER) genes (Pvull and Xbal in ERalpha, and Alul in ERAbeta with bone mineral density in the lumbar spine and forearm and with lipid profile was performed in 1098 postmenopausal women. Additionally, in a subpopulation of 280 women, who completed 1 year of treatment with estrogen plus progestin, the association between genotypes and the response to treatment in both plasma lipids and bone was investigated. In another untreated subpopulation of 443 women, genotype influence on the prevalence of vertebral fractures and on annual rate of bone loss during a mean follow-up period of 11 years was estimated. RESULTS: Baseline plasma lipids, bone mineral density, annual rate of bone loss and prevalence of spinal fractures were not significantly associated with polymorphisms in the ERbeta gene. The ERA polymorphism was significantly associated with bone loss from the distal forearm (P = 0.04) but not with bone loss from the spine. After 1 year of treatment with hormone therapy there was also a significant association between the ERbeta polymorphism and the response in total cholesterol (P = 0.02); while the ERalpha gene polymorphisms did not significantly influence the response to hormone therapy. CONCLUSIONS: In a large white population of postmenopausal women, ERalpha gene polymorphisms were not associated with bone mineral density or lipid profile at baseline or after hormone therapy. Conversely, the ERbeta genotype appeared to segregate with bone loss from the forearm and to modulate the decrease in total cholesterol during hormone therapy.     

Reduced bone mass in daughters of women with osteoporosis

To determine whether premenopausal daughters of women with postmenopausal osteoporosis have lower bone mass than other women of the same age, we measured the bone mineral content of the lumbar spine and femoral neck and midshaft, using dual-photon absorptiometry, in 25 postmenopausal women with osteoporotic compression fractures and in 32 of their premenopausal daughters; we then compared the results with those in normal controls. As compared with normal postmenopausal women, women with osteoporosis had lower bone mineral content in the lumbar spine, femoral neck, and femoral midshaft by 33, 24, and 15 percent, respectively (P less than 0.001 for each comparison by the one-tailed t-test). As compared with normal premenopausal women, the daughters of women with osteoporosis had lower bone mineral content at these sites by 7, 5, and 3 percent, respectively (P = 0.03, 0.07, and 0.15, respectively, by the one-tailed t-test). In terms of a standardized score, we calculated that the mean (+/- SEM) relative deficits in bone mineral content in the daughters of women with osteoporosis were 58 +/- 18 percent (lumbar spine) and 34 +/- 16 percent (femoral neck) of the relative deficits in their mothers. We conclude that daughters of women with osteoporosis have reduced bone mass in the lumbar spine and perhaps in the femoral neck; this reduction in bone mass may put them at increased risk for fractures. We also conclude that postmenopausal osteoporosis may result partly from a relatively low peak bone mass rather than from excessive loss of bone.     

Elevated arterial stiffness in postmenopausal women with osteoporosis

OBJECTIVES: Osteoporosis and increased pulse wave velocity (PWV) are cardiovascular risk factors. We investigated the relationship between PWV and bone mass in the lumbar spine in postmenopausal women. METHODS: We studied the PWV in 95 women; 38 postmenopausal women with normal spinal bone mineral density (BMD), 32 osteopenic postmenopausal women, and 25 osteoporotic postmenopausal women. The brachial-ankle PWV (baPWV) was measured using an automated device. The BMD of the lumbar spine (L2-L4) was measured using dual-energy X-ray absorptiometry. RESULTS: After adjusting for age and years since menopause, women with osteoporosis had a significantly higher baPWV than those with normal BMD (1500 +/- 220 cm/s versus 1340 +/- 215 cm/s; P < 0.05), but no significant differences in baPWV were seen between the osteoporotic and osteopenic groups or between the osteopenic and normal BMD groups. In univariate regression analysis, the baPWV was significantly negatively correlated with BMD (r = -0.450, P < 0.01), and significantly positively correlated with age (r = 0.601, P < 0.01), years since menopause (r = 0.577, P < 0.01), systolic blood pressure (r = 0.295, P < 0.01), and diastolic blood pressure (r = 0.264, P < 0.05), but was not with other variables. In multivariate regression analysis, the baPWV was significantly correlated with BMD (P < 0.05), but not with other variables. CONCLUSIONS: Postmenopausal women with osteoporosis may have elevated arterial stiffness, suggesting that osteoporotic postmenopausal women may have a higher risk of cardiovascular disease.     

Bone density measured by dual energy X-ray absorptiometry in Qatari women

BACKGROUND: Over the past 10 years, osteoporosis has emerged as a major public health problem. It is characterized by low bone mass with micro architectural deterioration of bone tissue resulting in increase bone fragility and susceptibility to fractures. Bone mineral density measurements are widely used to diagnose osteoporosis and to assess its severity. Commercial dual-energy X-rays absorptiometry (DXA) scanners used to determine bone mineral density (BMD) contains reference data for different populations. AIM: The aim of this study was to determine reference values for Qatari female population and to compare them with values from western and other Arab countries. METHODS: A cross-sectional study of 574 Qatari women aged between 20 and 69 years was carried out using DXA scan to establish reference values of bone mineral density. Measurements were taken at the lumbar spine and proximal femur. The data were compared with normative taken by Caucasians, Kuwaiti, Lebanese and Saudi women over five decades of age. RESULTS: Our results showed that the Qatari subjects showed the expected decline in BMD at spinal sites with age after peaking at 30-39 years age group, and for femoral site at 40-49 years. The BMD values of the spine of Qatari women were lower than Caucasian and Kuwaiti women but higher than the Lebanese and similar to Saudi women. The BMD values of the total femur were higher in Qatari females than Caucasians, Kuwaitis, Lebanese and Saudis in the age group of 40-59, but lower in the age group 60-69 years. Of the 147 studied Qatari women in the age group (50-69) years, the T-score was normal (>-1 S.D.) in 79 subjects (53.7%), in the osteopenic range (-1 to -2.5 S.D.) in 51 subjects (34.7%) and in the osteoporotic range (<-2.5 S.D.) in 17 subjects (11.6%). CONCLUSION: BMD value of Qatari females are lower than Caucasians and Kuwaitis at the spine, and at the total femur in the age group 60-69 years, but higher values of total femur in the age group 40-59 years. Osteoporosis is common among menopausal Qatari women and should be considered a matter of public concern.     

Age-related change in the strength of correlation of lumbar spine bone mineral density with other regions

OBJECTIVES: To investigate whether the strength of correlation of lumbar spine bone mineral density (BMD) with other regions differs with age. METHODS: Subjects were 336 premenopausal women aged 20-49 years and 218 postmenopausal women aged 50-69 years with right-side dominance. Age, height, weight, and years since menopause (YSM) were recorded. Subjects were classified into five subgroups at 10-year increments. BMD of the arms, lumbar spine (L2-4), pelvis, legs, and total body were measured by dual-energy X-ray absorptiometry (DEXA). RESULTS: Regional and total body BMD did not differ among women aged in their 20s, 30s, and 40s. However, in women aged over 50, regional and total body BMD gradually decreased with age. The strength of correlation of lumbar spine BMD with the left arm, right arm, left leg, right leg, and total body BMD gradually increased with advancing age (r=0.422-0.715, 0.376-0.714, 0.476-0.721, 0.491-0.734, and 0.642-0.800, respectively). However, the strength of correlation of lumbar spine BMD with pelvis BMD remained unchanged (r=0.512-0.622). CONCLUSIONS: Correlation of lumbar spine BMD with extremities BMD gradually strengthens with advancing age, while higher correlation of lumbar spine BMD with pelvis BMD remains unchanged. When lumbar spine BMD is predicted using values at sites such as forearm BMD, we should consider the patient's age.     

Prevention of postmenopausal osteoporosis. A comparative study of exercise, calcium supplementation, and hormone-replacement therapy

BACKGROUND. Osteoporosis among older women is a major public health problem. We studied the effects of three approaches to the prevention of osteoporosis in women with low bone density. METHODS. One hundred twenty postmenopausal women (mean [+/- SD] age, 56 +/- 4) who were selected because they had low forearm bone density were enrolled in a double-blind, placebo-controlled, randomized study comparing the effects of an exercise regimen (exercise group, n = 41), exercise plus dietary calcium supplementation (exercise-calcium group, n = 39), and exercise plus continuous replacement of estrogen and progesterone (exercise-estrogen group, n = 40). Periodically during the two-year study period, we measured the women's bone density at three forearm sites, measured indexes of calcium metabolism, and recorded symptom scores. A comparison group of 42 women (mean age, 55.5 +/- 3.1) with normal bone density was also followed for two years. RESULTS. Significant bone loss in the distal forearm occurred in the group with normal bone density (control group) and the exercise group (change, -2.7 percent and -2.6 percent of the base-line value per year, respectively). Bone loss at the distal forearm site was significantly lower in the exercise-calcium group (-0.5 percent of the base-line value per year), and bone density increased at this site in the exercise-estrogen group (+2.7 percent of the base-line value per year). Bone loss at the median forearm site was significantly lower in the exercise-calcium group (-1.3 percent of the base-line value per year) than in the exercise group (-2.4 percent), and bone density at this site increased significantly in the exercise-estrogen group (+0.8 percent of the base-line value per year). Breast tenderness occurred in 47 percent of the women in the exercise-estrogen group but in only 20 percent in the other two treatment groups. Vaginal bleeding occurred at some time in 52 percent of the women who had not had a hysterectomy in the exercise-estrogen group, as compared with 11 percent and 12.5 percent, respectively, in the exercise and exercise-calcium groups. CONCLUSIONS. In postmenopausal women with low bone density, bone loss can be slowed or prevented by exercise plus calcium supplementation or estrogen-progesterone replacement. Although the exercise-estrogen regimen was more effective than exercise and calcium supplementation in increasing bone mass, it also caused more side effects.     

Aging of bone density in the second metacarpal.

Bone weight, bone and cortical areas, and apparent and true bone densities (W/BV and W/CV) were measured on the second metacarpals of 114 male and 114 female Japanese, aged 30 to 98 years. Measurements were taken from midshaft cross-sections 2 mm thick, using an electron balance and an image analyzing system. The mean values of these variables were greater in men than in women at all ages. Bone area stayed almost unchanged regardless of age. Bone weight and cortical area decreased linearly with advancing age. The respective rates of decrease per decade observed for the these variables were 3.1% and 2.9% in men and 5.5% and 4.8% in women. Apparent bone density decreased gradually with age after the fourth decade in women. While, in men, it stayed almost unchanged or increased slightly until the fifth decade and then, decreased gradually with age. The rate of decrease per decade was accelerated after the fifth decade in women and after the sixth in men, being 10.3% and 8.1% in each gender, respectively. The mean loss of bone was about twice as great in women as in men. In women, significant differences (p less than 0.01) were found in these variables after the seventh decade compared with the preceding age group. However, true bone density (W/CV) stayed almost unchanged regardless of age, being about 2.0 in men and about 1.9 in women. Osteoporosis could be primarily a manifestation of normal aging, including the postmenopausal estrogen deficiency in women, regardless of gender or race.     

Association of estrogen receptor alpha gene polymorphisms with bone mineral density in postmenopausal Indian women

Bone mineral density (BMD) is the major determinant of osteoporotic fracture risk with a particular genetic background. However, consensus on the association of BMD with specific gene locus has not been reached. In the present study, we investigated the potential association of estrogen receptor alpha (ER alpha) gene intron I polymorphisms with BMD in 246 postmenopausal Indian women (average age 54.2+/-3.4 years). All the subjects were genotyped for XbaI and PvuII polymorphisms and underwent BMD measurements at spine and hip by dual energy X-ray absorptiometery. The average BMD of subjects with the genotypes XX and PP (absence of restriction sites for XbaI and PvuII, respectively) was 12.7 and 5.4% higher at the spine and 13.1 and 4.6% higher at the hip, respectively, than those with genotypes xx and pp. In age vs. BMD scatterplot, the intercept and slope of regression lines for genotypes xx and pp at spine and hip demonstrated comparatively rapid decrease in BMD across the age. The genotype XX was significantly prevalent (p<0.001) in women with normal bone mass (32%) and genotype xx in women with osteoporotic bone mass (35.3%), within the group. A significantly higher relative risk was associated with xx genotype. The study concludes that genetic variations at ER alpha gene locus, perhaps, are associated with BMD in Indian women and may influence some determinant of bone metabolism resulting in accelerated bone loss with age.     

Association between breast cancer and bone mineral density: the Dubbo Osteoporosis Epidemiology Study

BACKGROUND: The association between bone mineral density and breast cancer was investigated in a nested case-control study, involving 30 breast cancer cases and 120 controls, aged 68+/-6 (mean +/-S.D.) years, as part of the Dubbo Osteoporosis Epidemiology Study (Australia). METHODS: Bone mineral density (BMD, g/cm(2)) at the femoral neck and lumbar spine was measured by dual energy X-ray absorptiometry. Anthropometric data and reproductive history were collected by direct interview using a structured questionnaire. RESULTS: In univariate conditional logistic regression analysis, lower age at menarche, longer overall duration of lifetime ovulation and higher bone density were associated with higher risk of breast cancer. Among the breast cancer cases, 20% of subjects had lumbar spine BMD greater than 1.20 g/cm(2) (or 2.5 S.D. above the mean) compared with less than 1% of the controls. After adjusting for the effects of duration of lifetime ovulation and body mass index, each 0.1 g/cm(2) increase in lumbar spine and femoral neck BMD was associated with a 2.1-fold (95% CI: 1.3-3.4) and 1.5-fold (1.0-2.4) respectively, higher risk of breast cancer. Further adjustment for age at menarche, hormone replacement therapy, and parity did not alter the result. Thus, postmenopausal BMD, which is affected by lifetime exposure to estrogen, is also related to risk of breast cancer. Importantly, it is estimated that estrogen therapy in osteoporotic women, even if raising the risk of breast cancer by 70% as suggested by some studies, would not elevate their risk to the level experienced by their non-osteoporotic counterparts. CONCLUSION: While the mechanism of this relationship remains to be explored, these data support the concept that lifetime exposure to estrogen is an indicator of risk of both breast cancer and osteoporosis. However, the use of estrogen in osteoporosis treatment would not elevate the risk of breast cancer in osteoporotic women up to the level experienced by their non-osteoporotic counterparts.     

Bone mineral density in older non-Hispanic Caucasian and Mexican-American women: relationship to lean and fat mass

PRIMARY OBJECTIVE: The prevalence of osteoporotic fracture is higher in non-Hispanic Caucasian (NHC) than Mexican-American (MA) women in the USA. The present study examined bone mineral density (BMD) in these two ethnic groups and the association between BMD and body composition. RESEARCH DESIGN: Cross-sectional. SUBJECTS: Sixty-two NHC and 54 MA women, aged 60-86 years, with a body mass index (kgm(-2)) of <30. METHODS: BMD (gcm(-2)) of the spine (L2-4), hip (femoral neck, trochanter, Ward's triangle) and whole body was determined by dual-energy X-ray absorptiometry (DXA). Bone mineral-free lean mass (LM) and fat mass (FM) and several ratios of body fat distribution were also assessed by DXA. RESULTS: There was no difference in age (NHC, 69.5+/-0.7; MA 69.5+/-0.9 years; mean +/- SEM) or body mass, but MA women were shorter with a higher truncal adiposity (p < 0.001). There was no significant difference in BMD between groups, however, adjusting for height resulted in higher hip and whole body BMD in MA women (p < 0.01). When volumetric bone density was calculated (bone mineral apparent density; BMAD, gcm(-3)), a trend for higher values in MA women was observed at the femoral neck (p = 0.018). LM contributed independently to BMD at the spine and hip in NHC women, with FM also contributing at the femoral neck. In MA women, LM was an independent contributor to lumbar spine and trochanter BMD, and both LM and FM contributed to whole body BMD. However, the effects of LM and FM were removed in both groups when BMD was adjusted for body or bone size, the only exception being at the trochanter in NHC women. CONCLUSIONS: These results indicate that MA women have higher bone density at the proximal femur than NHC women, which may partially account for their lower rate of hip fracture. Further, differences in bone density between the two ethnic groups do not appear to be dependent on soft-tissue composition.     

Age and sex differences in bone density of the second metacarpal in its midshaft cross-section

On the basis of the midshaft cross-section of the second metacarpal in 102 male and 96 female Japanese, aged 30 to 98 years, age- and sex-related differences of bone mass and density are examined. Bone mass and density are almost always greater in males than in females. Cortical mass and apparent bone density decrease gradually with age after 45 years of age in both sexes. The decreasing rate is about twice as great in females as in males. The sex difference increases gradually with age, especially after the sixth decade. However, true bone density remains almost constant, regardless of age, until the seventh decade in both sexes. The maximum density layer is more deeply located at the radial side than at the ulnar, and also more so in males than in females, corresponding to the differences in cortical thickness. The relative depth of this layer to the bone width is about 15% at the radial side and 12% at the ulnar in males and about 12% and 10% at each side in females, respectively.     

阿仑膦酸钠和阿法骨化醇联合治疗严重骨质流失和骨质疏松性骨折

背景：阿仑膦酸钠和阿法骨化醇均可抑制骨质疏松性骨折患者骨转换,增加骨矿物密度。 目的：观察阿仑膦酸钠和阿法骨化醇联合治疗患有严重骨质流失和骨质疏松性骨折患者的效果。 方法：纳入严重骨质流失和骨质疏松性骨折患者,进行阿仑膦酸钠和阿法骨化醇联合治疗2年。 结果与结论：相比治疗前,阿仑膦酸钠和阿法骨化醇联合治疗后患者腰椎骨密度增加(P < 0.05),随后尿Ⅰ型胶原N末端肽水平和血清碱性磷酸酶活性减少(P < 0.05)。证实,阿仑膦酸钠和阿法骨化醇联合治疗患有严重的骨质流失和骨质疏松性骨折患者疗效好。     

Osteocalcin and bone alkaline phosphatase in the serum of women with liver disease

To identify the types of liver disease in which osteopenia is a prominent feature and to understand the mechanisms of bone loss, bone mineral density was measured in the lumbar spine and hip, bone alkaline phosphatase, osteocalcin, and biochemical markers of calcium homeostasis were measured in 42 women, aged 33 to 52, with chronic liver disease and in 299 healthy women of similar age. In control women, bone alkaline phosphatase and osteocalcin correlated negatively with bone density at all sites (p less than 0.05). In women with liver disease, osteocalcin correlated negatively with bone density in the lumbar spine (p less than 0.007), whereas bone alkaline phosphatase did not correlate with bone density at any site. Bone alkaline phosphatase correlated positively with osteocalcin in control women (p = 0.001) and negatively with osteocalcin in women with liver disease (p = 0.03). Serum bone alkaline phosphatase in women with liver disease was increased significantly over serum bone alkaline phosphatase of control women, probably because of decreased clearance owing to defective function or decreased numbers of hepatic asialoglycoprotein receptors. Bone density was lower in the lumbar spines and hips of women with primary sclerosing cholangitis, primary biliary cirrhosis, and chronic active hepatitis or fibrosis without cirrhosis than in the lumbar spine and hips of control women. However, the differences were not significant, possibly because of the small sample size. It is concluded that, in liver disease, osteocalcin is a more reliable marker of osteoblastic function than bone alkaline phosphatase. Although our results show that bone density may decrease in women with cholestatic liver disease, larger studies are needed to determine the degree of osteopenia.     

Ovarian aging and bone metabolism in menstruating women aged 35-50 years

OBJECTIVES: The aim of this study was to investigate the relationships between the levels of gonadotrophins, estradiol, inhibin-b and bone mass and turn-over in regularly menstruating women aged 35-50 years. METHODS: The study group included 87 healthy volunteers from the community aged 35-50 years. Bone mineral density of lumbar vertebras, wards triangle, throchanter, femur neck, bone resorption and formation markers were studied as well as the serum levels of gonadotrophins, estradiol and inhibin-b on the day 3 of menstrual cycle. RESULTS: The gonadotrophin levels showed significant positive relation with age, whereas inhibin-b and estradiol levels showed significant negative correlation with age. The gonadotrophins and estradiol levels had no significant association with bone mass and bone formation markers. Increased gonadotrophin (p < 0.001) levels and decreased inhibin-b (p < 0.01) levels independent from age were correlated with increased bone resorption. Gonadotrophins, estradiol, age, inhibin-b, body mass index (BMI) were the confounding factors for bone resorption (p = 0.015, R(2) = 0.190) and lumbar bone mass (p = 0.041, R(2) = 0.148). Multivariate analysis showed an independent contribution of inhibin-b and BMI in the prediction of lumbar bone mass. CONCLUSION: This findings suggested that estradiol was not the only factor responsible for bone loss and decrease in reproductive function because increased gonadotrophins and decreased inhibin-b levels might trigger some changes in bone metabolism prior to the menopause.     

Relationship between self-reported periodontal status and skeletal bone mineral density in Japanese postmenopausal women

OBJECTIVE: Several investigators have linked periodontal disease progression and low skeletal bone mineral density in postmenopausal women. However, little is known about whether self-reported periodontal status is the reflection of skeletal bone mineral density. We investigated whether self-reported poor periodontal status is associated with low skeletal bone mineral density in postmenopausal women. DESIGN: Relationships among self-reported periodontal status, number of teeth remaining, and bone mineral density of the lumbar spine and the femoral neck were evaluated in 253 Japanese postmenopausal women (mean +/- SD, 56.6 +/- 7.7) recruited from the patients who visited our clinic for bone mineral assessment between 1997 and 2003. Self-reported periodontal symptoms included gingival swelling, gingival bleeding, purulent discharge, and tooth mobility at the time of bone mineral assessment. RESULTS: Analysis of covariance adjusted for age, height, weight, years since menopause, duration of estrogen use, and regular oral care revealed that subjects without periodontal symptoms had significantly higher BMD of the lumbar spine than did those with periodontal symptoms (mean +/- SEM, 0.962 +/- 0.014 vs 0.921 +/- 0.013; P = 0.038); however, there were no significant differences in the number of remaining teeth and bone mineral density of the femoral neck between them. The odds of low spine bone mineral density in subjects with periodontal symptoms was 2.01 (95% CI = 1.15 to 3.50). CONCLUSION: Our results suggest that self-reported poor periodontal status may be associated with low bone mineral density of the lumbar spine in postmenopausal women.     

The effect of modelling and remodelling on human vertebral body architecture.

Vertebral bone strength is determined by several factors: cortical thickness, bone size, trabecular bone density, and microarchitecture. All these factors change with age as a result of the two dynamic processes: remodelling and modelling. When the changes become pronounced, osteoporotic fractures occur. There is a different aging pattern for men and women: 1. Men achieve a higher peak bone mass than women (mainly because of a larger cross-sectional area of their bones); 2. Men have no accelerated bone loss in middle age; and 3. Men seem to be able to compensate for their loss of cancellous bone strength by increasing their vertebral cross-sectional area with age. The general pattern, for both men and women is, though, that of an extreme (70-80%) decline in whole vertebral body strength during normal aging. The accompanying decline in bone density is much less pronounced (35-45%). This clearly illustrates the power relationship between bone density and strength. However, the role of changes in trabecular bone microarchitecture for vertebral bone strength during aging still needs to be determined.