Osteoporosis: screening, prevention, and management**Presented at the 47th Annual Meeting of the American Fertility Society, Orlando, Florida, October 21 to 24, 1991

Assessment of the relationship between gut microbiota and bone mineral density: a two-sample Mendelian randomization study

Background

Emerging evidence from observational studies and clinical trials suggests a connection between the gut microbiota and variations in bone mineral density (BMD). Nonetheless, the specific association between gut microbiota and BMD alterations at different skeletal sites has not been comprehensively explored. To address this, we employed Genome-Wide Association Study (GWAS) summary statistics from a publicly accessible database, conducting a two-sample Mendelian Randomization analysis to elucidate the potential causal relationship between gut microbiota composition and BMD.

Methods

This study utilized two distinct thresholds for screening instrumental variables (IVs), followed by an extensive series of quality control procedures to identify IVs that were significantly related to exposure. Gut microbiota were classified into two sets based on hierarchical levels: phylum, class, order, family, and genus. Bone mineral density (BMD) data were systematically collected from four skeletal sites: femoral neck, lumbar spine, forearm, and heel. For Mendelian Randomization (MR) analysis, robust methods including Inverse-Variance Weighting (IVW) and the Wald Ratio Test were employed. Additional analytical tests such as the Outlier Test, Heterogeneity Test, 'Leave-One-Out' Test, and Pleiotropy Test were conducted to assess the impact of horizontal pleiotropy, heterogeneities, and the genetic variation stability of gut microbiota on BMD causal associations. The MR Steiger Directionality Test was applied to exclude studies with potential directional biases.

Results

In this two-sample Mendelian randomization analysis, we utilized five sets of exposure GWAS (Genome-Wide Association Studies) summary statistics and four sets of outcome GWAS summary statistics. The initial analysis, applying a threshold of p < 5 × 10-6, identified 48 significant causal relationships between genetic liability in the gut microbiome and bone mineral density (BMD). A subsequent analysis with a more stringent threshold of p < 5 × 10-8 uncovered 14 additional causal relationships. Upon applying the Bonferroni correction, 9 results from the first analysis and 10 from the second remained statistically significant.

Conclusion

Our MR analysis revealed a causal relationship between gut microbiota and bone mineral density at all sites, which could lead to discoveries in future mechanistic and clinical studies of microbiota-associated osteoporosis.

Causal Effects of Plasma Proteome on Osteoporosis and Osteoarthritis

The two-sample Mendelian randomization (MR) study revealed a causal association of plasma proteins with osteoporosis (OP) and osteoarthritis (OA). Bone mineral density (BMD) is the gold standard for the clinical assessment of OP. Recent studies have shown that plasma proteins play an essential role in the regulation of bone development. However, the causal association of plasma proteins with BMD and OA remains unclear. We estimated the effects of 2889 plasma proteins on 2 BMD phenotypes and 6 OA phenotypes using two-sample MR analysis based on the genome-wide association study summary statistics. Then, we performed sensitivity analysis and reverse-direction MR analysis to evaluate the robustness of the MR analysis results, followed by gene ontology (GO) enrichment analysis and KEGG pathway analysis to explore the functional relevance of the identified plasma proteins. Overall, we observed a total of 257 protein-estimated heel BMD associations, 17 protein-total-body BMD associations, 2 protein-all-OA associations, and 2 protein-knee-OA associations at P_FDR < 0.05. Reverse-direction MR analysis demonstrated that there was little evidence of the causal association of BMD and OA with plasma proteins. GO enrichment analysis and KEGG pathway analysis identified multiple pathways, which may be involved in the development of OP and OA. Our findings recognized plasma proteins that could be used to regulate changes in OP and OA, thus, providing new insights into protein-mediated mechanisms of bone development.

Identification of pleiotropic loci underlying hip bone mineral density and trunk lean mass

Bone mineral density (BMD) and lean body mass (LBM) not only have a considerable heritability each, but also are genetically correlated. However, common genetic determinants shared by both traits are largely unknown. In the present study, we performed a bivariate genome-wide association study (GWAS) meta-analysis of hip BMD and trunk lean mass (TLM) in 11,335 subjects from 6 samples, and performed replication in estimated heel BMD and TLM in 215,234 UK Biobank (UKB) participants. We identified 2 loci that nearly attained the genome-wide significance (GWS, p < 5.0 × 10-8) level in the discovery GWAS meta-analysis and that were successfully replicated in the UKB sample: 11p15.2 (lead SNP rs12800228, discovery p = 2.88 × 10-7, replication p = 1.95 × 10-4) and 18q21.32 (rs489693, discovery p = 1.67 × 10-7, replication p = 1.17 × 10-3). The above 2 pleiotropic loci may play a pleiotropic role for hip BMD and TLM development. So our findings provide useful insights that further enhance our understanding of genetic interplay between BMD and LBM.

Two novel pleiotropic loci associated with osteoporosis and abdominal obesity

Aiming to uncover a shared genetic basis of abdominal obesity and osteoporosis, we performed a bivariate GWAS meta-analysis of femoral neck BMD (FNK-BMD) and trunk fat mass adjusted by trunk lean mass (TFMadj) in 11,496 subjects from 6 samples, followed by in silico replication in the large-scale UK Biobank (UKB) cohort. A series of functional investigations were conducted on the identified variants. Bivariate GWAS meta-analysis identified two novel pleiotropic loci 12q15 (lead SNP rs73134637, p = 3.45 × 10-7) and 10p14 (lead SNP rs2892347, p = 2.63 × 10-7) that were suggestively associated and that were replicated in the analyses of related traits in the UKB sample (osteoporosis p = 0.06 and 0.02, BMI p = 0.03 and 4.61 × 10-3, N up to 499,520). Cis-eQTL analysis demonstrated that allele C at rs73134637 was positively associated with IFNG expression in whole blood (N = 369, p = 0.04), and allele A at rs11254759 (10p14, p = 9.49 × 10-7) was negatively associated with PRKCQ expression in visceral adipose tissue (N = 313, p = 0.04) and in lymphocytes (N = 117, p = 0.03). As a proof-of-principle experiment, the function of rs11254759, which is 235 kb 5'-upstream from PRKCQ gene, was investigated by the dual-luciferase reporter assay, which clearly showed that the haplotype carrying rs11254759 regulated PRKCQ expression by upregulating PRKCQ promoter activity (p = 4.60 × 10-7) in an allelic specific manner. Mouse model analysis showed that heterozygous PRKCQ deficient mice presented decreased fat mass compared to wild-type control mice (p = 3.30 × 10-3). Mendelian randomization analysis demonstrated that both FNK-BMD and TFMadj were causally associated with fracture risk (p = 1.26 × 10-23 and 1.18 × 10-11). Our findings may provide useful insights into the genetic association between osteoporosis and abdominal obesity.

A review on osteoclast diseases and osteoclastogenesis inhibitors recently developed from natural resources

Natural products have been investigated as potential candidates of novel therapeutics and play a crucial role in advanced medicinal drugs. Natural resources, including local medicinal plants (especially folk medicinal plants), animals, bacteria, and fungi have been used for more than a century, and are precious gifts from nature, providing potential medicines with high safety. Osteoclast-related diseases, such as osteoporosis, rheumatoid arthritis, Paget's disease, osteoclastoma, and periprosthetic osteolysis, are currently the most common reasons for bone inflammation, pain and fractures, resulting in low quality of life. However, the curative effects of current therapeutic drugs for these osteoclast-related diseases are limited, and long-term treatment is needed. Further, in severe cases, surgical treatments are necessary, which may cause unaffordable expenses and subsequent influences such as neuralgia, mental stress, and even development of cancer. Thus, safer inhibitors and potential drugs with enhanced curative effects and quick relief are needed to treat patients with osteoclast diseases. This review aims to introduce the main osteoclast-related diseases and some of the recently developed naturally sourced inhibitors against osteoclastogenesis, also it is desired to attract people's attention on using widely available natural resources for the evolution of new types of osteoclast inhibitors with minimal or no side-effects upon long-term treatments.

Causal link between lipid profile and bone mineral density: A Mendelian randomization study

The level of serum lipids is associated with bone mineral density (BMD), an important skeletal trait. Yet the causality has not been determined. Here we performed a Mendelian randomization (MR) analysis to test potential causal links between BMD and lipid profile, i.e., low-density lipoprotein cholesterol (LDC-c), total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-c). We observed causal effect of LDL-c, TC and TG to BMD, and reversely the effect of BMD to HDL-c. We further explored the effect of body mass index (BMI) in these causalities and found that the effect of LDL-c, TC and TG to BMD is independent of BMI. Our findings provided useful information in the clinical relevance of blood lipids on BMD variation and osteoporosis risk.

Joint Association Analysis Identified 18 New Loci for Bone Mineral Density

Bone mineral density (BMD) at various skeletal sites have shared genetic determinants. In the present study, aiming to identify shared loci associated with BMD, we conducted a joint association study of a genomewide association study (GWAS) and a meta-analysis of BMD at different skeletal sites: (i) a single GWAS of heel BMD in 142,487 individuals from the UK Biobank, and (ii) a meta-analysis of 30 GWASs of total body (TB) BMD in 66,628 individuals from the Genetic Factors for Osteoporosis (GEFOS) Consortium. The genetic correlation coefficient of the two traits was estimated to be 0.57. We performed joint association analysis with a recently developed statistical method multi-trait analysis of GWAS (MTAG) to account for trait heterogeneity and sample overlap. The joint association analysis combining samples of up to 209,115 individuals identified 18 novel loci associated with BMD at the genomewide significance level (α = 5.0 × 10^-8 ), explaining an additional 0.43% and 0.60% of heel-BMD and TB-BMD heritability, respectively. The vast majority of the identified lead SNPs or their proxies exerted local expression quantitative trait loci (cis-eQTL) activity. Credible risk variants, defined as those SNPs located within 500 kilobases (kb) of the lead SNP and with p values within two orders of magnitude of the lead SNP, were enriched in transcription factor binding sites (p = 3.58 × 10^-4 ) and coding regions (p = 5.71 × 10^-4 ). Fifty-six candidate genes were prioritized at these novel loci using multiple sources of information, including several genes being previously reported to play a role in bone biology but not reported in previous GWASs (PPARG, FBN2, DEF6, TNFRSF19, and NFE2L1). One newly identified gene, SCMH1, was shown to upregulate the expression of several bone biomarkers, including alkaline phosphatase (ALP), collagen type 1 (COL-I), osteocalcin (OCN), osteopontin (OPN), and runt-related transcription factor 2 (RUNX2), in mouse osteoblastic MC3T3-E1 cells, highlighting its regulatory role in bone formation. Our results may provide useful candidate genes for future functional investigations. © 2019 American Society for Bone and Mineral Research.

Joint study of two genome-wide association meta-analyses identified 20p12.1 and 20q13.33 for bone mineral density

In the present study, aiming to identify loci associated with osteoporosis, we conducted a joint association study of 2 independent genome-wide association meta-analyses of femoral neck and lumbar spine bone mineral densities (BMDs): 1) an in-house study of 6 samples involving 7484 subjects, and 2) the GEFOS-seq study of 7 samples involving 32,965 subjects. The in-house samples were imputed by the 1000 genomes project phase 3 reference panel. SNP-based association test was applied to 7,998,108 autosomal SNPs in each meta-analysis, and for each SNP the 2 association signals were then combined for joint analysis and for mutual replication. Combining the evidence from both studies, we identified 2 novel loci associated with BMDs at the genome-wide significance level (α=5.0×10-8): 20p12.1 (rs73100693 p=2.65×10-8, closest gene MACROD2) and 20q13.33 (rs2380128 p=3.44×10-8, OSBPL2). We also replicated 7 loci that were reported by two recent studies on heel and total body BMD. Our findings provide useful insights that enhance our understanding of bone development, osteoporosis and fracture pathogenesis.

Relationship between bone mineral density, its associated physiological factors, and tooth loss in postmenopausal Korean women

BACKGROUND

Previous studies have proposed a relationship between bone mineral density (BMD) and oral health. However, the relationship between BMD and tooth loss in female individuals is not yet well understood. Therefore, the aim of this study was to assess the association between BMD, including its related physiological factors, and tooth loss among postmenopausal women in Korea.

METHODS

A total of 3,992 postmenopausal women aged 50 years or above were selected from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys, which were cross-sectional in design and conducted from 2008 to 2011. The participants' BMD and number of teeth were assessed by radiologists and dentists. Socioeconomic characteristics and female-related physiological factors, including menarche age, duration of menopause, number of pregnancies, age at first child's birth, and duration of oral contraceptive or female hormone use, were surveyed.

RESULTS

Participants who had lower BMD had significantly fewer teeth (p < 0.001). Female-related physiological factors, including the duration of menopause, number of pregnancies, age at first child's birth, duration of oral contraceptive or female hormone use, and calcium intake level, showed a significant relationship with the number of teeth. Using multiple regression analysis, BMD, duration of menopause, age at first child's birth, and duration of female hormone use significantly influenced the number of teeth.

CONCLUSIONS

BMD and its related physiological factors in female individuals showed a significant relationship with the number of teeth in postmenopausal Korean women, implicating osteoporosis as a risk factor for tooth loss in postmenopausal women.

The assessment of bone mineral content and density of the lumbar spine and proximal femur in US submariners

The submarine environment is unique in that there is limited space and no sunlight, which may negatively affect skeletal health and lead to accelerated bone loss, osteoporosis, and fractures.

INTRODUCTION

The primary purpose of this study was to determine whether there was an association with submarine service, specifically time spent at sea, and bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine and dual proximal femur (total hip and femoral neck) measured by DXA.

METHODS

This is a cross-sectional study of 462 submariners 20-91 years old. Variables included in the analysis were age, height, race, alcohol intake, tobacco use, fracture history, conditions, and medications known to cause bone loss and osteoporosis and submarine service.

RESULTS

Of the submarine service predictors, only serving onboard a diesel submarine was determined to be independently associated with a reduction in BMD of the total hip and femur neck, while no submarine service predictor increased the odds of having low BMD. In submariners 50+ years old, the age-adjusted prevalence of osteopenia was 15.7 % (lumbar spine) and 40.4 % (femur neck), while the prevalence of osteoporosis was 4.8 % (lumbar spine) and 4.2 % (femur neck), rates that did not differ from NHANES 2005-2008. In submariners <50 years old, 3.1 % was below the expected range for age. The proportion of submariners 50+ years old that met the FRAX criteria for pharmacological treatment was 12 %.

CONCLUSIONS

Intermittent periods of submergence that can range from a few days to 3+ months do not appear to compromise skeletal health differently than the general population.

Quantitative ultrasound at the phalanges in monitoring alendronate therapy

This study evaluated the efficacy of quantitative ultrasound (QUS) at the phalanges in monitoring alendronate treatment. Seventy-nine postmenopausal women were enrolled: 46 subjects entered therapy with alendronate, the remaining 33 did not follow any therapeutic regimen. All subjects underwent phalangeal ultrasound measurement before starting treatment and after 12 mo. Two QUS parameters were measured: AD-SoS (Amplitude Dependent Speed of Sound) in m/s, and BTT (Bone Transmission Time) in micros. Mean age of subjects at the beginning of the study was 58.7 +/- 6.5 y, mean BMI was 26.6 +/- 4.4 kg/m(2), mean time since menopause was 6.7 +/- 5.0 y; no significant differences could be observed between the groups (p > 0.05). At 12-mo follow-up a significant increase of both QUS parameters was observed: +18.8 +/- 24.4 m/s for AD-SoS, p < 0.0001; +0.05 +/- 0.08 micros for BTT, p < 0.001. In the nontreated group AD-SoS was stable (+1.0 +/- 33.7 m/s), as well as BTT (-0.07 +/- 0.25 micros), p = n.s. for both. In the treated group the percentage of responders was 65.2% for AD-SoS and 50.0% for BTT. The percentage of non responders was 13% for AD-SoS and 15.2% for BTT. The results confirm that the effect of alendronate treatment may be suggested by QUS at the phalanges after 12 mo of treatment.

QUS in monitoring raloxifene and estrogen-progestogens: a 4-year longitudinal study

The aim of the study is to evaluate the effectiveness of phalangeal quantitative ultrasound (QUS) in monitoring the treatment with raloxifene or estrogen-progestogens in postmenopausal women attending an Italian Menopause Centre. Caucasian women (n = 268) were enrolled in the study and underwent annual check-ups between October 1998 and October 2004. All were measured with the IGEA DBM Sonic Bone Profiler (BP) at the startup of treatment and in the following years. Three groups were identified: subjects not receiving treatment (n = 144), subjects treated with raloxifene (n = 53) and subjects treated with estrogen-progestogens (n = 71). The three analyzed groups were similar for age, weight and menopausal age. A significant decrease in amplitude-dependent speed of sound (AD-SoS) and Ultrasound Bone Profile Index (UBPI; p < 0.05) was observed in the nontreated group, whereas a positive effect in treated groups could be evidenced in the follow-up. In particular, a significant positive effect (p < 0.05) on AD-SoS corrected for age in the group treated with raloxifene has been observed, whereas in the group treated with estrogen-progestogens a nonsignificant positive effect on AD-SoS corrected for age was observed. The absolute AD-SoS value was maintained over the years of follow-up. The UBPI data show a slowing down of the bone loss in the treated groups, especially in the raloxifene group, in contrast with the significant decrease in the nontreated group. The result of this study shows the DBM Sonic Bone Profiler is an efficient device to monitor the effects of treatment, not only in the strict control settings of clinical trials, but also in clinical practice.

Effects of third-generation aromatase inhibitors on bone

Low oestradiol levels in women are associated with decreased bone mineral density (BMD) and increased fracture risk. The third-generation aromatase inhibitors (AIs; anastrozole, letrozole, and exemestane) are used in the treatment of early and advanced breast cancer and act by substantially reducing oestrogen synthesis in postmenopausal women. However, due to their mechanism of action, there is concern regarding the long-term effects of these agents on bone, particularly when used in the adjuvant setting. In this paper, the currently available data on the effects of the third-generation AIs on markers of bone turnover, BMD, and fracture risk are reviewed, with the emphasis on results in the adjuvant treatment of early breast cancer. These data suggest that both the steroidal (exemestane) and non-steroidal (anastrozole and letrozole) AIs appear to affect bone turnover. Conclusions regarding any clinically relevant differences between these agents are difficult to make, and further data are awaited from long-term adjuvant use of these three agents in ongoing clinical studies. Postmenopausal women are at increased risk of osteoporosis and fracture, and the increasing use of AIs in the adjuvant treatment of postmenopausal breast cancer patients will require appropriate consideration of fracture risk, with the use of anti-osteoporotic therapies, if necessary.

Effects of estriol on proliferative activity and expression of insulin-like growth factor-I (IGF-I) and IGF-I receptor mRNA in cultured human osteoblast-like osteosarcoma cells

The present study was undertaken to elucidate whether estriol (E3) affects the proliferative activity and the expression of insulin-like growth factor-I (IGF-I) mRNA and IGF-I receptor (IGF-IR) mRNA in cultured human osteoblast-like osteosarcoma cells (HOS TE85). In this study, the effects of E3 on cultured HOS TE85 cells were compared with those of 17 beta-estradiol (E2). HOS TE85 cells were subcultured in phenol red-free Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum for 72 h and then stepped down to serum-free conditions for an additional 72 h in the absence or presence of E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l). Treatment with either E3 (3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in an increase in the number of cultured HOS TE85 cells and their uptake of bromodeoxyuridine. Northern blot hybridization with a IGF-I cDNA probe revealed that RNA prepared from cultured HOS TE85 cells contained IGF-I mRNA transcripts of 1.8, 4.4 and 7.5 kb. Treatment with either E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in increased expression of the three mRNA transcripts relative tot hose in untreated control cultures. Semi-quantitative, reverse transcription polymerase chain reaction analysis showed that the 440-bp IGF-IR mRNA transcript was present in HOS TE85 cells and that treatment with either E3 or E2 did not affect the IGF-IRmRNA expression in these cells. These results demonstrate that E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) exerts profound effects on the proliferative potential of cultured HOS TE85 cells, compatible with that of E2 (3.67 x 10(-8) mol/l), through the induction of IGF-I mRNA expression without affecting IGF-IR mRNA expression in these cells.

Short-term calcium supplementation has no effect on biochemical markers of bone remodeling in early postmenopausal women

INTRODUCTION

This study was designed to assess changes in biochemical markers of bone remodeling in early postmenopausal women receiving calcium supplementation.

MATERIALS AND METHODS

In a randomized cross-over study of eighteen weeks duration, the effect of a 6-week calcium supplementation (1000 mg calcium carbonate) on biochemical markers of bone resorption (collagen type I cross-linked C- and N-telopeptides) and bone formation (osteocalcin, total and bone-specific alkaline phosphatase), and total serum calcium was assessed in 27 early postmenopausal women.

RESULTS

While total serum calcium levels increased significantly due to calcium supplementation (p<0.05), biochemical markers of both bone resorption and formation remained virtually unchanged.

CONCLUSION

In contrast to other investigations, there was no significant short-term effect of calcium supplementation on biochemical markers of either bone resorption or formation.

The female athlete. Before and beyond puberty

As the twentieth century progressed, the female athlete became an accepted participant of sports at all levels. This article reviews various aspects of female sports participation. After an historical perspective, selected comments are provided on psychologic and physiologic aspects. Concepts of adolescent gynecology are reviewed, including breast and menstrual problems and pregnancy. Other areas reviewed include iron deficiency anemia, stress urinary incontinence, and sports injuries in female athletes.

Usual dietary isoflavone intake, bone mineral density, and bone metabolism in postmenopausal women

Clinical trials of isoflavone supplementation and bone density have been of relatively short duration and yielded inconsistent results. Few studies examined the effects of usual dietary isoflavone intake on bone density, and none examined the effects on markers of bone turnover. This cross-sectional study examines the association of usual, unsupplemented dietary soy intake with bone density at the lumbar spine and hip and markers of bone turnover in postmenopausal women. Participants were 208 postmenopausal Southern California women aged 45-74 years. Information on behavioral and lifestyle factors was obtained, and dietary intake of isoflavones over the past year was assessed with a standardized questionnaire. Bone density was measured at the spine and hip with dual energy x-ray absorptiometry (DEXA). Urinary type I collagen cross-linked N-telopeptides (N-Tx) and pyridinium cross-links (PYR), both markers of bone resorption, and bone alkaline phosphatase (BAP), a marker of bone formation, were assayed. After adjustment for age and obesity, women with the highest daily intake of dietary genistein had N-Tx concentrations 18% lower than those of women who reported no daily genistein consumption (mean 37.29 vs. 45.44, respectively, p = 0.01). After adjustment for all covariates, there were trends toward significant differences in N-Tx (p = 0.09) and spine bone density (p = 0.07), whereby women with the highest level of isoflavone consumption had greater bone density at the spine. These results suggest that usual, unsupplemented dietary isoflavone consumption may be protective against bone loss in postmenopausal women through a reduction in bone resorption.

Hormone replacement therapy at the threshold of 21st century

The management of postmenopausal women has become a major focus for the medical profession. The menopause era should progress from a period of "chaos" to an orderly understanding of the many issues related to the menopause and hormone replacement therapy (HRT). Although HRT has beneficial clinical effect and positive benefit/risk ratio, understanding of the side effects and weight gain, and, especially, a fear of cancer limit compliance. New data from long-term, controlled, prospective studies on the effects of different HRT schedules on cancer, cardiovascular disease and osteoporotic fracture risk are needed. HRT should be considered either as for prevention or for individualized care since women experience menopause as individuals, care should be taken not to make inappropriate generalizations. The priority should be the administration of appropriate medication to women with the best result in order to improve health care and quality of life. New therapeutic options will offer substantial medical advancement for the treatment of postmenopausal women.

Postmenopausal osteoporosis management

Osteoporosis is perhaps the widest-ranging social, physical, and economic impact of estrogen deficiency. Postmenopausal bone loss is the major determinant of osteoporosis. Osteoporotic risk can be determined by measuring bone mineral density using dual X-ray absorptiometry. The radiation free quantitative bone ultrasound is emerging in the assessment of bone structure giving reliable estimates of fracture risk. Diet and exercise are important in determining a woman's risks for osteoporosis. Hormone replacement therapy clearly decreases bone turnover and prevents postmenopausal bone loss and reduces fractures. Tibolone as well as raloxifene prevent bone loss and solid data demonstrate a reduction of vertebral fractures after raloxifene administration.

Changes in bone mineral density with age, menopausal status and body mass index in Turkish women

OBJECTIVE

The aim was to evaluate changes in bone mineral density (BMD) with age and body mass index (BMI) in healthy pre- and postmenopausal women living in the urban areas of Turkey.

DESIGN

The study was prospective, carried out from 1993 to 1997.

SETTING

The study carried out at a university hospital, the Istanbul University Cerrahpasa School of Medicine, Turkey.

PATIENTS

The study group consisted of 849 healthy women of ages 20-84 years, admitted to the Istanbul University Cerrahpasa School of Medicine. The cases were divided into age groups, starting with 20-29 years and ending with 70 years and over. For regression analysis, the cases were further regrouped as 20-39, 40-59 and 60 years and over. Dual energy X-ray absorptiometry (DEXA) was used to measure BMD in the lumbar vertebrae (L2-L4) and in the classical locations of the proximal femur such as the femoral neck, the Ward's triangle and the trochanter. Multiple regression analysis was performed for the evaluation of annual changes in BMD with respect to age and/or BMI.

RESULTS

A significant decrease in BMD started especially in the 40-49 age group, matching the average age of menopause in the study population. In contrast to the non-significant changes in the 20-39 age group, a significant decrease in BMD in the 40-59 age group, which included the average age of menopause, was detected in all locations (p < 0.0001). In addition to the significant effect of the menopause on BMD, an association between BMD and BMI was found in every location and age group (p = 0.02 to p < 0.0001). The total bone loss in the 70 and over age group, in comparison with the 30-39 age group, was 18.78% in L2-L4, 21.69% in the femoral neck, 32.68% in the Ward's triangle and 14.11% in the trochanter. Corresponding values between age groups 70 and over and 60-69 were 0.25%, 7.62%, 11.94% and 8.29%, respectively. Women in the older age groups had a slower decline in BMD in the lumbar vertebrae, in comparison with the proximal femur. Moreover, the maximum postmenopausal total bone mineral loss was in the Ward's triangle.

CONCLUSIONS

The present results, confirming the results of other studies, have revealed a significant association between BMD and the menopausal status of women in the Turkish population. Additionally, a significant correlation has been detected between BMI and BMD, regardless of location and age.

Gynecologic health and disease

Traditionally the obstetrician/gynecologist has been the sole provider of health care for women. As the United States moves toward a system of greater managed care, however, family practitioners, internists, and other physician extenders (physician assistants, nurse-practitioners, and nurse-midwives) are the first-line providers for many women. These practitioners have the opportunity to influence behavioral changes and promote healthy habits by identifying risk factors and their potential consequences.

Effects of combined low dose of the isoflavone derivative ipriflavone and estrogen replacement on bone mineral density and metabolism in postmenopausal women

OBJECTIVES

To assess the pattern of biochemical markers of bone metabolism and vertebral bone mineral density in early postmenopausal women treated with combined ipriflavone and low dose conjugated estrogens.

METHODS

Bone biochemical markers and vertebral bone density were evaluated in a longitudinal, comparative, 2 year study conducted in postmenopausal women treated with sole calcium supplementation (500 mg/day), or with either ipriflavone (IP) at the standard dose (600 mg/day) plus the same calcium dose, low dose conjugated estrogens (CE) (0.3 mg/day) plus calcium, or low dose IP (400 mg/day) plus low dose CE (0.3 mg/day) plus calcium. The results were analyzed by repeated measures analysis of variance, as appropriate.

RESULTS

No modifications of both urinary excretion of hydroxyproline and plasma osteocalcin levels were observed in calcium and in CE-treated women, while vertebral bone density significantly decreased (P < 0.0001) in both groups. In IP or IP + CE-treated women, plasma osteocalcin did not show any modification, while urinary hydroxyproline showed a significant (P < 0.05) decrease, that paralleled a significant (P < 0.05) increase in vertebral bone density.

CONCLUSION

Postmenopausal IP administration, at the standard dose of 600 mg/day, can prevent the increase in bone turnover and the decrease in bone density that follow ovarian failure. The same effect can be obtained with the combined administration of low dose (400 mg/day) IP with low dose (0.3 mg/day) CE.

Bone density changes in postmenopausal women with the administration of ipriflavone alone or in association with low-dose ERT

Ipriflavone is a synthetic flavonoid that has been shown to exert a direct inhibitory effect on osteoclastic activity and possibly stimulate the osteoblast activity in different experimental models. The aim of the present study was to evaluate the effects of either ipriflavone alone or ipriflavone plus low dose hormone replacement therapy (HRT) in the prevention of postmenopausal bone loss. Patients were randomly allocated to different treatment groups receiving calcium (500 mg/day, control group), continuous HRT (25 or 50 micrograms/day of transdermal 17 beta-estradiol) plus medrogestone 5 mg/day for 12 days/month, ipriflavone at the standard dose of 600 mg/day, or finally ipriflavone 600 mg/day plus 17 beta-estradiol 25 micrograms/day plus medrogestone 5 mg/day for 12 days/month. No significant differences in basal levels of biochemical markers of bone turnover or in basal bone mineral density (BMD) values were evident in the different groups. In the control group after 12 months, spine BMD showed a significant (p < 0.05) 3.41% decrease. The pattern of BMD modification was significantly different from controls in the high dose HRT group (+1.84%), the ipriflavone group (+0.11%), and the combined ipriflavone/HRT group (-0.22%). Conversely, the BMD pattern in the low dose HRT group (-0.55%) was similar to that observed in controls. Thus, present results confirm that ipriflavone and 50 micrograms/day of transdermal 17 beta-estradiol are effective measures in the prevention of postmenopausal osteopenia. A lower transdermal estrogen dose is unable to increase the antiresorptive effect of ipriflavone and did not exert any further action in the prevention of postmenopausal osteopenia.

Implementation of an osteoporosis research program with a mobile dual-energy X-ray absorptiometry unit: the Montana/Wyoming experience

To expedite recruitment, and subject participation, for a large clinical osteoporosis therapy trial utilizing the bisphosphonate ibandronate, an integrated network of 13 satellite clinical sites was developed, linked by a mobile clinic vehicle transporting a dual-energy X-ray absorptiometry (DXA) unit. A predominantly rural area of the United States (Montana, northern Wyoming) was accessed for the project, due to the large pool of potential subjects living in this area who were not yet involved in osteoporosis clinical studies. The results of the project to date (through 10 months) confirm the feasibility of such a study design, with 1774 subjects screened by DXA for the study, and 280 (15.8%) accepted. The mobile DXA unit has functioned according to specifications for a stationary DXA machine, with the stability of spine phantom measurements over 10 months assessed as a coefficient of variation of 0.46%. The success of the project validates the concept of performing clinical osteoporosis therapy trials in previously underutilized rural community settings, facilitated by a satellite site network and mobile clinic.

Estrogen therapy and osteoporosis: principles & practice

Postmenopausal osteoporosis is linked clearly to estrogen deprivation. Recent research has identified estrogen receptors in bone cells and in other organ systems that help to regulate bone remodeling and calcium homeostasis. Long-term use of estrogen in appropriate doses reduces the risk of hip fractures by 50% to 60% and the risk of vertebral deformation by 90%. This protective effect is maintained as long as estrogen is taken and adequate levels of biologically active estrogen are achieved. Thus, the type, dose, and route of administration of estrogen need to be individualized and the efficacy of treatment monitored by annual bone density testing and selective ultilization of biochemical bone markers. The ability of estrogen therapy to increase bone mass is enhanced by added androgens and progestin therapy, calcium supplementation, and exercise.

Bone loss rate in the lumbar spine: a comparison between natural and surgically induced menopause

OBJECTIVE

To compare the bone loss between natural and surgically induced menopause by dual photon absorbsiometry (DPA) and quantitative computed tomography (QCT).

METHODS

The study group included 365 women, who were in menopause for at least 6 months. Of all patients, 272 became menopausal naturally and 93 surgically. Spinal bone mineral density (BMD) of the women was determined by DPA in 201 patients and by QCT in 164. Regression analysis was used to correlate BMD and months since menopause.

RESULTS

Measurements with DPA did not show any significant difference in bone loss between natural and surgical menopause patients, whereas in the group of patients of whom BMD is measured by QCT, a relatively increased bone loss rate is found in surgically induced menopause patients.

CONCLUSIONS

Oopherectomized women seemed to suffer a relatively higher bone loss rate compared with natural menopause.

Effects of continuous percutaneous estradiol administration on skeletal turnover in postmenopausal women: a 1-year prospective controlled study

The aim of this study was to investigate the short and long term effects of continuous percutaneous administration of estradiol (E2) cream on skeletal turnover in women in surgical postmenopause. Forty women were randomly divided into two groups, one treated with a single daily application of 3 mg/day E2 cream continuously for 12 months, the other receiving placebo cream. Forearm densitometry was performed before and at the end of treatment. Serum E2, osteocalcin (BGP), alkaline posphatase (AP) and urinary N-telopeptide of type I collagen (NTX) were also measured at baseline, month 4 and 12 of the protocol. At month 4, bone turnover was also assessed by evaluating 99mtechnetium-methylene diphosphonate (99mTc-MDP) skeletal uptake. Changes in E2, BGP, AP and NTX as well as 99mTc-MDP skeletal uptake in hormone group vs. placebo were significant after 4 months of treatment. At month 12, proximal site densitometry showed no variation in either group whereas the percentage of variation in distal site measurements resulted significantly different with an increase in the hormone group and a reduction in the placebo group. In conclusion continuous percutaneous administration of E2 cream was effective in rapidly reducing bone turnover in postmenopausal women and in counteracting the accelerated postmenopausal bone loss.

Salmon calcitonin plus intravaginal estriol: an effective treatment for the menopause

OBJECTIVE

Intravaginal estriol (E3) effectively improves postmenopausal genito-urinary disturbances, without stimulating endometrial proliferation. The aim of the present study was to evaluate the effect of intravaginal estriol (E3) plus nasal spray salmon calcitonin (sCT), to improve neurovegetative symptoms and to prevent the decline of bone mineral density (BMD) of postmenopausal women.

METHODS

Two hundred and fourteen (214) healthy postmenopausal women were treated for 12 months with: (1) E3 (0.5 mg every other day) + Ca (0.5 g/day); (2) E3 + Ca + sCT (50 IU x 2/day); (3) sCT + Ca; (4) Ca. Climacteric complaints, such as hot flushes and sweating, BMD at the distal 1/10 of the radius, analyzed by dual photon absorptiometry, urinary excretion of hydroxyproline and serum alkaline phosphatase were evaluated at baseline and every 6 months. At the same time, patient compliance and drug tolerability were evaluated.

RESULTS

E3 but not sCT, improved hot flushes and sweating. E3 blunted but not completely counteracted the BMD decline observed in women treated with only Ca, and reduced urinary hydroxyproline excretion. sCT markedly increased BMD values and reduced both urinary hydroxyproline excretion and serum alkaline phosphatase. These effects were not potentiated by E3 coadministration. All treatments were well tolerated.

CONCLUSIONS

Present data indicate that the combined administration of intravaginal E3 and sCT may represent an alternative therapeutic regimen for those postmenopausal women who do not accept or have contraindications to classical hormone replacement therapy.

Falls and hip fracture. A reasonable basis for possibilities for prevention? Some preliminary data from the MEDOS study Mediterranean Osteoporosis Study

The Mediterranean Osteoporosis Study (MEDOS), a multicentre study on incidence, risk factors, and means of prevention of hip fracture in the Mediterranean region, started in 1986 and involved 14 centres, in Portugal, Spain, France, Italy, Greece, and Turkey. The design includes a case-control study comparing 8,185 individuals in age groups above 50 (2,816 cases and 5,369 controls; two controls per case). Information on falls was only collected for a small fraction of the controls. In a questionnaire including 160 main questions eleven referred to circumstances around the fall. Falls were classified according to a) high risk environment, e.g. occurred in darkness and b) high risk fallers, e.g. confusion, reduced functional ability. There was great variation between centra for a majority of the results. However, 2/3 of fractures happened during daylight. 9% of fractures, same for both males and females, took place in darkness. Females have more indoor fractures than males. Around 15% of fractures took place in connection with going to the toilet. Mental factors play a minor role as reported immediate cause to the fall. Before the fall that caused the hip fracture between 28-84% could get up from a chair without any difficulties. Of the males 0-26% lived alone as against 0-37% or females.

CONCLUSION

The data on circumstances around the fall shows a complex pattern with substantial variation between different cultures, but where a, however, minority took place under risk circumstances that have a clear preventive potential.

Results of conference questionnaire to participants on key issues in the prevention of osteoporosis

At a conference on recent progress in the prevention of osteoporosis a questionnaire on some key issues in prevention was distributed and replied to before the conference. Response rate was 63%. In general the expectations on the impacts of prevention were high. Life style changes were judged to be important, although somewhat weak scientific evidence. Cost effectiveness of preventive measures for osteoporosis were rated relatively high. More data on the place of oestrogen replacement therapy was needed for the oldest age-group, 75+ years. The attitude towards screening was positive. Respondents believed that hip fracture incidence would increase substantially in the world by the year 2020.

Factors associated with menstrual irregularities and decreased bone mineral density in female athletes

Menstrual irregularities occur in some female athletes. The most extreme form of menstrual irregularity is amenorrhea, which has been linked to significant decreases in vertebral bone density and increases in injury prevalence. Many authors have sought to determine the causal factors of athletic amenorrhea, some of which include hormonal status, training and physical parameters, nutritional balance, and psychological stress. The purpose of this paper was to compare studies that have examined the relationship of these variables to menstrual irregularities and bone density. Controversy exists regarding the relative contribution of these variables. The etiology is likely multifactorial and should be evaluated as such. Clinicians treating female athletes must be knowledgeable about the negative consequences associated with menstrual irregularities. Furthermore, it is critical that clinicians provide thorough patient education in order to prevent injuries and the long-term loss of bone density. Appropriate medical and/or psychological referral of the athlete with menstrual irregularities may be necessary.

Practical management of postmenopausal women with low bone mineral density

For the management of postmenopausal women with low bone mineral density (BMD), the gynecologist, as a primary care physician, should play a central role in preventing osteoporotic fracture by educating them for elimination of risk factors and for healthy life-style and by providing an appropriate drug therapy. Because the risk of fracture usually increases after BMD decreases as much as 20-30% of peak bone mass, it is practically reasonable to set this level of BMD as a criteria for the initiation of management. As for a drug treatment, it is better to combine estrogen, the first choice drug, with progestogens to counteract any neoplastic effect of unopposed estrogen on the endometrium. Bisphosphonates and calcitonin, which are inhibitors of bone resorption, provide an alternative in prevention and treatment of postmenopausal bone loss in case of contraindication for estrogen or in those women who are unwilling to take estrogen.

Treatment of postmenopausal vertebral osteopenia with monofluorophospate: a long-term calcium-controlled study

The aim of the present study was to assess the effects of the new fluorine pro-drug monofluorophosphate (MFP) in postmenopausal women with vertebral osteopenia and high bone turnover. We enrolled postmenopausal women (PMW, 43-59 years) who had had a natural menopause 2-5 years before the study, had vertebral bone mineral density (BMD) < 1 SD from the premenopausal mean, and had at least one of the biochemical markers of bone remodeling > 1 SD over the mean for premenopausal women. Patients were randomly divided into two treatment groups (group 1, 500 mg/day of oral calcium; group 2, MFP at the dose of 20 mg F-equivalents + 600 mg calcium/day) for 2 years (n = 21 in each group). The lumbar vertebral (L2-4) BMD and total body bone mineral (TBBM) were measured by dual-energy X-ray absorptiometry (Lunar DPX, Lunar Corporation, USA). Urinary hydroxyproline excretion (OH-P/Cr), plasma bone Gla protein (BGP) and serum alkaline phosphatase (AP) were assayed. In group 1 the markers of bone turnover and vertebral BMD did not show any significant modification, while TBBM showed a significant (p < 0.05) decrease after 24 months. In group 2 a significant (p < 0.05) decrease in OH-P/Cr (-23.9 +/- 2.0%), and an increase in both BGP (+19.4 +/- 2.6%) and AP (+10.3 +/- 2.6%) levels were observed after 24 months of MFP administration. In this group, both vertebral BMD (+5.01 +/- 0.9%, p < 0.01) and TBBM (+4.0 +/- 0.6%, p < 0.05) showed a significant increase after 24 months. Present results suggest that, in osteopenic PMW, MFP administration induces a significant increase in vertebral BMD without impairment of cortical bone, with a reduction in bone resorption and an increase in bone formation rate.

Bone metabolism changes after transdermal estradiol dose reduction during estrogen replacement therapy: a 1-year prospective study

Twenty-four surgically menopausal women were randomly allocated to one of two transdermally-administered estrogen replacement therapies (ERT): Group A was administered Estradiol (E2) TTS 0.05 mg/day for 6 months and 0.025 mg/day for the following six months and group B, E2 TTS 0.10 mg/day for the first 6 months and 0.05 mg/day for the following 6 months. For both groups, the treatment regimen was based upon the twice-weekly application of transdermal patches to the lower abdomen for three weeks a month. Serum E2, alkaline phosphatase (AP), osteocalcin (BGP) and urinary hydroxyproline (OHP) excretion levels were measured before the operation, at the beginning of ERT and after 6 and 12 months of treatment. Bone mineral density (BMD) in the distal regions of the forearms was measured by single photon absorptiometry at the start of the study and after 6 and 12 months. In Group A, both mean cortical and trabecular BMD had increased by, respectively, 1.53% and 2.17% after 6 months of therapy; after the second 6 months a significant decrease was observed in both parameters (2.40% and 3.62%, respectively). In Group B, mean cortical and trabecular BMD increased by 1.50% and 2.10%, respectively (significant increase in trabecular bone) after the first 6 months of treatment; after the following 6 months, these values persisted (+0.15 and -0.03%, respectively). Mean AP, OHP and BGP serum levels rose after the operation. In Group A, AP and OHP showed a significant decrease after the first 6 months (-34.90% and -30.90%), followed by an increase at the last evaluation of 22.50% and 35.50%, that reached statistical significance only for OHP.(ABSTRACT TRUNCATED AT 250 WORDS)