Evaluation of methods for prediction of bone mineral density by clinical and biochemical variables in perimenopausal women

Osteoporosis among Postmenopausal Women in Jordan: A National Cross-Sectional Study

Osteoporosis is considered a widespread health problem that affects senior citizens, particularly older women, after the menopause. This national study aimed to estimate the prevalence of osteoporosis among Jordanian postmenopausal women and to determine the association of demographic and nutritional factors, such as calcium and vitamin D supplement intake, with osteoporosis in postmenopausal women. A cross-sectional study was conducted among 884 postmenopausal women aged ≥50 years. A multistage sampling technique was used to select participants from three geographic regions of Jordan (north, middle, and south). The data were collected from the participants by a team of field researchers comprising men and women through a standard questionnaire. The prevalence of osteoporosis was 19.8% among postmenopausal Jordanian women. The study results showed that age (p ˂ 0.001), geographic region (p = 0.019), occupation (p = 0.002), and educational level (p = 0.001) were significantly associated with osteoporosis. Moreover, osteoporosis was significantly associated with calcium and vitamin D supplement intake (p < 0.05). There is a high prevalence of osteoporosis among postmenopausal Jordanian women. Therefore, there is a need to educate women at this age, and probably at an earlier age, to prevent or reduce the development of osteoporosis.

Bone alkaline phosphatase and urine hydroxyproline assay in pre and postmenopausal women in the state of sikkim and its correlation with bone mineral density

Introduction:

Osteoporosis could be viewed as a metabolic disease. The WHO guidelines for diagnosing osteoporosis reflect structural damage only and not the metabolic imbalance that leads to it. Biochemical markers of bone turnover have been shown to provide valuable information for diagnosing and monitoring metabolic bone disease. The present study analyzed bone-specific alkaline phosphatase (BALP) and urinary hydroxyproline in pre- and postmenopausal women and correlated them with changes in bone mineral density (BMD) in the state of Sikkim. The study also intended to know the ethnicity-based disease burden in Sikkim.

Materials and Methods:

A hospital-based cross-sectional study was done at a tertiary hospital in Sikkim. Blood and 24-h urine samples from 50 premenopausal and 50 postmenopausal women were analyzed for total alkaline phosphatase (ALP), BALP, and Urine Hydroxyproline. BMD was measured using the quantitative ultrasound technique by Achilles densitometer.

Results:

There was a statistically significant increase in serum calcium (P = 0.01), ALP (P = 0.01), and urine hydroxyproline (P = 0.03) levels in postmenopausal women as compared to premenopausal women. Although ALP was higher in postmenopausal women, BALP isoform was more elevated in premenopausal women (P = 0.001). BMD was significantly lower in postmenopausal women (P < 0.001). It was also noted that there was a significant difference in BMD between tribal and nontribal populations (P = 0.003). Total ALP and BALP as the bone formation marker and urine hydroxyproline as a bone resorption marker added statistically significant r to BMD prediction (P < 0.05).

Conclusion:

In this study, BALP combined with Urine Hydroxyproline was helpful as a screening biomarker to predict osteoporosis in postmenopausal women.

Osteoprotective Roles of Green Tea Catechins

Osteoporosis is the second most common disease only secondary to cardiovascular disease, with the risk of fracture increasing with age. Osteoporosis is caused by an imbalance between osteoblastogenesis and osteoclastogenesis processes. Osteoclastogenesis may be enhanced, osteoblastogenesis may be reduced, or both may be evident. Inflammation and high reactive oxygen enhance osteoclastogenesis while reducing osteoblastogenesis by inducing osteoblast apoptosis and suppressing osteoblastic proliferation and differentiation. Catechins, the main polyphenols found in green tea with potent anti-oxidant and anti-inflammatory properties, can counteract the deleterious effects of the imbalance of osteoblastogenesis and osteoclastogenesis caused by osteoporosis. Green tea catechins can attenuate osteoclastogenesis by enhancing apoptosis of osteoclasts, hampering osteoclastogenesis, and prohibiting bone resorption in vitro. Catechin effects can be directly exerted on pre-osteoclasts/osteoclasts or indirectly exerted via the modulation of mesenchymal stem cells (MSCs)/stromal cell regulation of pre-osteoclasts through activation of the nuclear factor kB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system. Catechins also can enhance osteoblastogenesis by enhancing osteogenic differentiation of MSCs and increasing osteoblastic survival, proliferation, differentiation, and mineralization. The in vitro effects of catechins on osteogenesis have been confirmed in several animal models, as well as in epidemiological observational studies on human subjects. Even though randomized control trials have not shown that catechins provide anti-fracture efficacy, safety data in the trials are promising. A large-scale, placebo-controlled, long-term randomized trial with a tea regimen intervention of optimal duration is required to determine anti-fracture efficacy.

Quantitative prediction of bone mineral density by using bone turnover markers in response to antiresorptive agents in postmenopausal osteoporosis: A model-based meta-analysis

AIMS

This study aimed to predict time course of bone mineral density (BMD) by using corresponding response of bone turnover markers (BTMs) in women with postmenopausal osteoporosis under antiresorptive treatments.

METHODS

Data were extracted from literature searches in accessible public database. Time courses of percent change from baseline in serum C-telopeptide of type 1 collagen (sCTX) and N-telopeptide of type 1 collagen were described by complex exponential onset models. The relationship between BTM changes and BMD changes at lumbar spine and total hip was described using a multiscale indirect response model.

RESULTS

The dataset included 41 eligible published trials of 5 US-approved antiresorptive agents (alendronate, ibandronate, risedronate, zoledronic acid and denosumab), containing over 28 800 women with postmenopausal osteoporosis. The time courses of BTM changes for different drugs were differentiated by maximal effect and onset rate in developed model, while sCTX responses to zoledronic acid and denosumab were captured by another model formation. Furthermore, asynchronous relationship between BTMs and BMD was described by a bone remodelling-based semimechanistic model, including zero-order production and first-order elimination induced by N-telopeptide of type 1 collagen and sCTX, separately. After external and informative validations, the developed models were able to predict BMD increase using 1-year data.

CONCLUSION

This exploratory analysis built a quantitative framework linking BTMs and BMD among antiresorptive agents, as well as a modelling approach to enhance comprehension of dynamic relationship between early and later endpoints among agents in a certain mechanism of action. Moreover, the developed models can offer predictions of BMD from BTMs supporting early drug development.

Tea consumption and bone health in Chinese adults: a population-based study

Tea is a worldwide drink with controversial effect on bone health. The sex-specific associations are unrevealed among general population. This study showed that prolonged moderate tea consumption benefited bone health in women, while no additional benefit with stronger tea. However, tea consumption was not associated with bone health in men.

INTRODUCTION

Tea consumption has been shown a potentially beneficial effect on bone health in postmenopausal women. However, little is known about such association in men, and whether stronger tea instead harms bone health due to elevated urinary excretion of calcium associated with caffeine in the tea. The aim of this study was to examine the association between various metrics of tea consumption and bone health.

METHODS

The present study included 20,643 participants from the China Kadoorie Biobank (CKB), who have finished both baseline survey (2004-2008) and a re-survey (2013-2014). They were aged 38-86 years at re-survey. Tea consumption was self-reported at both baseline and re-survey. Bone mineral density (BMD) was measured using calcaneal quantitative ultrasound once at re-survey.

RESULTS

Compared with non-consumers, prolonged weekly tea consumers in women was associated with higher calcaneus BMD measures, with β (95% CI) of 0.98 (0.22, 1.74) for BUA, 4.68 (1.74, 7.61) for SOS, and 1.95 (0.81, 3.10) for SI. Among prolonged weekly tea consumers, no linear increase in BMD measures with the amount of tea leaves added was observed. The SOS and SI were higher in consumers with tea leaves 3.0-5.9 g/day than in those with < 3.0 g/day, but were reduced to non-significant for those with ≥ 6.0 g/day. Tea consumption was not associated with calcaneus BMD measures in men.

CONCLUSION

Prolonged moderate tea consumption benefited bone health in women but not in men. For stronger tea consumption with more tea leaves added, neither benefit nor harm to bone health was observed.

An assessment of the relation between bone mineral density and clinic-demographic properties and life quality during postmenopausal period

OBJECTIVES

This study was conducted to assess the relation between bone mineral density (BMD) and clinic-demographic properties and life quality during postmenopausal period.

METHODS

The study group consisted of 172 postmenopausal women who applied to the physical therapy and rehabilitation outpatient clinic at a training and research hospital in Ankara, the capital of Turkey. The Survey Form, The 36-item Short Form Health Survey (SF-36) and the FRAX™ were used as data collection tools in this study.

RESULTS

The osteoporosis and osteopenia frequencies were respectively 28.5% and 42.4% in this study. The 10-year major osteoporotic fracture risk was 5.15% and the femur fracture risk was estimated as 0.9%. In this study, there was a positive and significant relation found between the L1⁢-⁢4 and FN T-score and SF-36 scale score average (p< 0.05). There was a significant relation between the body mass index and SF-36 subscale 'mental health' (p< 0.05). In this study, the most significant determinant of life quality was exhibited as the "L1⁢-⁢4 T-score" (β= 55.509, p= 0.000).

CONCLUSIONS

We determined that approximately one of every four women had osteoporosis and as the BMD dropped, the life quality of the women declined. Hence, we think that improving the awareness of health professionals working in this field is essential.

Analysis of Bone Alkaline Phosphatase as a Marker for the Diagnosis of Osteoporosis in Men under Androgen Ablation

The objective of this study was to evaluate the usefulness of serum determination of bone alkaline phosphatase (BAP) in the diagnosis of osteoporosis in men with prostate cancer under androgen ablation. Serum levels of BAP and bone mineral density (BMD) were assessed in 110 patients with non-metastatic, treated prostate cancer. Fifty-eight patients were under androgen deprivation during a period between two and 96 months and 52 had been submitted only to radical prostatectomy. Mean serum BAP was 11.8 ng/mL in patients with normal BMD, 16.7 ng/mL in patients with osteopenia (p. 0.058), and 19.3 ng/mL in patients with osteoporosis (p=0.044). The correlation between serum BAP and BMD was significant (p. 0.006) but with an index of only 0.26. Receiver operating characteristic analysis for the diagnosis of osteoporosis showed an area under the curve of 0.608. None of the cutoff points that provided specificities of 75%, 90% and 95% gave significant distributions. The positive and negative predictive values as well as the odds ratios were not of any clinical usefulness. We conclude that serum BAP should not be considered a good marker for the diagnosis of osteoporosis in men with prostate cancer. Therefore, BAP serum determination cannot replace bone densitometry as a diagnostic tool.

Updated association of tea consumption and bone mineral density: A meta-analysis

BACKGROUND

Current studies evaluating the association of tea consumption and bone mineral density (BMD) have yielded inconsistent findings. Therefore, we conducted a meta-analysis to assess the relationship between tea consumption and BMD.

METHODS

The PubMed, Embase, and Cochrane Library databases were comprehensively searched, and a meta-analysis performed of all observational studies assessing the association of tea consumption and BMD. Forest plots were used to illustrate the results graphically. The Q-test and I statistic were employed to evaluate between-study heterogeneity. Potential publication bias was assessed by the funnel plot.

RESULTS

Four cohort, 1 case-control, and 8 cross-sectional studies including a total of 12,635 cases were included. Tea consumption was shown to prevent bone loss [odds ratio (OR): 0.66; 95% confidence interval (CI), 0.47-0.94; P = 0.02], yielding higher mineral densities in several bones, including the lumbar spine [standardized mean difference (SMD): 0.19; 95% CI, 0.08-0.31; P = 0.001], hip (SMD: 0.19; 95% CI, 0.05-0.34; P = 0.01), femoral neck [mean difference (MD): 0.01; 95% CI, 0.00-0.02; P = 0.04], Ward triangle (MD: 0.02; 95% CI, 0.01-0.04; P = 0.001), and greater trochanter (MD: 0.03; 95% CI, 0.02-0.04; P < 0.00001), than the non-tea consumption group.

CONCLUSION

This meta-analysis provided a potential trend that tea consumption might be beneficial for BMD, especially in the lumbar spine, hip, femoral neck, Ward triangle, and greater trochanter, which might help prevent bone loss.

Tea flavonoids for bone health: from animals to humans

Osteoporosis is a skeletal disease characterized by a deterioration of bone mass and bone quality that predisposes an individual to a higher risk of fragility fractures. Emerging evidence has shown that the risk for low bone mass and osteoporosis-related fractures can be reduced by nutritional approaches aiming to improve bone microstructure, bone mineral density, and strength. Tea and its flavonoids, especially those of black tea and green tea, have been suggested to protect against bone loss and to reduce risk of fracture, due to tea's antioxidant and anti-inflammatory properties. Based on the results of animal studies, moderate intake of tea has shown to benefit bone health as shown by mitigation of bone loss and microstructural deterioration as well as improvement of bone strength and quality. Epidemiological studies have reported positive, insignificant, and negative impacts on bone mineral density at multiple skeletal sites and risk of fracture in humans with habitual tea consumption. There are limited human clinical trials that objectively and quantitatively assessed tea consumption and bone efficacy using validated outcome measures in a population at high risk for osteoporosis, along with safety monitoring approach. This review summarizes the current state of knowledge of laboratory animal research, epidemiological observational studies, and clinical trials assessing the skeletal effects of tea and its active flavonoids, along with discussion of relevant future directions in translational research.

Tea and bone health: steps forward in translational nutrition

Osteoporosis is a major health problem in the aging population worldwide. Cross-sectional and retrospective evidence indicates that tea consumption may be a promising approach in mitigating bone loss and in reducing risk of osteoporotic fractures among older adults. Tea polyphenols enhance osteoblastogenesis and suppress osteoclastogenesis in vitro. Animal studies reveal that intake of tea polyphenols have pronounced positive effects on bone as shown by higher bone mass and trabecular bone volume, number, and thickness and lower trabecular separation via increasing bone formation and inhibition of bone resorption, resulting in greater bone strength. These osteoprotective effects appear to be mediated through antioxidant or antiinflammatory pathways along with their downstream signaling mechanisms. A short-term clinical trial of green tea polyphenols has translated the findings from ovariectomized animals to postmenopausal osteopenic women through evaluation of bioavailability, safety, bone turnover markers, muscle strength, and quality of life. For future studies, preclinical animal studies to optimize the dose of tea polyphenols for maximum osteoprotective efficacy and a follow-up short-term dose-response trial in postmenopausal osteopenic women are necessary to inform the design of randomized controlled studies in at-risk populations. Advanced imaging technology should also contribute to determining the effective dose of tea polyphenols in achieving better bone mass, microarchitecture integrity, and bone strength, which are critical steps for translating the putative benefit of tea consumption in osteoporosis management into clinical practice and dietary guidelines.

Predicting nonlinear changes in bone mineral density over time using a multiscale systems pharmacology model

A mathematical model component that extends an existing physiologically based multiscale systems pharmacology model (MSPM) of calcium and bone homeostasis was developed, enabling prediction of nonlinear changes in lumbar spine bone mineral density (LSBMD). Data for denosumab, a monoclonal antibody osteoporosis treatment, dosed at several levels and regimens, was used for fitting the BMD component. Bone marker and LSBMD data extracted from the literature described on/off-treatment effects of denosumab over 48 months [Miller, P.D. et al. Effect of denosumab on bone density and turnover in postmenopausal women with low bone mass after long-term continued, discontinued, and restarting of therapy: a randomized blinded phase 2 clinical trial. Bone 43, 222–229 (2008)]. An indirect model linking bone markers to LSBMD was embedded in the existing MSPM, reasonably predicting nonlinear increases in LSBMD during treatment (24 months); LSBMD declines following discontinuation and increases upon treatment reinstitution. This study demonstrates the utility of MSPM extension to describe a phenomena of interest not originally in a model, and the ability of this updated MSPM to predict nonlinear longitudinal changes in the clinically relevant endpoint, LSBMD, with denosumab treatment.

Bone mineral density, polyphenols and caffeine: a reassessment

Several studies have shown beneficial associations between tea consumption and bone mineral density (BMD) and fracture risk. Current investigations into potential mechanisms of benefit are focused upon the F and polyphenol components of tea. However, previous studies have pointed towards caffeine consumption as a potential risk factor for low BMD and high fracture risk. Tea, therefore, represents an interesting paradox as a mildly caffeinated beverage that may enhance bone health. Fruit and vegetable intake has also been associated with BMD, and it is now apparent that several fruit and vegetable components, including polyphenols, may contribute positively to bone health. Evidence surrounding the function(s) of polyphenol-rich foods in bone health is examined, along with more recent studies challenging the relevance of caffeine consumption to in vivo Ca balance. Plant foods rich in polyphenols such as tea, fruit and vegetables, as significant factors in a healthy diet and lifestyle, may have positive roles in bone health, and the negative role of caffeine may have been overestimated. The present review covers evidence of dietary mediation in positive and negative aspects of bone health, in particular the roles of tea, fruit and vegetables, and of caffeine, flavonoids and polyphenols as components of these foods. Since the deleterious effects of caffeine appear to have been overstated, especially in respect of the positive effects of flavonoids, it is concluded that a reassessment of the role of caffeinated beverages may be necessary.

Effect of green tea and Tai Chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial

Postmenopausal women with osteopenia received green tea polyphenols (GTP) supplement and/or Tai Chi exercise for 6 months. Bone turnover biomarkers, calcium metabolism, and muscle strength were measured. This study showed that GTP supplementation and Tai Chi exercise increased bone formation biomarkers and improved bone turnover rate. Tai Chi exercise increased serum parathyroid hormone. GTP supplementation, Tai Chi exercise, and the combination of the two all improved muscle strength in postmenopausal women with osteopenia.

INTRODUCTION

This study evaluated the effect of GTP supplementation and Tai Chi (TC) exercise on serum markers of bone turnover (bone-specific alkaline phosphatase, BAP, and tartrate-resistant acid phosphatase, TRAP), calcium metabolism, and muscle strength in postmenopausal osteopenic women.

METHODS

One hundred and seventy-one postmenopausal osteopenic women were randomly assigned to four groups: (1) placebo (500 mg starch/day), (2) GTP (500 mg GTP/day), (3) placebo + TC (placebo plus TC training at 60 min/session, three sessions/week), and (4) GTP + TC (GTP plus TC training). Overnight fasting blood and urine samples were collected at baseline, 1, 3, and 6 months for biomarker analyses. Muscle strength was evaluated at baseline, 3, and 6 months. One hundred and fifty subjects completed the 6-month study.

RESULTS

Significant increases in BAP level due to GTP intake (at 1 month) and TC (at 3 months) were observed. Significant increases in the change of BAP/TRAP ratio due to GTP (at 3 months) and TC (at 6 months) were also observed. Significant main effect of TC on the elevation in serum parathyroid hormone level was observed at 1 and 3 months. At 6 months, muscle strength significantly improved due to GTP, TC, and GTP + TC interventions. Neither GTP nor TC affected serum TRAP, serum and urinary calcium, and inorganic phosphate.

CONCLUSION

In summary, GTP supplementation and TC exercise increased BAP and improved BAP/TRAP ratio. TC exercise increased serum parathyroid hormone. GTP supplementation, TC exercise, and the combination of the two all improved muscle strength in postmenopausal women with osteopenia.

Green tea polyphenols and Tai Chi for bone health: designing a placebo-controlled randomized trial

BACKGROUND

Osteoporosis is a major health problem in postmenopausal women. Evidence suggests the importance of oxidative stress in bone metabolism and bone loss. Tea consumption may be beneficial to osteoporosis due to its antioxidant capability. However, lack of objective data characterizing tea consumption has hindered the precise evaluation of the association between tea ingestion and bone mineral density in previous questionnaire-based epidemiological studies. On the other hand, although published studies suggest that Tai Chi (TC) exercise can benefit bone health and may reduce oxidative stress, all studies were conducted using a relatively healthy older population, instead of a high-risk one such as osteopenic postmenopausal women. Therefore, this study was designed to test an intervention including green tea polyphenol (GTP) and TC exercise for feasibility, and to quantitatively assess their individual and interactive effects on postmenopausal women with osteopenia.

METHODS/DESIGN

One hundred and forty postmenopausal women with osteopenia (defined as bone mineral density T-score at the spine and/or hip between 1 to 2.5 SD below the reference database) were randomly assigned to 4 treatment arms: (1) placebo group receiving 500 mg medicinal starch daily, (2) GTP group receiving 500 mg of GTP per day, (3) placebo+TC group receiving both placebo treatment and TC training (60-minute group exercise, 3 times per week), and (4) GTP+TC group receiving both GTP and TC training for 24 weeks. The outcome measures were bone formation biomarker (serum bone alkaline phosphatase), bone resorption biomarker (serum tartrate resistant acid phosphatase), and oxidative DNA damage biomarker (urinary 8-hydroxy-2'-deoxyguanosine). All outcome measures were determined at baseline, 4, 12, and 24 weeks. Urinary and serum GTP concentrations were also determined at baseline, 4, 12, and 24 weeks for bioavailability. Liver function was monitored monthly for safety. A model of repeated measurements with random effect error terms was applied. Traditional procedures such as ANCOVA, chi-squared analysis, and regression were used for comparisons.

DISCUSSION

We present the rationale, design, and methodology of a placebo-controlled randomized trial to investigate a new complementary and alternative medicine strategy featuring a dietary supplement and a mind-body exercise for alleviating bone loss in osteopenic postmenopausal women.

Green tea and bone metabolism

Osteoporosis is a major health problem in both elderly women and men. Epidemiological evidence has shown an association between tea consumption and the prevention of age-related bone loss in elderly women and men. Ingestion of green tea and green tea bioactive compounds may be beneficial in mitigating bone loss of this population and decreasing their risk of osteoporotic fractures. This review describes the effect of green tea or its bioactive components on bone health, with an emphasis on (i) the prevalence and etiology of osteoporosis; (ii) the role of oxidative stress and antioxidants in osteoporosis; (iii) green tea composition and bioavailability; (iv) the effects of green tea and its active components on osteogenesis, osteoblastogenesis, and osteoclastogenesis from human epidemiological, animal, as well as cell culture studies; (v) possible mechanisms explaining the osteoprotective effects of green tea bioactive compounds; (vi) other bioactive components in tea that benefit bone health; and (vii) a summary and future direction of green tea and bone health research and the translational aspects. In general, tea and its bioactive components might decrease the risk of fracture by improving bone mineral density and supporting osteoblastic activities while suppressing osteoclastic activities.

Bone metabolism in type 2 diabetes and role of thiazolidinediones

PURPOSE OF REVIEW

To assess bone turnover both at the biochemical and organ level in patients with type 2 diabetes (T2D) and the effects of the thiazolidinediones.

RECENT FINDINGS

Studies have shown a decreased bone formation and an increased risk of fractures in patients with T2D. Changes in bone strength from glycation of collagen and negative calcium balance from calcium loss in the urine due to hyperglycaemia may also be seen. The thiazolidinediones affect bone turnover by increasing the formation of adipocytes instead of the bone-forming osteoblasts from the common mesenchymal stem cell. A decreased bone formation with decreased bone density and an increased risk of fractures has been observed among users of thiazolidinediones. Differences exist between type 1 diabetes (T1D) and T2D with a much higher increase in the risk of hip fractures in T1D than in T2D compared with the general population. The often higher body mass index in T2D than in T1D appears to explain some of the differences in risk of fractures.

SUMMARY

Diabetes is a hitherto overlooked risk factor for osteoporosis and fractures. Thiazolidinediones may increase risk of fractures and should not be used by patients at risk of fractures. More research is needed.

Clinical application of biochemical markers of bone turnover

With the ageing population in most countries, disorders of bone and mineral metabolism are becoming increasingly relevant to every day clinical practice. Consequently, the interest in, and the need for effective measures to be used in the screening, diagnosis and follow-up of such pathologies have markedly grown. Together with clinical and imaging techniques, biochemical tests play an important role in the assessment and differential diagnosis of metabolic bone disease. In recent years, the isolation and characterisation of cellular and extracellular components of the skeletal matrix have resulted in the development of molecular markers that are considered to reflect either bone formation or bone resorption. These biochemical indices are non-invasive, comparatively inexpensive and, when applied and interpreted correctly, helpful tools in the diagnostic and therapeutic assessment of metabolic bone disease. This review provides an overview of the current evidence regarding the clinical use of biochemical markers of bone remodelling in bone disease, with an emphasis on osteoporosis.

Age-related changes of serum bone alkaline phosphatase and cross-linked C-telopeptides of type I collagen and the relationship with bone mineral density in Chinese women

BACKGROUND

Previous studies have shown that bone turnover rate changes with age. At the same time, there is no definitive research regarding age-related changes of bone turnover level and its association with bone mineral density (BMD) in Chinese mainland women.

METHODS

In a cohort of 663 Chinese mainland women aged 20-70 years, serum bone alkaline phosphatase (BAP) and serum cross-linked C-telopeptides of type I collagen (sCTX) were measured to evaluate the state of bone formation and resorption, respectively. BMD was measured in the posteroanterior spine, supine lateral spine, hip and forearm using a dual-energy X-ray absorptiometry.

RESULTS

The cubic polynomial regression model best fit age-related changes in serum BAP (R2=0.398, p<0.001) and sCTX concentrations (R2=0.148, p<0.001) with largest R2 from comparison 8 different regression models. Their values reached a minimal level in the 30-39 years age group, and increased dramatically in the 40-59 years groups. There was a decreasing trend of BAP in women >60 years. The levels of BAP and sCTX were inversely correlated to BMD in various skeletal regions over the entire population (r=-0.096 to -0.357, p<0.05). sCTX was a significant predictor of a T-score< or =-2.5 of BMD in postmenopausal women with sCTX levels above mean+2 SD of women aged 30-39 years compared with other postmenopausal women, which indicated by odds ratios 1.9-3.7 (p<0.05) for various skeletal regions, especially for the lateral lumbar spine (2.2, p<0.01), Ward's triangle (3.7, p<0.01), and ultradistal end of radius + ulna (2.8, p<0.001).

CONCLUSIONS

Age-dependent serum BAP and sCTX were inversely correlated to BMD, and sCTX was a useful parameter for the prediction of a low T-score of BMD at skeletal sites with abundant cancellous bone in postmenopausal women.

Anti-resorptive therapy for the prevention of postmenopausal osteoporosis : when should treatment begin?

Osteoporosis is a condition associated with decreased bone strength and an increased fracture risk. It may be defined based on bone mineral density (BMD) with a T-score at the hip or spine of less than -2.5 standard deviations in young healthy individuals or from an osteoporotic fracture (i.e. a fracture occurring after low-energy trauma or no apparent trauma). Risk factors predisposing to fractures include: increasing age; female gender; low BMD; a prior fragility fracture; a family history of fragility fractures; low bodyweight; lack of estrogen in women (i.e. post menopause); corticosteroid use; smoking; a number of diseases; deficiency in calcium and vitamin D; an increased risk of falls (i.e. impaired vision); immobilization; and Caucasian race. The more risk factors that are present the higher the risk of fractures over the following 10 years. The need to initiate preventive therapy with anti-osteoporotic treatment increases steeply with the absolute fracture risk. Indications for referral for dual energy x-ray absorptiometry measurement of BMD include: age >65 years; age <65 years in postmenopausal women with any of the risk factors already mentioned; premature menopause (<45 years); prolonged amenorrhea (>1 year) in younger women; fragility fractures; and diseases or conditions known to lead to osteoporosis.Anti-resorptive therapies include calcium plus vitamin D, bisphosphonates (alendronate, etidronate, risedronate, ibandronate), selective estrogen receptor modulators (raloxifene), hormone replacement therapy, and calcitonin. Guidelines from several countries on when to initiate anti-resorptive therapy state that therapy may be started in patients with a prior fragility fracture (some guidelines state that in this situation no BMD measurements are necessary) or in patients with a T-score of less than -2.5 (some guidelines state that additional risk factors need to be present in this situation). Some guidelines state that anti-resorptive therapy may be initiated in patients with a T-score in the osteopenic range (from -1 to -2.5, i.e. not frank osteoporosis) in the presence of other risk factors. The cost effectiveness of anti-resorptive therapy increases with the absolute fracture risk. In some scenarios, treatment with bisphosphonates may be cost effective in a 50-year-old woman with an absolute hip fracture risk of >or=1.1% over the next 10 years.

Performance of four clinical screening tools to select peri- and early postmenopausal women for dual X-ray absorptiometry

Several methods to select postmenopausal women for dual X-ray absorptiometry (DXA) have been proposed. We decided to compare the performance of three clinical decision rules (SCORE, ORAI, OST) with the usual case-finding strategy based on the presence of a major risk factor for future fracture (CFMRF). The study subjects were 2009 healthy, white, peri- or early postmenopausal women participating in the Danish Osteoporosis Prevention Study (DOPS). DXA results expressed as T-scores and scores on SCORE, ORAI, OST and CFMRF were extracted from the DOPS database. First, we evaluated the screening tools as originally described by the developers. The resulting sensitivities and specificities ranged from 18% to 92% and from 66% to 85%, respectively. Only OST achieved a high sensitivity (92%) with respect to femoral neck T-score < or = -2.5; however, the sensitivity with respect to lumbar spine T-score < or = -2.5 was only 51%. Next, the performance of the screening tools was evaluated against T-score < or = -2.0 (and T-score < or = -2.5) in at least one of the regions: femoral neck, total hip or lumbar spine. Using ROC curve analysis, we determined cut-offs yielding sensitivities as close as possible to 90%. The CFMRF and the ORAI tool were too coarse to yield 90% sensitivity. The performances of OST and SCORE were equal from a clinical perspective in that the sensitivities and the specificities varied from 89% to 94% and from 23% to 28%, respectively. The performance of CFMRF was no better than could be expected by chance, yielding a sensitivity of 19% and a specificity of 85%. Applying SCORE or OST 75% of the women would have to be referred for densitometry to identify 90% of the women with T-score < or = -2.0 (or T-score < or = -2.5) in at least one region. In conclusion, our results question the utility of all the evaluated tools for screening peri- and early postmenopausal women for low BMD. However, if a decision on referral has to be made, it may be based on the simple OST rule, which performed as well as or better than any of the other tools.

Forearm bone mineral density in 1294 middle-aged women: a strong predictor of fragility fractures

The aim of this study was to find out whether a single bone mineral density (BMD) measurement performed at middle age in early postmenopausal women could predict future fragility fractures. The Malmo Preventive Project, a population-based cardiovascular prevention study, included a subgroup of 1294 women, mean age 53, on which forearm BMD measurements were made using single-photon absorptiometry (SPA). Risk ratios (RRs) were calculated for an age-adjusted decrease in BMD of one standard deviation. During the 9-yr follow-up, 65 women sustained 86 fractures. The data were analyzed with Cox's proportional hazard analysis. The relative risk for sustaining any fragility fracture were 2.02 (95% confidence interval [CI] = 1.56-2.61) and 1.62 (CI = 1.26-2.08) at the distal and proximal forearm BMD measurement, respectively. The risk increase was significant for forearm fracture at the distal BMD level (RR = 1.94; range = 1.40-2.68) and at the proximal BMD level (RR = 1.77; range = 1.29-2.42). Our study is one of the first to show that a BMD measurement in a population at age 50 can predict fracture over almost 10 yr, indicating that early identification of women with increased fracture risk is possible, and the cost-effectiveness of such an approach needs to be further evaluated.

Biochemical markers of bone remodeling

Because of the aging population in most countries, disorders of bone and mineral metabolism are becoming increasingly relevant to everyday clinical practice. Consequently, the interest in, and the need for effective measures to be used in the screening, diagnosis, and follow-up of such pathologies has markedly grown. Together with clinical and imaging techniques, laboratory tests play an important role in the assessment and differential diagnosis of metabolic bone disease.