Skeletal microstructural abnormalities in postmenopausal women with chronic obstructive pulmonary disease

Mechanisms of osteoporosis associated with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a disease characterized by chronic respiratory symptoms due to inflammatory and destructive changes of the lung leading to progressive airflow obstruction. Fragility fractures associated with osteoporosis are among major comorbidities and have significant impacts on quality of life and prognosis of patients with COPD. Evidence suggests that both decreased bone mineral density (BMD) and impaired bone quality contribute to bone fragility and resultant fractures in COPD. Although various clinical risk factors of osteoporosis have been described, mechanisms of COPD-associated osteoporosis are still largely unknown. In addition, its specific treatment has not been established, either. Previous studies have suggested involvement of low BMI and sarcopenia in the pathogenesis of COPD-associated osteoporosis. In this narrative review, we will propose critical roles of vitamin D deficiency and inflammation, both of which are often present in COPD and may underlie the development of osteosarcopenia and impaired bone quality, ultimately causing fractures in COPD patients.

The impact of chronic obstructive pulmonary disease on bone strength

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related disease that develops in middle-aged and older adults, often due to smoking habits, and has been noted to cause bone fragility. COPD is a risk factor for osteoporosis and fragility fracture, and a high prevalence of osteoporosis and incidence of vertebral fractures have been shown in patients with COPD. Findings of lung tissue analysis in patients with COPD are primarily emphysema with a loss of alveolar septal walls, and the severity of pulmonary emphysema is negatively correlated with thoracic spine bone mineral density (BMD). On the other hand, epidemiological studies on COPD and fracture risk have reported a BMD-independent increase in fracture risk; however, verification in animal models and human bone biopsy samples has been slow, and the essential pathogenesis has not been elucidated. The detailed pathological/molecular mechanisms of musculoskeletal complications in patients with COPD are unknown, and basic research is needed to elucidate the mechanisms. This paper discusses the impacts of COPD on bone strength, focusing on findings in animal models in terms of bone microstructure, bone metabolic dynamics, and material properties.

Effects of elastase-induced emphysema on muscle and bone in mice

Chronic obstructive pulmonary disease (COPD) causes sarcopenia and osteoporosis. However, the mechanisms underlying muscle and bone loss as well as the interactions between muscle and bone in the COPD state remain unclear. Therefore, we herein investigated the effects of the COPD state on muscle and bone in mice intratracheally administered porcine pancreatic elastase (PPE). The intratracheal administration of PPE to mice significantly reduced trabecular bone mineral density (BMD), trabecular bone volume, trabecular number, cortical BMD and cortical area. It also significantly decreased grip strength, but did not affect muscle mass or the expression of myogenic differentiation-, protein degradation- or autophagy-related genes in the soleus and gastrocnemius muscles. Among the myokines examined, myostatin mRNA levels in the soleus muscles were significantly elevated in mice treated with PPE, and negatively related to grip strength, but not bone parameters, in mice treated with or without 2 U PPE in simple regression analyses. Grip strength positively related to bone parameters in mice treated with or without PPE. In conclusion, we showed that a PPE model of COPD in mice exerts dominant effects on bone rather than skeletal muscles. Increased myostatin expression in the soleus muscles of mice in the COPD state may negatively relate to a reduction in grip strength, but not bone loss.

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Relationships Between Pulmonary Function and Composite Indices of Femoral Neck Strength in Korean Men (KNHANES IV)

BACKGROUND

Despite the close relationship between osteoporosis and chronic pulmonary diseases, few studies have evaluated relationships between pulmonary functions and bone quality. We investigated associations between pulmonary function test results and femoral neck strength indices (SIs) in Korean men.

METHODS

This population-based, cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey IV on 936 men aged ≥ 19 years. Pulmonary functions (forced vital capacity [FVC] and forced expiratory volume in one second [FEV₁]) were measured using a dry rolling seal spirometer. Femoral neck SIs, relative to load, were calculated by hip dual-energy X-ray absorptiometry for compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI).

RESULTS

The 443 (47.3%) of the 936 men were current smokers. FVC, FVC percentage with respect to the expected normal value, FEV₁, and FEV₁ percentage with respect to the expected normal value (FEV₁p) were positively associated with CSI and BSI after adjusting for confounders, including smoking history (β = 0.003-0.223, P = 0.005-0.036). FEV₁ and FEV₁p were positively associated with ISI (β = 0.000-0.014, P = 0.010-0.025). Of components of femoral neck SIs, bone mineral density was correlated with FEV₁ and FEV₁p (β = 0.001-0.037, P = 0.017-0.019). After adjusting for all confounders, all femoral neck SIs increased with FVC quintiles (P for trends = 0.001-0.012), and CSI and BSI increased with FEV₁ quintiles (P for trends = 0.034-0.043).

CONCLUSION

Reduced pulmonary function was correlated with reduced femoral neck strength, even after adjusting for smoking history in Korean men. Femoral neck SIs might be useful tools for evaluating bone health in men with reduced pulmonary function.

Increased bone resorption by long-term cigarette smoke exposure in animal model

Introduction

Aims

Methods

Results

Conclusion

Bone Marrow Adiposity in Premenopausal Women With Type 2 Diabetes With Observations on Peri-Trabecular Adipocytes

CONTEXT

No study has yet evaluated the relationships among bone marrow adiposity (BMA), bone histomorphometry (BH), and glycemic control in premenopausal women with type 2 diabetes (T2DM).

OBJECTIVE

We aimed to assess the effect of glycemic control on BMA, correlate the parameters of BH with BMA, and correlate BMA with the use of hypoglycemic agents and with bone mineral density (BMD).

METHODS

This was a cross-sectional study that evaluated 26 premenopausal women with T2DM who were divided into groups with HbA1c < 7% (good control [GC], n = 10) and HbA1c > 7% (poor control [PC], n = 16). BMA parameters (adipocyte number [Ad.N], total adipocyte perimeter [Ad.Pm], total adipocyte area [Ad.Ar], percentage adipocyte volume per marrow volume [Ad.V/Ma.V]) and peri-trabecular adipocyte number divided by bone surface (Ad.N/BS) were evaluated. BH static (bone volume fraction [BV/TV], osteoid thickness [O.Th], osteoid surface/bone surface [OS/BS]) and dynamic parameters and serum insulin-like growth factor-1 were measured. BMA data were compared between the GC and PC groups. Correlations were performed.

RESULTS

Ad.N, Ad.Pm, and Ad.Ar were higher in PC (all, P = 0.04). HbA1c correlated positively with Ad.N/BS (P < 0.01) and Ad.N/BS correlated negatively with O.Th (P < 0.01) and OS/BS (P = 0.02). Positive and negative correlations were observed between insulin and metformin use, respectively, with all adipocyte parameters except Ad.N/BS (P < 0.05). Structural parameters were negatively correlated with the BMA. BMD of the femoral neck (r = -549, P < 0.01) and total femur (r = -0.502, P < 0.01) were negatively correlated with Ad.V/Ma.V.

CONCLUSION

Poor glycemic control is associated with hyperplasia and hypertrophy of BMAs and with lower BV/TV. Ad.N/BS, a new BMA parameter, is correlated with HbA1c and negatively with O.Th. The use of insulin seems to stimulate the expansion of BMA while that of metformin has the opposite effect. These findings suggest that the increase in BMA may play a role in the T2DM bone disease; on the other hand, good glycemic control might help prevent it.

Increased Medical and Implant-Related Complications in Total Hip Arthroplasty Patients With Underlying Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been associated with impaired bone metabolism. The purpose of this study is to investigate rates of readmission, respiratory complications, implant-related complications, and revision after total hip arthroplasty (THA) in patients with and without underlying COPD.

METHODS

The PearlDiver Mariners database was used to divide patients undergoing primary THA (CPT-27130) into two cohorts: 1) THA with COPD (including asthma) or 2) THA without COPD. The incidence of 30-day readmission, COPD exacerbation, pneumonia, other respiratory complications as well as dislocations, mechanical loosening, and joint prosthetic infection was calculated through logistic regression. The risk of THA revision was also assessed through Cox-proportional hazards regression. All regression controlled for age, gender, and medical comorbidities found to be associated with COPD.

RESULTS

Between 2010 and 2018, 97,784 THA patients with COPD and 338,243 THA patient without COPD were studied. THA patients with COPD had higher risk of 30-day readmission (aOR = 1.17, 95% CI 1.11-1.23, P < .0001). There was higher risk of 30-day pneumonia (aOR = 2.07, 95% CI 1.76-2.44, P < .0001). THA patients with COPD also faced higher risk of 30-day dislocations (aOR = 1.31, 95% CI 1.19-1.45, P < .0001), joint prosthetic infections (aOR = 1.25, 95% CI 1.14-1.37, P < .0001), and periprosthetic fracture (aOR = 1.19, 95% CI 1.07-1.32, P = .0015). Regarding revisions, 3.3% of THA patients with COPD underwent THA revision at 1 year, a higher risk than THA patients without COPD (aOR = 1.11, 95% CI 1.06-1.16, P < .0001).

CONCLUSION

Patients undergoing THA with underlying COPD face a higher rate of comorbidities, respiratory complications, implant complications, and revision surgeries, than patients without COPD.

LEVEL OF EVIDENCE

III.

[Osteoporosis in pneumological diseases : Joint guideline of the Austrian Society for Bone and Mineral Research (ÖGKM) and the Austrian Society for Pneumology (ÖGP)]

Chronic inflammation induces proinflammatory cytokine cascades. In addition to systemic inflammation, hypoxemia, hypercapnia, a catabolic metabolism, gonadal or thyroid dysfunction, musculoskeletal dysfunction and inactivity as well as vitamin D deficiency contribute to an increased risk of fragility fractures. Iatrogenic causes of osteoporosis are long-term use of inhaled or systemic glucocorticoids (GC). Inhalative GC application in asthma is often indicated in childhood and adolescence, but interstitial lung diseases such as chronic organizing pneumonia, COPD, sarcoid or rheumatic diseases with lung involvement are also treated with inhalative or oral GC. In patients with cystic fibrosis, malabsorption in the context of pancreatic insufficiency, hypogonadism and chronic inflammation with increased bone resorption lead to a decrease in bone structure. After lung transplantation, immunosuppression with GC is a risk factor.The underlying pneumological diseases lead to a change in the trabecular and cortical bone microarchitecture and to a reduction in osteological formation and resorption markers. Hypercapnia, acidosis and vitamin D deficiency can accelerate this process and thus increase the individual risk of osteoporotic fragility fractures.A bone mineral density measurement with a T‑Score < -2.5 is a threshold value for the diagnosis of osteoporosis; in contrast the vast majority of all osteoporotic fractures occur with a T‑Score > -2.5. A history of low-trauma fracture indicates osteological therapy.All antiresorptive or anabolic drugs approved in Austria for the treatment of osteoporosis are also indicated for pneumological patients with an increased fragility fracture risk of bone fractures in accordance with the national reimbursement criteria.

Executive summary of clinical practice guide on fracture risk in lifestyle diseases

Accumulating evidence has shown that patients with lifestyle diseases such as type 2 diabetes mellitus, chronic kidney disease, and chronic obstructive pulmonary disease are at increased risk of osteoporotic fracture. Fractures deteriorate quality of life, activities of daily living, and mortality as well as a lifestyle disease. Therefore, preventing fracture is an important issue for those patients. Although the mechanism of the lifestyle diseases-induced bone fragility is still unclear, not only bone mineral density (BMD) reduction but also bone quality deterioration are involved in it. Because fracture predictive ability of BMD and FRAX^® is limited, especially for patients with lifestyle diseases, the optimal management strategy should be established. Thus, when the intervention of the lifestyle diseases-induced bone fragility is initiated, the deterioration of bone quality should be taken into account. We here review the association between lifestyle diseases and fracture risk and proposed an algorism of starting anti-osteoporosis drugs for patients with lifestyle diseases.

Risk Factors and Management of Osteoporosis Post-Transplant

Bone and mineral disorders are common after organ transplantation. Osteoporosis post transplantation is associated with increased morbidity and mortality. Pathogenesis of bone disorders in this particular sub set of the population is complicated by multiple co-existing factors like preexisting bone disease, Vitamin D deficiency and parathyroid dysfunction. Risk factors include post-transplant immobilization, steroid usage, diabetes mellitus, low body mass index, older age, female sex, smoking, alcohol consumption and a sedentary lifestyle. Immunosuppressive medications post-transplant have a negative impact on outcomes, and further aggravate osteoporotic risk. Management is complex and challenging due to the sub-optimal sensitivity and specificity of non-invasive diagnostic tests, and the underutilization of bone biopsy. In this review, we summarize the prevalence, pathophysiology, diagnostic tests and management of osteoporosis in solid organ and hematopoietic stem cell transplant recipients.

COPD as an independent risk factor for osteoporosis and fractures

Fractures are common in individuals with COPD and occur at higher bone mass values than expected. COPD appears to be an important risk factor for bone fragility.

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of osteoporosis and fractures, but screening and prophylactic measures to prevent both disorders are often neglected in this population. This case-control study assessed the prevalence of osteopenia, osteoporosis, and fractures in patients with COPD, and identified potential risk factors for fractures in this population.

METHODS

Overall, 91 patients with COPD (COPD group; COPDG) and 81 age- and sex-matched controls (control group; CG) were assessed with bone mineral density (BMD), thoracic/lumbar spine radiographs, and serum PTH and 25-hydroxyvitamin D (25[OH]D) levels. The occurrence of prior fractures was retrieved from clinical history.

RESULTS

The prevalence of total fractures in the COPDG was 57.1% (odds of fracture 4.7 times greater compared with the CG), and the femoral neck T-score emerged as the best predictor of fractures. Compared with the CG, the COPDG had lower spine and femoral BMD (p ≤ 0.01) and 25(OH)D levels (p = 0.01) and 2.6 times greater odds of osteoporosis. Among men, vertebral fractures were more prevalent in the COPDG versus CG (25.9% vs. 6.5%, respectively, p = 0.01). The odds of fracture increased with femoral neck T-scores ≤ - 2.7 in the CG and ≤ - 0.6 in the COPDG.

CONCLUSION

These results add robust evidence to an increased odds of osteoporosis and fractures in COPD. Fractures in the COPDG occurred at higher BMD values than expected, suggesting that COPD may be an independent marker of fracture risk, reinforcing a need for regular osteoporosis screening with BMD measurement and prophylaxis of fractures in patients with this disorder.

Bone Histomorphometry in Young Patients With Type 2 Diabetes is Affected by Disease Control and Chronic Complications

CONTEXT

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of fractures. No study has evaluated the correlation of bone histomorphometry (BH) parameters with glycemic control and presence of chronic complications (CCs) in premenopausal women with T2DM.

OBJECTIVES

To evaluate BH and correlate them with the degree of glycemic control and presence of CCs.

DESIGN, SETTINGS, AND PATIENTS

This was a cross-sectional study conducted at a tertiary medical center. Twenty-six premenopausal women with T2DM were divided into groups with glycated hemoglobin HbA1c < 7% (good control, GC; n = 10) and HbA1c > 7% (poor control, PC; n = 16), and further subdivided into groups with (n = 9) and without (n = 17) CCs. BH parameters (bone volume [bone volume per total volume, BV/TV], trabecular thickness [Tb.Th], trabecular number [Tb.N], trabecular separation [Tb.Sp], osteoid thickness [O.Th], osteoid surface [osteoid surface per bone surface, OS/BS]), mineralizing surface [MS/BS], bone formation rate [BFR]), mineral apposition rate [MAR]) as well as serum pentosidine (PEN) and insulin-like growth factor (IGF)-1 were measured. The BH data were compared among the groups and with a BH control group (control group, CG, n = 15) matched by age, sex, and race.

RESULTS

BV/TV was increased in GC (P < .001) and PC (P = .05) groups and O.th (P = .03) was smaller in the PC group than in the CG. A comparison of the groups with and without CCs with the CG showed in the group with CCs, O.Th was smaller(P = .01) and BV/TV similar to the CG (P = .11). HbA1c correlated negatively with O.Th (P = .02) and OS/BS (P = .01). There was no correlation of BH to PEN and IGF-1.

CONCLUSION

BH in premenopausal patients with T2DM is affected by disease control and chronic complications.

Bone disease following solid organ transplantation: A narrative review and recommendations for management from The European Calcified Tissue Society

INTRODUCTION

Solid organ transplantation is an established therapy for end-stage organ failure. Both pre-transplantation bone disease and immunosuppressive regimens result in rapid bone loss and increased fracture rates.

METHODS

The European Calcified Tissue Society (ECTS) formed a working group to perform a systematic review of existing literature on the consequences of end-stage kidney, liver, heart, and lung disease on bone health. Moreover, we assessed the characteristics of post-transplant bone disease and the skeletal effects of immunosuppressive agents and aimed to provide recommendations for the prevention and treatment of transplantation-related osteoporosis.

RESULTS

Characteristics of bone disease may differ depending on the organ that fails, but patients awaiting solid organ transplantation frequently depict a wide spectrum of bone and mineral abnormalities. Common features are a decreased bone mass and impaired bone strength with consequent high fracture risk, all of which are aggravated in the early post-transplantation period.

CONCLUSION

Both the underlying disease leading to end-stage organ failure and the immunosuppression regimens implemented after successful organ transplantation have detrimental effects on bone mass, quality and strength. Given existing ample data confirming the high frequency of bone disease in patients awaiting solid organ transplantation, we recommend that all transplant candidates should be assessed for osteoporosis and fracture risk and, if indicated, treated before and after transplantation. Since bone loss in the early post-transplantation period occurs in virtually all solid organ recipients and is associated with glucocorticoid administration, the goal should be to use the lowest possible dose and to taper and withdraw glucocorticoids as early as possible.

Trabecular bone score in active or former smokers with and without COPD

BACKGROUND

Smoking is a recognized risk factor for osteoporosis. Trabecular bone score (TBS) is a novel texture parameter to evaluate bone microarchitecture. TBS and their main determinants are unknown in active and former smokers.

OBJECTIVE

To assess TBS in a population of active or former smokers with and without Chronic Obstructive Pulmonary Disease (COPD) and to determine its predictive factors.

METHODS

Active and former smokers from a pulmonary clinic were invited to participate. Clinical features were recorded and bone turnover markers (BTMs) measured. Lung function, low dose chest Computed Tomography scans (LDCT), dual energy absorptiometry (DXA) scans were performed and TBS measured. Logistic regression analysis explored the relationship between measured parameters and TBS.

RESULTS

One hundred and forty five patients were included in the analysis, 97 (67.8%) with COPD. TBS was lower in COPD patients (median 1.323; IQR: 0.13 vs 1.48; IQR: 0.16, p = 0.003). Regression analysis showed that a higher body mass index (BMI), younger age, less number of exacerbations and a higher forced expiratory volume-one second (FEV1%) was associated with better TBS (β = 0.005, 95% CI:0.000-0.011, p = 0.032; β = -0.003, 95% CI:-0.007(-)-0.000, p = 0.008; β = -0.019, 95% CI:-0.034(-)-0.004, p = 0.015; β = 0.001, 95% CI:0.000-0.002, p = 0.012 respectively). The same factors with similar results were found in COPD patients.

CONCLUSIONS

A significant proportion of active and former smokers with and without COPD have an affected TBS. BMI, age, number of exacerbations and the degree of airway obstruction predicts TBS values in smokers with and without COPD. This important information should be considered when evaluating smokers at risk of osteoporosis.

Bone mineral density and vertebral fractures and their relationship with pulmonary dysfunction in patients with chronic obstructive pulmonary disease

To evaluate bone mineral density (BMD) and morphometric vertebral fractures (MVF) in chronic obstructive pulmonary disease (COPD) patients in comparison with two control groups. BMD was lower in the disease group (DG) and was associated with the worst disease severity and prognosis. The prevalence of MVF was high and greater in the DG than in the control groups.

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is associated with osteoporosis and vertebral fractures. It is still unclear whether the presence of fractures and changes in bone mineral density (BMD) are associated with disease severity and prognosis. The aim of this study was to evaluate BMD and morphometric vertebral fractures (MVF) in COPD patients in comparison with two control groups and to correlate these parameters with indices of COPD severity (VEF1 and GOLD) and prognosis (BODE).

METHODS

This was a cross-sectional study in COPD patients (disease group, DG) who underwent BMD and vertebral fracture assessment (VFA). Two control groups were used: smokers without COPD (smoker group, SG) and healthy never-smoker individuals (never-smoker group, NSG).

RESULTS

The DG comprised 121 patients (65 women, mean age 67.9 ± 8.6 years). Altered BMD was observed in 88.4% of the patients in the DG, which was more prevalent when compared with the control groups (p < 0.001). The BMD values were lower in the DG than in the control groups (p < 0.05). BMD was associated with the worst disease severity and prognosis (p < 0.05). The prevalence of MVF was high (57.8%) and greater than that in the SG (23.8%) and the NSG (14.8%; p < 0.001). The prevalence of fractures was not associated with disease severity and prognosis.

CONCLUSIONS

COPD patients have a higher prevalence of MVF and low BMD, and the latter was associated with the severity and poor prognosis of the disease.

Abnormal microarchitecture and stiffness in postmenopausal women using chronic inhaled glucocorticoids

Postmenopausal (PM) women using inhaled glucocorticoids (IGCs) had substantial abnormalities in volumetric BMD (vBMD), microarchitecture, and stiffness using high resolution peripheral computed tomography (HRpQCT) compared to age- and race-matched controls. Abnormalities were most severe at the radius. These preliminary results suggest that there may be major, heretofore unrecognized, skeletal deficits in PM women using IGCs.

INTRODUCTION

While oral glucocorticoids are well recognized to have destructive skeletal effects, less is known about the effects of IGCs. The detrimental skeletal effects of IGCs may be greatest in PM women, in whom they compound negative effects of estrogen loss and aging. The goal of this study was to evaluate microarchitecture and stiffness in PM women using chronic IGCs.

METHODS

This case-control study compared PM women using IGCs for ≥ 6 months (n = 20) and controls matched for age and race/ethnicity (n = 60). Skeletal parameters assessed included areal BMD (aBMD) by DXA, trabecular and cortical vBMD and microarchitecture by HRpQCT of the radius and tibia, and whole bone stiffness by finite element analysis.

RESULTS

By DXA, mean values in both groups were in the osteopenic range; hip aBMD was lower in IGC users (P < 0.04). By HRpQCT, IGC users had lower total, cortical, and trabecular vBMD at both radius and tibia (all P < 0.05). IGC users had lower cortical thickness, lower trabecular number, greater trabecular separation and heterogeneity at the radius (all P < 0.03), and greater heterogeneity at the tibia (P < 0.04). Whole bone stiffness was lower in IGC users at radius (P < 0.03) and tended to be lower at the tibia (P = 0.09).

CONCLUSIONS

PM women using IGCs had substantial abnormalities in vBMD, microarchitecture, and stiffness compared to controls. These abnormalities were most severe at the radius. These preliminary results suggest that there may be major, heretofore unrecognized, skeletal deficits in PM women using IGCs.

Magnetic resonance imaging based assessment of bone microstructure as a non-invasive alternative to histomorphometry in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) adversely affects bone microarchitecture and increases fracture risk. Historically, bone biopsy has been the 'gold standard' for evaluating renal bone disease but is invasive and infrequently performed. High-resolution magnetic resonance imaging (MRI) quantifies bone microarchitecture noninvasively. In patients with CKD, it has not been compared with results derived from bone biopsy or with imaging using dual energy X-ray absorptiometry (DXA).

METHODS

Fourteen patients with end-stage kidney disease (ESKD) underwent MRI at the distal tibia, bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA; hip and spine) and transiliac bone biopsies with histomorphometry and microcomputed tomography (micro-CT). All patients had biomarkers of mineral metabolism. Associations were determined by Spearman's or Pearson's rank correlation coefficients.

RESULTS

MRI indices of trabecular network integrity, surface to curve ratio (S/C) and erosion index (EI), correlated to histomorphometric trabecular bone volume (S/C r = 0.85, p = 0.0003; EI r = -0.82, p = 0.001), separation (S/C r = -0.58, p = 0.039; EI r = 0.79, p = 0.0012) and thickness (S/C, r = 0.65, p = 0.017). MRI EI and trabecular thickness (TbTh) also correlated to micro-CT trabecular separation (EI r = 0.63, p = 0.02; TbTh r = -0.60, p = 0.02). Significant correlations were observed between histomorphometric mineralization and turnover indices and various MRI parameters. MRI-derived trabecular parameters were also significantly related to femoral neck BMD.

CONCLUSIONS

This study highlights the heterogeneity of bone microarchitecture at differing skeletal sites. MRI demonstrates significant, relevant associations to important bone biopsy and DXA indices and warrants further investigation to assess its potential to non-invasively evaluate changes in bone structure and quality over time.

Deterioration of Cortical Bone Microarchitecture: Critical Component of Renal Osteodystrophy Evaluation

BACKGROUND

Cortical bone is a significant determinant of bone strength and its deterioration contributes to bone fragility. Thin cortices and increased cortical porosity have been noted in patients with chronic kidney disease (CKD), but the "Turnover Mineralization Volume" classification of renal osteodystrophy does not emphasize cortical bone as a key parameter. We aimed to assess trabecular and cortical bone microarchitecture by histomorphometry and micro-CT in patients with CKD G5 and 5D (dialysis).

METHODS

Transiliac bone biopsies were performed in 14 patients undergoing kidney transplantation (n = 12) and parathyroidectomy (n = 2). Structural parameters were analysed by histomorphometry and micro-CT including trabecular bone volume, thickness (TbTh), number (TbN) and separation and cortical thickness (CtTh) and porosity (CtPo). Indices of bone remodelling and mineralisation were obtained and relationships to bone biomarkers examined. Associations were determined by Spearman's or Pearson's rank correlation coefficients.

RESULTS

By micro-CT, trabecular parameters were within normal ranges in most patients, but all patients showed very low CtTh (127 ± 44 µm) and high CtPo (60.3 ± 22.5%). CtPo was inversely related to TbN (r = -0.56; p = 0.03) by micro-CT and to TbTh (r = -0.60; p = 0.024) by histomorphometry and correlated to parathyroid hormone values (r = 0.62; p = 0.021). By histomorphometry, bone turnover was high in 50%, low in 21% and normal in 29%, while 36% showed abnormal patterns of mineralization. Significant positive associations were observed between osteoblast surface, osteoclast surface, mineralization surface and bone turnover markers.

CONCLUSIONS

Deterioration of cortical -microarchitecture despite predominantly normal trabecular parameters reinforces the importance of comprehensive cortical evaluation in patients with CKD.

Independent association of bone mineral density and trabecular bone score to vertebral fracture in male subjects with chronic obstructive pulmonary disease

Osteoporosis is a major comorbidity of chronic obstructive pulmonary disease (COPD), but the mechanism of bone fragility is unknown. We demonstrated that trabecular bone score, a parameter of bone quality, was associated with systemic inflammation and was a significant determinant of vertebral fracture independent of bone mineral density.

INTRODUCTION

COPD is a major cause of secondary osteoporosis. However, the mechanism of bone fragility is unclear. We previously reported that vertebral fracture was highly prevalent in male COPD patients. To obtain clues to the mechanism of COPD-associated osteoporosis, we attempted to identify determinants of prevalent vertebral fracture in this study.

METHODS

In this cross-sectional study, we recruited 61 COPD males and examined pulmonary function, vertebral fractures, bone mineral density (BMD), trabecular bone score (TBS), bone turnover markers, and inflammatory parameters. Determinants of the bone parameters were examined by multivariable analyses.

RESULTS

The prevalence of any and grade 2 or 3 fractures was 75.4 and 19.7%, respectively. Osteoporosis and osteopenia defined by BMD were present in 37.7 and 39.3%, respectively. TBS was significantly lower in higher Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages compared to GOLD 1. Multivariable logistic regression analysis revealed that both TBS and BMD were independent determinants of grade 2 or 3 vertebral fractures (OR = 0.271, 95%CI 0.083-0.888, p = 0.031; OR = 0.242, 95%CI 0.075-0.775, p = 0.017) after adjustment for age. Correlates of TBS included age, BMD, high-sensitivity C-reactive protein (hsCRP), pulmonary function parameters, parathyroid hormone, and Tracp-5b. In multivariable regression analysis, hsCRP was the only independent determinant of TBS besides age and BMD. In contrast, independent determinants of BMD included body mass index and, to a lesser extent, 25-hydroxyvitamin D.

CONCLUSION

Both BMD and TBS were independently associated with grade 2 or 3 vertebral fracture in COPD male subjects, involving distinct mechanisms. Systemic inflammation, as reflected by increased hsCRP levels, may be involved in deterioration of the trabecular microarchitecture in COPD-associated osteoporosis, whereas BMD decline is most strongly associated with weight loss.

Impaired rib bone mass and quality in end-stage cystic fibrosis patients

BACKGROUND

Advancements in research and clinical care have considerably extended the life expectancy of cystic fibrosis (CF) patients. However, with this extended survival come comorbidities. One of the leading co-morbidities is CF-related bone disease (CFBD), which progresses with disease severity and places patients at high risk for fractures, particularly of the ribs and vertebrae. Evidence that CF patients with vertebral fractures had higher bone mineral density (BMD) than the nonfracture group led us to postulate that bone quality is impaired in these patients. We therefore examined rib specimens resected at the time of lung transplant in CF patients to measure parameters of bone quantity and quality.

METHODS

In this exploratory study, we analysed 19 end-stage CF and 13 control rib specimens resected from otherwise healthy lung donors. BMD, bone microarchitecture, static parameters of bone formation and resorption and microcrack density of rib specimens were quantified by imaging, histomorphometric and histological methods. Variables reflecting the mineralization of ribs were assessed by digitized microradiography. The degree of bone mineralization (g/cm³) and the heterogeneity index of the mineralization (g/cm³) were calculated for trabecular and cortical bone.

RESULTS

Compared to controls, CF ribs exhibited lower areal and trabecular volumetric BMD, decreased trabecular thickness and osteoid parameters, and increased microcrack density, that was particularly pronounced in specimens from patients with CF-related diabetes. Static parameters of bone resorption were similar in both groups. Degree of mineralization of total bone, but not heterogeneity index, was increased in CF specimens.

CONCLUSION

The combination of reduced bone mass, altered microarchitecture, imbalanced bone remodeling (maintained bone resorption but decreased formation), increased microdamage and a small increase of the degree of mineralization, may lead to decreased bone strength, which, when coupled with chronic coughing and chest physical therapy, may provide an explanation for the increased incidence of rib fractures previously reported in this population.

Natural Killer Cell Development and Maturation Revisited: Possible Implications of a Novel Distinct Lin-CD34+DNAM-1brightCXCR4+ Cell Progenitor

Since the first description of natural killer (NK) cells, the view on their role in innate immunity has evolved considerably. In addition to first-line defense against transformed and pathogen-infected autologous cells, NK cells contribute to modulate adaptive immune responses and in some cases acquire specialized functions, including exhausted, adaptive, and decidual NK cells. NK cells derive from CD34⁺ progenitors, in vivo and in vitro; however, it is unclear whether the high phenotype diversity in vivo may be generated from these precursors alone. The recent characterization of a novel CD34⁺DNAM-1^brightCXCR4⁺ precursor giving rise to apparently licensed and functional maturing NK cells may suggest the possibility for a higher than expected common lymphocyte precursor diversity and a consequently higher peripheral NK cell phenotype variability. Here, we review the evidences on NK cell central and peripheral development from CD34⁺ precursors and propose a possible updated reading frame based on the characterization of CD34⁺DNAM-1^brightCXCR4⁺ cell progenies, which favors the possibility of concurrent NK cell maturation from different CD34⁺ precursors.

Fragility Fracture Incidence in Chronic Obstructive Pulmonary Disease (COPD) Patients Associates With Nanoporosity, Mineral/Matrix Ratio, and Pyridinoline Content at Actively Bone-Forming Trabecular Surfaces

Chronic obstructive pulmonary disease (COPD) is associated with low areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) and altered microstructure by bone histomorphometry and micro-computed tomography. Nevertheless, not all COPD patients sustain fragility fractures. In the present study, we used Raman microspectroscopic analysis to determine bone compositional properties at actively forming trabecular surfaces (based on double fluorescent labels) in iliac crest biopsies from 19 postmenopausal COPD patients (aged 62.1 ± 7.3 years). Additionally, we analyzed trabecular geometrical centers, representing tissue much older than the forming surfaces. Eight of the patients had sustained fragility fractures, and 13 had received treatment with inhaled glucocorticoids. None of the patients had taken oral glucocorticoids. The monitored parameters were mineral/matrix ratio (MM), nanoporosity, and relative glycosaminoglycan (GAG), lipid, and pyridinoline contents (PYD). There were no significant differences between the glucocorticoid-treated patients and those who did not receive any. On the other hand, COPD patients sustaining fragility fractures had significantly lower nanoporosity and higher MM and PYD values compared with COPD patients without fragility fractures. To the best of our knowledge, this is the first study to discriminate between fracture and non-fracture COPD patients based on differences in the material properties of bone matrix. Given that these bone material compositional differences are evident close to the cement line (a major bone interface), they may contribute to the inferior bone toughness and coupled with the lower lumbar spine bone mineral density values result in the fragility fractures prevalent in these patients. © 2016 American Society for Bone and Mineral Research.

Prevalence of Osteoporosis and Its Risk Factors in Men with COPD in Qazvin

Introduction. Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. Proper diagnosis of osteoporosis as a systemic adverse effect of COPD is of significant importance. The present study aimed at evaluating the prevalence of osteoporosis and its risk factors in men suffering from COPD in Qazvin (2014). Methods. This descriptive-analytical study was conducted on 90 patients with COPD using random sampling. Anthropometric data and results from physical examination were collected. Pulmonary function test and bone mineral densitometry were done for all participants as well. Results. The prevalence of osteopenia and osteoporosis in COPD patients was 31.5 and 52.8 percent, respectively. Bone mineral density (BMD) at the femoral neck was associated significantly with body mass index (BMI), increased severity of COPD, and use of oral corticosteroid (P < 0.05). Conclusion. The results showed that patients' BMI and severity of COPD are two valuable risk factors for osteoporosis screening in COPD patients.

Osteoporosis Associated with Chronic Obstructive Pulmonary Disease

Recent epidemiological studies have revealed that osteoporosis is closely associated with common chronic diseases including diabetes, hypertension, chronic kidney disorders, and chronic obstructive pulmonary disease (COPD). COPD is a chronic inflammatory airway disease but now well known to be associated with various systemic comorbidities including osteoporosis. Osteoporosis and osteoporotic fractures are extremely common in COPD patients, which have significant impacts on their quality of life (QOL), activities of daily life (ADL), respiratory function, and possibly their prognosis. COPD-associated osteoporosis is however extremely under-recognized, hence undertreated. Recent studies have suggested that both decreased bone mineral density (BMD) and impaired bone quality compromise bone strength causing fractures in COPD. In COPD patients, various general clinical risk factors for osteoporosis are present including smoking, older age, low body weight, and physical inactivity. In addition, disease-related risk factors such as decreased pulmonary function, inflammation, glucocorticoid use and vitamin D deficiency/insufficiency have been linked to the development of osteoporosis in COPD. Increased awareness of osteoporosis in COPD, especially that of high prevalence of vertebral fractures is called upon among general physicians as well as pulmonologists. Routine screening for osteoporosis and risk assessment of fractures will enable physicians to diagnose COPD patients with comorbid osteoporosis at an early stage. Timely prevention of developing osteoporosis together with appropriate treatment of established osteoporosis may improve QOL and ADL of the COPD patients, preserve their lung function and eventually result in better prognosis in these patients.

The Skeletal Effects of Inhaled Glucocorticoids

The skeletal effects of inhaled glucocorticoids are poorly understood. Children with asthma treated with inhaled glucocorticoids have lower growth velocity, bone density, and adult height. Studies of adults with asthma have reported variable effects on BMD, although prospective studies have demonstrated bone loss after initiation of inhaled glucocorticoids in premenopausal women. There is a dose-response relationship between inhaled glucocorticoids and fracture risk in asthmatics; the risk of vertebral and non-vertebral fractures is greater in subjects treated with the highest doses in the majority of studies. Patients with COPD have lower BMD and higher fracture rates compared to controls, however, the majority of studies have not found an additional detrimental effect of inhaled glucocorticoids on bone. While the evidence is not conclusive, it supports using the lowest possible dose of inhaled glucocorticoids to treat patients with asthma and COPD and highlights the need for further research on this topic.

Skeletal Implications of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with numerous comorbidities, among which osteoporosis is of high significance. Low bone mass and the occurrence of fragility fractures is a common finding in patients with COPD. Typical risk factors related directly or indirectly to these skeletal complications include systemic inflammation, tobacco smoking, vitamin D deficiency, and treatment with oral or inhaled corticosteroids. In particular, treatment with glucocorticoids appears to be a strong contributor to bone changes in COPD, but does not fully account for all skeletal complications. Additional to the effects of COPD on bone mass, there is evidence for COPD-related changes in bone microstructure and material properties. This review summarizes the clinical outcomes of low bone mass and increased fracture risk, and reports on recent observations in bone tissue and material in COPD patients.

COPD and osteoporosis: links, risks, and treatment challenges

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease associated with various systemic comorbidities including osteoporosis. Osteoporosis and its related fractures are common and have significant impacts on quality of life and even respiratory function in patients with COPD. COPD-associated osteoporosis is however extremely undertreated. Recent studies have suggested that both decreased bone mineral density (BMD) and impaired bone quality contribute to bone fragility, causing fractures in COPD patients. Various clinical risk factors of osteoporosis in COPD patients, including older age, emaciation, physical inactivity, and vitamin D deficiency, have also been described. It is critically important for pulmonologists to be aware of the high prevalence of osteoporosis in COPD patients and evaluate them for such fracture risks. Routine screening for osteoporosis will enable physicians to diagnose COPD patients with comorbid osteoporosis at an early stage and give them appropriate treatment to prevent fracture, which may lead to improved quality of life as well as better long-term prognosis.

Risk and clinical predictors of osteoporotic fracture in East Asian patients with chronic obstructive pulmonary disease: a population-based cohort study

INTRODUCTION

Osteoporosis is becoming an impending epidemic in the Asia-Pacific region. The association between risk of osteoporotic fracture (OTPF) and chronic obstructive pulmonary disease (COPD) in East Asian patients is yet to be fully examined. We conducted a nationwide population-based retrospective cohort study of 98,700 patients aged ≥50 years with or without COPD using a national administrative claims dataset.

MATERIALS AND METHODS

The patients were divided into COPD and comparison groups comprising 19,740 and 78,960 patients, respectively. The groups were 1 to 4 matched for age, gender, index date, diabetes mellitus, pre-existing osteoporosis and chronic kidney disease. Information such as the geographic area where southern part represented more sunshine exposure, smoking-related diagnoses, alcohol use disorder, whether there was regular use of inhaled corticosteroids and oral corticosteroids, vitamin D prescriptions, Charlson-Deyo comorbidity index score, and other relevant medical comorbidities were extracted for analysis. They were followed up until OTPF or the end of the year 2013. The outcome measure was an osteoporotic vertebral fracture and other long-bone fractures. A multivariate Cox model was constructed to derive adjusted hazard ratios (aHR) for OTPF with corresponding 95% confidence intervals (CI) after controlling for age, sex, insurance premium category, vitamin D prescription, osteoporosis, and coronary heart disease (CHD). Kaplan-Meier curves of the probability of OTPF-free survival for each cohort were compared using the log-rank test. Patients with OTPF during the first follow-up year were excluded from the overall risk calculation. Contributing factors to the increased risk of OTPF in COPD patients were examined in a sensitivity analysis.

RESULTS

After a total follow-up of 68,743 patient-years for the COPD group and 278,051 patient-years for the matched comparison group, the HR for OTPF was 1.24 (95% CI [1.02-1.51]; P = 0.0322) in COPD patients. The aHR was increased by 30% for vertebral OTPF (aHR = 1.297, 95% CI [1.020-1.649]; P = 0.0339). Differential lag time sensitivity analysis revealed a progressively elevated risk up to 8-fold increase in women (aHR = 8.0 (95% CI [1.81-35.4]; P < 0.01)) during the fifth follow-up year. COPD patients with pre-existing osteoporosis or given vitamin D prescription harbor a sustained increased risk up to the 5th (aHR, 4.1; 95% CI [1.61-10.35]) and third (aHR, 2.97; 95% CI [1.48-5.97]) follow-up year, respectively.

CONCLUSIONS

Our nationwide population-based cohort study demonstrates that East Asian COPD patients aged 50 and beyond do harbor a modestly increased risk for osteoporotic vertebral fractures particularly for those who are female, have pre-existing osteoporosis or require vitamin D prescription.

'Emergency exit' of bone-marrow-resident CD34(+)DNAM-1(bright)CXCR4(+)-committed lymphoid precursors during chronic infection and inflammation

During chronic inflammatory disorders, a persistent natural killer (NK) cell derangement is observed. While increased cell turnover is expected, little is known about whether and how NK-cell homeostatic balance is maintained. Here, flow cytometric analysis of peripheral blood mononuclear cells in chronic inflammatory disorders, both infectious and non-infectious, reveals the presence of a CD34(+)CD226(DNAM-1)(bright)CXCR4(+) cell population displaying transcriptional signatures typical of common lymphocyte precursors and giving rise to NK-cell progenies with high expression of activating receptors and mature function and even to α/β T lymphocytes. CD34(+)CD226(bright)CXCR4(+) cells reside in bone marrow, hardly circulate in healthy donors and are absent in cord blood. Their proportion correlates with the degree of inflammation, reflecting lymphoid cell turnover/reconstitution during chronic inflammation. These findings provide insight on intermediate stages of NK-cell development, a view of emergency recruitment of cell precursors, and upgrade our understanding and monitoring of chronic inflammatory conditions.

Subtle changes in bone mineralization density distribution in most severely affected patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is associated with low aBMD as measured by DXA and altered microstructure as assessed by bone histomorphometry and microcomputed tomography. Knowledge of bone matrix mineralization is lacking in COPD. Using quantitative backscatter electron imaging (qBEI), we assessed cancellous (Cn.) and cortical (Ct.) bone mineralization density distribution (BMDD) in 19 postmenopausal women (62.1 ± 7.3 years of age) with COPD. Eight had sustained fragility fractures, and 13 had received treatment with inhaled glucocorticoids. The BMDD outcomes from the patients were compared with healthy reference data and were correlated with previous clinical and histomorphometric findings. In general, the BMDD outcomes for the patients were not significantly different from the reference data. Neither the subgroups of with or without fragility fractures or of who did or did not receive inhaled glucocorticoid treatment, showed differences in BMDD. However, subgroup comparison according to severity revealed 10% decreased cancellous mineralization heterogeneity (Cn.CaWidth) for the most severely affected compared with less affected patients (p=0.042) and compared with healthy premenopausal controls (p=0.021). BMDD parameters were highly correlated with histomorphometric cancellous bone volume (BV/TV) and formation indices: mean degree of mineralization (Cn.CaMean) versus BV/TV (r=0.58, p=0.009), and Cn.CaMean and Ct.CaMean versus bone formation rate (BFR/BS) (r=-0.71, p<0.001). In particular, those with lower BV/TV (<50th percentile) had significantly lower Cn.CaMean (p=0.037) and higher Cn.CaLow (p=0.020) compared with those with higher (>50th percentile) BV/TV. The normality in most of the BMDD parameters and bone formation rates as well as the significant correlations between them suggests unaffected mineralization processes in COPD. Our findings also indicate no significant negative effect of treatment with inhaled glucocorticoids on the bone mineralization pattern. However, the observed concomitant occurrence of relatively lower bone volumes with lower bone matrix mineralization will both contribute to the reduced aBMD in some patients with COPD.

Osteoporosis in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related chronic inflammatory pulmonary disease associated with significant morbidity and mortality worldwide. COPD is associated with various comorbidities found in all stages of COPD. The comorbidities have significant impact in terms of morbidity, mortality, and economic burden in COPD. Management of comorbidities should be incorporated into the comprehensive management of COPD as this will also have an effect on the outcome in COPD patients. Various comorbidities reported in COPD include cardiovascular disease, skeletal muscle dysfunction, anemia, metabolic syndrome, and osteoporosis. Osteoporosis is a significant comorbidity in COPD patients. Various risk factors, such as tobacco smoking, systemic inflammation, vitamin D deficiency, and the use of oral or inhaled corticosteroids (ICSs) are responsible for its occurrence in patients with COPD. This review will focus on the prevalence, pathogenesis, risk factors, diagnosis, and treatment of osteoporosis in COPD patients.

Association of chronic obstructive pulmonary disease and smoking status with bone density and vertebral fractures in male lung cancer screening participants

We studied the vertebral fracture prevalence on low-dose chest computed tomography (CT) in male lung cancer screening participants and the association of fractures and bone density with chronic obstructive pulmonary disease (COPD) and smoking. 1140 male current and former smokers with ≥ 16.5 packyears from the NELSON lung cancer screening trial were included. Age, body mass index, and smoking status were registered. CT scans and pulmonary function tests were obtained on the same day. On CT, vertebral fractures and bone density were measured. The cohort had a mean age of 62.5 years (standard deviation 5.2) old; 531 (46.6%) had quit smoking; and 437 (38.3%) had COPD. Of the group, 100 (8.8%) participants had a vertebral fracture. Fracture prevalence was higher in current compared to former smokers (11.3% versus 5.8%, p = 0.001), but similar in participants with COPD compared to those without (9.6% versus 8.3%, p = 0.430). The multivariable adjusted odds ratio for fracture presence was 1.79 (95% CI: 1.13-2.84) in current smokers and 1.08 (95% CI: 0.69-1.67) in COPD participants. Bone density was lower in current compared to former smokers (103.2 HU versus 108.7 HU, p = 0.006) and in participants with COPD compared to those without [100.7 Hounsfield Units (HU) versus 108.9 HU, p < 0.001]. In multivariate analysis, smoking status and COPD status were independently associated with bone density, corrected for age and body mass index. In conclusion, our study shows that lung cancer screening participants have a substantial vertebral fracture burden. Fractures are more common in current smokers, who also have lower bone density. We could not confirm that COPD is independently associated with vertebral fractures.

Bone disease after transplantation: osteoporosis and fractures risk

Organ transplantation is the gold standard therapy for several end-stage diseases. Bone loss is a common complication that occurs in transplant recipients. Osteoporosis and fragility fractures are serious complication, mainly in the first year post transplantation. Many factors contribute to the pathogenesis of bone disease following organ transplantation. This review address the mechanisms of bone loss including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and management of bone loss in the transplant recipient should be included in their post transplant follow-up in order to prevent fractures.

Circulatory osteoprotegerin is related to osteoporosis of the hip in patients with COPD

BACKGROUND

Osteoprotegerin (OPG), a potent inhibitor of osteoclastogenesis, decreases bone resorption and has protective effects on bone mineral density (BMD). Recently we have shown that the adipose-tissue derived OPG relates to BMD in patients with chronic obstructive pulmonary disease (COPD), a condition associated with increased risk of osteoporosis.

OBJECTIVE

Here we aimed to investigate the potential of circulatory OPG to reflect hip BMD in patients with COPD.

PATIENTS AND METHODS

In 56 subjects with COPD [age, 61.7 ± 6.7 years; forced expiratory volume in 1 s (FEV1), 53.6 ± 19.2% predicted], total femur BMD was assessed by dual energy X-ray absorptiometry, serum OPG and β-crosslaps, a marker of increased bone resorption, by commercially available assays.

RESULTS

From patients with normal hip BMD (n = 32, T-score 0.1 ± 0.8) to those with osteopenia (n = 14, T-score -1.6 ± 0.4) and osteoporosis (n = 10, T-score -3.4 ± 0.7) serum OPG levels significantly increased (6.6 ± 1.8 versus 7.2 ± 2.9 and versus 8.6 ± 1.5 pmol/l, p = 0.036). In addition, hip T-scores were directly related to FEV1, and inversely to β-crosslaps (R = 0.40, p = 0.002; R = 0.38, p = 0.01, respectively). In multivariate analysis, OPG independently predicted hip T-scores after adjustments for age, gender, FEV1, and β-crosslaps (p = 0.011, adjusted R(2) = 0.354). Area under receiver operator curve for OPG as a discriminator of osteoporosis was 0.787 (95% CI, 0.653-0.921) (p = 0.005).

CONCLUSIONS

Present results suggest that osteoporosis of the hip is associated with increased circulatory levels of OPG in patients with COPD. OPG might serve as a biomarker of this COPD-related comorbidity.

Bone stiffness and failure load are related with clinical parameters in men with chronic obstructive pulmonary disease

Osteoporosis is frequently seen in patients with chronic obstructive pulmonary disease (COPD). Because research on bone structure and bone strength in COPD patients is limited, the objectives of this pilot study were as follows: (1) to compare bone structure, stiffness, and failure load, measured at the peripheral skeleton, between men with and without COPD after stratification for areal bone mineral density (aBMD); and (2) to relate clinical parameters with bone stiffness and failure load in men with COPD. We included 30 men with COPD (normal aBMD, n = 18; osteoporosis, n = 12) and 17 men without COPD (normal aBMD, n = 9; osteoporosis, n = 8). We assessed pack-years of smoking, body mass index (BMI), fat free mass index (FFMI), pulmonary function (forced expiratory volume in 1 second [FEV1 ], FEV1 /forced vital capacity [FVC], diffusion capacity for carbon monoxide [DLCO], and transfer coefficient for carbon monoxide [KCO]), and extent of emphysema. Bone structure of the distal radius and tibia was assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), and bone stiffness and failure load of the distal radius and tibia were estimated from micro finite element analysis (µFEA). After stratification for aBMD and COPD, men with osteoporosis showed abnormal bone structure (p < 0.01), lower bone stiffness (p < 0.01), and lower failure load (p < 0.01) compared with men with normal aBMD, and men with COPD had comparable bone structure, stiffness, and failure load compared with men without COPD. In men with COPD, lower FFMI was related with lower bone stiffness, and failure load of the radius and tibia and lower DLCO and KCO were related with lower bone stiffness and failure load of the tibia after normalization with respect to femoral neck aBMD. Thus, this pilot study could not detect differences in bone structure, stiffness, and failure load between men with and without COPD after stratification for aBMD. FFMI and gas transfer capacity of the lung were significantly related with bone stiffness and failure load in men with COPD after normalization with respect to femoral neck aBMD.

Osteoporosis in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is being regarded as a heterogeneous disease with clinically significant pulmonary and extrapulmonary manifestations, such as emphysema, cardiovascular disease and osteoporosis. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and, consequently, an increased risk of fracture. Fractures resulting from osteoporosis might contribute to increased morbidity and mortality, particularly in COPD patients. The high prevalence of osteoporosis in COPD patients is assumed to be due to common risk factors, such as older age and tobacco smoking, and COPD-specific risk factors, such as systemic inflammation, vitamin D deficiency and the use of oral or inhaled corticosteroids. This review provides a state-of-the-art summary of the prevalence, pathophysiology, diagnosis, risk factors and treatment of osteoporosis in COPD patients. It also discusses potential mechanisms linking COPD with osteoporosis.

COPD and associated comorbidities: a review of current diagnosis and treatment

Health care utilization and costs associated with chronic obstructive pulmonary disease (COPD) continue to increase, notwithstanding evidence-based management strategies described by major respiratory societies. Cardiovascular diseases, asthma, diabetes and its precursors (obesity and metabolic syndrome), depression, cognitive impairment, and osteoporosis are examples of common comorbidities that can affect or be affected by COPD. Appropriate diagnosis and management (from a pharmacologic and nonpharmacologic perspective) of COPD and its associated comorbidities are important to ensure optimal patient care. An evolving understanding of COPD as a multimorbid disease that affects an aging population, rather than just a lung-specific disease, necessitates an integrated, tailored disease-management approach to improve prognoses and reduce costs.

Corticosteroid-induced osteoporosis: an update for dermatologists

Long-term corticosteroid treatment is the most common secondary cause of bone loss. Patients treated with long-term corticosteroid therapy may develop osteopenia or osteoporosis, and many have fractures. It is difficult to predict which corticosteroid-treated patients will develop significant skeletal complications because of variability in the underlying diseases treated with corticosteroids, and because of variation in corticosteroid dose over time. Corticosteroid therapy causes an alteration in the ratio between osteoprotegerin (OPG) and receptor activator of nuclear factor κ B (RANK) ligand (RANKL), which leads to early increased bone resorption for the first 3-6 months, with long-term treatment leading primarily to suppression of bone formation. Recently published recommendations advise the use of bisphosphonates or teriparatide in high-risk patients, depending on fracture risk assessed by bone mineral density testing. This article gives an update of current knowledge regarding the pathophysiology, clinical presentation and evaluation, and prevention and treatment of patients with corticosteroid-induced osteoporosis.

Osteoporosis after transplantation

Transplantation is an established therapy for end-stage diseases of kidney, lung, liver, and heart among others. Osteoporosis and fragility fractures are serious complications of organ transplantation, particularly in the first post-transplant year. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. This review addresses the mechanisms of bone loss that occurs both in the early and late post-transplant periods, including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac, and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient are also discussed.

Recommendations for Diagnosis and Management of Osteoporosis in COPD Men

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for osteoporosis and fractures because of lifestyle factors, systemic effects of the disease, side effects of treatment, and comorbidities. The initial evaluation of COPD men for osteoporosis must include a detailed medical history and physical examination, assessment of COPD severity, and additional tests, as suggested by results of clinical evaluation. Osteoporosis is diagnosed on the basis of bone mineral density (BMD) measurement with DEXA of the lumbar spine and hip, but fracture risk assessments tools, as FRAX, could be used as useful supplements to BMD assessments for therapeutics interventions. The prevention and treatment of osteoporosis in COPD involves nonpharmacologic and pharmacologic measures, as lifestyle measures and nutritional recommendations, management of COPD treatment (based on the use of limited corticosteroids doses), and drug therapy (bisphosphonates, teriparatide). In this paper, the current recommendations for diagnosis and management of osteoporosis in COPD men, based on recent medical bibliography, are presented and discussed.

Relationship between osteoporosis and adipose tissue leptin and osteoprotegerin in patients with chronic obstructive pulmonary disease

INTRODUCTION

The role of fat-bone interactions in the pathogenesis of osteoporosis in chronic obstructive pulmonary disease (COPD) is poorly understood. Our aim was to investigate expressions of leptin and osteoprotegerin (OPG) in the adipose tissue, and their relationships to osteoporosis in patients with COPD.

METHODS

In 39 patients with stable COPD, bone mineral density (BMD) and body composition was assessed by Dual Energy X-Ray Absorptiometry. Serum leptin was determined by the enzyme-linked immunosorbent assay, and bone turnover markers osteocalcin and β-crosslaps by the electrochemiluminiscence immunoassays. Subcutaneous adipose tissue samples were analyzed using real-time PCR.

RESULTS

Twenty-one patients without, and 18 with osteoporosis were enrolled (35 men; age 62.2 ± 7.3years). Compared to patients without osteoporosis, those with the disease had significantly lower serum levels and adipose tissue expressions of leptin, in association with increased serum β-crosslaps (p=0.028, p=0.034, p=0.022, respectively). Log adipose tissue leptin was inversely related to serum β-crosslaps (p=0.015), and directly to serum leptin (p<0.001) and to the total, femoral, and lumbar BMD and T-score (p<0.02 for all relationships). Adipose tissue OPG expression was related to all variables of bone density except for lumbar BMD and T-score (p<0.05 for all relationships). Log adipose tissue leptin and OPG expressions predicted femoral T-score independently of age, gender and pulmonary function (p<0.001, adjusted R(2)=0.383; p=0.008, adjusted R(2)=0.301, respectively). Introducing body mass (or fat mass) index into these models eliminated independent predictive value of leptin and OPG expressions.

CONCLUSION

Our results suggest that adipose tissue leptin and OPG expressions are related to osteoporosis in patients with COPD, and appear to act as mediators between fat mass and BMD.