Role of active and environmental tobacco smoke on susceptibility to osteoporosis in women undergoing dual-X-ray absorptiometry

PURPOSE

Current smoking is a risk factor for osteoporosis (Op), but few data are available regarding the passive smoke impact on Op susceptibility. This cross-sectional study aimed to evaluate the association between the smoking habits and Op in community-dwelling women undergoing dual-energy X-ray absorptiometry (DXA).

METHODS

On 01/06/2018, general practitioners from "COMEGEN" Medical Cooperative, Naples, Italy, selected the medical records from the last 10 years of women who had a measurement of bone mineral density performed and simultaneously completed a questionnaire about their smoking behaviour and their cohabiters'. The binary logistic regression analysis was used to estimate the role of passive smoke on the risk of Op, adjusting for age and body mass index (BMI).

RESULTS

Among 10,616 subjects, 3942 were currently smokers [CS; mean age 69.4 ± 10.4 years; BMI 27.0 ± 4.9 kg/m2], 873 were passive smokers (PS; mean age 67.8 ± 11.6 years; BMI 27.0 ± 4.9 kg/m2) and 5781 were never smokers (NS; mean age 67.8 ± 11.6 years; body mass index (BMI) 27.0 ± 4.9 kg/m2). Of all, 8562 women (mean age 70.3 ± 10.2 yrs; BMI 27.0 ± 4.9 kg/m2) received the Op diagnosis. PS showed an increased Op risk compared to NS [odds ratio (OR) 1.38 (1.14-1.67)] and comparable to CS [OR 1.02 (0.84-1.24)].

CONCLUSION

The study results demonstrate an association between passive smoke and Op in community-dwelling women already presenting with susceptibility to Op according to Italian essential assistance levels, suggesting that passive and active smoke are equivalent Op risk factors in women.

Diagnosis and treatment of Paget's disease of bone: position paper from the Italian Society of Osteoporosis, Mineral Metabolism and Skeletal Diseases (SIOMMMS)

INTRODUCTION

Paget's disease of bone is a focal skeletal disorder causing bone deformities and impairing bone quality. Despite the prevalence of asymptomatic cases is increasing, the progression of the disease can lead to invalidating complications that compromise the quality of life. Doubts on clinical and therapeutic management aspects exist, although beneficial effects of antiresorptive drugs, particularly bisphosphonates are known. However, limited information is available from randomized controlled trials on the prevention of disease complications so that somewhat contrasting positions about treatment indications between expert panels from the main scientific societies of metabolic bone diseases exist. This task force, composed by expert representatives appointed by the Italian Society of Osteoporosis, Mineral Metabolism and Skeletal Diseases and members of the Italian Association of Paget's disease of bone, felt the necessity for more specific and up to date indications for an early diagnosis and clinical management.

METHODS

Through selected key questions, we propose evidence-based recommendations for the diagnosis and treatment of the disease. In the lack of good evidence to support clear recommendations, available information from the literature together with expert opinion of the panel was used to provide suggestions for the clinical practice.

RESULTS AND CONCLUSION

Description of the evidence quality and support of the strength of the statements was provided on each of the selected key questions. The diagnosis of PDB should be mainly based on symptoms and the typical biochemical and radiological features. While treatment is mandatory to all the symptomatic cases at diagnosis, less evidence is available on treatment indications in asymptomatic as well as in previously treated patients in the presence of biochemical recurrence. However, given the safety and long-term efficacy of potent intravenous bisphosphonates such as zoledronate, a suggestion to treat most if not all cases at the time of diagnosis was released.

Pathophysiology and Management of Type 2 Diabetes Mellitus Bone Fragility

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.

Recent advances in models for screening potential osteoporosis drugs

INTRODUCTION

Osteoporosis is a growing health and health-economic problem due to the increased proportion of elderly people in the population. Basic and clinical advances in research over the past two decades have led to the development of different compounds with antiresorptive or anabolic activity on bone that improved substantially the management of patients with osteoporosis over calcitonin or estrogen replacement. New compounds are in preclinical and clinical development. Areas covered: In this review, the authors review the approaches for the preclinical and clinical development of antiresorptive and anabolic agents for osteoporosis, particularly focusing on the recent advances in technology and in the understanding of skeletal biology, together with their implications on novel osteoporosis drug discovery. Expert opinion: Based on the available evidence from the approved drugs for the treatment osteoporosis as well as from the different compounds under clinical development, it has become clear that long term nonclinical pharmacological studies with either bone quality and off-target effects as the main outcomes should be required for new drugs intended to treat osteoporosis. At the same time, basic and clinical advances in research have underlined the necessity to develop new technologies and new models for a thorough screening of the effects of new drugs on the different components of skeletal aging and bone fragility that cannot be assessed by bone mass measurement.

MicroRNAs in bone diseases

MicroRNAs are small, noncoding single-stranded RNAs that have emerged as important posttranscriptional regulators of gene expression, with an essential role in vertebrate development and different biological processes. This review highlights the recent advances in the function of miRNAs and their roles in bone remodeling and bone diseases. MicroRNAs (miRNAs) are a class of small (∼22 nt), noncoding single-stranded RNAs that have emerged as important posttranscriptional regulators of gene expression. They are essential for vertebrate development and play critical roles in different biological processes related to cell differentiation, activity, metabolism, and apoptosis. A rising number of experimental reports now indicate that miRNAs contribute to every step of osteogenesis and bone homeostasis, from embryonic skeletal development to maintenance of adult bone tissue, by regulating the growth, differentiation, and activity of different cell systems inside and outside the skeleton. Importantly, emerging information from animal studies suggests that targeting miRNAs might become an attractive and new therapeutic approach for osteoporosis or other skeletal diseases, even though there are still major concerns related to potential off target effects and the need of efficient delivery methods in vivo. Moreover, besides their recognized effects at the cellular level, evidence is also gathering that miRNAs are excreted and can circulate in the blood or other body fluids with potential paracrine or endocrine functions. Thus, they could represent suitable candidates for becoming sensitive disease biomarkers in different pathologic conditions, including skeletal disorders. Despite these promising perspectives more work remains to be done until miRNAs can serve as robust therapeutic targets or established diagnostic tools for precision medicine in skeletal disorders.

The association of body composition and sex hormones with quantitative ultrasound parameters at the calcaneus and phalanxes in elderly women

We investigated the associations of body composition and sex hormones with quantitative ultrasound (QUS) parameters carried out at different skeletal sites. In 897 postmenopausal women (64.1 ± 6.6 years) we measured QUS at the calcaneus (stiffness) by Achilles-GE and at phalanxes (amplitude-dependent speed of sound [AD-SOS], bone transmission time [BTT], and ultrasound bone profile index [UBPI]) by Bone Profiler-IGEA. In all subjects we measured fat mass (FM), lean mass (LM), android fat, and gynoid fat by DXA. In all subjects we also assessed serum testosterone (T), estradiol (E(2)), sex-hormone binding globulin, free estrogen index (FEI), free androgen index, 25-hydroxyvitamin D (25OHD), bone alkaline phosphatase (B-ALP), and type I collagen β carboxy telopeptide. Both E(2) and FEI showed weak but significant correlations with stiffness and QUS parameters at phalanxes. No significant relationships were found between T and QUS. BMI and LM were positively correlated with stiffness (r = 0.14 and r = 0.17, respectively), whereas BMI and FM showed negative correlations with AD-SOS, BTT, and UBPI. 25OHD showed positive relationships with stiffness and QUS at phalanxes. In multivariate models LM and age were associated with stiffness whereas E(2) and age were significant predictors of BTT. AD-SOS was negatively associated with FM, B-ALP, and age but positively with E(2) and 25OHD. In postmenopausal women QUS parameters at the calcaneus and at phalanxes are significantly, but diversely, associated with body composition, sex hormones, 25OHD, and bone turnover markers.

Vitamin D deficiency and primary hyperparathyroidism

Vitamin D via its receptor has essential actions on parathyroid cells, inhibiting PTH secretion, and parathyroid cell proliferation. While the effects of vitamin D depletion in the pathogenesis of secondary hyperparathyroidism in elderly individuals or in the occurrence of parathyroid hyperplasia in patients with renal insufficiency are well established, the association between hypovitaminosis D and primary hyperparathyroidism (P-HPT) has only recently become appreciated. In different cohorts of patients with P-HPT, vitamin D deficiency has been recently associated with higher PTH levels, larger adenomas, and a more severe phenotype (including osteitis fibrosa cystica) as well as negative post-operative outcomes following parathyroidectomy. Despite current guidelines recommend measurement of serum 25OHD (25-hydroxy-cholecalciferol) in P-HPT and their repletion if the levels are <20 ng/ml, future well-designed trials of vitamin D supplementation in P-HPT patients with coexisting vitamin D deficiency are needed to evaluate the risk/benefit profile of this treatment.

Mechanisms of impaired bone strength in type 1 and 2 diabetes

Diabetes and osteoporosis are common and complex disorders with an enormous health burden that can be often associated especially in middle-age and elderly individuals. Although there is raising awareness of the higher fractures rates among patients with type 1 (DM1) and 2 (DM2) diabetes, there are few data available on the pathogenetic mechanisms responsible for this increased risk. Importantly, several experimental and clinical observations suggest that bone abnormalities associated with diabetes may differ, at least in part, from those associated with senile or post-menopausal osteoporosis. This implies that specific preventive and therapeutic strategies have to be developed and tested to prevent fractures in DM1 and DM2 patients. It is also likely that shared (i.e. due to glucose-toxicity) as well as different (i.e. due to insulin levels or other hormones) mechanisms may be associated with bone fragility in DM1 and DM2. Moreover, the hypothesis of an endocrine role of the skeleton in the regulation of glucose metabolism and insulin sensitivity has been recently proposed by experimental observations. This review summarizes the recent clinical and experimental advances on glucose tolerance, bone fragility and osteoporosis associated with diabetes.

Epidemiological, clinical, and genetic characteristics of Paget's disease of bone in a rural area of Calabria, Southern Italy

BACKGROUND

The prevalence of Paget's disease of bone (PDB) is unknown in peninsular Southern Italy, although an elevated clinical severity of the disease was reported in patients from Campania.

AIM

This study was performed to evaluate the epidemiological and genetic characteristics of PDB in a rural area of Calabria, the southernmost region in the Italian peninsula.

SUBJECTS AND METHODS

We examined 1068 consecutive pelvic radiographs of patients older than 40 yr referred for any reason to the "Spinelli" Hospital, Belvedere Marittimo, from January 1st 2004 to December 31st 2006. In subjects with radiological findings of pelvic PDB, a 99m Technetium methylene diphosphonate bone scan and the sequence analysis of the sequestosome 1 (SQSTM1) gene were subsequently performed.

RESULTS

In the examined geographic area, the crude radiographic prevalence of pelvic PDB was 0.74% (8/1068; male:female 5:3, mean age 71.6 ± 13.1 yr) whereas the estimated overall prevalence of PDB between 0.82% and 1.21%. PDB patients from Calabria showed clinical characteristics similar to those reported in patients from Campania. The disease was also frequently complicated by osteoarthritis and the right side of the body was more affected than the left. The SQSTM1 gene analysis revealed the presence of a novel missense mutation (M401V) in exon 8 in one subject with a familial and aggressive form of PDB.

CONCLUSION

The study results confirmed that patients with PDB from rural districts of Southern Italy show an earlier onset and an increased clinical severity of the disease that appears mostly independent from the presence of germinal SQSTM1 mutations.

Bone fragility in men: where are we?

Osteoporosis in men is an increasingly important clinical issue. About one in three osteoporotic fractures occur in men, and the consequences of these fractures are generally more severe than in women. Despite these evidences, osteoporosis remains under-recognized and undertreated in men. This review provides a summary of recent developments about the causes, pathogenesis, and treatment of osteoporosis in men.

Perspectives in the treatment and prevention of osteoporosis

Osteoporosis is a chronic skeletal condition characterized by compromised bone strength. This disorder affects a substantial proportion of the elderly population and causes notable morbidity, deterioration in quality of life and mortality due to associated fragility fractures. Over the past two decades the range of therapeutic options for the treatment of osteoporosis and fracture prevention has increased dramatically with the development of potent antiresorptive and anabolic agents. This review summarizes the effects of existing treatment options and of promising new therapies for osteoporosis prevention and treatment.

Serum OPG and RANKL levels before and after intravenous bisphosphonate treatment in Paget's disease of bone

Paget's disease of bone (PDB) is a focal disorder of bone remodeling characterized by increased osteoclast-mediated bone resorption. Even though increasing evidence indicates enhanced nuclear factor-kB (NF-kB) signaling as a common mechanism involved in PDB and other related disorders, few studies investigated circulating osteoprotegerin (OPG) and receptor of activator of NF-kB-ligand (RANKL) levels in PDB patients. In this study we explored the relationships between OPG or RANKL levels and bone turnover markers in a group of patients with PDB, before and after intravenous bisphosphonate treatment (pamidronate 60 mg). Both OPG and RANKL were markedly elevated in PDB patients with respect to control groups (healthy or osteoporotic postmenopausal women and elderly men) and were positively associated with bone turnover markers. Higher levels of these cytokines were observed in polyostotic than monostotic PDB cases. The ratio between RANKL and OPG was more than 3-fold higher in PDB patients than in controls. Interestingly, in the group of patients treated with pamidronate, we found an increase in OPG levels that become statistically significant after 3 and 6 months from treatment. A trend toward a decrease in RANKL levels after treatment was also observed. The RANKL/OPG ratio was significantly reduced after 3 and 6 months of therapy. In contrast, in patients classified as non-responders, OPG and RANKL levels after pamidronate infusion did not significantly differ with respect to pre-treatment values. Thus, the positive effect of amino bisphosphonates in the treatment of PDB may be due to either direct or indirect suppression of RANKL-induced bone resorption through decreased RANKL and increased OPG production.

Bone metabolism in men: role of aromatase activity

Sex steroid hormones play an important role in the maintenance of bone mass in males and in females. Even though androgens are the major sex steroids in men, direct and indirect evidence emerged suggesting that estrogens may also play a major role in male skeletal health. Since the testes account for only 15% of circulating estrogens in males, the remaining 85% comes from peripheral aromatization of androgen precursors in different tissues, including bone. Human models of aromatase deficiency clearly demonstrated the critical importance of the conversion of androgens into estrogens in regulating male skeletal homeostasis. Aromatase- deficient men showed tall stature due to continued longitudinal growth, unfused epiphyses, high bone turnover, and osteopenia. Interventional studies in adult men using aromatase inhibition confirmed that estrogens are important in controlling bone remodeling. Importantly either inherited (i.e. due to common polymorphisms at the human aromatase CYP19 gene) or acquired (i.e. by diseases or different compounds) variation in aromatase ability to convert androgen precursors into estrogen may also be relevant for skeletal homeostasis.

Prevalence of Helicobacter pylori infection in male patients with osteoporosis and controls

Cytokines that regulate bone turnover (tumor necrosis factor-alpha, interleukin-6, etc.) may influence the pathogenesis of skeleton disorders, such as osteoporosis. Since Helicobacter pylori infection increases the systemic levels of inflammatory cytokines, we investigated the possibility that this infection increases the risk of developing osteoporosis and affects the bone metabolism in a group of male patients with osteoporosis. We examined 80 osteoporotic male patients and 160 controls for serum antibodies to H. pylori and the CagA protein and determined, in patients alone, the most important biochemical and instrumental parameters of the disease. Fifty-one patients (63.7%) and 107 controls (66.8%) were seropositive for H. pylori infection (nonsignificant); 30 infected patients (58.8%) and 43 infected controls (40.1%) were positive for anti-CagA antibodies (P = 0.028; OR = 2.13). Levels of estradiol in infected CagA-positive patients were significantly lower than in infected CagA-negative patients (28.5 [SD = 10.18] vs. 39.5 [SD = 14.50] pg/ml; P = 0.002) and uninfected patients (35.2 [SD = 12.7] pg/ml; P = 0.028). Levels of urinary cross-laps(a marker of bone resorption) were increased in patients infected by CagA-positive strains compared to patients infected by CagA-negative strains (282.9 [SD = 103.8] vs. 210.5 [SD = 150.1]microg/mmol; P = 0.048) and uninfected patients (204.3 [SD = 130.1] microg/mmol; P = 0.016). Differences among uninfected and infected patients, independent of CagA status, were observed for other markers of bone turnover, but they did not reach statistical significance. Infection by CagA-positive H. pylori strains is more prevalent in men with osteoporosis, who show reduced systemic levels of estrogens and increased bone turnover. H. pylori infection by strains expressing CagA may therefore be considered a risk factor for osteoporisis in men.

Estrogen receptor gene polymorphisms and the genetics of osteoporosis: a HuGE review

Osteoporosis (OMIM166710) is a common skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue with increased susceptibility to fracture. Osteoporosis has a complex etiology and is considered a multifactorial polygenic disease in which genetic determinants are modulated by hormonal, environmental, and nutritional factors. Estrogens are known to play an important role in regulating bone homeostasis and preventing postmenopausal bone loss. They act through binding to two different estrogen receptors (ERs), ER alpha (OMIM133430) and ER beta (OMIM601663), which are members of the nuclear receptor superfamily of ligand-activated transcription factors. Different polymorphisms have been described in both the ER alpha and ER beta genes. Although a large number of association studies have been performed, the individual contribution of these polymorphisms to the pathogenesis of osteoporosis remains to be universally confirmed. Moreover, an important aim in future work will be to define their functional molecular consequences and their interaction with the environment in the causation of the osteoporotic phenotype. A further promising application of these polymorphisms comes from their pharmacogenomic implications, with the possibility of providing better guidance for therapeutic regimens, such as estrogen replacement therapy and selective ER modulators. At the moment, no recommendations for population-based screening can be made.

Professional sport activity and micronutrients: effects on bone mass

Osteoporosis is the most prevalent metabolic bone disease among developed countries. Although bone mass and density are certainly determined by various concurrent factors such as genetics, hormones, life-style and the environment, and although the genetic program has a critical role in growth and in bone peak development, for their realization an adequate nutritional intake of nutrients and regular exercise are always necessary and may represent a way to prevent osteoporosis and fractures. Exercise and especially high-impact sport activity during growth and adolescence increases bone mineral density (BMD) in weight-loaded skeletal regions. Aerobics, weight bearing and resistance exercises may also be effective in increasing BMD in post-menopausal women. Even though most of the research on nutritional components has focused almost exclusively on calcium and vitamin D, there is now considerable interest in the effects of a variety of other nutrients on bone status.

Feasibility of quantitative ultrasound measurements on the humerus of newborn infants for the assessment of the skeletal status

Quantitative ultrasound (QUS), although widely used in adults has, so far, been scarcely employed in newborn infants and children. This study aimed to evaluate the feasibility of the use of QUS in newborn children and the factors influencing QUS parameters. In 140 consecutive healthy full-term newborn babies (76 male and 64 female; gestational age: 39.5 +/- 1.5 weeks) QUS parameters were assessed within 3 days of the child's birth at the distal diaphysis of the humerus by use of Bone Profiler, after an appropriate modification of caliper and software. In all subjects we evaluated the amplitude-dependent speed of sound (AD-SoS) (meters per second), the characterizing graphic trace parameters [signal dynamic (SDy), fast wave amplitude (FWA) and bone transmission time (BTT)], SoS (meters per second), that is, the speed of sound calculated on the first peak, and hBTT, that is, the interval time between the first peak of the ultrasound and when this reaches the speed of 1,570 m/s, which is the velocity of ultrasound in the soft tissue. This latter parameter allows one to measure bone tissue independently of soft tissue. QUS measurements were also performed at the phalanges on all mothers (age range 24-38 years), who also completed a self-report questionnaire on their obstetric history, smoking and dietary habits and family history of osteoporosis. In 73 mothers and their children QUS was repeated after 12 months. All QUS parameters were slightly higher in male than in female newborn infants but the difference was not significant. BTT and hBTT of neonates showed a significant relationship with birth weight (r = 0.20; P < 0.05 and r = 0.37; P < 0.01, respectively) and with cranial circumference (r = 0.22; P < 0.05 and r = 0.36; P < 0.01, respectively). In newborn infants none of the QUS parameters was significantly influenced by maternal QUS or by maternal smoking and calcium intake. In a model of multiple regression analysis the cranial circumference was the only parameter entered into the model, explaining approximately 15% of hBTT value. At month 12 AD-SoS and SoS were slightly lower than at birth (-11% and -0.1%, respectively), whereas both BTT and hBTT showed a significant (P < 0001) increase. The present study demonstrated the feasibility of the use of QUS, as assessed by a new measurement approach at the humerus, in the evaluation of skeletal status in neonates. BTT and, above all, hBTT, appears to be the best parameter for both evaluation of skeletal status at birth and monitoring of bone growth in the first year of life.