Evaluation of persistence and adherence to teriparatide treatment in patients affected by severe osteoporosis (PATT): a multicenter observational real life study

INTRODUCTION

Osteoporosis is a chronic condition leading to an increased risk of developing fractures, with high morbidity and mortality in aging population. Efficacy of anti-osteoporotic treatment is based on drug potency but also on compliance and persistence to treatment regimen, which is very low, as already described for other diseases. Teriparatide (TPTD) is the first anabolic agent developed for the treatment of osteoporosis. Since it appears that persistence to Teriparatide declines over time, aim of this pilot multicenter observational study was to evaluate persistence and adherence to TPTD (20 μg daily injection regimen for 18 months) treatment (PATT) in patients affected by severe osteoporosis in an every day clinical practice.

METHODS

Patients affected by severe osteoporosis were selected among those who referred to 5 different specialized centers for osteoporosis in North, Center and South of Italy. A sample of 475 women with severe postmenopausal osteoporosis treated with TPTD in accordance to the Italian osteoporosis guidelines was included. At the beginning of TPTD treatment patients were instructed on the use of the device by the referring specialist of the center, a resident fellow or a nurse. Bone biochemical markers were evaluated the same morning and after 1, 3, 6, 12 and 18 months. Patients were visited at time 0 and after 6, 12 and 18 months for clinical follow up.

RESULTS

The results included observations of 441/475 patients (98% women) who completed the 18 months treatment; mean age for women was 73±8 and for men 65±9. After 6 months of TPTD treatment persistence was of 89,79%, 87,75% after 12 months and 86,85% after 18 months. Adherence was of 100% at 6,12 and 18 months. Total dropouts were 13,15% (71/441), which was usually higher within the first 6 months of TPTD treatment. Most common adverse events (arthralgies 2,7%, dizziness 1,8%, migraine 1,8%, depression 1,6%, hypertension 1,1%) were reported in 62/441 patients (14%) of patients, but were not reason for stopping treatment.

CONCLUSIONS

The persistence and adherence to TPTD treatment obtained in this multicenter observational real life study was very high as compared to studies performed by others. These encouraging results suggest that different key factors such quality of information, frequency of visits, motivations given to patients, opportunity to call the doctor might play a pivotal role in the high persistence and adherence to TPTD treatment obtained in our study and need to be carefully considered before prescribing chronic anti-osteoporotic therapy.

Negative association between trunk fat, insulin resistance and skeleton in obese women

AIM

To evaluate the potential interference of trunk fat (TF) mass on metabolic and skeletal metabolism.

METHODS

In this cross-sectional study, 340 obese women (mean age: 44.8 ± 14 years; body mass index: 36.0 ± 5.9 kg/m(2)) were included. Patients were evaluated for serum vitamin D, osteocalcin (OSCA), inflammatory markers, lipids, glucose and insulin (homeostasis model assessment of insulin resistance, HOMA-IR) levels, and hormones profile. Moreover, all patients underwent measurements of bone mineral density (BMD; at lumbar and hip site) and body composition (lean mass, total and trunk fat mass) by dual-energy X-ray absorptiometry.

RESULTS

Data showed that: (1) high TF mass was inversely correlated with low BMD both at lumbar (P < 0.001) and hip (P < 0.01) sites and with serum vitamin D (P < 0.0005), OSCA (P < 0.0001) and insulin-like growth factor-1 (IGF-1; P < 0.0001) levels; (2) a positive correlation was found between TF and HOMA-IR (P < 0.01), fibrinogen (P < 0.0001) and erythrocyte sedimentation rate (P < 0.0001); (3) vitamin D levels were directly correlated with IGF-1 (P < 0.0005), lumbar (P < 0.006) and hip (P < 0.01) BMD; and (4) inversely with HOMA-IR (P < 0.001) and fibrinogen (P < 0.0005).Multivariate analysis demonstrated that only vitamin D was independent of TF variable.

CONCLUSION

In obese women, TF negatively correlates with BMD independently from vitamin D levels. Reduced IGF-1 and increased inflammatory markers might be some important determinants that account for this relationship.

Approach in glucocorticoid-induced osteoporosis prevention: results from the Italian multicenter observational EGEO study

Glucocorticoid-induced osteoporosis (GIO) is the most frequent cause of secondary osteoporosis. GIO is linked to glucocorticoids (GC) daily assumption with maximum effect within first months of treatment and decreasing to basal levels as the therapy is discontinued. In Italy, primary prevention of GIO is suggested when GC therapy (prednisone >5 mg/day or equivalent) is taken for longer than 3 months. Lazio GISMO (Italian Group for Study and Diagnosis of Bone Metabolism Diseases) group organized the GC and Osteoporosis Epidemiology study (EGEO) to evaluate physician's approach in preventing GIO. The study involved 19 osteoporosis centers. Patients taking long-term GC therapy were recruited and information collected: medical history and anthropometric data, GC therapy, primary disease, physician's specialty, osteopororosis screening, and pharmacological intervention. The study included 1334 patients. Mean age was 63 ± 13 yr; 243 (18%) patients had a history of falls from standing position in the previous 12 months, 78 (35%) vertebral fractures, 91 (41%) fractures other than vertebral, 27 (12%) femoral fractures, and 27 (12%) multiple sites fractures. The molecules of GC more often prescribed were prednisone and 6-metil prednisolone. One thousand and forty patients (78%) were taking GC for more than 6 months. GC therapy was prescribed more frequently by rheumatologists (62%). Antiosteoporotic drugs for GIO prevention were prescribed in 431 patients (32%). Among the patients, only 27% (360) received calcium and vitamin D supplements, and 39% (319) treated by rheumatologists received anti-resorptive drugs. In conclusion, our data show that in Italy, as already described elsewhere, only a small subpopulation of GC-treated patients was supported by an anti-osteoporotic therapy, indicating the need to further stimulate awareness of both patients and specialists, prescribing GC therapy, to an appropriate and prompt GIO prevention.

Trunk fat negatively influences skeletal and testicular functions in obese men: clinical implications for the aging male

Osteocalcin (OSCA) seems to act as a negative regulator of energy metabolism and insulin sensitivity. Evidence from male rodents suggests that OSCA may also regulate testosterone (T) synthesis. Using a cross-sectional design, we evaluated OSCA, 25(OH) vitamin D, T, 17 β -estradiol (E2), homeostasis model assessment of insulin resistance (HOMA-IR), and body composition in 86 obese (mean BMI = 34) male subjects (18-69 yr old). Independently from BMI, an inverse relationship between trunk fat percentage and plasma T (r (2) = -0.26, P < 0.01) and between HOMA-IR and OSCA levels (r (2) = -0.22, P < 0.005) was found. OSCA levels, as well as vitamin D, decreased significantly for higher BMI with significant differences above 35 (P < 0.01). A direct correlation between T and bone mineral density at lumbar (BMDL) and neck (BMDH) (P < 0.001, r (2) = -0.20; P < 0.001, r (2) = -0.24) was found, independently from age. An inverse correlation between E2 levels, BMDL, and BMDH (P < 0.001, r (2) = -0.20; P < 0.001, r (2) = -0.19) was observed. These data provide new evidences that a relationship between trunk fat mass, insulin sensitivity, OSCA and T synthesis occurs. This new relationship with skeletal health has relevant implications for the aging male, suggesting OSCA as a novel marker of metabolic and gonadal health status.

Effectiveness of teriparatide treatment on back pain-related functional limitations in individuals affected by severe osteoporosis: a prospective pilot study

INTRODUCTION

Vertebral fractures have been associated with back pain, functional limitations and reduced health-related quality of life (HRQoL). Teriparatide is the first effective anabolic agent that demonstrated to significantly reduce the risk of vertebral fracture by 65%, as compared to placebo. The aims of this study were to evaluate the effectiveness of teriparatide treatment on back pain-related functional limitations and to investigate on patients HRQoL.

MATERIALS AND METHODS

In this prospective observational pilot study osteoporotic patients, who were prescribed teriparatide therapy and a supplementation of calcium and vitamin D, were asked to answer to two self-administered questionnaires: the Spine Pain Index (SPI) and the SF-12 (at the recruitment, after 6, 12, and 18 months).

RESULTS

Fifty-two women were evaluated (mean age of 70.58 yrs). The mean SPI score passed from 50.01 at baseline to 32.20 at 18 months. The mean SF-12 PCS score passed from 30.00 at baseline to 36.79 at 18 months, while the mean SF-12 MCS score was already within the normality range at baseline, constantly improving during the 18 months.

CONCLUSION

In conclusion, 18 months of treatment with teriparatide has to be considered an effective therapeutic option for women with severe osteoporosis and vertebral fractures, in a real-life clinical setting, to improve both back pain related disability and quality of life.

Effects of long-acting testosterone undecanoate on bone mineral density in middle-aged men with late-onset hypogonadism and metabolic syndrome: results from a 36 months controlled study

We evaluated the effects of long-term testosterone replacement therapy (TRT) on the bone mineral density (BMD) in obese patients with metabolic syndrome (MS) and late-onset hypogonadism (LOH). Sixty men (mean age 57 ± 10) with low serum testosterone (T < 320 ng/dL) and MS regardless the presence of osteoporosis were enrolled. Forty men received intramuscular T-undecanoate (TU) four times/year for 36 months and 20 age-matched hypogonadal men with MS in whom T treatment was contraindicated were used as controls. Hormonal, biochemical markers, vertebral and femoral BMD by dual-energy x-ray absorptiometry were measured. At baseline, overall patients had mild osteopenia (lumbar BMD= 0.891 ± 0.097 g/cm(2); femoral BMD= 0.847 ± 0.117 g/cm(2)). TU induced a significant improvement of bone mass after 36 months (lumbar BMD=1.053 ± 0.145 g/cm(2); p < 0.002; femoral BMD=0.989 ± 0.109; p < 0.003 g/cm(2)) with a 5%/year increase and a significant reduction in hs-CRP without changes in body mass index. A direct relationship between serum T and BMD increments at the lumbar (r(2) = 0.66, p < 0.0001) and femoral (r(2) =0.52, p < 0.0001) sites was demonstrated. Study adherence was 50% without serious side effects. Long-term TRT in middle-aged men with LOH and MS determines a significant increase in both vertebral and femoral BMD related to increased serum T levels, probably independently from estradiol modifications.

Concerns about serum androgens monitoring during testosterone replacement treatments in hypogonadal male athletes: a pilot study

INTRODUCTION

A well-tailored testosterone replacement treatment (TRT) in male hypogonadal athletes plays a pivotal role to restore physiological performances, to reduce health risks, and to guarantee the ethic of competition. Few studies evaluated individual androgens profiles during TRT in trained individuals.

AIM

The aim of this article was to verify the efficacy in restoring eugonadal serum and urinary androgens profiles after testosterone enanthate (TE) and gel (TG) administration.

METHODS

Ten male Caucasian-trained volunteers affected by severe hypotestosteronemia (<8 nmol/L) were included. Serum androgens and urinary testosterone metabolites were evaluated, in the same subjects, before and weekly for 5 weeks after both a single intramuscular TE injection (250 mg) and during a daily administration of TG (50 mg/die of testosterone), respectively.

MAIN OUTCOME MEASURES

The main outcome measures of this article were serum total testosterone (TT), dihydrotestosterone (DHT), calculated free and bioavailable testosterone (cFT, cBioT), 17-β-estradiol, and urinary glucuronide testosterone metabolites.

RESULTS

Supraphysiological TT concentrations were observed in 50% of our volunteers until 7 days after TE and in the 4% of total samples after TG. Serum DHT was high both after TE (all volunteers on day 7 and 50% on day 14) and during TG (32% of total samples). A relatively low number of samples showed normal cFT and cBioT both after TE and TG (20-44%, respectively). Urinary metabolites were related to the type of treatment and to serum androgens profile and resulted in the normal ranges from 15% to 60% of total samples.

CONCLUSION

Besides well-known variations of mean serum TT, we showed a high percentage of serum and urinary samples with abnormal androgens, being TG safer than TE. We conclude that monitoring TRT with TT only may be inaccurate because of abnormal fluctuations of other circulating androgens. Further studies to identify the appropriate markers of eugonadism during TRT are highly warranted both in athletes and in non-athletes.

Cadmium-induced apoptosis and necrosis in human osteoblasts: role of caspases and mitogen-activated protein kinases pathways

Cadmium is a widespread environmental pollutant which induces severe toxic alterations, including osteomalacia and osteoporosis, likely by estrogen receptor-dependent mechanisms. Indeed, cadmium has been described to act as an endocrine disruptor and its toxicity is exerted both in vivo and in vitro through induction of apoptosis and/or necrosis by not fully clarified intracellular mechanism(s) of action. Aim of the present study was to further investigate the molecular mechanism by which cadmium might alter homeostasis of estrogen target cells, such as osteoblast homeostasis, inducing cell apoptosis and/or necrosis. Human osteoblastic cells (hFOB 1.19) in culture were used as an in vitro model to characterize the intracellular mechanisms induced by this heavy metal. Cells were incubated in the presence/ absence of 10-50 μM cadmium chloride at different times and DNA fragmentation and activation of procaspases- 8 and -3 were induced upon CdCl(2) treatment triggering apoptotic and necrotic pathways. Addition of caspase-8 and -3 inhibitors (Z-IETD-FMK and Z-DQMD-FMK) partially blocked these effects. No activation of procaspase-9 was observed. To determine the role of mitogen-activated protein kinases (MAPK) in these events, we investigated c-jun N-terminal kinase (JNK), p38 and extracellular signal-regulated protein kinase (ERK1/2) phosphorylation which were activated by 10 μM CdCl(2). Chemical inhibitors of JNK, p38, and ERK1/2, SP600125, SB202190, and PD98059, significantly reduced the phosphorylation of the kinases and blunted apoptosis. In contrast, caspase inhibitors did not reduce the cadmium-induced MAPK phosphorylation, suggesting an independent activation of these pathways. In conclusion, at least 2 pathways appear activated by cadmium in osteoblasts: a direct induction of caspase-8 followed by activation of caspase-3 and an indirect induction by phosphorylation of ERK1/2, p38, and JNK MAPK triggering activation of caspase-8 and -3.

Is obesity in women protective against osteoporosis?

The belief that obesity is protective against osteoporosis has recently come into question. The latest epidemiologic and clinical studies have shown that a high level of fat mass might be a risk factor for osteoporosis and fragility fractures. Further, increasing evidence seems to indicate that different components of the metabolic syndrome, ie, hypertension, increased triglycerides, reduced high-density lipoprotein cholesterol, are also potential risk factors for the development of low bone mineral density and osteoporosis. This review considers both the older and more recent data in the literature in order to evaluate further the relationship between fat tissue and bone tissue.

Baseline characteristics of the population enrolled in the Italian Observational Study on Severe Osteoporosis (ISSO)

OBJECTIVES

Baseline characteristics of the population enrolled in the ISSO study, designed to evaluate the incidence of vertebral and non-vertebral fractures in Italian patients with severe osteoporosis treated according to clinical practice over 24 months observation.

METHODS

Prospective observational study in 783 post-menopausal women and men entering 18-month treatment with teriparatide in a community setting at 57 centres in Italy. Characterisation included demographics, fracture risk factors, bone mineral density, fracture status, Health-Related Quality of Life (HRQoL) measured by the European Quality of Life Questionnaire, EQ-5D, and back pain assessed by VAS.

RESULTS

Most patients were elderly women (90.5%), mean age±SD was 72.9±8.8 years. Nearly all (91.3%) had experienced ≥ 1 vertebral fracture (mean±SD, 3.6±2.2 per patient), 37.5% had ≥ 1 non-vertebral fracture (mean±SD, 1.4±0.7 per patient). Nearly all patients were suffering from back pain (94.9%), which had significantly restricted their daily activities (51.7%) and had likely or very likely been caused by vertebral fractures (29.2% and 55.8%, respectively). Mean EuroQoL EQ-5D index value was 0.58±0.25 and VAS score 49.2±23.6. Non-vertebral fractures, back pain and multiple vertebral fractures were associated with lower HRQoL (EuroQoL-5D Index both p<0.001, EQ-5D VAS score p=0.025 and p<0.016, respectively). Many patients were physically inactive (81.1%). One third (34.7%) of population had co-morbidities and 60.5% were on chronic concomitant treatments. Few subjects reported a maternal history of osteoporosis (15.5%), regular consumption of alcohol (13.3%) or were current smokers (11.5%). Nearly two-thirds (71.5%) had already been treated for osteoporosis, mainly with bisphosphonates. Calcium and vitamin D supplements were taken by 13% and 15.5% of the total population, respectively.

CONCLUSIONS

At enrollment, the population of ISSO study mostly consisted in aging women, who had osteoporosis with high fracture risk, poor HRQoL and suffered from significant back pain. Most of them had already been treated by bisphosphonates but without calcium and vitamin D supplements. Back pain, as well as non-vertebral and multiple vertebral fractures, were associated with lower HRQoL.

Differential characteristics of bone quality and bone turnover biochemical markers in patients with hip fragility fractures and hip osteoarthritis: results of a clinical pilot study

BACKGROUND AND AIMS

Bone density and quality alterations worsen the ability of osteoporotic bone to support prosthetic implants. The aim of our study was to evaluate potential differences in bone quality and bone turnover markers in aged individuals undergoing surgery for hip fragility fracture or hip osteoarthritis.

METHODS

Eighteen subjects with hip fragility fractures (Hip Fracture Group), 35 subjects with osteoarthritis of the hip (Hip Osteoarthritis Group) and 19 subjects with normal femoral bone mineral density (Control Group) were evaluated. Serum and urinary bone markers were assayed preoperatively in all surgical patients, and within 48 hours after fracture in the Hip Fracture, Osteoarthritis and Control groups. Histomorphometric analysis was performed on surgical samples.

RESULTS

A significant alteration in calcium and PTH serum levels with hyperparathyroidism was observed in the Hip Fracture Group compared with Hip Osteoarthritis and Control Groups. C-Terminal telopeptides of type I-collagen (CTx) and tartrate resistant-acid phosphatase (TRAP), markers of bone resorption, were increased in the Hip Fracture Group compared with both Osteoarthritis and Control Groups (CTx: p<0.0007 and p<0.0039 respectively; TRAP: p<0.002 and p<0.0007). All subjects were vitamin D3-deficient, but no differences were found among the different groups. In addition, histomorphometric data showed better maintained connectivity in the Osteoarthritis Group compared with the Hip Fracture Group (p<0.0001).

CONCLUSIONS

Our data show significant differences in bone turnover markers in patients undergoing hip prosthesis for fragility fractures, compared with patients operated for hip osteoarthritis.

Exposure to phosphodiesterase type 5 inhibitors stimulates aromatase expression in human adipocytes in vitro

INTRODUCTION

Prolonged tadalafil administration in men with erectile dysfunction is associated with increased testosterone (T): estradiol (E(2)) ratio mainly related to reduction of E(2) levels.

AIM

To investigate the presence of phosphodiesterase type 5 (PDE5) isoenzyme in primary human visceral adipocytes and whether different PDE5 inhibitors (PDE5i) could directly modulate aromatase (ARO) expression in differentiated human visceral adipocytes in culture.

MAIN OUTCOME MEASURES

PDE5 mRNA and protein expression in primary human visceral adipocytes as well as mRNA and protein expression of ARO, with functional activity after selective PDE5 blockade by tadalafil and sildenafil.

METHODS

Purified primary human visceral pre-adipocytes were differentiated ex vivo and were exposed to tadalafil or sildenafil (1 µM) for different intervals of time (6-12-24-96 hours). ARO mRNA content and expression were measured by Western Blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), respectively. T and E(2) in supernatants were measured by ELISA also in the presence of letrozole.

RESULTS

Differentiated adipocytes were found to express detectable levels of PDE5 transcripts. Acute exposure (6 hours) to both PDE5i tadalafil and sildenafil increased ARO mRNA expression by 4.7- and 2.8-fold, respectively (P < 0.001). ARO mRNA and protein levels were increased by the treatment with PDE5i in a time- and dose-dependent manner. Such effect was mimicked by 8-bromo-cGMP but was lost after 24 and 96 hours; differently, the PDE3B specific inhibitor milrinone (1 µM), displayed no effect. Accordingly, long-term exposure (24 and 96 hours) to PDE5i caused a significant increase in E(2) concentrations in the supernatant (1.7 and 2 fold, respectively; P < 0.001), with a parallel reduction of T (15% and 30%, respectively; P < 0.001). Such effect was reversed by the co-incubation with the specific ARO-inhibitor letrozole.

CONCLUSIONS

Our results demonstrate that PDE5 is expressed in human visceral adipocytes and that acute exposure to PDE5i selectively stimulates ARO expression, which is related to a specific PDE5 blockade. We speculate that modulation of ARO activity by PDE5i could be one of the mechanisms responsible, at least in part, for the beneficial effects of PDE5i on endothelial and metabolic functions.

[Guidelines for the diagnosis, prevention and treatment of osteoporosis]

The guidelines for the osteoporosis management were first drafted by a working group and then critically evaluated by the board of SIOMMMS. The most relevant points are:

DEFINITION

Osteoporosis is defined as a quantitative and qualitative deterioration of bone tissue leading to increased risk of fracture. Postmenopausal and senile osteoporosis are defined as primitive.

DIAGNOSIS

The cornerstone for the diagnosis of osteoporosis is the measurement of bone mineral density (BMD) by DXA (dual-energy X-ray absortiometry) at the femoral neck with T-score values <-2.5, following the WHO definition. Other DXA sites or technologies for measuring bone mass are also acceptable when the former is not accessible. A BMD evaluation is recommended to all women above 65 years of age. At younger age or in man the bone assessment is recommended only in subjects with specific risk factors. A control of bone mass measurement is seldom required before 2 years.

DIFFERENTIAL DIAGNOSIS

A few biochemical tests such as serum and urinary calcium, protein electrophoresis, serum creatinine and ESR are usually sufficient to exclude most secondary types of osteoporosis. The value of the so called bone turnover markers for the diagnosis and follow-up of osteoporosis remains uncertain. Several secondary forms of osteoporosis require a specific diagnostic and therapeutic management.

PREVENTION

The osteoporosis prevention should be based on the elimination of specific risk factors such as inadequate calcium and vitamin D intake, smoking and sedentary life. The use of pharmacological agents in subjects with BMD values >-2.5 is usually not justified. Pharmacological intervention: The use of drugs registered for the treatment of osteoporosis are recommended when the benefits overcome the risk. This is the case only when the risk of fracture is rather high. FRAX is recognized as a useful tool for easily estimate the long-term fracture risk. SIOMMMS with these guidelines is committed to validate and further develop this diagnostic tool.

Expression of parathyroid hormone-related protein in human inflamed dental pulp

INTRODUCTION

The aim of this study was to investigate the presence and the role of the parathyroid hormone-related protein (PTH-rP) in the inflamed pulp.

MATERIALS AND METHODS

Thirty-four pulp tissue specimens (24 inflamed and 10 normal pulps) from extracted third molars were studied. The presence of PTH-rP was observed by using immunohistochemistry. Negative controls were performed using non immunized rabbit or mouse serum, omitting the primary antibody.

RESULTS

The analysis of all the sections of normal pulps showed the presence of PTHrP positive cells only in the odontoblastic zone and in few fibroblasts. Instead all inflamed pulps showed PTHrP positive cells both in vascular zone and in pulp stroma, as well as in the odontoblastic and subodontoblastic zone.

CONCLUSION

Several works proved that this peptide plays a role even in angiogenesis process, but its function is controversial. It is possible to hypothesize that PTHrP stimulates angiogenesis, but it is recommended to further conduct research on this area.

Is obesity protective for osteoporosis? Evaluation of bone mineral density in individuals with high body mass index

BACKGROUND

Obese individuals often present comorbidities while they appear protected against the development of osteoporosis. However, few and contradictory data are now available on skeletal modifications in obese patients. The aim of this study was to characterise bone mineral density (BMD) in overweight (BMI > 25 < 29.9) and obese (BMI > 30) patients.

METHODS

We selected 398 patients (291 women, 107 men, age 44.1 + 14.2 years, BMI 35.8 + 5.9 kg/m(2)) who underwent clinical examination, blood tests and examination of body composition. Subjects with chronic conditions or taking medications interfering with bone metabolism, hormonal and nutritional status and recent weight loss were excluded.

RESULTS

Interestingly, 37% (n = 146) of this population showed a significantly lower than expected lumbar BMD: 33% (n = 98) of women showed a T-score -1.84 +/- 0.71, and 45% (n = 48) of men showed a T-score -1.88 +/- 0.64. When the population was divided into subgroups based on different BMI, it was noted that overweight (BMI > 25 < 29.9) was neutral or protective for BMD, whereas obesity (BMI > 30) was associated with a low bone mass, compatible with a diagnosis of osteoporosis. No differences were observed in hormones and lipid profiles among subgroups.

CONCLUSIONS

Our results indicate that a subpopulation of obese patients has a significant low lumbar BMD than expected for age. Thus, a careful characterisation of skeletal metabolism might be useful in all obese individuals to avoid fragility fractures later in life.

Management of glucocorticoids-induced osteoporosis: role of teriparatide

Glucocorticoids (GC)-induced osteoporosis (GIOP) is the most common cause of secondary osteoporosis, which leads to an increased fracture risk in patients. The normal bone turnover depends on a balance between osteoblasts and osteoclasts activity and GC can cause a rapid bone loss, decreasing bone formation and increasing bone resorption. The decreased bone formation is mainly due to the GC-induced apoptosis of both osteoblasts and osteocytes, while the increased bone resorption is due to the increased life-span of pre-existing osteoclasts. Bisphosphonates are clearly effective in preventing and treating GIOP but anabolic therapeutic strategies are the new promising therapeutic alternative. Experimental and clinical studies indicate that teriparatide, the active (1–34) parathyroid hormone (PTH) molecule, is efficacious for the treatment of GIOP, being able to induce an increase in bone mass in these patients. Intermittent administration of human PTH (1–34) stimulates bone formation by increasing osteoblast number. Additionally, human PTH (1–34) modulates the level and/or activity of locally produced growth factors and cytokines. Teriparatide has been demonstrated in several clinical studies to significantly decrease the incidence of fractures in patients affected by GIOP. It has recently received an indication for GIOP and its label indication has also been expanded.

Glucocorticoid-induced osteoporosis: an osteoblastic disease

It is well-known that glucocorticoid-induced osteoporosis (GIO) is the most common form of secondary osteoporosis. It is estimated that 30% to 50% of patients receiving chronic glucocorticoid therapy suffer vertebral or hip fractures, which are often asymptomatic. Vertebral fractures occur early after exposure to glucocorticoids, at a time when bone mineral density (BMD) declines rapidly. Glucocorticoids impair osteoblast homeostasis and induce apoptosis of both osteoblasts and osteocytes, leading to suppression of bone formation. Glucocorticoids also favor osteoclastogenesis and, as a consequence, increase bone resorption. The end-point of these alterations is a net decrease in BMD and alterations in bone quality. Bisphosphonates have been approved for both prevention and treatment of GIO. At the present time, anabolic therapeutic agents are still under investigation.

Osteoblast-conditioned medium promotes proliferation and sensitizes breast cancer cells to imatinib treatment

Inhibition of platelet-derived growth factor receptor (PDGFR) signaling restricts the growth of human breast cancer in the bone of nude mice. We hypothesized that osteoblast-secreted substances may alter the response capacity of breast cancer cells to the PDGFRs tyrosine kinase inhibitor imatinib mesylate. We found that osteoblast-conditioned medium (OCM) increases the proliferation rate of the estrogen receptor negative (ER-) MDA-MB-231 and of the ER+ MCF-7 human breast cancer cell lines and the growth-promoting effect on ER+ cells is independent from estrogen. OCM significantly improved the dose- and the time-dependent sensitivity of the tumor cells to the anti-proliferative effect of imatinib. We also found that MDA-MB-231 and MCF-7 cells express the two PDGFRs subtypes, PDGFR-alpha and PDGFR-beta, and OCM treatment increases the expression of the PDGFRs. Furthermore, imatinib inhibited the phosphorylation rate of its target tyrosine kinase receptors. We conclude that bone microenvironment, through osteoblast-secreted substances may cause estrogen-independent proliferation of breast cancer cells by a mechanism mediated by the induction of PDGFRs expression. The enhanced sensitivity of OCM-treated breast cancer cells to imatinib would justify investigation on the efficacy of imatinib in bone breast cancer metastasis.

Cadmium induces mitogenic signaling in breast cancer cell by an ERalpha-dependent mechanism

Breast cancer (BC) is linked to estrogen exposure. Estradiol (E2) stimulates BC cells proliferation by binding the estrogen receptor (ER). Hormone-related cancers have been linked to estrogenic environmental contaminants. Cadmium (Cd) a toxic pollutant, acts as estrogens in BC cells. Purpose of our study was to evaluate whether Cd regulates MCF-7 cell proliferation by activating ERK1/2, Akt and PDGFRalpha kinases. Cd increased cell proliferation and the ER-antagonist ICI 182,780 blunted it. To characterize an ER-dependent mechanism, ERalpha/beta expression was evaluated. Cd decreased ERalpha expression, but not ERbeta. Cd also increased ERK1/2, Akt and PDGFRalpha phosphorylation while ICI blocked it. Since stimulation of phosphorylation was slower than expected, c-fos and c-jun proto-oncogenes, and PDGFA were analyzed. Cd rapidly increased c-jun, c-fos and PDGFA expression. Cells were also co-incubated with the Cd and specific kinases inhibitors, which blocked the Cd-stimulated proliferation. In conclusion, our results indicate that Cd increases BC cell proliferation in vitro by stimulating Akt, ERK1/2 and PDGFRalpha kinases activity likely by activating c-fos, c-jun and PDGFA by an ERalpha-dependent mechanism.

Effect of titanium carbide coating on the osseointegration response in vitro and in vivo

Titanium has limitations in its clinical performance in dental and orthopaedic applications. This study describes a coating process using pulsed laser deposition (PLD) technology to produce surfaces of titanium carbide (TiC) on titanium substrates and evaluates the biological response both in vitro and in vivo. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of 18.6-21.5% TiC in the surface layer, accompanied by oxides of titanium 78.5-81.4% in the following concentrations: 11.1-13.0% Ti(2)O(3), 50.8-55.8% TiO(2), 14.5-14.7% TiO. Expression of genes central to osteoblast differentiation (alkaline phosphatase, A2 pro-collagen type 1, osteocalcin, BMP-4, TGFbeta and Cbfa-1) were up-regulated in all cell lines (primary human osteoblasts, hFOB1.19 and ROS.MER#14) grown on TiC compared with uncoated titanium when measured by semiquantitative PCR and real time-PCR, whilst genes involved in modulation of osteoclastogenesis and osteoclast activity (IL-6 and M-CSF) were unchanged. Bone density was shown to be greater around TiC-coated implants after 2 and 4 weeks in sheep and both 4 and 8 weeks in rabbits compared to uncoated titanium. Rapid bone deposition was demonstrated after only 2 weeks in the rabbit model when visualized with intravital staining. It is concluded that coating with TiC will, in comparison to uncoated titanium, improve implant hardness, biocompatibility through surface stability and osseointegration through improved bone growth.