Vertebral fractures in males with type 2 diabetes treated with rosiglitazone

Screening for endogenous hypercortisolism in patients with osteoporosis and fractures: why, when and how

Skeletal comorbidities are frequent and clinically relevant findings in Cushing's syndrome (CS) since an uncoupled suppressed bone formation and enhanced bone resorption leads to a marked skeletal damage with a rapid increase of fracture risk. Reduced Bone Mineral Density (BMD) has been consistently reported and osteopenia or osteoporosis are typical findings in patients with CS. Vertebral Fractures (VFs) are frequently reported and may occur even in patients with an only mild reduction of BMD. Since CS is diagnosed late due to often difficult biochemical and radiological confirmation as well as to signs and symptoms common in other much more frequent diseases an approach suggested for overcoming underdiagnosis is to screen patients with manifestations which may overlap with those of CS such as arterial hypertension, diabetes mellitus and osteoporosis. Our review will focus on the rationale and best practice for screening osteoporotic patients for CS.

Morphometric vertebral fractures at hospitalization associate with Long COVID occurrence

PURPOSE

Long COVID is a multisystemic syndrome leading to significant morbidity. To date, a comprehensive characterization of underlying risk factors is still being defined. Osteoporosis and vertebral fractures (VFs) were associated with worse acute COVID-19 and impaired respiratory recovery after hospitalization. Therefore, we aimed to assess the potential relationship between VFs and the occurrence of the Long COVID syndrome.

METHODS

Patients hospitalized for acute COVID-19 and subsequently seen in our outpatient follow-up clinic 6-months after discharge were evaluated. We retrospectively included patients with available lateral chest X-rays performed at admission suitable for VFs assessments. We excluded patients with active neoplasia, and those managed at home or those hospitalized in ICU. Long COVID was diagnosed with a multidisciplinary evaluation.

RESULTS

One-hundred sixty-two patients were included in the study. At least one VF was found in 42 patients at presentation (25.9%). Patients with VFs were significantly older and predominantly males. Long COVID was diagnosed in 25 patients (15.4%). No differences were found between patients with and without Long COVID regarding demographics and comorbidities; however, those with Long COVID were characterized by a higher prevalence of VFs at time of hospitalization for acute COVID-19 (48% vs. 22%, p = 0.01). After matching patients with and without VFs in a 1:1 ratio for demographics, comorbidities, and COVID-19 severity, a total of 84 patients were analysed and those presenting VFs were characterized by a significant higher prevalence of Long COVID (28.6% vs. 9.5%, p = 0.04) and VFs resulted as the only significant independent risk factor for Long COVID occurrence.

CONCLUSIONS

We observed that prevalent VFs detected at hospital admission were distinctive clinical features of patients presenting with Long COVID 6-months after discharge, independently from acute disease severity and other confounding factors. This highlights a potential detrimental association between skeletal fragility and the development of Long COVID.

Vitamin D and hip protectors in osteosarcopenia: a combined hip fracture preventing approach

Osteosarcopenia is an emerging clinical condition highly prevalent in the older people. Affected subjects due to their intrinsic skeletal fragility and propensity to falls are at elevated risk of hip fractures which can increase morbidity and mortality. Strategies for attenuating the impact of predisposing factors on hip fractures are not yet well defined and should derive from multidisciplinary care and collaborations. Our aim was to narratively review available data on the preventive role of vitamin D and hip protectors on hip fractures in older patients with sarcopenia. Older subjects are at high risk of vitamin D deficiency and of falls due to several concomitant factors besides osteosarcopenia. Vitamin D protective actions against hip fractures may be mediated by both skeletal (increased mineralization) and extra-skeletal (reduced risk of falls) actions. Hip protectors may act downstream attenuating the effects of falls although their use is still not yet enough widespread due to the suboptimal compliance obtained by traditional hard devices. Concomitant use of vitamin D and hip protectors may represent an effective strategy in the prevention of hip fractures which need to be tested in ad hoc designed clinical trials.

Novel approach to bone comorbidity in resistant acromegaly

Active acromegaly may lead to irreversible complications. Among them, acromegaly osteopathy and fragility (vertebral and hip) fractures have emerged as frequent and precocious events in the natural history of the disease, being correlated with longer disease duration and higher growth hormone (GH) levels, accounting for patients' reported poor quality of life, physical performance and other life-impacting complications. Differently from primary osteoporosis, bone mineral density is not a reliable tool to predict fracture risk in this clinical setting, as patients with active disease frequently have normal or slightly reduced bone mass; whereas bone quality is particularly compromised, as determined by low trabecular bone score (TBS) in patients with active disease as compared to healthy controls or patients with cured/controlled disease. The evidence of impaired bone microstructure has been profoundly investigated with different computed tomography (CT) techniques, reporting low trabecular number and thickness as well as wide but more porous cortical bone, providing an explanation for such a high prevalence of vertebral fractures (up to 40-50% in selected cohorts). Since data on bone-active drugs are scanty, disease control remains a cornerstone to prevent fractures. Nonetheless, some potential protective effects may derive from vitamin D supplementation and pasireotide therapies, independently from disease status. Aim of this manuscript is to review the current and emerging evidence on skeletal fragility in patients with active and resistant acromegaly.

Modern approach to bone comorbidity in prolactinoma

Prolactinomas account for more than half of pituitary adenomas, and besides their clinical impact on fertility and gonadal function, they lead to detrimental effects on bone. Patients with prolactinoma are prone to deterioration of bone structure caused not only by prolactin (PRL) induced hypogonadism but also by its direct actions on bone cells and calcium metabolism. However, clinical studies have shown inconsistent evidence regarding whether PRL could have a deleterious effect independently from gonadal insufficiency on skeletal integrity. Seminal studies from our group reported an increased prevalence of vertebral fractures (VFs) in both female and male patients with prolactinoma. Treatment of prolactinoma with dopamine agonists can restore gonadal function and improve bone mineral density. Since the presence of VFs may be related to more aggressive disease, bone comorbidities in prolactinoma should be managed by a multidisciplinary team in line with the recent concept of 'pituitary tumors centers of excellence'. The review aims to evaluate the mechanism of PRL actions on bone, as well as to provide practical indications for a modern approach to the management of skeletal complications of patients with prolactin-secreting adenoma considering different clinical characteristics and outcomes.

New insights into the vitamin D/PTH axis in endocrine-driven metabolic bone diseases

BACKGROUND

Endocrine regulation of bone metabolisms is the focus of the "Skeletal Endocrinology" series of meetings.

AIMS

To report on the outcome of the discussion on the role of vitamin D/PTH axis in endocrine osteopathies held during the 10th Skeletal Endocrinology Meeting which took place in Stresa (Italy) in March 2023.

OUTCOMES

Vitamin D/PTH axis has relevant influence on several outcomes in the general population and in patients affected by endocrinopathies such as hypoparathyroidism and secreting pituitary adenomas.

CONCLUSIONS

Assessing the status of the vitamin D/PTH axis and using vitamin D and PTH as therapeutic agents is mandatory in several endocrine-related bone metabolic conditions.

High prevalence of vertebral fractures associated with preoperative cortisol levels in patients with recent diagnosis of Cushing disease

BACKGROUND/OBJECTIVE

Morphometric vertebral fractures (VFs) and osteopathy are prevalent and clinically significant complications of Cushing disease (CD). However whether they represent an early occurrence in the natural progression of the disease is an ongoing debate. This study aimed to assess the prevalence and determinants of VFs in patients newly diagnosed with CD.

PATIENTS AND METHODS

This cross-sectional case-control study recruited 75 newly diagnosed CD patients and compared them with a control group of individuals without pituitary disorders or secondary forms of osteoporosis. Demographic, clinical and biochemical data were collected. The VFs were assessed using preoperative lateral chest radiography.

RESULTS

We found a significantly higher prevalence of VFs in the CD group than in the control group (58.7% vs. 14.5%; P < 0.001). Among the CD patients with VFs, 27 (61.4%) showed moderate/severe VFs. The CD patients with VFs had significantly higher preoperative 8 am serum cortisol (8ASC) levels than those without VFs (P < 0.001). The preoperative 4 pm adrenocorticotropic hormone (ACTH) levels (P = 0.031), preoperative 0 am ACTH levels (P = 0.021) and systolic blood pressure were slightly higher in CD patients with VFs than in those without VFs (P = 0.028). A binary multiple logistic analysis showed that 8ASC was an independent predictor of VF risk (P = 0.003). The optimal cut-off value of the preoperative serum 8ASC level for predicting VFs was 22.18 ng/mL.

CONCLUSIONS

This is the first study reporting a high prevalence of radiologic VFs in recently diagnosed CD patients. VFs may represent an early manifestation of CD and may be related to cortisol levels. Therefore, VF assessment should be included in the workup during CD diagnosis.

New tools for bone health assessment in secreting pituitary adenomas

Pituitary hormones regulate skeletal physiology, and excess levels affect bone remodeling and alter bone microstructure. Vertebral fractures (VFs) are an early phenomenon of impaired bone health in secreting pituitary adenomas. However, they are not accurately predicted by areal bone mineral density (BMD). Emerging data demonstrate that a morphometric approach is essential for evaluating bone health in this clinical setting and is considered to be the gold standard method in acromegaly. Several novel tools have been proposed as alternative or additional methods for the prediction of fractures, particularly in pituitary-driven osteopathies. This review highlights the novel potential biomarkers and diagnostic methods for bone fragility, including their pathophysiological, clinical, radiological, and therapeutic implications in acromegaly, prolactinomas, and Cushing's disease.

High Prevalence of Vertebral Fractures Associated With Preoperative GH Levels in Patients With Recent Diagnosis of Acromegaly

CONTEXT

Osteopathy and morphometric vertebral fractures (VFs) are emerging complications in acromegaly. However, the prediction of VFs in this clinical setting is still a matter of uncertainty, and it is debated whether they are an early event in the natural history of the disease.

OBJECTIVE

We aimed to evaluate the prevalence and determinants of morphometric VFs in patients with recently diagnosed acromegaly.

METHODS

We enrolled 92 patients (43 men/49 women) on admission to the neurosurgery unit before transsphenoidal surgery, and compared them with control individuals without secondary forms of osteoporosis and pituitary disorders. We performed a VF assessment on preoperative chest x-ray images and collected biochemical, demographic, and clinical data.

RESULTS

We detected a significantly higher prevalence of VFs (33.7%) in patients with acromegaly than in controls (P = .001). Among the patients with acromegaly and VFs, 12 (38.7%) showed multiple VFs, and 5 (16.1%) showed moderate/severe VFs. Patients with VFs had higher random serum growth hormone (GH) levels than those with no VFs (P = .03), but there was no difference in insulin-like growth factor-1 (IGF-1) (P = .07) and IGF-1/Upper Normal Limit ratio (P = .08). Free 3,5,3'-triiodothyronine was slightly lower in patients with acromegaly and VFs than in those without VFs (P = .05). In multiple logistic analysis, GH was independently associated with risk for VFs (P = .003). The preoperative serum GH cutoff value that predicted VFs was 12 ng/mL.

CONCLUSION

For the first time, high prevalence of radiological VFs is reported in patients with recent diagnosis of acromegaly. Therefore, we can hypothesize that VFs are an early phenomenon of acromegaly and related to GH levels. VF assessment should be included in the workup at the diagnosis of acromegaly.

Bone mass and microarchitecture in T2DM patients and corticosteroids therapy: the Bushehr Elderly Health program

Purpose

Our study examined whether T2DM and glucocorticoids treatment affect bone quality and quantity that are measured by Bone Mineral Density (BMD) and Trabecular Bone Score (TBS).

Materials & methods

Participants in this study were 2294 women and men aged over 60 years who participated in stage II of the Bushehr Elderly Health (BEH) program. Patients with T2DM and those who received glucocorticoids were included. BMD was detected using the DXA method and the TBS of L1-L4 was evaluated by TBS iNsight® software. To evaluate the correlation between TBS and BMD levels with diabetes and taking corticosteroids sex-specific multivariable linear regression models were appplied.

Results

TBS and BMD were not significantly different in those who had received glucocorticoids versus those who did not.T2DM revealed a significant association with both BMD and TBS in men (beta = 0.12, p < 0.001 and beta = 0.063, p = 0.03, respectively). BMD values were significantly higher in diabetic women (beta = 0.073, p < 0.01). BMI had a significant association with both TBS and BMD but in an opposite direction, in women and men (BMD: beta = -0.22, -0.24, and regarding TBS: beta = 0.37, 0.25, all p-values < 0.001).

Conclusion

Our findings showed that T2DM had major effects on BMD in both men and women. However, T2DM only affects TBS in men. Furthermore, neither BMD nor TBS were affected by GC intake in men or women.Based on the variable importance of covariates, BMI was the most influential factor on both BMD and TBS, although in opposite directions, in both sexes.

Vitamin D Levels Are Associated With Blood Glucose and BMI in COVID-19 Patients, Predicting Disease Severity

CONTEXT

A high prevalence of vitamin D (VD) deficiency in COVID-19 patients has been reported and hypothesized to increase COVID-19 severity likely because of its negative impact on immune and inflammatory responses. Furthermore, clear associations between hypovitaminosis D and fat body mass excess and diabetes, factors associated with COVID-19 severity, have been widely recognized.

OBJECTIVE

The aim of this study was to evaluate in COVID-19 patients the relationship between VD levels and inflammatory response, body mass index (BMI), blood glucose (GLU), and disease severity.

METHODS

Patients admitted to San Raffaele-Hospital for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing VD metabolism. 25-Hydroxyvitamin D levels, plasma GLU levels, BMI, and inflammatory parameters were evaluated at admission.

RESULTS

A total of 88 patients were included. Median VD level was 16.3 ng/mL and VD deficiency was found in 68.2% of patients. VD deficiency was found more frequently in male patients and in those affected by severe COVID-19. Regression analyses showed a positive correlation between VD and PaO2/FiO2 ratio, and negative correlations between VD and plasma GLU, BMI, neutrophil/lymphocyte ratio, C-reactive protein, and interleukin 6. Patients with both hypovitaminosis D and diabetes mellitus, as well those with hypovitaminosis D and overweight, were more frequently affected by a severe disease with worse inflammatory response and respiratory parameters, compared to those without or just one of these conditions.

CONCLUSION

We showed, for the first-time, a strict association of VD levels with blood GLU and BMI in COVID-19 patients. VD deficiency might be a novel common pathophysiological mechanism involved in the detrimental effect of hyperglycemia and adiposity on disease severity.

Type 2 diabetes and bone fragility- An under-recognized association

BACKGROUND AND AIMS

Diabetes and osteoporosis are common chronic disorders with growing prevalence in the aging population. Skeletal fragility secondary to diabetes increases the risk of fractures and is underestimated by currently available diagnostic tools like fracture risk assessment (FRAX) and dual-energy X-ray absorptiometry (DXA). In this narrative review we describe the relationship and pathophysiology of skeletal fragility and fractures in Type 2 diabetes (T2DM), effect of glucose lowering medications on bone metabolism and the approach to diagnosing and managing osteoporosis and bone fragility in people with diabetes (PWD).

METHODS

A literature search was conducted on PubMed for articles in English that focused on T2DM and osteoporosis or bone/skeletal fragility. Articles considered to be of direct clinical relevance to physicians practicing diabetes were included.

RESULTS

T2DM is associated with skeletal fragility secondary to compromised bone remodeling and bone turnover. Long duration, poor glycemic control, presence of chronic complications, impaired muscle function, and anti-diabetic medications like thiazolidinediones (TZD) are risk factors for fractures among PWD. Conventional diagnostic tools like DXA and FRAX tool underestimate fracture risk in diabetes. Presence of diabetes does not alter response to anti-osteoporotic treatment in post-menopausal women.

CONCLUSION

Estimation of fragility fracture risk should be included in standard of care for T2DM along with screening for traditional complications. Physicians should proactively screen for and manage osteoporosis in people with diabetes. It is important to consider effects on bone health when selecting glucose lowering agents in people at risk for fragility fractures.

Effects of Medical Treatment of Prostate Cancer on Bone Health

Medical treatment of prostate cancer (PC) is multidisciplinary, resulting in prolonged survival. Androgen-deprivation therapy (ADT) can have negative effects on skeletal metabolism, particularly if combined with glucocorticoids. We discuss the pathophysiology and effects of ADT and glucocorticoids on skeletal endpoints, as well as the awareness and management of bone fragility. Coadministration of glucocorticoids is necessary with abiraterone because this causes a novel acquired form of 17-hydroxylase deficiency and synergistically increases the risk of fracture by affecting bone quality. Bone antiresorptive agents [selective estrogen receptor modulators (SERMS), bisphosphonates, and denosumab] increase bone mineral density (BMD) and in some instances reduce fracture risk in PC patients on ADT. Awareness and management of bone health in PC can be improved by integrating endocrinologists into the multidisciplinary PC team.

Radiological Thoracic Vertebral Fractures are Highly Prevalent in COVID-19 and Predict Disease Outcomes

CONTEXT AND OBJECTIVE

COVID-19 has become the most relevant medical issue globally. Despite several studies that have investigated clinical characteristics of COVID-19 patients, no data have been reported on the prevalence of vertebral fractures (VFs). Since VFs may influence cardiorespiratory function and disease outcomes, the aim of this study was to assess VFs prevalence and clinical impact in COVID-19.

DESIGN AND PATIENTS

This was a retrospective cohort study performed at San Raffaele Hospital, a tertiary health care hospital in Italy. We included COVID-19 patients for whom lateral chest x-rays at emergency department were available. VFs were detected using a semiquantitative evaluation of vertebral shape on chest x-rays.

RESULTS

A total of 114 patients were included in this study and thoracic VFs were detected in 41 patients (36%). Patients with VFs were older and more frequently affected by hypertension and coronary artery disease (P < 0.001, P = 0.007, P = 0.034; respectively). Thirty-six (88%) patients in VFs+ group compared to 54 (74%) in VFs- group were hospitalized (P = 0.08). Patients with VFs more frequently required noninvasive mechanical ventilation compared with those without VFs (P = 0.02). Mortality was 22% in VFs+ group and 10% in VFs- group (P = 0.07). In particular, mortality was higher in patients with severe VFs compared with those with moderate and mild VFs (P = 0.04).

CONCLUSIONS

VFs may integrate the cardiorespiratory risk of COVID-19 patients, being a useful and easy to measure clinical marker of fragility and poor prognosis. We suggest that morphometric thoracic vertebral evaluation should be performed in all suspected COVID-19 patients undergoing chest x-rays.

Glucose-Lowering Drugs and Fracture Risk-a Systematic Review

PURPOSE OF REVIEW

Diabetes mellitus (DM) is associated with increased fracture risk. The aim of this systematic review was to examine the effects of different classes of glucose-lowering drugs on fracture risk in patients with type 2 DM. The heterogeneity of the included studies did not allow formal statistical analyses.

RECENT FINDINGS

Sixty studies were included in the review. Metformin, dipeptidylpeptidase-IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter 2-inhibitors do not appear to increase fracture risk. Results for insulin and sulphonylureas were more disparate, although there may be an increased fracture risk related to hypoglycemia and falls with these treatments. Glitazones were consistently associated with increased fracture risk in women, although the evidence was sparser in men. New glucose-lowering drugs are continuously being developed and better understanding of these is leading to changes in prescription patterns. Our findings warrant continued research on the effects of glucose-lowering drugs on fracture risk, elucidating the class-specific effects of these drugs.

Spinal AMP kinase activity differentially regulates phrenic motor plasticity

Acute intermittent hypoxia (AIH) elicits phrenic motor plasticity via multiple distinct cellular mechanisms. With moderate AIH, phrenic motor facilitation (pMF) requires G_q protein-coupled serotonin type 2 receptor activation, ERK MAP kinase activity, and new synthesis of brain-derived neurotrophic factor. In contrast, severe AIH elicits pMF by an adenosine-dependent mechanism that requires exchange protein activated by cAMP, Akt, and mammalian target of rapamycin (mTOR) activity, followed by new tyrosine receptor kinase B protein synthesis; this same pathway is also initiated by G_s protein-coupled serotonin 7 receptors (5-HT₇). Because the metabolic sensor AMP-activated protein kinase (AMPK) inhibits mTOR-dependent protein synthesis, and mTOR signaling is necessary for 5-HT₇ but not 5-HT₂ receptor-induced pMF, we hypothesized that spinal AMPK activity differentially regulates pMF elicited by these distinct receptor subtypes. Serotonin type 2A receptor [5-HT_2A; (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride] or 5-HT₇ (AS-19) receptor agonists were administered intrathecally at C₄ (3 injections, 5-min intervals) while recording integrated phrenic nerve activity in anesthetized, vagotomized, paralyzed, and ventilated rats. Consistent with our hypothesis, spinal AMPK activation with 2-deoxyglucose or metformin blocked 5-HT₇, but not 5-HT_2A receptor-induced pMF; in both cases, pMF inhibition was reversed by spinal administration of the AMPK inhibitor compound C. Thus, AMPK differentially regulates cellular mechanisms of serotonin-induced phrenic motor plasticity.NEW & NOTEWORTHY Spinal AMP-activated protein kinase (AMPK) overactivity, induced by local 2-deoxyglucose or metformin administration, constrains serotonin 7 (5-HT₇) receptor-induced (but not serotonin type 2A receptor-induced) respiratory motor facilitation, indicating that metabolic challenges might regulate specific forms of respiratory motor plasticity. Pharmacological blockade of spinal AMPK activity restores 5-HT₇ receptor-induced respiratory motor facilitation in the presence of either 2-deoxyglucose or metformin, showing that AMPK is an important regulator of 5-HT₇ receptor-induced respiratory motor plasticity.

High bone marrow fat in patients with Cushing's syndrome and vertebral fractures

PURPOSE

The evaluation of skeletal fragility in Cushing's syndrome (CS) is a clinical challenge, since dual-energy X-ray absorptiometry (DXA) does not capture abnormalities in bone microstructure induced by glucocorticoid excess. Hypercortisolism was shown to increase bone marrow adiposity, but it is still unknown whether high bone marrow fat (BMF) as measured by vertebral magnetic resonance spectroscopy may predict fracture risk in this clinical setting. In this cross-sectional study, we evaluated the association between BMF and vertebral fractures (VFs) in patients with CS.

METHODS

Twenty patients (5 M, age 44 ± 13 years) with active CS were evaluated for morphometric VFs, lumbar spine BMF, and bone mineral density (BMD). Fifteen healthy volunteers (4 M, age 43 ± 12 years) acted as control group for BMF evaluation.

RESULTS

BMF was significantly higher in CS patients vs. controls (52.0% vs. 27.0%, p < 0.01), and was directly correlated with patients' age (p = 0.03), 24-hours urine-free cortisol (p = 0.03), midnight serum cortisol (p = 0.02), and serum CTX (p = 0.01). Patients with VFs (13 cases) showed significantly higher BMF vs. patients without VFs (65.0% vs. 24.0%, p = 0.03). Fractured patients with either normal BMD or osteopenia showed comparable BMF to fractured patients with either osteoporosis or low BMD for age (p = 0.71). When the analysis was restricted to patients with normal BMD or osteopenia, VFs were still significantly associated with higher BMF (p = 0.05).

CONCLUSIONS

This study provides a first evidence that vertebral adiposity may be a marker of hypercortisolism-induced skeletal fragility and measurement of spine BMF could have a role in the diagnostic work-up for the assessment of fracture risk in CS.

Diabetes pharmacotherapy and effects on the musculoskeletal system

Persons with type 1 or type 2 diabetes have a significantly higher fracture risk than age-matched persons without diabetes, attributed to disease-specific deficits in the microarchitecture and material properties of bone tissue. Therefore, independent effects of diabetes drugs on skeletal integrity are vitally important. Studies of incretin-based therapies have shown divergent effects of different agents on fracture risk, including detrimental, beneficial, and neutral effects. The sulfonylurea class of drugs, owing to its hypoglycemic potential, is thought to amplify the risk of fall-related fractures, particularly in the elderly. Other agents such as the biguanides may, in fact, be osteo-anabolic. In contrast, despite similarly expected anabolic properties of insulin, data suggests that insulin pharmacotherapy itself, particularly in type 2 diabetes, may be a risk factor for fracture, negatively associated with determinants of bone quality and bone strength. Finally, sodium-dependent glucose co-transporter 2 inhibitors have been associated with an increased risk of atypical fractures in select populations, and possibly with an increase in lower extremity amputation with specific SGLT2I drugs. The role of skeletal muscle, as a potential mediator and determinant of bone quality, is also a relevant area of exploration. Currently, data regarding the impact of glucose lowering medications on diabetes-related muscle atrophy is more limited, although preclinical studies suggest that various hypoglycemic agents may have either aggravating (sulfonylureas, glinides) or repairing (thiazolidinediones, biguanides, incretins) effects on skeletal muscle atrophy, thereby influencing bone quality. Hence, the therapeutic efficacy of each hypoglycemic agent must also be evaluated in light of its impact, alone or in combination, on musculoskeletal health, when determining an individualized treatment approach. Moreover, the effect of newer medications (potentially seeking expanded clinical indication into the pediatric age range) on the growing skeleton is largely unknown. Herein, we review the available literature regarding effects of diabetes pharmacotherapy, by drug class and/or by clinical indication, on the musculoskeletal health of persons with diabetes.

High Prevalence of Radiological Vertebral Fractures in Women on Thyroid-Stimulating Hormone-Suppressive Therapy for Thyroid Carcinoma

CONTEXT

Bone loss and nonvertebral fractures have been reported in patients with differentiated thyroid carcinoma (DTC) undergoing thyroid-stimulating hormone (TSH) suppressive therapy. Radiological vertebral fractures (VFs) are an early and clinically crucial marker of bone fragility.

OBJECTIVE AND DESIGN

A cross-sectional study to evaluate the prevalence and determinants of radiological VFs in women receiving l-thyroxine (L-T4) therapy for DTC.

PATIENTS AND INTERVENTIONS

A total of 179 consecutive women (median age, 59 years; n = 178 postmenopausal) who had undergone thyroidectomy for DTC and were currently receiving L-T4 were evaluated for radiological VFs and bone mineral density (BMD). There were three TSH target levels [<0.5 mU/L, group 1 (n = 83); 0.5 to 1.0 mU/L, group 2 (n = 50); >1.0 mU/L, group 3 (n = 46)].

RESULTS

VFs were found in 51 patients (28.5%), with significantly (P < 0.001) higher prevalence in group 1 (44.6%) as compared with group 2 (24.0%) and group 3 (4.3%). VF prevalence was not significantly different among patients in group 1 with normal BMD, osteopenia, or osteoporosis, whereas in groups 2 and 3, VFs were more frequent in patients with osteoporosis than in those with either osteopenia or normal BMD. In the whole population, VFs were significantly and independently associated with TSH level <1.0 mU/L; densitometric diagnosis of osteoporosis at lumbar spine, femoral neck, or total hip; age of patients; and duration of L-T4 therapy.

CONCLUSION

The prevalence of VFs was high in women with DTC who were undergoing long-term, suppressive L-T4 therapy.

Real-life management and outcome of thyroid carcinoma-related bone metastases: results from a nationwide multicenter experience

PURPOSE AND PATIENTS

The M.O.S.CA.TI. (Metastases of the Skeleton from CArcinoma of the ThyroId) is a multicenter, retrospective study investigating the real-life outcome and management of bone metastases (BM) in 143 patients (63 M, 80 F; median age 64 years, range 11-87) with differentiated thyroid carcinoma (DTC).

RESULTS

Radio-active iodine (RAI) treatment was performed in 131 patients (91.6%), surgical approach and/or external radiotherapy in 68 patients (47.6%), and anti-resorptive bone-active drugs in 32 patients (22.4%; in 31 zoledronate and in one denosumab). At the start of treatment, 24 patients (75.0%) receiving anti-resorptive bone-active drugs had at least one clinical skeletal-related event (SRE) (p < 0.001). One or more clinical SREs (pathological fractures and/or malignant hypercalcemia and/or spinal cord compression) developed in 53 patients (37.1%). Development of SREs was significantly associated with metachronous BM (hazard ratio (HR) 2.04; p = 0.04), localization of BM to cervical spine (HR 3.89; p = 0.01), and lack of avid RAI uptake (HR 2.66; p = 0.02). Thirty-nine patients (27.3%) died in correlation with development of SREs (HR 6.97; p = 0.006) and localization of BM to the hip (HR 3.86; p = 0.02). Moreover, overall mortality was significantly decreased by RAI therapy (HR 0.10; p = 0.02), whereas no significant effects were induced by bone-active drugs (p = 0.36), external radiotherapy (p = 0.54), and surgery (p = 0.43) of BM.

CONCLUSIONS

SREs are very frequent in BM from DTC and they impact patient survival. In the real life, the use of bone-active drugs is currently limited to zoledronate in patients with pre-existing SREs. In this clinical setting, RAI therapy, but not zoledronate, decreased mortality.

Thiazolidinedione drugs in the treatment of type 2 diabetes mellitus: past, present and future

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.

Diabetes in Cushing Disease

PURPOSE OF REVIEW

This review focuses on the pathophysiological and clinical aspects of diabetes mellitus occurring in patients with Cushing disease (CD).

RECENT FINDINGS

Insulin resistance and impairment in insulin secretion are both involved in the pathogenesis of glucocorticoid-induced diabetes. Correction of glucocorticoid excess does not always resolve abnormalities of glucose homeostasis, and correction of hyperglycaemia is specifically required. In fact, insulin resistance may persist even after correction of glucocorticoid excess and diabetes needs to be treated for long term. On the other hand, emerging drugs used in the treatment of CD, such as the novel somatostatin analog pasireotide, may have direct effects on glucose homeostasis regardless of control of cortisol excess. Diabetes mellitus is a frequent and early complication of CD with important diagnostic, prognostic and therapeutic implications. Specifically, diagnosis of CD in patients with diabetes may be difficult due to potential misinterpretation of markers of cortisol hypersecretion. Moreover, diabetes mellitus is often difficult to be controlled in CD requiring a careful and dedicated therapeutic approach. Finally, the coexistence of diabetes may influence the therapeutic decision making in CD, since drugs used in this setting may variably influence glucose homeostasis regardless of control of hypercortisolism.

Fracture risk in patients with type 2 diabetes mellitus and possible risk factors: a systematic review and meta-analysis

Aim

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of bone fractures. A variable increase in fracture risk has been reported depending on skeletal site, diabetes duration, study design, insulin use, and so on. The present meta-analysis aimed to investigate the association between T2DM with fracture risk and possible risk factors.

Methods

Different databases including PubMed, Institute for Scientific Information, and Scopus were searched up to May 2016. All epidemiologic studies on the association between T2DM and fracture risk were included. The relevant data obtained from these papers were analyzed by a random effects model and publication bias was assessed by funnel plot. All analyses were done by R software (version 3.2.1) and STATA (version 11.1).

Results

Thirty eligible studies were selected for the meta-analysis. We found a statistically significant positive association between T2DM and hip, vertebral, or foot fractures and no association between T2DM and wrist, proximal humerus, or ankle fractures. Overall, T2DM was associated with an increased risk of any fracture (summary relative risk =1.05, 95% confidence interval: 1.04, 1.06) and increased with age, duration of diabetes, and insulin therapy.

Conclusion

Our findings strongly support an association between T2DM and increased risk of overall fracture. These findings emphasize the need for fracture prevention strategies in patients with diabetes.

Growth hormone receptor isoforms and fracture risk in adult-onset growth hormone-deficient patients

INTRODUCTION

Growth hormone deficiency is considered the most important factor determining skeletal fragility in hypopituitary patients. Osteoblasts and chondrocytes express growth hormone (GH) receptor. Two GH receptor isoforms (GHRi) have been identified: they differ for the presence/absence of a protein fragment encoded by exon 3 of GHR gene. Consequently, three genotypes were identified: carriers of both the full-length proteins (flfl-GHR), carriers of one full-length protein and one deleted protein (fld3-GHR) and carriers of both deleted proteins (d3d3-GHR). This polymorphism confers a higher sensitivity to endogenous GH and to recombinant human GH (rhGH); its effect on bone metabolism and skeletal fragility is unknown. The aim of this article was to investigate the role of GHRi in predicting skeletal fragility in adult-onset GHD (AO-GHD) patients.

SUBJECTS AND METHODS

A cross-sectional study was conducted to investigate the association between the d3-GHR isoform and the prevalence of morphometric vertebral fractures (VFs) in AO-GHD. Ninety-three AO-GHD were enrolled. Forty-nine patients carried flfl-GHRi (52·7%), and 44 patients (47·3%) carried at least one allele of the d3-GHR isoform. Thirty-two VFs were documented. Fifty-seven patients underwent rhGH replacement therapy.

RESULTS

Median age was significantly higher in fractured patients as compared to nonfractured ones; d3-carrier patients showed a lower VF risk as compared to flfl-GHRi (OR: 0·37, 95% IC: 0·24-0·55, P < 0·0001). This finding was also confirmed in AO-GHD undergoing rhGH replacement therapy.

CONCLUSION

This study suggests that d3-GHR may protect AO-GHD particularly when treated with rhGH from the risk of VFs.

Efficacy and safety of canagliflozin in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

BACKGROUND

Canagliflozin is a new SGLT2 inhibitor which has been approved as an adjunct to diet and exercise for the treatment of adults with type 2 diabetes (T2D) mellitus in more than 30 countries. To evaluate the efficacy and safety of canagliflozin in patients with T2D, we carried out a meta-analysis of phase III clinical trials to offer an additional evidence of the efficacy and safety of canagliflozin for evidence-based clinical practice, strictly restricting the treatment durations to 26 weeks (core period) and 52 weeks (extension period).

METHODS

Randomized controlled trials (RCTs) published in English were searched in PubMed, Embase, and the Cochrane Library database (before April 2016). The studies reporting the efficacy and safety of canagliflozin in patients with T2DM were considered. Two authors separately performed data extraction. The differences were discussed and resolved. Pooled weighted mean differences (WMDs) or relative risks and 95% confidence intervals (CIs) were computed by using either fixed- or random-effects models.

RESULTS

At the end of the selection process, 7 RCTs were collected and included in the present analysis. Placebo-subtracted WMDs (%) of glycosylated hemoglobin (HbA1c) were -0.63 (95% CI: -0.77, -0.49) and -0.80 (95% CI: -0.98, -0.62) for canagliflozin 100 and 300 mg, respectively, from baseline to week 26. At week 26, canagliflozin 100 and 300 mg significantly reduced the body weight from baseline when compared with that of placebo, with a WMD of -2.23 and -3.00 in percent changes (P < 0.001 for both). The fasting and postmeal glucose, blood pressure (BP), and triglycerides were also reduced. These reductions were sustained over 52 weeks but had no significant differences between the 100 and 300 mg doses. The overall safety of canagliflozin was good, with the exception of high incidence of genital mycotic infections and osmotic diuresis-related adverse events.

CONCLUSION

Canagliflozin was found to reduce HbA1c, fasting and postmeal glucose, body weight, BP, and triglycerides, and it was generally well tolerated in patients with T2DM.

Italian Society for the Study of Diabetes (SID)/Italian Endocrinological Society (SIE) guidelines on the treatment of hyperglycemia in Cushing's syndrome and acromegaly

Hyperglycemia is a common feature associated with states of increased growth hormone secretion and glucocorticoid levels. The purpose of these guidelines is to assist clinicians and other health care providers to take evidence-based therapeutic decisions for the treatment of hyperglycemia in patients with growth hormone and corticosteroid excess. Both the SID and SIE appointed members to represent each society and to collaborate in Guidelines writing. Members were chosen for their specific knowledge in the field. Each member agreed to produce-and regularly update-conflicts of interest. The authors of these guidelines prepared their contributions following the recommendations for the development of Guidelines, using the standard classes of recommendation shown below. All members of the writing committee provided editing and systematic review of each part of the manuscript, and discussed the grading of evidence. Consensus was guided by a systematic review of all available trials and by interactive discussions.

Italian Society for the Study of Diabetes (SID)/Italian Endocrinological Society (SIE) guidelines on the treatment of hyperglycemia in Cushing's syndrome and acromegaly

BACKGROUND

Hyperglycemia is a common feature associated with states of increased growth hormone secretion and glucocorticoid levels.

AIMS

The purpose of these guidelines is to assist clinicians and other health care providers to take evidence-based therapeutic decisions for the treatment of hyperglycemia in patients with growth hormone and corticosteroid excess.

METHODOLOGY

Both the SID and SIE appointed members to represent each society and to collaborate in Guidelines writing. Members were chosen for their specific knowledge in the field. Each member agreed to produce--and regularly update--conflicts of interest. The Authors of these guidelines prepared their contributions following the recommendations for the development of Guidelines, using the standard classes of recommendation shown below. All members of the writing committee provided editing and systematic review of each part of the manuscript, and discussed the grading of evidence. Consensus was guided by a systematic review of all available trials and by interactive discussions.

Endocrine causes of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. The prevalence of NAFLD is increasing, becoming a substantial public health burden. NAFLD includes a broad spectrum of disorders, from simple conditions such as steatosis to severe manifestations such as fibrosis and cirrhosis. The relationship of NAFLD with metabolic alterations such as type 2 diabetes is well described and related to insulin resistance, with NAFLD being recognized as the hepatic manifestation of metabolic syndrome. However, NAFLD may also coincide with endocrine diseases such as polycystic ovary syndrome, hypothyroidism, growth hormone deficiency or hypercortisolism. It is therefore essential to remember, when discovering altered liver enzymes or hepatic steatosis on radiological exams, that endocrine diseases can cause NAFLD. Indeed, the overall prognosis of NAFLD may be modified by treatment of the underlying endocrine pathology. In this review, we will discuss endocrine diseases that can cause NALFD. Underlying pathophysiological mechanisms will be presented and specific treatments will be reviewed.

Correlates of fractures in elderly, diabetic outpatients

It is widely recognized that patients presenting diabetes are at increased risk for fractures. In a retrospective case-control study, 101 cases were selected from medical charts of outpatients older than 70 with diabetes mellitus and a fracture within the past 5 years. Glycosylated hemoglobin (HbA1c) had been measured within 4 months around the assessment. Each case was matched for sex and age with one control, diabetic patient with no fracture. HbA1c level was similar in both groups. Patients with fractures presented significantly lower BMIs than controls, and had a higher rate of declared osteoporosis and comorbidity. A small number of cases were using vitamin D supplements while more were treated with benzodiazepine, opiates and Selective serotonin reuptake inhibitors (SSRI). This study suggests that, rather than the tight control of blood glucose, other factors such as medication and comorbidity could be associated with fracture risk in elderly diabetics.

Oral anti-diabetic drugs and fracture risk, cut to the bone: safe or dangerous? A narrative review

Fracture risk is higher in older adults with type 2 diabetes and may be influenced by treatments for diabetes. Oral anti-diabetic drugs have different effects on bone metabolism. The purpose of this review is to describe the effects of these drugs on bone metabolism and fracture risk. Osteoporosis is a progressive skeletal disorder that is characterized by compromised bone strength and increased risk of fracture. This condition has become an important global health problem, affecting approximately 200 million people worldwide. Another chronic and highly prevalent condition is diabetes mellitus, which affects more than 380 million people; both type 1 and type 2 diabetes are risk factors for fracture. Type 2 diabetes, in particular, is associated with impaired bone strength, although it is characterized by normal or elevated bone mineral density. Several therapeutic strategies are available to achieve the best outcomes in the management of diabetes mellitus but these have different effects on bone metabolism. The purpose of this narrative review is to describe the effects of oral hypoglycemic agents (metformin, sulfonylureas, thiazolidinediones, meglitinides, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-dependent glucose transporter 2 inhibitors) on bone metabolism and on the risk of developing fragility fractures in patients with type 2 diabetes. Both diabetes and osteoporosis represent a significant burden in terms of healthcare costs and quality of life. It is very important to choose therapies for diabetes that ensure good metabolic control whilst preserving skeletal health.

Emerging drugs for Cushing's disease

INTRODUCTION

Considering the effects of uncontrolled hypercortisolism on morbidity and mortality, there is a clear need for effective medical therapy for patients with Cushing's disease (CD). Therefore, the search for new medical effective tools remains active, and already promising results have been obtained.

AREAS COVERED

The importance of the design and conduct of trials to validate old drugs or to test new compounds is discussed. The results of the ongoing clinical trials, targeting the specific properties of drugs, such as ketoconazole, LCI699, mifepristone, etomidate and pasireotide, are also reported. The authors also emphasise the advantages and drawbacks of each particular drug, and the potential combined use of agents with complementary mechanisms of action.

EXPERT OPINION

CD is an excellent example of a situation where effective therapy is essential, but where the balance of risk and benefit must be carefully judged. Metyrapone is the drug of choice when rapid control of the hypercortisolaemia is required, ketoconazole represents a good second-line drug, although in the future LCI699 may be a better alternative. Mifepristone can also be used in the rare situation when previous drugs are inappropriate. Etomidate is useful where immediate parenteral action is required. For drugs working directly on the pituitary, cabergoline is occasionally effective and pasireotide can be attempted in patients with mild CD.

Effect of ketoconazole on lobeglitazone pharmacokinetics in Korean volunteers

PURPOSE

Lobeglitazone, a peroxisome proliferator-activated receptor-γ agonist, is metabolized primarily by the cytochrome P450 (CYP) 3A4 isoenzyme. Individuals concomitantly taking lobeglitazone and a CYP3A4 inhibitor may experience some adverse effects secondary to increased systemic exposure to lobeglitazone. To address such potential concern, we evaluated the effects of ketoconazole, a prototypic CYP3A4 inhibitor, on the pharmacokinetic (PK) properties and associated adverse effects of lobeglitazone.

METHODS

A PK drug-drug interaction study was conducted in healthy individuals between 20 and 45 years old in a randomized, open-label, 2-way crossover design. Even though the PK study was performed on a single dose of lobeglitazone, multiple ketoconazole doses were given to ensure that the full extent of inhibition of CYP3A4 was maintained during the PK sampling. All study participants received a single oral dose of lobeglitazone 0.5 mg with or without 9 oral 200-mg doses of ketoconazole pretreatment twice daily. The primary PK parameter end points (AUC and Cmax) were estimated using noncompartmental analysis, and the 90% CIs for the geometric mean ratios (ratio of lobeglitazone and ketoconazole to lobeglitazone alone) were investigated. Tolerability (adverse events, vital signs, ECG, and laboratory tests) was also assessed.

FINDINGS

A total of 24 Korean men (mean age, 26 years; age range, 20-32 years; mean weight, 68 kg; weight range, 59-81 kg) completed the study and were evaluable for lobeglitazone PK properties and tolerability. The mean (SD) Cmax values of lobeglitazone with and without ketoconazole were 49 (7) ng/mL and 48 (6) ng/mL at 1.5 and 1.0 hours after dosing, respectively. The mean (SD) AUC∞ values were 532 (117) ng·h/mL and 405 (110) ng·h/mL, respectively. Although the Cmax was not significantly affected, the geometric mean ratio for AUC∞ was increased by a point estimate of 1.33 (90% CI, 1.23-1.44). A single oral administration of lobeglitazone 0.5 mg with or without ketoconazole pretreatment did not produce any clinically significant adverse effects on vital signs, 12-lead ECG profiles, or laboratory tests.

IMPLICATIONS

The administration of lobeglitazone, 0.5 mg alone or in combination with multiple doses of ketoconazole, was generally well tolerated. The systemic exposure of lobeglitazone was increased to a modest extent by pretreatment with 9 twice-daily doses of ketoconazole. Clinicaltrials.gov identifier: NCT01330563.

Bone turnover, bone mineral density, and fracture risk in acromegaly: a meta-analysis

CONTEXT

GH excess causes an increase in bone turnover, but the consequences in terms of skeletal fragility have long been uncertain due to the heterogeneity of studies dealing with this topic.

OBJECTIVE

We conducted a meta-analysis of studies examining the effects of acromegaly on bone turnover, bone mineral density (BMD), and fractures. Furthermore, we evaluated the effects of sex, gonadal status, and activity of disease on skeletal end-points in acromegaly.

DATA SOURCES

We conducted MEDLINE and EMBASE systematic searches up to December 31, 2013.

STUDY ELIGIBILITY CRITERIA

Studies conducted in patients with acromegaly and reporting at least one determinant of skeletal fragility.

DATA EXTRACTION AND ANALYSIS

Study design, patient characteristics, interventions, and outcomes were independently extracted by two authors. We calculated the standardized mean difference (SMD) of bone turnover and BMD differences, whereas fractures were presented as relative frequencies in acromegaly and odds ratios between patients and controls.

RESULTS

Forty-one studies fulfilled eligibility criteria and were therefore selected for data extraction and analysis. A total of 1935 patients were included (eight to 206 per study). Acromegaly patients had higher bone formation (SMD, 1.49; 95% confidence interval [CI], 0.97-2.01; P < .0001) and bone resorption (SMD, 1.57; 95% CI, 1.03-2.10; P < .0001) as compared to control subjects, without significant differences in lumbar spine BMD. BMD at the femoral neck tended to be higher in acromegaly patients vs control subjects (SMD, 0.67; 95% CI, 0.07-1.27; P = .03). Patients with acromegaly had high frequency of vertebral fractures (odds ratio, 8.26; 95% CI, 2.91-23.39; P < .0001), in close relationship with male gender, hypogonadism, and active acromegaly.

LIMITATIONS

LIMITATIONS included heterogeneous study protocols with possible variability in the assessment of skeletal end-points.

CONCLUSIONS

Skeletal fragility is an emerging complication of acromegaly.

Medication-induced osteoporosis: screening and treatment strategies

Drug-induced osteoporosis is a significant health problem and many physicians are unaware that many commonly prescribed medications contribute to significant bone loss and fractures. In addition to glucocorticoids, proton pump inhibitors, selective serotonin receptor inhibitors, thiazolidinediones, anticonvulsants, medroxyprogesterone acetate, aromatase inhibitors, androgen deprivation therapy, heparin, calcineurin inhibitors, and some chemotherapies have deleterious effects on bone health. Furthermore, many patients are treated with combinations of these medications, possibly compounding the harmful effects of these drugs. Increasing physician awareness of these side effects will allow for monitoring of bone health and therapeutic interventions to prevent or treat drug-induced osteoporosis.

Osteoporosis in Human Immunodeficiency Virus Patients - An Emerging Clinical Concern

The advent of highly active anti-retroviral therapy (HAART) has significantly improved the survival of human immunodeficiency virus (HIV)-infected patients transforming the HIV infection from a fatal illness into a manageable chronic disease. As the number of older HIV-infected individuals increases, several ageing-related co-morbidities including osteopenia/osteoporosis and fractures have emerged. Patients exposed to HIV infection and its treatment may develop fragility fractures with potential significant impact on quality of life and survival. However, the awareness of HIV-related skeletal fragility is still relatively low and most HIV-infected patients are not investigated for osteoporosis and treated with anti-osteoporotic drugs in daily clinical practice. This article reviews the literature data on osteoporosis and osteopenia in HIV infection, focusing on the pathophysiological, clinical and therapeutic aspects of fragility fractures.

The anti-diabetic drug metformin does not affect bone mass in vivo or fracture healing

SUMMARY

The present study shows no adverse effects of the anti-diabetic drug metformin on bone mass and fracture healing in rodents but demonstrates that metformin is not osteogenic in vivo, as previously proposed.

INTRODUCTION

In view of the increased incidence of fractures in patients with type 2 diabetes mellitus (T2DM), we investigated the effects of metformin, a widely used T2DM therapy, on bone mass and fracture healing in vivo using two different rodent models and modes of metformin administration.

METHODS

We first subjected 12-week-old female C57BL/6 mice to ovariectomy (OVX). Four weeks after OVX, mice received either saline or metformin administered by gavage (100 mg/kg/daily). After 4 weeks of treatment, bone micro-architecture and cellular activity were determined in tibia by micro-CT and bone histomorphometry. In another experiment, female Wistar rats aged 3 months were given only water or metformin for 8 weeks via the drinking water (2 mg/ml). After 4 weeks of treatment, a mid-diaphyseal osteotomy was performed in the left femur. Rats were sacrificed 4 weeks after osteotomy and bone architecture analysed by micro-CT in the right tibia while fracture healing and callus volume were determined in the left femur by X-ray analysis and micro-CT, respectively.

RESULTS

In both models, our results show no significant differences in cortical and trabecular bone architecture in metformin-treated rodents compared to saline. Metformin had no effect on bone resorption but reduced bone formation rate in trabecular bone. Mean X-ray scores assessed on control and metformin fractures showed no significant differences of healing between the groups. Fracture callus volume and mineral content after 4 weeks were similar in both groups.

CONCLUSIONS

Our results indicate that metformin has no effect on bone mass in vivo or fracture healing in rodents.

Investigational anti-hyperglycemic agents: the future of type 2 diabetes therapy?

As the pandemic of type 2 diabetes spreads globally, clinicians face many challenges in treating an increasingly diverse patient population varying in age, comorbidities, and socioeconomic status. Current therapies for type 2 diabetes are often unable to alter the natural course of the disease and provide durable glycemic control, and side effects in the context of individual patient characteristics often limit treatment choices. This often results in the progression to insulin use and complex regimens that are difficult to maintain. Therefore, a number of agents are being developed to better address the pathogenesis of type 2 diabetes and to overcome limitations of current therapies. The hope is to provide more options for glucose lowering and complication reduction with less risk for hypoglycemia and other adverse effects. These agents include newer incretin-based therapies and PPAR agonists, as well as new therapeutic classes such as sodium-coupled glucose cotransporter 2 inhibitors, free fatty acid receptor agonists, 11-β-hydroxysteroid dehydrogenase type 1 inhibitors, glucokinase activators, and several others that may enter clinical use over the next decade. Herein we review these agents that are advancing through clinical trials and describe the rationale behind their use, mechanisms of action, and potential for glucose lowering, as well as what is known of their limitations.

Diabetes and osteoporosis: Action of gastrointestinal hormones on the bone

A 62-year-old woman consulted for evaluation of treatment for her type 2 diabetes diagnosed four years ago. He had been received treatment with metformin 850mg twice, with no chronic associated complications. She had hypertension and dyslipidemia. She was being treated with candesartan/hydrochlorothiazide 32/12.5mg and atorvastatin 40mg. Her weight was 92kg and height 162cm (BMI, 35.1kg/m(2)). The last analysis showed fasting glucose 168mg/dl and glycated hemoglobin 7.5%, Microalbuminuria was negative. Blood pressure and lipid profile were within the therapeutic range. Two years ago she suffered a nontraumatic Colle's fracture in her left arm for which she was taking a daily calcium and vitamin D supplement and weekly alendronate. In summary, this is an obese female patient with type 2 diabetes mellitus and inadequate metabolic control, She also has a history of fragility fracture. How should this patient be evaluated and treated?

Predictors of the rate of BMD loss in older men: findings from the CHAMP study

Though bone loss tends to accelerate with age there are modifiable factors that may influence the rate of bone loss even in very old men.

INTRODUCTION

The aim of this 2-year longitudinal study was to examine potential predictors of change in total hip bone mineral density (BMD) in older men.

METHODS

The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia. For this study, 1,122 men aged 70-97 years had baseline and follow-up measures of total hip BMD measured with dual X-ray absorptiometry. Data about mobility, muscle strength, balance, medication use, cognition, medical history and lifestyle factors were collected using questionnaires and clinical assessments. Serum 25-hydroxyvitamin D [25(OH)D] was also measured. Multivariate linear regression models were used to assess relationships between baseline predictors and change in BMD.

RESULTS

Over a mean of 2.2 years, there was a mean annualised loss of total hip BMD of 0.006 g/cm(2)/year (0.6 %) and hip BMC of 0.14 g/year (0.3 %). Annual BMD loss accelerated with increasing age, from 0.4 % in men aged between 70 and 75 years, to 1.2 % in men aged 85+ years. In multivariate regression models, predictors of faster BMD loss were anti-androgen, thiazolidinedione and loop-diuretic medications, kidney disease, poor dynamic balance, larger hip bone area, older age and lower serum 25(OH)D. Factors associated with attenuated bone loss were walking for exercise and use of beta-blocker medications. Change in BMD was not associated with baseline BMD, smoking, alcohol consumption, BMI, frailty, or osteoarthritis.

CONCLUSION

There was considerable variation in the rate of hip bone loss in older men. Walking, better balance and beta blockers may attenuate the acceleration of BMD loss that occurs with age.

Spinal deformity index in patients with type 2 diabetes

The objective of this study is to investigate bone metabolism, density, and quality in patients with diabetes type 2 using DEXA and spinal deformity index (SDI), a surrogate index of bone quality. Fifty-six patients with type 2 diabetes were studied; exclusion criteria were diseases and medications that affect bone and mineral metabolism. Mean age was 65 ± 7 years. Mean diabetes duration was 10 ± 7 years and mean HbA1C was 6.6 ± 0.5 %. BMI was 30 ± 4. Fifty-six sex, age, and BMI matched served as controls. All subjects underwent a clinical and biochemical examination. Spinal and femoral neck BMD were measured by DEXA, and a spine radiography was performed to assess vertebral fractures and to calculate SDI. Mean serum 25-OH vitamin D levels were 19.6 ± 3.7 ng/ml in patients and 30 ± 14 ng/ml in controls (p < 0.01). PTH serum levels were 47.9 ± 40 pg/ml in patients versus 37 ± 5.3 pg/ml in controls (p < 0.01). At lumbar spine there was a significant difference between patients and controls only for T-score (p = <0.01), while at femoral neck there was a difference in BMD (p < 0.01) and in T-score (p < 0.01). Radiological vertebral fractures were found in 46 % of patients and 17 % of controls (p < 0.05). SDI was higher in patients than in controls (p < 0.05). The percentage of fractures with T-score BMD greater than -2.5 was 69 % in patients and 10 % in controls (p < 0.05). As a conclusion, BMD was similar in patients and in controls, while SDI value was higher in patients; therefore, SDI was more specific than BMD for the diagnosis of osteoporosis due to metabolic diseases.

The effects of thiazolidinediones on human bone marrow stromal cell differentiation in vitro and in thiazolidinedione-treated patients with type 2 diabetes

Thiazolidinedione (TZD) therapy has been associated with an increased risk of bone fractures. Studies in rodents have led to a model in which decreased bone quality in response to TZDs is due to a competition of lineage commitment between osteoblasts (OBs) and adipocytes (ADs) for a common precursor cell, resulting in decreased OB numbers. Our goal was to investigate the effects of TZD exposure on OB-AD lineage determination from primary human bone marrow stromal cells (hBMSCs) both in vitro and in vivo from nondiabetic subjects and patients with type 2 diabetics. Our experimental design included 2 phases. Phase 1 was an in vitro study of TZD effects on the differentiation of hBMSCs into OBs and ADs in nondiabetic subjects. Phase 2 was a randomized, placebo-controlled trial to determine the effects of 6-month pioglitazone treatment in vivo on hBMSC differentiation using AD/OB colony forming unit assays in patients with type 2 diabetes. In vitro, TZDs (pioglitazone and rosiglitazone) enhanced the adipogenesis of hBMSCs, whereas neither altered OB differentiation or function as measured by alkaline phosphatase activity, gene expression, and mineralization. The ability of TZDs to enhance adipogenesis occurred at a specific time/stage of the differentiation process, and pretreating with TZDs did not further enhance adipogenesis. In vivo, 6-month TZD treatment decreased OB precursors, increased AD precursors, and increased total colony number in patients with type 2 diabetes. Our results indicate that TZD exposure in vitro potently stimulates adipogenesis but does not directly alter OB differentiation/mineralization or lineage commitment from hBMSCs. However, TZD treatment in type 2 diabetic patients results in decreased osteoblastogenesis from hBMSCs compared with placebo, indicating an indirect negative effect on OBs and suggesting an alternative model by which TZDs might negatively regulate bone quality.