Association Between Papillary Thyroid Carcinoma and Vertebral Fracture

Suppression of TSH levels associated with levothyroxine treatment is a known risk factor for fracture. However, it is unclear whether patients with papillary thyroid carcinoma (PTC) have a higher risk of vertebral fracture (VF) before TSH suppression. The aim of the study was to examine whether the risk of VF is higher in PTC than in healthy subjects. A hospital-based, matched case-control study was conducted comparing PTC and healthy individuals. We enrolled 43 postoperative patients with PTC scheduled for radioiodine therapy and 43 age- and sex-matched healthy controls. Serum and urinary biological parameters, bone mineral density (BMD), and presence of VFs were evaluated in both groups. We compared these indices using χ2 and Mann-Whitney U-test and analyzed the association between PTC and VF by logistic regression analysis. The PTC group had higher BMI, HbA1c and phosphorus, and lower intact PTH than the control group. Lumbar and femoral neck BMD did not differ between the two groups. Prevalence of VFs was significantly higher in the PTC group (44.1%) than in the control group (16.3%). Multivariate logistic regression analyses adjusted for age, sex, and BMI identified PTC as being associated with the presence of VFs (odds ratio, 5.63; 95% confidence interval: 1.82 to 17.5). This relationship remained significant after additional adjustment for HbA1c and BMD. There is an association between PTC and a risk of VF independent of sex, BMI, glucose metabolism, and BMD, suggesting the importance of fracture risk assessment before TSH suppression.

Progressive Thymic Hyperplasia With Graves' Disease: A Case Report

We treated a 36-year-old man with thymic hyperplasia complicated with Graves' disease. Thymic hyperplasia was observed on thoracic computed tomography (CT) three months after the onset of thyrotoxicosis symptoms. One month after thiamazole initiation, he displayed drug-induced liver injury and underwent a total thyroidectomy. Seven months after surgery, we observed a dramatic reduction of thymic size associated with normalizing the soluble interleukin-2 receptor (sIL-2R) levels. The rapid development of hyperplasia after the onset of thyrotoxicosis and the restoration in thymus volume after total thyroidectomy associated with suppression of sIL-2R, in this case, suggests the complexity of the pathogenesis of thymic hyperplasia in the thyrotoxicosis.

Graves' disease after exposure to the SARS-CoV-2 vaccine: a case report and review of the literature

BACKGROUND

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) is characterized by immune system dysregulation after exposure to adjuvants, such as aluminum. Although cases of autoimmune thyroid diseases caused by ASIA have been reported, Graves' disease is one of the rarer diseases. There are some reports that vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause ASIA. Here, we describe a case of Graves' disease following SARS-CoV-2 vaccination and a review of the literature.

CASE PRESENTATION

A 41-year-old woman was admitted to our hospital because of palpitations and fatigue. Two weeks after receiving the second SARS-CoV-2 vaccine (BNT162b2, Coronavirus Modified Uridine messenger RNA (mRNA) Vaccine, Pfizer), she developed fatigue and gradually worsened. On admission, she exhibited thyrotoxicosis (thyroid-stimulating hormone (TSH) < 0.01 mIU/L (0.08-0.54), free triiodothyronine (FT3) 33.2 pmol/L (3.8-6.3), and free thyroxine (FT4) 72.1 pmol/L (11.6-19.3)) and palpitations associated with atrial fibrillation. TSH receptor antibody (TRAb) was positive (TRAb 5.0 IU/L (< 2.0)), and ^99mTc scintigraphy showed diffuse uptake in the thyroid gland, suggesting that the thyrotoxicosis in this case was caused by Graves' disease. Thiamazole was prescribed to correct her condition, and soon after this treatment was initiated, her symptoms and thyroid hormone levels were significantly reduced.

CONCLUSIONS

This case report reinforces the potential correlation between ASIA affecting the thyroid and SARS-CoV-2 mRNA vaccines. The clinical course suggests that it is essential to consider the possibility of developing ASIA, such as Graves' disease, after exposure to the SARS-CoV-2 vaccine.

Successful Control of Hypercalcemia with Sorafenib, Evocalcet, and Denosumab Combination Therapy for Recurrent Parathyroid Carcinoma

Parathyroid carcinoma (PC) is a rare type of endocrine cancer. Recurrence and metastasis are common after surgery, and refractory hypercalcemia often leads to a poor prognosis. However, there are currently no specific strategies for PC recurrence. We herein report a 61-year-old Japanese man with metastatic PC who was treated with sorafenib, a multikinase inhibitor. In this case, the serum calcium level was under control for 10 months after the initiation of sorafenib. This case suggests that combination therapy with sorafenib, evocalcet, and denosumab may be an alternative, stronger management option for refractory hypercalcemia in recurrent PC.

Thyroid crisis caused by metastatic thyroid cancer: an autopsy case report

BACKGROUND

Thyroid crisis is a life-threatening condition in thyrotoxic patients. Although differentiated thyroid cancer is one of the causes of hyperthyroidism, reports on thyroid crisis caused by thyroid cancer are quite limited. Here, we describe a case of thyroid crisis caused by metastatic thyroid cancer.

CASE PRESENTATION

A 91-year-old woman was admitted to our hospital because of loss of appetite. Two years prior to this hospitalization, she presented with subclinical thyrotoxicosis and was diagnosed with histologically unidentified thyroid cancer with multiple metastases, and she refused aggressive medical interventions. On admission, she exhibited extreme thyrotoxicosis, and the presence of fever, severe tachycardia, impaired consciousness, and heart failure revealed the presence of thyroid crisis. All thyroid autoantibodies were negative. Multidisciplinary conservative treatment was initiated; however, she died on the fifth day after admission. Autopsy revealed the presence of primary anaplastic thyroid carcinoma and multiple metastatic foci arising from follicular thyroid carcinoma. Both primary and metastatic follicular thyroid carcinoma likely induced thyrotoxicosis, which could have been exacerbated by anaplastic thyroid carcinoma.

CONCLUSIONS

Even though the trigger of thyroid crisis in this patient is not clear, the aggravated progression of her clinical course suggests that careful monitoring of thyroid hormones and appropriate intervention are essential for patients with thyroid cancer.

Osteomalacia caused by atypical renal tubular acidosis with vitamin D deficiency: a case report

Osteomalacia is a systemic metabolic bone disease. Hypophosphatemia is one of the most important causes of impaired mineralization. Here, we describe a case of osteomalacia associated with atypical renal tubular acidosis. A 43-year-old woman was admitted to our hospital due to sustained unrelieved bilateral flank pain. She had a history of fragile fracture with vitamin D deficiency and had been treated with active vitamin D. On admission, she presented with hypophosphatemia, hypocalcemia, high bone-specific alkaline phosphatase level, bone pain, and low bone mineral density. Multiple areas of uptake were also confirmed by bone scintigraphy, and she was diagnosed with osteomalacia. An increased dose of alfacalcidol was initiated for her vitamin D deficiency; her symptoms remained unstable and unrelieved. Her blood gas examination revealed metabolic acidosis without an increase in the anion gap (HCO₃^- 11.8 mEq/L, anion gap 3.2 mEq/L). Tubular dysfunction, tubular damage, kidney stones, and inadequate urinary acidification were all observed, suggesting the presence of renal tubular acidosis from a combination of both distal and proximal origin. She also had overt proteinuria, decreased renal function, and hypothalamic hypogonadism. In addition to alfacalcidol, sodium bicarbonate and oral phosphorus supplementation were initiated. After this prescription, her pain dramatically improved in association with the restoration of acid-base balance and electrolytes; renal dysfunction and proteinuria were unaltered. This case indicated that careful assessments of tubular function and acid-base balance are essential for the management of osteomalacia in addition to the evaluation of the calcium/phosphate balance and vitamin D status.

A pregnant woman with an autonomously functioning thyroid nodule: a case report

BACKGROUND

The epidemiology and natural history of autonomously functioning thyroid nodules (AFTNs) have not been elucidated. Here we report the pregnant Japanese woman with an AFTN.

CASE PRESENTATION

The patient was a 31-year-old woman who was hospitalized due to the placenta previa associated with threatened abortion at the 16 weeks of her third pregnancy. At her second pregnancy, she was euthyroid but had a single, 2.3 cm nodule on her right thyroid lobe. Her thyroid hormone level was trended increased with her pregnancy progression, and the thyrotoxic state was remained after delivery. Before her third pregnancy, her hyper-vascular nodule enlarged to 3.4 cm at regular monitoring. When she visited our hospital, she was at 16 weeks of pregnancy and had thyrotoxicosis with negative TSH-receptor antibody. She delivered a baby weighing 2615 g without hypothyroidism at 39 weeks of pregnancy by natural delivery. After delivery, a ^99mTc scintigram showed a hot spot in her right thyroid lobe. She was diagnosed with AFTN and treated with methimazole while nursing.

CONCLUSIONS

This case showed that hCG stimulation during pregnancy caused thyroid nodule enlargement and enhanced thyroid hormone production. The pregnancy could be the pathological stimulus and provides chance to diagnosis for AFTNs.

Graves' disease and vertebral fracture: Possible pathogenic link in postmenopausal women

BACKGROUND AND OBJECTIVE

Thyrotoxicosis is associated with accelerated bone turnover and increases the risk of fractures and osteoporosis. Graves' disease is the most common cause of hyperthyroidism. However, studies that examined risk factors associated with fragility fractures only in patients with Graves' disease are limited. Here, we investigated whether the risk of vertebral fracture (VF) of postmenopausal Graves' disease patients is high and tried to identify the risk factors for VF in that population.

DESIGN AND METHODS

Forty-three postmenopausal women with Graves' disease were enrolled. Physical and biochemical indices, thyroid indices and bone mineral density (BMD) were measured, and lateral X-rays were obtained to evaluate VFs. Age- and sex-matched healthy individuals were enrolled as the control group (n = 86).

RESULTS

The prevalence of VFs (35% vs 17%, P < .05), osteoporosis (63% vs 33%, P < .01) and severe osteoporosis (40% vs 17%, P < .01) was significantly higher in the Graves' disease group. Although there was no significant difference in either thyroid hormone levels or the positive ratio of thyroid antibodies, the prevalence of thyroid-stimulating antibody (TSAb) was significantly higher in Graves' disease patients with VF compared to without (100% vs 68%, P < .05). Multivariate logistic regression analyses adjusted for age identified Graves' disease as being associated with the presence of VFs (OR 2.72, 95% CI: 1.13-6.54, P < .05) in postmenopausal women.

CONCLUSIONS

Postmenopausal Graves' disease patients had high risks of VF and severe osteoporosis. TSAb could be involved as a risk factor for VF in postmenopausal Graves' disease.

A case of insulin-like growth factor 2-producing gastrointestinal stromal tumor with severe hypoglycemia

BACKGROUND

Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome that secretes incompletely processed high molecular weight insulin growth factor 2 (big-IGF2), which results in stimulation of the insulin receptor and subsequently induces hypoglycemia. Gastrointestinal stromal tumor (GIST) is a common intestinal mesenchymal neoplasm of the gastrointestinal tract. The most frequent site of GIST is the stomach; NICTH induced by IGF2-producing stomach GISTs is rare.

CASE PRESENTATION

An 84-year-old man was admitted to the hospital due to impaired consciousness (JCS II-10) in the morning. At the time of admission, his serum glucose was 44 mg/dL; his consciousness was restored with 20 ml of 50% glucose. To avoid hypoglycemia, a continuous intravenous infusion of glucose as well as dietary intervention was required. At the time of hypoglycemia, the levels of insulin and C-peptide were suppressed. Additionally, IGF1 levels were below the normal range. Abdominal computed tomography revealed that he had a large lobulated mass (116 × 70 × 72 mm) around the gastric corpus. Pathological analysis of biopsy specimens identified disarray of spindle cells and positivity for c-kit as well as strong positivity for DOG-1. Further analysis revealed high levels of Ki-67 (Mib-1 index: 15.5%) and mitotic index (7/50HPF); the tumor was diagnosed as high-risk GIST, and complete surgical resection was performed. Hypoglycemia resolved immediately after tumor resection. The resected tumor specimen was positive for IGF2 staining, and big-IGF2 (11-18 kDa) was detected in preoperative serum and tumor samples; the patient was diagnosed with NICTH due to an IGF2-producing tumor.

CONCLUSIONS

NICTH is rare in GIST of the stomach; however, the large GIST could produce big-IGF2 and subsequently cause severe hypoglycemia, requiring prompt evaluation and complete tumor resection.

SUN-412 Graves’ Disease Displayed as a Risk Factor of Vertebral Fracture Even in Premenopausal Women

Background

Hyperthyroidism is a known risk factor for osteoporosis and fractures especially in older men and postmenopausal women. However, it remains unclear whether younger patients with Graves’ diseases are at a higher risk of fracture compared to healthy individuals.

Objective

This study aimed to clarify whether premenopausal women with Graves’ disease represents a risk factor for vertebral fracture (VF).

Patients and Methods

We enrolled 30 premenopausal women (mean age, 32 ± 10 years) who were diagnosed with Graves’ disease at our institution between April 2007 and December 2017. We also enrolled 40 healthy control women who visited our hospital. The control subjects were confirmed to have no endocrine disease or any condition that might affect bone metabolism. None of the study subjects had taken drugs known to influence bone and calcium metabolism such as vitamin D, bisphosphonates, or glucocorticoids. Also, none has taken an oral contraceptive. Serum and urinary biological parameters, alkaline phosphatase (ALP), glycosylated hemoglobin (HbA1c), creatinine, serum calcium, total cholesterol, intact parathyroid hormone, free triiodothyronine (Free T3), free thyroxin (Free T4), thyroid-stimulating hormone (TSH) and urinary type I collagen cross-linked N-telopeptides (NTX; a bone resorption marker) were compared between the groups. Bone mineral density (BMD) of the lumbar spine and femoral neck was determined using dual-energy X-ray absorptiometry and vertebral fractures were diagnosed from lateral X-rays of the thoracic and lumbar spine. The chi-square and unpaired t-tests for two groups comparison were utilized to determine the statistical significance (P &lt; 0.05). Multiple logistic regression analyses were proceeded after adjustments for variables.

Results

Patients with Graves’ disease displayed the higher ALP, eGFR, Ca, free T3, free T4 and urinary NTX levels, and lower body mass index (BMI), Alb, total cholesterol and intact PTH compared to controls.

The prevalence of VFs was significantly higher in patients with Graves’ disease (20.0%) than in controls (2.5%, &lt;0.05). Such association remained significant even after adjustment for age, BMI, ALP, eGFR and free T3, but except for BMD. Among premenopausal patients with Graves’ disease, the values of several parameters, such as BMI, ALP, HbA1c, serum Ca, intact PTH and BMD and the prevalence of thyroid related antibodies did not differ significantly between those with and without VF; subjects with VF were older and exhibited lower free T3, free T4 and urinary NTX levels compared to subjects without VF. The mean value of lumbar BMD T score in subjects with VF among premenopausal patients with graves’ disease was -1.0, indicating osteopenia.

Conclusions

VF risk could be elevated even in the premenopausal women with Graves’ disease, although the BMD risk levels is not equivalent to that of osteoporosis.

Papillary thyroid carcinoma is a risk factor for severe osteoporosis

INTRODUCTION

Thyroid-stimulating hormone (TSH)-suppressive therapy is recommended after surgical treatment in high-risk papillary thyroid carcinoma (PTC) patients. TSH-suppressive therapy is a known risk factor for osteoporosis and fractures. However, whether patients with PTC themselves are at a higher risk of osteoporosis than healthy individuals remains unclear. This study aimed to clarify whether PTC is a risk factor for osteoporosis.

MATERIALS AND METHODS

Serum and urinary biochemical parameters, bone mineral density (BMD), and presence of vertebral fractures (VFs) and non-VFs were evaluated in 35 PTC patients and 35 age- and sex-matched healthy individuals. We compared the parameters between PTC and control subjects and performed multiple logistic regression analyses after adjustments for variables.

RESULTS

Patients with PTC had higher body mass index (BMI) and hemoglobin (Hb)A1c, as well as lower eGFR and intact PTH than controls (p < 0.05, each). There were no significant differences in the prevalence of osteoporosis and VFs and non-VFs between patients with PTC and controls. However, the prevalence of severe osteoporosis diagnosed according to WHO criteria was significantly higher in PTC subjects (34.3%) than in controls (11.4%, p < 0.05). Multivariate logistic regression analyses adjusted for age, BMI, eGFR and HbA1c identified PTC as being associated with the presence of severe osteoporosis (odds ratio, 4.20; 95% confidence interval, 1.05-16.8; p < 0.05).

CONCLUSIONS

We identified PTC as a risk factor for severe osteoporosis, independent of BMI, renal function and glucose profile.

Bazedoxifene Ameliorates Homocysteine-Induced Apoptosis via NADPH Oxidase-Interleukin 1β and 6 Pathway in Osteocyte-like Cells

Homocysteine (Hcy) increases oxidation and inflammation; however, the mechanism of Hcy-induced bone fragility remains unclear. Because selective estrogen modulators (SERMs) have an anti-oxidative effect, SERMs may rescue the Hcy-induced bone fragility. We aimed to examine whether oxidative stress and pro-inflammatory cytokines such as interleukin (IL)-1β and IL-6 are involved in the Hcy-induced apoptosis of osteocytes and whether bazedoxifene (BZA) inhibits the detrimental effects of Hcy. We used mouse osteocyte-like cell lines MLO-Y4-A2 and Ocy454. Apoptosis was examined by DNA fragmentation ELISA and TUNEL staining, and gene expression was evaluated by real-time PCR. Hcy 5 mM significantly increased expressions of NADPH oxidase (Nox)1, Nox2, IL-1β, and IL-6 as well as apoptosis in MLO-Y4-A2 cells. Nox inhibitors, diphenyleneiodonium chloride and apocynin, significantly suppressed Hcy-induced IL-1β and IL-6 expressions. In contrast, an IL-1β receptor antagonist and an IL-6 receptor monoclonal antibody had no effects on Hcy-induced Nox1 and Nox2 expressions, but significantly rescued Hcy-induced apoptosis. BZA (1 nM-1 μM) and 17β estradiol 100 nM significantly rescued Hcy-induced apoptosis, while an estrogen receptor blocker ICI 182,780 reversed the effects of BZA and 17β estradiol. BZA also rescued Hcy-induced apoptosis of Ocy454 cell, and ICI canceled the effect of BZD. Moreover, BZA significantly ameliorated Hcy-induced expressions of Nox1, Nox2, IL-1β, and IL-6, and ICI canceled the effects of BZA on their expressions. Hcy increases apoptosis through stimulating Nox 1 and Nox 2-IL-1β and IL-6 expressions in osteocyte-like cells. BZA inhibits the detrimental effects of Hcy on osteocytes via estrogen receptor.

Insulin-Like Growth Factor-I Protects Against the Detrimental Effects of Advanced Glycation End Products and High Glucose in Myoblastic C2C12 Cells

Previous studies suggested that advanced glycation end products (AGEs) and insulin-like growth factor-I (IGF-I) are involved in the mechanism of diabetes-induced sarcopenia. In this study, we examined effects of treatments with AGEs and/or IGF-I for 24 h on myogenic differentiation and apoptosis in mouse myoblastic C2C12 cells. Real-time PCR and Western blot were performed to investigate mRNA and protein expressions, and apoptosis was examined by using a DNA fragment detection ELISA kit. AGE3 significantly decreased mRNA and protein expressions of MyoD and Myogenin, whereas IGF-I significantly increased them and attenuated the effects of AGE3. AGEs significantly decreased endogenous IGF-I mRNA expression and suppressed IGF-I-induced Akt activation. High glucose (22 mM) significantly increased mRNA expression of Rage, a receptor for AGEs, while IGF-I significantly decreased it. DNA fragment ELISA showed that AGE2 and AGE3 significantly increased apoptosis of C2C12 cells, whereas IGF-I significantly suppressed the AGE2- and AGE3-induced apoptosis. In contrast, high glucose enhanced AGE3-induced apoptosis. IGF-I significantly attenuated the effects of high glucose plus AGE3 on the mRNA and protein expressions of MyoD and Myogenin as well as the apoptosis. These findings indicate that AGEs inhibit myogenic differentiation and increase apoptosis in C2C12 cells, and that high glucose increases RAGE and enhances the AGE3-induced apoptosis, suggesting that AGEs and high glucose might contribute to the reduction of muscle mass and function. Moreover, IGF-I attenuated the detrimental effects of AGEs and high glucose in myoblastic cells; thus, IGF-I-Akt signal could be a therapeutic target of DM-induced sarcopenia.

Overweight and underweight are risk factors for vertebral fractures in patients with type 2 diabetes mellitus

The aim of this cross-sectional study was to examine the association between body mass index (BMI) and the prevalence of vertebral fracture (VF) in Japanese patients with type 2 diabetes (T2DM). A total of 798 patients with T2DM were enrolled. VF was determined semi-quantitatively using lateral X-ray films. The association between BMI quartiles (Q1: ≤ 21.2 kg/m², Q2: 21.3-23.4 kg/m², Q3: 23.5-25.8 kg/m², Q4: 25.9≤ kg/m²) and the presence of VF was examined. Multiple logistic regression analyses adjusted for age, sex, diabetes duration, hemoglobin A1c (HbA1c), estimated glomerular filtration rate, and albumin showed that Q1, Q3, and Q4 were significantly associated with an increased VF risk compared to Q2, which served as a reference [Q1; odds ratio (OR) = 1.91, 95% confidence interval (CI) 1.24-2.95, p = 0.004, Q3; OR = 1.65, 95% CI 1.07-2.55, p = 0.023, and Q4; OR = 2.18, 95% CI 1.39-3.41, p < 0.001]. Moreover, these associations remained significant after additional adjustment for femoral neck T-score, a bone resorption marker, urinary N-terminal cross-linked telopeptide of type-I collagen, and use of insulin and thiazolidinedione. Our study shows for the first time that both overweight and underweight were associated with the bone mineral density (BMD)-independent risk of VF in patients with T2DM. Therefore, body weight control should be considered as a protective measure against diabetes-related bone fragility.

Phloretin Suppresses Bone Morphogenetic Protein-2-Induced Osteoblastogenesis and Mineralization via Inhibition of Phosphatidylinositol 3-kinases/Akt Pathway

Phloretin has pleiotropic effects, including glucose transporter (GLUT) inhibition. We previously showed that phloretin promoted adipogenesis of bone marrow stromal cell (BMSC) line ST2 independently of GLUT1 inhibition. This study investigated the effect of phloretin on osteoblastogenesis of ST2 cells and osteoblastic MC3T3-E1 cells. Treatment with 10 to 100 µM phloretin suppressed mineralization and expression of osteoblast differentiation markers, such as alkaline phosphatase (ALP), osteocalcin (OCN), type 1 collagen, runt-related transcription factor 2 (Runx2), and osterix (Osx), while increased adipogenic markers, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid-binding protein 4, and adiponectin. Phloretin also inhibited mineralization and decreased osteoblast differentiation markers of MC3T3-E1 cells. Phloretin suppressed phosphorylation of Akt in ST2 cells. In addition, treatment with a phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor, LY294002, suppressed the mineralization and the expression of osteoblast differentiation markers other than ALP. GLUT1 silencing by siRNA did not affect mineralization, although it decreased the expression of OCN and increased the expression of ALP, Runx2, and Osx. The effects of GLUT1 silencing on osteoblast differentiation markers and mineralization were inconsistent with those of phloretin. Taken together, these findings suggest that phloretin suppressed osteoblastogenesis of ST2 and MC3T3-E1 cells by inhibiting the PI3K/Akt pathway, suggesting that the effects of phloretin may not be associated with glucose uptake inhibition.

A scoring assessment tool for the risk of vertebral fractures in patients with type 2 diabetes mellitus

BACKGROUND

Development of assessment tool for fracture risk is an urgent task, because bone mineral density (BMD) is less useful for evaluating fracture risk in type 2 diabetes mellitus (T2DM).

SUBJECTS AND METHODS

In total, 808 T2DM patients were enrolled in this cross-sectional study. To develop a scoring assessment tool using clinical risks for vertebral fracture (VF), we evaluated which variables were associated with VF by logistic regression analysis, and categorized these variables based on cut-off values obtained by using receiver operating characteristic (ROC) curves. For calculation of the score, the relative weight of the factors was determined, and a tentative score was assigned. Then, cut-off point of the score was examined to predict VF.

RESULTS

Logistic regression analyses showed that age, diabetes duration, body mass index (BMI), serum albumin, and T score at femoral neck (FN-T score) were associated with VF risk. Parameter estimates for each risk factor obtained by logistic analyses were converted to risk scores (maximum score 23). ROC analysis showed that 8.5 was the cut-off value for detecting VF. Multiple logistic regression analysis adjusted for confounding factors showed that score ≥9 was significantly associated with an increased risk of prevalent VF (odds ratio 1.99, 95% confidence interval 1.22-3.24, p = 0.006).

CONCLUSIONS

This is the first study to show that a scoring assessment tool using age, duration of diabetes, BMI, serum albumin, and FN-T score is useful to estimate VF risk in patients with T2DM, being more sensitive than BMD alone in detecting bone fragility.

Higher Serum Uric Acid is a Risk Factor of Vertebral Fractures in Postmenopausal Women with Type 2 Diabetes Mellitus

Purpose Serum uric acid (UA) level may affect bone metabolism because it has an anti-oxidative effect. However, whether serum UA level is associated with a fracture risk in type 2 diabetes mellitus (T2DM) is unclear. We thus aimed to clarify the association between serum UA and bone parameters in T2DM.

Methods We conducted a cross-sectional study to investigate the association of serum UA with bone mineral density (BMD) at lumbar spine (LS) and femoral neck (FN), bone turnover markers such as osteocalcin and urine type I collagen cross-linked N-telopeptide (uNTX), and the prevalence of vertebral fractures (VF) in 356 postmenopausal women and 512 men with T2DM.

Results Multiple regression analyses adjusted for age, duration of diabetes, hemoglobin A1c, body mass index and log (serum creatinine) showed that serum UA level was significantly and negatively associated with uNTX in postmenopausal women with T2DM, whereas it was not associated with osteocalcin or BMD at each site. In men, serum UA was not associated with BMD or bone turnover markers. Because postmenopausal women with VF were significantly older and had longer duration of diabetes, higher serum creatinine level and lower BMD than those without it, logistic regression analyses adjusted for these confounding factors were performed. Higher serum UA level was significantly associated with the presence of VF.

Conclusions The present study showed that higher serum UA is a risk factor for VF independently of BMD in postmenopausal women with T2DM.

Higher Serum Uric Acid is a Risk Factor of Reduced Muscle Mass in Men with Type 2 Diabetes Mellitus

OBJECTIVE

Sarcopenia has been recognized as a diabetic complication, and hyperuricemia is often accompanied by type 2 diabetes mellitus (T2DM). However, it is unknown whether serum uric acid (UA) levels are associated with reduced muscle mass in T2DM.

METHODS

We conducted a cross-sectional study to investigate the association of serum UA with muscle mass in 401 subjects with T2DM (209 men and 192 postmenopausal women). The relative skeletal muscle mass index (RSMI) was evaluated using whole-body dual-energy x-ray absorptiometry.

RESULTS

Multiple regression analyses adjusted for body weight, age, serum creatinine, hemoglobin A1c (HbA1c), and duration of T2DM showed that serum UA was negatively associated with RSMI in all subjects and men with T2DM (β=-0.13, p=0.001 and β=-0.17, p=0.003, respectively). Moreover, logistic regression analyses adjusted for these confounding factors showed that a higher serum UA level was significantly associated with low RSMI in men with T2DM [odds ratio (OR)=1.94, 95% confidence interval (CI)=1.10-3.45 per SD increase, p=0.023]. In addition, higher serum UA levels were significantly associated with low RSMI after additional adjustment for age, duration of T2DM, HbA1c level, serum creatinine level, and sex in all subjects with T2DM [OR=1.80, 95% CI=1.20-2.72 per SD increase, p=0.005].

CONCLUSIONS

The present study showed for the first time that higher serum UA is an independent risk factor of reduced muscle mass in men with T2DM.

Assessment using serum insulin-like growth factor-I and bone mineral density is useful for detecting prevalent vertebral fractures in patients with type 2 diabetes mellitus

Bone mineral density (BMD) is less useful for evaluating fracture risk in type 2 diabetes. This study showed for the first time that combined evaluation by serum insulin-like growth factor-I and BMD is useful to assess the risk of vertebral fracture in postmenopausal women and men with type 2 diabetes.

INTRODUCTION

BMD is less useful for evaluating fracture risk in type 2 diabetes mellitus (T2DM). We aimed to examine the usefulness of combined evaluation by BMD and serum insulin-like growth factor-I (IGF-I) to assess the risk of vertebral fracture (VF) in T2DM.

METHODS

In this cross-sectional study, 412 postmenopausal women and 582 men with T2DM, whose BMD, bone turnover markers, and serum IGF-I were measured, were enrolled. The association of BMD alone, serum IGF-I alone, and combined assessment by BMD and IGF-I with the presence of VF was examined.

RESULTS

Multiple logistic regression analyses showed that IGF-I as well as BMD T-score at lumbar (L) and femoral neck (FN) were significantly associated with VF except for IGF-I in men, respectively. Receiver operating characteristic curves showed that the cutoff values of IGF-I, L T-score and FN T-score were 127 ng/mL, - 1.78, and - 2.02 in postmenopausal women and 127 ng/mL, - 1.67, and - 1.24 in men. Based on the cutoff vales, the subjects were divided into four categories. The category of lower IGF-I and lower T-scores had a significant increased risk of VF compared to higher IGF-I and higher T-scores both in postmenopausal women and in men. The sensitivity and specificity of the combined assessment to detect VF were better compared to using BMD alone or IGF-I alone.

CONCLUSIONS

This is the first study to show that in addition to BMD measurement, the assessment using serum IGF-I is useful to estimate the prevalence of VF in patients with T2DM.

Acute suppurative thyroiditis caused by thyroid papillary carcinoma in the right thyroid lobe of a healthy woman

Background

The thyroid gland is resistant to microbial infection, because of its organ characteristics such as encapsulation, iodine content, and rich blood supply. Therefore, acute suppurative thyroiditis (AST), as a bacterial infection of the thyroid gland, is rarely seen. AST typically takes places on the left side the neck region in children, because of the coincidence of the left piriform sinus fistula, as a most common route of infection. AST is also usually seen in immunocompromised hosts. Herein, we report a rare case of AST in the right thyroid lobe of adult woman without any immunocompromised condition.

Case presentation

A 59-year-old woman was introduced to our hospital for the further examination with fever, sore throat, and right anterior neck swelling. The patient appeared not to be immunodeficient. Neck ultrasonography showed a 47-mm, hypoechoic, heterogeneous nodule with ill-defined margins and irregular form, suggesting a right thyroid malignant nodule. Fine needle aspiration (FNA) biopsy specimen revealed numerous number of neutrophils in the background without nuclear atypia. Based on the clinical course and cytology, AST was confirmed to be diagnosed. Complete response was obtained by an intravenous administration of antimicrobial agents within a week. Image findings such as CT scan did not show any piriform sinus fistula. Four months later, neck ultrasonography showed a significant decrease in size of the nodule in the right thyroid gland to 27 mm, but the lesion still resembled a malignant nodule. So, FNA was repeated again and cytological examination confirmed papillary thyroid carcinoma (PTC). The patient subsequently underwent total thyroidectomy and bilateral level D1 lymph node dissection. Histological findings revealed a 20-mm PTC in the right lobe with sternothyroid muscle invasion of the tumor.

Conclusions

This report represents a rare case of AST associated with PTC on the right side of thyroid gland, found in a healthy adult woman. The reason why AST coincided with malignant thyroid tumor is unclear. We have to take it into our account that malignant tumor may exist in the background when AST is identified on the right side of thyroid gland with a healthy subject.

Inhibition of adenosine monophosphate-activated protein kinase suppresses bone morphogenetic protein-2-induced mineralization of osteoblasts via Smad-independent mechanisms

Previous studies showed that adenosine monophosphate-activated protein kinase (AMPK), which plays as an intracellular energy sensor, promotes the differentiation and mineralization of osteoblasts via enhancing expression of bone morphogenetic protein (BMP)-2, which is a potent inducer of osteoblastogenesis. Thus, the aim of this study was to examine the roles of AMPK in BMP-2-induced osteoblastogenesis. We used a murine osteoblastic cell line MC3T3-E1 and a murine marrow stromal cell line ST2. BMP-2 (50 and 100 ng/mL) stimulated alkaline phosphatase (ALP) activity and enhanced mineralization of MC3T3-E1 cells, while the effects of BMP-2 were partly abolished by an inhibitor of AMPK, ara-A (0.1 mM). Real-time PCR showed that BMP-2 significantly increased the mRNA expressions of Alp, osteocalcin (Ocn), Runx2, Osterix and Dlx-5 in MC3T3-E1 cells, while co-incubation of ara-A significantly decreased the BMP-2-stimulated expression of Alp, Ocn, and Runx2. Moreover, co-incubation of ara-A suppressed the BMP-2-induced upregulation of Alp and Ocn in ST2 cells. Western blot analysis showed that BMP-2 phosphorylated Smad1/5 although it did not affect AMPK phosphorylation in MC3T3-E1 cells. Furthermore, a BMP receptor inhibitor LDN-193189 inhibited the phosphorylation of Smad1/5, but did not affect AMPK. In addition, co-incubation of ara-A did not affect BMP-2-induced phosphorylation of Smad1/5. These findings suggest that the inhibition of AMPK activation reduces the osteo-inductive effects of BMP-2 by decreasing the expression of Alp, Ocn, and Runx2 through Smad-independent mechanisms in osteoblastic cells.

Osteoblast AMP-Activated Protein Kinase Regulates Postnatal Skeletal Development in Male Mice

Studies have shown that AMP-activated protein kinase (AMPK), a crucial regulator of energy homeostasis, plays important roles in osteoblast differentiation and mineralization. However, little is known about in vivo roles of osteoblastic AMPK in bone development. Thus, to investigate in vivo roles of osteoblast AMPK, we conditionally inactivated Ampk in osterix (Osx)-expressing cells by crossing Osx-Cre mice with floxed AMPKα1 to generate mice lacking AMPKα1 in osteoblasts (Ampk-/- mice). Compared with wild-type and Ampk+/- mice, Ampk-/- mice displayed retardation of postnatal bone development, although bone deformity was not observed at birth. Microcomputed tomography showed significant reductions in trabecular bone volume, cortical bone length, and density, as well as increased cortical porosity in femur as well as development defects of skull in 8-week-old Ampk-/- mice. Surprisingly, histomorphometric analysis demonstrated that the number of osteoclasts was significantly increased, although bone formation rate was not altered. Loss of trabecular network connections and mass, as well as shortened growth plates and reduced thickness of cartilage adjacent to the growth plate, was observed in Ampk-/- mice. In primary cultured osteoblasts from calvaria, the expressions of alkaline phosphatase, type 1 collagen, osteocalcin, bone morphogenetic protein 2, Runx2, and osterix were significantly inhibited in Ampk-/- osteoblasts, whereas the expression of receptor activator of nuclear κB ligand (RANKL) and the RANKL/osteoprotegerin ratio were significantly increased. These findings indicate that osteoblastic AMPK plays important roles in bone development in vivo and that deletion of AMPK in osteoblasts decreases osteoblastic differentiation and enhances bone turnover by increasing RANKL expression.

Glucose uptake inhibition decreases expressions of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteocalcin in osteocytic MLO-Y4-A2 cells

Bone and glucose metabolism are closely associated with each other. Both osteoblast and osteoclast functions are important for the action of osteocalcin, which plays pivotal roles as an endocrine hormone regulating glucose metabolism. However, it is unknown whether osteocytes are involved in the interaction between bone and glucose metabolism. We used MLO-Y4-A2, a murine long bone-derived osteocytic cell line, to investigate effects of glucose uptake inhibition on expressions of osteocalcin and bone-remodeling modulators in osteocytes. We found that glucose transporter 1 (GLUT1) is expressed in MLO-Y4-A2 cells and that treatment with phloretin, a GLUT inhibitor, significantly inhibited glucose uptake. Real-time PCR and Western blot showed that phloretin significantly and dose-dependently decreased the expressions of RANKL and osteocalcin, whereas osteoprotegerin or sclerostin was not affected. Moreover, phloretin activated AMP-activated protein kinase (AMPK), an intracellular energy sensor. Coincubation of ara-A, an AMPK inhibitor, with phloretin canceled the phloretin-induced decrease in osteocalcin expression, but not RANKL. In contrast, phloretin suppressed phosphorylation of ERK1/2, JNK, and p38 MAPK, and treatments with the p38 inhibitor SB203580 and the MEK inhibitor PD98059, but not the JNK inhibitor SP600125, significantly decreased expressions of RANKL and osteocalcin. These results indicate that glucose uptake by GLUT1 is required for RANKL and osteocalcin expressions in osteocytes, and that inhibition of glucose uptake decreases their expressions through AMPK, ERK1/2, and p38 MAPK pathways. These findings suggest that lowering glucose uptake into osteocytes may contribute to maintain blood glucose levels by decreasing osteocalcin expression and RANKL-induced bone resorption.

Advanced Glycation End Product 3 (AGE3) Increases Apoptosis and the Expression of Sclerostin by Stimulating TGF-β Expression and Secretion in Osteocyte-Like MLO-Y4-A2 Cells

Advanced glycation end products (AGEs) cause bone fragility due to deterioration in bone quality. We previously reported that AGE3 induced apoptosis and inhibited differentiation via increased transforming growth factor (TGF)-β signaling in osteoblastic cells. Additionally, we demonstrated that AGE3 increased apoptosis and sclerostin expression and decreased receptor activator of nuclear factor-κB ligand (RANKL) expression in osteocyte-like cells. However, it remains unclear whether TGF-β signaling is involved in the effects of AGEs on apoptosis and the expression of sclerostin and RANKL in osteocytes. Effects of AGE3 on apoptosis of mouse osteocyte-like MLO-Y4-A2 cells were examined by DNA fragmentation ELISA. Expression of TGF-β, sclerostin, and RANKL was evaluated using real-time PCR, Western blotting, and ELISA kits. To block TGF-β signaling, we used SD208, a TGF-β type I receptor kinase inhibitor. AGE3 (200 µg/mL) significantly increased apoptosis and mRNA expression of Sost, the gene encoding sclerostin, and decreased Rankl mRNA expression in MLO-Y4-A2 cells. AGE3 significantly increased the expression of TGF-β. Co-incubation of SD208 with AGE3 significantly rescued AGE3-induced apoptosis in a dose-dependent manner. Moreover, SD208 restored AGE3-increased mRNA and protein expression of sclerostin. In contrast, SD208 did not affect AGE3-decreased mRNA and protein expression of RANKL. These findings suggest that AGE3 increases apoptosis and sclerostin expression through increasing TGF-β expression in osteocytes, and that AGE3 decreases RANKL expression independent of TGF-β signaling.

Primary Aldosteronism as a Risk Factor for Vertebral Fracture

CONTEXT

Some observational studies have revealed an association between excessive aldosterone levels and reduced bone mineral density (BMD). However, whether patients with primary aldosteronism (PA) are at higher risk of fracture than healthy individuals remains unclear.

OBJECTIVE

This study aimed to clarify whether PA represents a risk factor for vertebral fracture (VF).

DESIGN AND PATIENTS

We enrolled 56 patients with PA and 56 age- and sex-matched healthy individuals. Serum and urinary biological parameters, BMD, and presence of VFs were evaluated in both groups. We compared parameters between PA and control participants and performed multiple logistic regression analyses after adjustments for variables.

RESULTS

Patients with PA showed higher systolic and diastolic blood pressure, higher hemoglobin A1c (HbA1c) and triglycerides, higher urinary calcium-to-creatinine ratio, and lower high-density lipoprotein cholesterol than controls (P < 0.05, each). Prevalence of VFs was significantly higher in patients with PA (44.6%) than in controls (23.2%, P < 0.05). Patients with PA showed severe fracture more frequently than controls. Multivariate logistic regression analyses adjusted for age, sex, and body mass index identified PA as being associated with the presence of VFs (odds ratio, 3.13; 95% confidence interval, 1.30 to 7.51; P < 0.05). This association remained statistically significant after further adjustment for systolic and diastolic blood pressure, HbA1c, triglycerides, and high-density lipoprotein cholesterol but not after adjustment for calcium-to-creatinine ratio and BMD.

CONCLUSIONS

We identified PA as a risk factor for VF, independent of blood pressure, HbA1c, and lipid profile. Fracture severity was significantly higher in patients with PA than in age- and sex-matched controls.

Long-term efficacy and safety of vildagliptin add-on therapy in type 2 diabetes mellitus with insulin treatment

BACKGROUND

The use of dipeptidyl peptidase (DPP)-4 inhibitors in patients with type 2 diabetes treated with insulin may be beneficial. However, the long-term efficacy and safety of vildagliptin add-on therapy in these patients remains unclear.

SUBJECTS AND METHODS

A total of 73 patients with type 2 diabetes treated with insulin were randomly assigned to receive either add-on therapy of vildagliptin (n=37) or conventional therapy without DPP-4 inhibitors (n=36) for glucose control. Hemoglobin A1c (HbA1c) levels, dose and number of insulin injections, number of hypoglycemia episodes, and liver and renal function were monitored for 2years.

RESULTS

The baseline characteristics of subjects, including age, dose of insulin injections, or HbA1c levels, did not differ between the two groups. In the vildagliptin group, HbA1c levels significantly decreased and the significance of HbA1c reduction was maintained for 24months (from 8.0±1.2% to 7.4±1.0%, p<0.05, at the end of observational period). In addition, the dose and number of insulin injections significantly reduced (-5.6units, p<0.01, and -0.9 times, p<0.001). However, these parameters were unchanged in the control group. The number of patients who experienced three or more episodes of hypoglycemia per year was significantly lower in the vildagliptin group (n=4) than in the control group (n=11) (odds ratio, 0.28; 95% confidence interval, 0.08-0.97; p<0.05).

CONCLUSION

Vildagliptin as an add-on to insulin treatment for 24months was well tolerated and led to sustained reductions in HbA1c, the dose and number of insulin injections, and the risk of hypoglycemia.

Administration of anti-receptor activator of nuclear factor-kappa B ligand (RANKL) antibody for the treatment of osteoporosis was associated with amelioration of hepatitis in a female patient with growth hormone deficiency: a case report

BACKGROUND

Growth hormone deficiency (GHD) is associated with non-alcoholic fatty liver disease (NAFLD). A recent animal study showed that hepatocyte-specific receptor activator of nuclear factor-kappa B (RANK) knockout mice had significantly lower liver fat content compared with control mice concomitant with a decrease in production of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) from hepatocytes and kupffer cells. The role of anti-RANK ligand (RANKL) antibody for osteoporosis on hepatitis in patients with aGHD is still unknown.

CASE PRESENTATION

A forty-seven-year-old female patient was referred to our hospital to investigate chronic hepatitis caused by unknown etiology. She had past history of craniopharyngioma treated with craniotomy and post-surgical radiotherapy. She was for the first time diagnosed as panhypopituitarism including growth hormone deficiency and osteoporosis by endocrine examinations and bone mineral densitometry, respectively. In addition, non-alcoholic steatohepatitis (NASH) was histologically confirmed by liver biopsy in this time. Sixty mg anti-RANKL antibody, which was subcutaneously injected to treat the osteoporosis every six months after replacement of 5 mg hydrocortisone and 30 μg oral desmopressin, rapidly decreased the levels of her liver enzymes (ALT and γGTP were 133 to 72 U/L and 284 to 99 U/L at 16 months after the beginning of the treatment, respectively). Additional amelioration of liver dysfunction was not observed after growth hormone replacement.

CONCLUSIONS

The clinical course of the present case suggested that RANKL-RANK signaling may be a key pathological mechanism in establishment or development of NAFLD or NASH in patients with panhypopituitarism including GHD.

Visceral fat obesity increases serum DPP-4 levels in men with type 2 diabetes mellitus

OBJECTIVE

The relationship between serum DPP-4 level and visceral fat mass is still unclear in type 2 diabetes mellitus (T2DM). This study thus aimed to examine the association of visceral fat accumulation and metabolic syndrome with serum DPP-4 levels in T2DM.

METHODS

Visceral and subcutaneous fat areas were evaluated by performing computed tomography scan in 135 men with T2DM, who had never taken DPP-4 inhibitors or GLP-1 receptor agonists. We investigated the association between serum DPP-4 levels and visceral fat area as well as the presence of metabolic syndrome.

RESULTS

Multiple regression analysis adjusted for age, duration of T2DM, body mass index, serum creatinine, and HbA1c showed that serum DPP-4 levels were positively associated with visceral fat area (β=0.25, p=0.04), but not subcutaneous fat area (β=-0.18, p=0.13). In logistic regression analyses adjusted for the confounding factors described above, serum DPP-4 levels were positively associated with visceral fat obesity and metabolic syndrome [odds ratio (OR)=1.63, 95% confidence interval (CI)=1.00-2.66 per standard deviation (SD) increase, p=0.04; OR=1.77, 95%CI=1.09-2.88 per SD increase, p=0.02, respectively].

CONCLUSIONS

The present study showed that serum DPP-4 level was positively and specifically associated with accumulation of visceral fat and the presence of metabolic syndrome in men with T2DM.

Simvastatin rescues homocysteine-induced apoptosis of osteocytic MLO-Y4 cells by decreasing the expressions of NADPH oxidase 1 and 2

Clinical studies have shown that hyperhomocysteinemia is associated with bone fragility. Homocysteine (Hcy) induces apoptosis of osteoblastic cell lineage by increasing oxidative stress, which may contribute to Hcy-induced bone fragility. Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, ameliorate oxidative stress by regulating oxidant and anti-oxidant enzymes. However, the effects of statins on Hcy-induced apoptosis of osteocytes are unknown. This study was thus aimed to investigate whether or not statins prevent Hcy-induced apoptosis of osteocytic MLO-Y4 cells and regulate NADPH oxidase (Nox) expression. TUNEL staining showed that 5 mM Hcy induced apoptosis of MLO-Y4 cells, and that co-incubation of 10(-9) or 10(-8) M simvastatin significantly suppressed the apoptotic effect. Moreover, we confirmed the beneficial effect of simvastatin against Hcy's apoptotic effect by using a DNA fragment ELISA assay. However, TUNEL staining showed no significant effects of pravastatin, a hydrophilic statin, on the Hcy-induced apoptosis. Real-time PCR showed that Hcy increased the mRNA expressions of Nox1 and Nox2, whereas simvastatin inhibited the stimulation of Nox1 and Nox2 expressions by Hcy. In contrast, neither Hcy nor simvastatin had any effect on Nox4 expression. These findings indicate that simvastatin prevents the detrimental effects of Hcy on the apoptosis of osteocytes by regulating the expressions of Nox1 and Nox2, suggesting that statins may be beneficial for preventing Hcy-induced osteocyte apoptosis and the resulting bone fragility.

Serum dipeptidyl peptidase-4 is associated with multiple vertebral fractures in type 2 diabetes mellitus

OBJECTIVE

Patients with type 2 diabetes mellitus (T2DM) have a high risk of fracture although they have slightly higher bone mineral density (BMD). There is no evidence that dipeptidyl peptidase-4 (DPP-4) is involved in the bone fragility of the patients. The aim of this study was to investigate the association between serum DPP-4 levels and vertebral fractures (VFs) in men with T2DM.

DESIGN

We conducted a cross-sectional study and investigated the relationships between serum DPP-4 levels vs BMD at lumbar spine, femoral neck and radius, bone turnover markers and presence of VFs in 204 Japanese male patients.

RESULTS

Multiple regression analyses adjusted for confounders such as age, duration of diabetes, body mass index, serum creatinine, HbA1c, serum albumin, log(alanine transaminase), and log(C-reactive protein) showed that serum DPP-4 was positively associated with bone formation markers (bone-specific alkaline phosphatase and osteocalcin) as well as a bone resorption marker [tartrate-resistant acid phosphatase 5b (TRACP-5b)] (β = 0·25, P < 0·01; β = 0·17, P < 0·05; and β = 0·30, P < 0·01, respectively), but not BMD at each site. Multivariate logistic regression analyses adjusted for the confounders described above revealed that serum DPP-4 levels were associated with the presence of multiple VFs (odds ratio 1·61, 95% confidential interval 1·05-2·49 per SD increase, P < 0·05). This association was still significant after additional adjustment for any sites of BMD or bone turnover markers except for TRACP-5b.

CONCLUSIONS

We firstly showed that high level of serum DPP-4 is associated with prevalent multiple VFs independently of BMD and bone formation in men with T2DM.

Long-term Efficacy and Safety of Sitagliptin in Elderly Patients with Type 2 Diabetes Mellitus

Objective We herein conducted a retrospective study to evaluate the long-term efficacy and safety of sitagliptin treatment in elderly patients with type 2 diabetes mellitus. Methods We analyzed the changes in glycemic control in 112 Japanese type 2 diabetes patients over 65 years of age treated with 50 mg/day sitagliptin. Hemoglobin A1c (HbA1c) levels, liver and kidney functions, and usage of hypoglycemic agents were recorded for 24 months. Results HbA1c levels were significantly decreased, and the significance of HbA1c reduction was maintained during the observation period [from 7.7±1.1% to 7.2±0.7% (p<0.001) at the end of observational period]. The %change in HbA1c levels was significantly and negatively correlated with the baseline HbA1c levels (r=-0.51, p<0.001), but not with age, duration of diabetes, or the estimated glomerular filtration rate (eGFR). No patient experienced severe hypoglycemia episodes, and aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase, and the eGFR remained unchanged. The dose of sulfonylurea was finally decreased in 72% of patients treated with sulfonylurea. Conclusion Sitagliptin treatment continually decreases the HbA1c level for 24 months and is useful to reduce the dose of sulfonylurea in elderly patients with type 2 diabetes.

Activation of AMP-activated protein kinase protects against homocysteine-induced apoptosis of osteocytic MLO-Y4 cells by regulating the expressions of NADPH oxidase 1 (Nox1) and Nox2

BACKGROUND

Elevated plasma homocysteine (Hcy) level is associated with the risk of osteoporotic fracture. While Hcy increases oxidative stress, AMP-activated protein kinase (AMPK) activation ameliorates it. This study aimed to investigate whether Hcy induces apoptosis of osteocytic MLO-Y4 cells through regulating expressions of oxidant and anti-oxidant enzymes and determine the effects of AMPK activation by 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) and metformin on the Hcy-induced apoptosis of the cells.

RESULTS

DNA fragment ELISA and TUNEL staining assays showed that Hcy treatments (0.1-5.0 mM) induced apoptosis of MLO-Y4 cells in a dose-dependent manner. The detrimental effect of Hcy was partly but significantly reversed by an antioxidant (N-acetylcysteine) and NADPH oxidase (Nox) inhibitors (apocynin and diphenyleneiodonium). In addition, treatment with AICAR (0.05-0.1 mM) and metformin (10-100 μM) ameliorated Hcy-induced apoptosis of the cells. The favorable effect of metformin on Hcy-induced apoptosis was completely canceled by an AMPK inhibitor Ara-A. Hcy increased the expression levels of Nox1 and Nox2, while it had no effects on the expressions of Nox4 or the anti-oxidant enzymes, superoxide dismutase 1 and 2. Hcy-induced increases in the expressions of Nox1 and Nox2 decreased significantly by treatments with AICAR.

CONCLUSION

These findings suggest that Hcy induces apoptosis of osteocytes by increasing the expressions of Nox1 and Nox2, and AMPK activation by AICAR and metformin effectively prevents the detrimental reactions. Thus, AMPK activation may be a potent therapeutic candidate for preventing Hcy-induced osteocyte apoptosis and the resulting bone fragility.

An Open-label Longitudinal Study on the Efficacy of Switching from Insulin Glargine or Detemir to Degludec in Type 2 Diabetes Mellitus

OBJECTIVE

Insulin degludec (IDeg), a new long-acting basal insulin, and FlexTouch, a new injection device, recently became available in Japan. The efficacy and usefulness of IDeg and FlexTouch, compared with insulin glargine or detemir, were assessed in patients with type 2 diabetes mellitus.

METHODS

We performed an open-label longitudinal trial in 20 patients. After informed consent was obtained, all subjects recorded their self-monitoring data of the blood glucose (BG) level; thereafter, basal insulin was replaced by an IDeg-prefilled FlexTouch with the same dose and duration of time (2 weeks). After using FlexTouch, the patients were provided a device-specific questionnaire.

RESULTS

The patients were divided into two groups according to the dose of basal insulin (≥10 U and <10 U). Although the mean fasting BG levels were unchanged, the mean BG levels before basal insulin injection and its standard deviation were significantly reduced after switching to IDeg in the patients receiving a higher dose of basal insulin (mean BG before basal insulin injection: 164 to 144 mg/dL, p=0.002; mean standard deviation: 32 to 22, p=0.031); however, this difference was not observed in the patients receiving a lower dose. The patients with a shorter duration of diabetes and a single injection of insulin preferred FlexTouch compared with conventional insulin devices.

CONCLUSION

Replacing basal insulin with IDeg is useful for the stable and accurate control of blood glucose levels in type 2 diabetes for those receiving a higher dose of basal insulin. Furthermore, the patients with a shorter duration of diabetes and a single insulin injection preferred FlexTouch.

Advanced glycation end product 3 (AGE3) suppresses the mineralization of mouse stromal ST2 cells and human mesenchymal stem cells by increasing TGF-β expression and secretion

In diabetic patients, advanced glycation end products (AGEs) cause bone fragility because of deterioration of bone quality. We previously showed that AGEs suppressed the mineralization of mouse stromal ST2 cells. TGF-β is abundant in bone, and enhancement of its signal causes bone quality deterioration. However, whether TGF-β signaling is involved in the AGE-induced suppression of mineralization during the osteoblast lineage remains unknown. We therefore examined the roles of TGF-β in the AGE-induced suppression of mineralization of ST2 cells and human mesenchymal stem cells. AGE3 significantly (P < .001) inhibited mineralization in both cell types, whereas transfection with small interfering RNA for the receptor for AGEs (RAGEs) significantly (P < .05) recovered this process in ST2 cells. AGE3 increased (P < .001) the expression of TGF-β mRNA and protein, which was partially antagonized by transfection with RAGE small interfering RNA. Treatment with a TGF-β type I receptor kinase inhibitor, SD208, recovered AGE3-induced decreases in osterix (P < .001) and osteocalcin (P < .05) and antagonized the AGE3-induced increase in Runx2 mRNA expression in ST2 cells (P < .001). Moreover, SD208 completely and dose dependently rescued AGE3-induced suppression of mineralization in both cell types. In contrast, SD208 intensified AGE3-induced suppression of cell proliferation as well as AGE3-induced apoptosis in proliferating ST2 cells. These findings indicate that, after cells become confluent, AGE3 partially inhibits the differentiation and mineralization of osteoblastic cells by binding to RAGE and increasing TGF-β expression and secretion. They also suggest that TGF-β adversely affects bone quality not only in primary osteoporosis but also in diabetes-related bone disorder.

Creation of a dental X-ray unit with a contactless exposure control switch

OBJECTIVE

A new dental radiographic unit (DXRU) with a contactless switch for adjusting exposure conditions and a foot-pedal exposure switch was developed to prevent bacterial or viral contamination from patients and was compared with a conventional DXRU with a panel push-button switch with respect to user friendliness.

METHODS

45 fourth-year dental school students carried out intraoral radiography using both types of DXRU. Errors regarding dose shortages of X-rays were compared and a questionnaire completed.

RESULTS

22 (49%) of the 45 students failed to provide the correct radiographic exposure and the number of errors was 32 for the conventional DXRU, and 4 (9%) students failed to provide the correct radiographic exposure and the number of errors was 4 for our new DXRU, at the first stage (p < 0.001). At the second stage, the number of students who failed to provide the correct radiographic exposure and the number of errors decreased to 12 and 16, respectively, for the conventional DXRU (p < 0.05). 37 (82%) of the 45 students preferred our DXRU because of its contactless switch and the push-pedal exposure switch.

CONCLUSIONS

These data suggested that our new contactless mechanism should be used for other DXRUs for contamination control.

[Secondary osteoporosis or secondary contributors to bone loss in fracture. Effects of oxidative stress on bone metabolism]

Recent years, many reports showed that patients with diabetes mellitus, arteriosclerotic diseases and life style diseases have a higher fracture risk, and one of the reasons about it is an oxidative stress on bone metabolism. Oxidative stress, which is induced by life style diseases, aging and menopause, increases active oxygen production and fracture risk by affecting bone metabolism related cells and bone matrix proteins. Since there are few treatments against oxidative stress, so it is important to search further therapeutic agents. This report gives an outline of the effect of oxidative stress on bone metabolism in some conditions, such as diabetes mellitus, arteriosclerotic diseases, chronic kidney diseases and menopause.

Advanced glycation end products (AGEs), but not high glucose, inhibit the osteoblastic differentiation of mouse stromal ST2 cells through the suppression of osterix expression, and inhibit cell growth and increasing cell apoptosis

Diabetes mellitus is known to be associated with osteoporotic fractures through a decrease in osteoblastic bone formation rather than an increase in osteoclastic bone resorption. However, its precise mechanism is unknown, and we examined whether or not high glucose or advanced glycation end products (AGEs), which play key roles in the pathogenesis and complications of diabetes, would affect the osteoblastic differentiation, growth, and apoptosis of mouse stromal ST2 cells. Ten to 200 μg/mL AGE2 or AGE3 alone dose-dependently inhibited the mineralization. AGE2 or AGE3 alone (200 μg/mL) significantly inhibited alkaline phosphatase (ALP) activities as well as the mineralization of the cells (p < 0.01). In contrast, 22 mM glucose alone or in combination with 200 μg/mL AGE2 or AGE3 did not affect these cellular phenotypes. Real-time PCR showed that AGE2 or AGE3 alone (200 μg/mL) significantly decreased mRNA expressions of osteocalcin as well as osterix on day 14 (p < 0.01). Western blot analysis showed that AGE2 or AGE3 alone (200 μg/mL) also decreased the levels of Runx2 and osterix protein expressions on days 7 and 14. AGE2 or AGE3 significantly suppressed cell growth and increased apoptotic cell death in time- and dose-dependent manners (p < 0.01). Moreover, AGE3 alone (200 μg/mL) significantly increased mRNA expression of the receptor for AGEs (RAGE) on days 2 and 3 (p < 0.01). These results suggest that AGE2 and AGE3, but not high glucose, may inhibit the osteoblastic differentiation of stromal cells by decreasing osterix expression and partly by increasing RAGE expression, as well as inhibiting cell growth and increasing cell apoptosis.