Search

This comprehensive review critically examines the detrimental impacts of endocrine-disrupting chemicals (EDCs) on bone health, with a specific focus on substances such as bisphenol A (BPA), per- and polyfluoroalkyl substances (PFASs), phthalates, and dioxins. These EDCs, by interfering with the endocrine system’s normal functioning, pose a significant risk to bone metabolism, potentially leading to a heightened susceptibility to bone-related disorders and diseases. Notably, BPA has been shown to inhibit the differentiation of osteoblasts and promote the apoptosis of osteoblasts, which results in altered bone turnover status. PFASs, known for their environmental persistence and ability to bioaccumulate in the human body, have been linked to an increased osteoporosis risk. Similarly, phthalates, which are widely used in the production of plastics, have been associated with adverse bone health outcomes, showing an inverse relationship between phthalate exposure and bone mineral density. Dioxins present a more complex picture, with research findings suggesting both potential benefits and adverse effects on bone structure and density, depending on factors such as the timing and level of exposure. This review underscores the urgent need for further research to better understand the specific pathways through which EDCs affect bone health and to develop targeted strategies for mitigating their potentially harmful impacts.

This review article investigates solid organ transplantation-induced osteoporosis, a critical yet often overlooked issue, emphasizing its significance in post-transplant care. The initial sections provide a comprehensive understanding of the prevalence and multifactorial pathogenesis of transplantation osteoporosis, including factors such as deteriorating post-transplantation health, hormonal changes, and the impact of immunosuppressive medications. Furthermore, the review is dedicated to organ-specific considerations in transplantation osteoporosis, with separate analyses for kidney, liver, heart, and lung transplantations. Each section elucidates the unique challenges and management strategies pertinent to transplantation osteoporosis in relation to each organ type, highlighting the necessity of an organ-specific approach to fully understand the diverse manifestations and implications of transplantation osteoporosis. This review underscores the importance of this topic in transplant medicine, aiming to enhance awareness and knowledge among clinicians and researchers. By comprehensively examining transplantation osteoporosis, this study contributes to the development of improved management and care strategies, ultimately leading to improved patient outcomes in this vulnerable group. This detailed review serves as an essential resource for those involved in the complex multidisciplinary care of transplant recipients.

Background: Diabetic kidney disease (DKD) is associated with an elevated risk of fractures. However, little is known about the association between proteinuric or non-proteinuric DKD and the risk of hip fracture. Thus, we investigated the incidence of hip fractures among Korean adults with type 2 diabetes mellitus (T2DM) stratified by DKD phenotype. Methods: In this retrospective cohort study using the Korean National Health Insurance Service database, patients with T2DM who received at least one general health checkup between 2009 and 2012 were followed until the date of hip fracture, death, or December 31, 2018. We classified the DKD phenotype by proteinuria and estimated glomerular filtration rate (eGFR), as follows: no DKD (PU-GFR-), proteinuric DKD with normal eGFR (PU+GFR-), non-proteinuric DKD with reduced eGFR (PU-GFR+), and proteinuric DKD with reduced eGFR (PU+GFR+) Results: The cumulative incidence of hip fractures was highest in the PU+GFR+ group, followed by the PU-GFR+ group and the PU+GFR-group. After adjustment for confounding factors, the hazard ratio (HR) for hip fracture was still highest in the PU+GFR+group. However, the PU+GFR-group had a higher HR for hip fracture than the PU-GFR+ group (PU+GFR+: HR, 1.69; 95% confidence interval [CI], 1.57 to 1.81; PU+GFR-: HR, 1.37; 95% CI, 1.30 to 1.46; PU-GFR+: HR, 1.20; 95% CI, 1.16 to 1.24 using the PU-GFR-group as the reference category). Conclusion: The present study demonstrated that DKD was significantly associated with a higher risk of hip fracture, with proteinuria as a major determinant. [ABSTRACT FROM AUTHOR]

Background: Vitamin D plays an important role in the immune response against infection. The purpose of the present study was to investigate the influence of vitamin D deficiency on the progression of otitis media (OM) using an experimental rat model. Methods: Four-week-old male Sprague-Dawley rats (n=72) were divided into two groups based on their diet: a control diet group (n=36) and a vitamin D-deficient diet group (n=36). After 8 weeks of diet, experimental OM was induced by inoculation of nontypeable Haemophilus influenzae in the middle ear cavity. The rats were evaluated with otomicroscopy to determine the inflammation in the middle ear mucosa on days 1, 2, 4, 7, and 14 post-inoculation. Bullae from sacrificed rats were collected and analyzed histologically. Results: The middle ear mucosa from rats with vitamin D deficiency showed a significantly higher thickness than that of controls during the course of OM. The maximum mucosal thickness was 56.0±9.1 μm in the vitamin D deficiency group, and 43.9±9.8 μm in the control group, although there was no significant difference in the tympanic membrane score between the two groups evaluated with otomicroscopy. An immunohistochemical study showed increased expression of interleukin 6 (IL-6) and tumor necrosis factor α in rats manifesting vitamin D deficiency and decreased expression of IL-10 compared with controls. Conclusion: Our results showed that vitamin D deficiency may exacerbate the pathophysiological changes of OM via altered cytokine production. Therefore, maintaining vitamin D status in the optimal range may be beneficial for proper management of OM. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency remains common in all age groups and affects skeletal and non-skeletal health. Fibroblast growth factor 23 is a bone-derived hormone that regulates phosphate and 1,25-dihydroxyvitamin D homeostasis as a counter regulatory factor. 1,25-Dihydroxyvitamin D stimulates fibroblast growth factor 23 synthesis in bone, while fibroblast growth factor 23 suppresses 1,25-dihydroxyvitamin D production in the kidney. The aim of this study was to evaluate the effects of vitamin D3 intramuscular injection therapy on serum fibroblast growth factor 23 concentrations, and several other parameters associated with bone metabolism such as sclerostin, dickkopf-1, and parathyroid hormone. Methods: A total of 34 subjects with vitamin D deficiency (defined by serum 25-hydroxyvitamin D levels below 20 ng/mL) were randomly assigned to either the vitamin D injection group (200,000 units) or placebo treatment group. Serum calcium, phosphate, urine calcium/creatinine, serum 25-hydroxyvitamin D, fibroblast growth factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were serially measured after treatment. Results: Comparing the vitamin D injection group with the placebo group, no significant changes were observed in serum fibroblast growth factor 23, parathyroid hormone, or dickkopf-1 levels. Serum sclerostin concentrations transiently increased at week 4 in the vitamin D group. However, these elevated levels declined later and there were no statistically significant differences as compared with baseline levels. Conclusion: Serum fibroblast factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were not affected significantly by single intramuscular injection of vitamin D3. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the prevalence of obesity in Korean men with Klinefelter syndrome (KS) and the associated risk factors for obesity and hyperglycemia. Methods: Data were collected retrospectively from medical records from 11 university hospitals in Korea between 1994 and 2014. Subjects aged ≥18 years with newly diagnosed KS were enrolled. The following parameters were recorded at baseline before treatment: chief complaint, height, weight, fasting glucose level, lipid panel, blood pressure, testosterone, luteinizing hormone, folliclestimulating hormone, karyotyping patterns, and history of hypertension, diabetes, and dyslipidemia. Results: Data were analyzed from 376 of 544 initially enrolled patients. The rate of the 47 XXY chromosomal pattern was 94.1%. The prevalence of obesity (body mass index ≥25 kg/m2) in Korean men with KS was 42.6%. The testosterone level was an independent risk factor for obesity and hyperglycemia. Conclusion: Obesity is common in Korean men with KS. Hypogonadism in patients with KS was associated with obesity and hyperglycemia. [ABSTRACT FROM AUTHOR]

Background: γ-Glutamyl transferase (GGT) is a well-known marker of chronic alcohol consumption or hepatobiliary diseases. A number of studies have demonstrated that serum levels of GGT are independently associated with cardiovascular and metabolic disorders. The purpose of this study was to test if serum GGT levels are associated with bone mineral density (BMD) in Korean adults. Methods: A total of 462 subjects (289 men and 173 women), who visited Severance Hospital for medical checkup, were included in this study. BMD was measured using dual energy X-ray absorptiometry. Cross-sectional association between serum GGT and BMD was evaluated. Results: As serum GGT levels increased from the lowest tertile (tertile 1) to the highest tertile (tertile 3), BMD decreased after adjusting for confounders such as age, body mass index, amount of alcohol consumed, smoking, regular exercise, postmenopausal state (in women), hypertension, diabetes mellitus, and hypercholesterolemia. A multiple linear regression analysis showed a negative association between log-transformed serum GGT levels and BMD. In a multiple logistic regression analysis, tertile 3 of serum GGT level was associated with an increased risk for low bone mass compared to tertile 1 (odds ratio, 2.271; 95% confidence interval, 1.340 to 3.850; P=0.002). Conclusion: Serum GGT level was inversely associated with BMD in Korean adults. Further study is necessary to fully elucidate the mechanism of the inverse relationship. [ABSTRACT FROM AUTHOR]

Background: The present study evaluated the efficacy of a combination of ibandronate and cholecalciferol on the restoration of the levels of 25-hydroxyvitamin D (25[OH]D) and various bone markers in postmenopausal women with osteoporosis. Methods: This was a randomized, double-blind, active-controlled, prospective 16-week clinical trial conducted in 20 different hospitals. A total of 201 postmenopausal women with osteoporosis were assigned randomly to one of two groups: the IBN group, which received a once-monthly pill containing 150 mg ibandronate (n =99), or the IBN+ group, which received a once-monthly pill containing 150 mg ibandronate and 24,000 IU cholecalciferol (n=102). Serum levels of 25(OH)D, parathyroid hormone (PTH), and various bone markers were assessed at baseline and at the end of a 16-week treatment period. Results: After 16 weeks of treatment, the mean serum levels of 25(OH)D significantly increased from 21.0 to 25.3 ng/mL in the IBN+ group but significantly decreased from 20.6 to 17.4 ng/mL in the IBN group. Additionally, both groups exhibited significant increases in mean serum levels of PTH but significant decreases in serum levels of bone-specific alkaline phosphatase and C-telopeptide of type 1 collagen (CTX) at 16 weeks; no significant differences were observed between the groups. However, in subjects with a vitamin D deficiency, IBN+ treatment resulted in a significant decrease in serum CTX levels compared with IBN treatment. Conclusion: The present findings demonstrate that a once-monthly pill containing ibandronate and cholecalciferol may be useful for the amelioration of vitamin D deficiency in patients with postmenopausal osteoporosis. Moreover, this treatment combination effectively decreased serum levels of resorption markers, especially in subjects with a vitamin D deficiency, over the 16-week treatment period. [ABSTRACT FROM AUTHOR]

The majority of the vitamin D in our body is produced by cutaneous synthesis in response to sunlight. As more and more people live in cities and spend the bulk of their time indoors, it can be difficult to get sufficient sun exposure for adequate cutaneous production of vitamin D. Therefore, vitamin D insufficiency has become a very common health problem worldwide. The Korea National Health and Nutrition Examination Survey IV 2008 showed that the prevalence of vitamin D insufficiency, defined as a serum 25-hydroxyvitamin D [25(OH)D] level below 50 nmol/L, was 47.3% in males and 64.5% in females. Only 13.2% of males and 6.7% of females had a serum 25(OH)D level of greater than 75 nmol/L. In Korea, vitamin D insufficiency was more prevalent in young adults than in elderly people, likely due to the indoor lifestyle of younger people. Compared with the United States and Canada, Korea has a lower mean 25(OH)D level and a higher prevalence of vitamin D insufficiency. To improve the vitamin D status of the Korean population, more aggressive policies on food fortification and vitamin D supplementation are needed. [ABSTRACT FROM AUTHOR]

Bisphosphonates are the mainstay of osteoporosis treatment. Despite the fact that bisphosphonates have a relatively good safety record and are tolerated well by the majority of patients, serious adverse events have been associated with their use. A 41-year-old man had been diagnosed with osteoporosis and had taken etidronate 200 mg/day daily for 2 years due to the judgmental error. He was referred for the management of refractory bone pain and generalized muscle ache. Serum calcium, phosphate, 25-hydroxyvitamin D (25(OH)D), and immunoreactive parathyroid hormone (iPTH) were within normal range. Plain X-ray showed multiple fractures. Whole body bone scan confirmed multiple sites of increased bone uptakes. Tetracycline-labeled bone biopsy showed typical findings of osteomalacia. He was diagnosed with iatrogenic, etidronate-induced osteomalacia. The patient received daily parathyroid hormone (PTH) injection for 18 months. PTH effectively reverses impaired bone mineralization caused by etidronate misuse. Currently, he is doing well without bone pain. Bone mineral density significantly increased, and the increased bone uptake was almost normalized after 18 months. This case seems to suggest that human PTH (1-34) therapy, possibly in association with calcium and vitamin D, is associated with important clinical improvements in patients with impaired bone mineralization due to the side effect of bisphosphonate. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "The Relationship of Body Composition and Coronary Artery Calcification in Apparently Healthy Korean Adults" by Jung-Hee Yu et al in the 2013 issue.

BackgroundVitamin D deficiency remains common in all age groups and affects skeletal and non-skeletal health. Fibroblast growth factor 23 is a bone-derived hormone that regulates phosphate and 1,25-dihydroxyvitamin D homeostasis as a counter regulatory factor. 1,25-Dihydroxyvitamin D stimulates fibroblast growth factor 23 synthesis in bone, while fibroblast growth factor 23 suppresses 1,25-dihydroxyvitamin D production in the kidney. The aim of this study was to evaluate the effects of vitamin D3 intramuscular injection therapy on serum fibroblast growth factor 23 concentrations, and several other parameters associated with bone metabolism such as sclerostin, dickkopf-1, and parathyroid hormone.MethodsA total of 34 subjects with vitamin D deficiency (defined by serum 25-hydroxyvitamin D levels below 20 ng/mL) were randomly assigned to either the vitamin D injection group (200,000 units) or placebo treatment group. Serum calcium, phosphate, urine calcium/creatinine, serum 25-hydroxyvitamin D, fibroblast growth factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were serially measured after treatment.ResultsComparing the vitamin D injection group with the placebo group, no significant changes were observed in serum fibroblast growth factor 23, parathyroid hormone, or dickkopf-1 levels. Serum sclerostin concentrations transiently increased at week 4 in the vitamin D group. However, these elevated levels declined later and there were no statistically significant differences as compared with baseline levels.ConclusionSerum fibroblast factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were not affected significantly by single intramuscular injection of vitamin D3.