Evaluation and Management of Primary Hyperparathyroidism: Summary Statement and Guidelines from the Fifth International Workshop

The last international guidelines on the evaluation and management of primary hyperparathyroidism (PHPT) were published in 2014. Research since that time has led to new insights into epidemiology, pathophysiology, diagnosis, measurements, genetics, outcomes, presentations, new imaging modalities, target and other organ systems, pregnancy, evaluation, and management. Advances in all these areas are demonstrated by the reference list in which the majority of listings were published after the last set of guidelines. It was thus, timely to convene an international group of over 50 experts to review these advances in our knowledge. Four Task Forces considered: 1. Epidemiology, Pathophysiology, and Genetics; 2. Classical and Nonclassical Features; 3. Surgical Aspects; and 4. Management. For Task Force 4 on the Management of PHPT, Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology addressed surgical management of asymptomatic PHPT and non-surgical medical management of PHPT. The findings of this systematic review that applied GRADE methods to randomized trials are published as part of this series. Task Force 4 also reviewed a much larger body of new knowledge from observations studies that did not specifically fit the criteria of GRADE methodology. The full reports of these 4 Task Forces immediately follow this summary statement. Distilling the essence of all deliberations of all Task Force reports and Methodological reviews, we offer, in this summary statement, evidence-based recommendations and guidelines for the evaluation and management of PHPT. Different from the conclusions of the last workshop, these deliberations have led to revisions of renal guidelines and more evidence for the other recommendations. The accompanying papers present an in-depth discussion of topics summarized in this report. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Pharmacotherapy of obesity: an update on the available medications and drugs under investigation

Obesity is an epidemic and a public health threat. Medical weight management remains one of the options for the treatment of excess weight and recent advances have revolutionized how we treat, and more importantly how we will be treating obesity in the near future. Metreleptin and Setmelanotide are currently indicated for rare obesity syndromes, and 5 other medications (orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, semaglutide) are approved for non-syndromic obesity. Tirzepatide is about to be approved, and other drugs, with exciting novel mechanisms of action primarily based on incretins, are currently being investigated in different phases of clinical trials. The majority of these compounds act centrally, to reduce appetite and increase satiety, and secondarily, in the gastrointestinal tract to slow gastric emptying. All anti-obesity medications improve weight and metabolic parameters, with variable potency and effects depending on the specific drug. The currently available data do not support a reduction in hard cardiovascular outcomes, but it is almost certain that such data are forthcoming in the very near future. The choice of the anti-obesity medication needs to take into consideration the patient's clinical and biochemical profile, co-morbidities, and drug contra-indications, as well as expected degree of weight loss and improvements in cardio-renal and metabolic risk. It also remains to be seen whether precision medicine may offer personalized solutions to individuals with obesity, and whether it may represent the future of medical weight management along with the development of novel, very potent, anti-obesity medications currently in the pipeline.

Funding

None.

The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis

BACKGROUND

Disease severity and mortality rates due to COVID-19 infection are greater in the elderly and chronically ill patients, populations at high risk for vitamin D deficiency. Vitamin D plays an important role in immune function and inflammation. This systematic review and meta-analysis assesses the impact of vitamin D status and supplementation on COVID-19 related mortality and health outcomes.

METHODS

We searched four databases until December 18th 2020, and trial registries until January 20th 2021. Two reviewers screened the studies, collected data, assessed the risk of bias, and graded the evidence for each outcome across studies, independently and in duplicate. Pre-specified outcomes of interest were mortality, ICU admission, invasive and non-invasive ventilation, hospitalization, time of hospital stay, disease severity and SARS-CoV-2 positivity. We only included data from peer-reviewed articles in our primary analyses.

RESULTS

We identified 31 peer-reviewed observational studies. In our primary analysis, there was a positive trend between serum 25(OH)D level <20 ng/ml and an increased risk of mortality, ICU admission, invasive ventilation, non-invasive ventilation or SARS-CoV-2 positivity. However, these associations were not statistically significant. Mean 25(OH)D levels was 5.9 ng/ml (95% CI [-9.5, -2.3]) significantly lower in COVID-19 positive, compared to negative patients. The certainty of the evidence was very low. We identified 32 clinical trial protocols, but only three have published results to-date. The trials administer vitamin D doses of 357 to 60,000 IU/day, from one week to 12 months. Eight megatrials investigate the efficacy of vitamin D in outpatient populations. A pilot trial revealed a significant decrease in ICU admission with calcifediol, compared to placebo (OR = 0.003), but the certainty of the evidence was unclear. Another small trial showed that supplementation with cholecalciferol, 60,000 IU/day, decreased fibrinogen levels, but did not have an effect on D-dimer, procalcitonin and CRP levels, compared to placebo. The third trial did not find any effect of vitamin D supplementation on COVID-19 related health outcomes.

CONCLUSION

While the available evidence to-date, from largely poor-quality observational studies, may be viewed as showing a trend for an association between low serum 25(OH)D levels and COVID-19 related health outcomes, this relationship was not found to be statistically significant. Calcifediol supplementation may have a protective effect on COVID-19 related ICU admissions. The current use of high doses of vitamin D in COVID-19 patients is not based on solid evidence. It awaits results from ongoing trials to determine the efficacy, desirable doses, and safety, of vitamin D supplementation to prevent and treat COVID-19 related health outcomes.

Serum 25-Hydroxyvitamin D Levels: Variability, Knowledge Gaps, and the Concept of a Desirable Range

Hypovitaminosis D is prevalent worldwide but proportions vary widely between regions, depending on genetic and lifestyle factors, the threshold to define deficiency, and accuracy of 25-hydroxyvitamin D (25OHD) assays used. Latitude, pollution, concealing clothing, sun exposure, gender, dietary habits, and lack of government regulation account for up to 50% in variations in serum 25OHD levels, whereas genetic polymorphisms in the vitamin D pathway account for less than 5%. Organizations/societies have developed guidelines for recommended desirable 25OHD levels and vitamin D doses to reach them, but their applicability across age groups and populations are still debated. This article and the accompanying online Supporting Information highlight sources of variations in circulating 25OHD levels, uncertainties and knowledge gaps, and analytical problems facing 25OHD assays, while keeping efficacy and safety data as the dominant factors when defining a desirable range for 25OHD levels. We propose a desirable range of 20 to 40 ng/mL (50 to 100 nmol/L), provided precise and accurate assays are used. Although slightly lower levels, 15 to 20 ng/mL, may be sufficient for some infants and adults, higher levels, 40 to 60 ng/mL, may still be safe. This desirable range allows physicians to tailor treatment while taking season, lifestyle, vitamin D intake, and other sources of variation into account. We reserve 25OHD measurements for at-risk patients, defined by disease or lifestyle, and the use of 25OHD assays calibrated against the recommended international standards. Most target groups reach desirable target levels by a daily intake of 400 to 600 IU for children and 800 IU for adults. A total daily allowance of vitamin D of up to 1000 IU in the pediatric age groups, and up to 2000 IU in adults, tailored to an individual patient risk profile, is probably safe over long durations. Additional data are needed to validate the proposed range and vitamin D doses, especially in children, pregnant women, and non-white populations.

Vitamin D in the Middle East and North Africa

PURPOSE

The Middle East and North Africa (MENA) region registers some of the lowest serum 25‑hydroxyvitamin D [25(OH)D] concentrations, worldwide. We describe the prevalence and the risk factors for hypovitaminosis D, completed and ongoing clinical trials, and available guidelines for vitamin D supplementation in this region.

METHODS

This review is an update of previous reviews published by our group in 2013 for observational studies, and in 2015 for randomized controlled trials (RCTs) from the region. We conducted a comprehensive search in Medline, PubMed, and Embase, and the Cochrane Library, using MeSH terms and keywords relevant to vitamin D, vitamin D deficiency, and the MENA region, for the period 2012-2017 for observational studies, and 2015-2017 for RCTs. We included large cross-sectional studies with at least 100 subjects/study, and RCTs with at least 50 participants per arm.

RESULTS

We identified 41 observational studies. The prevalence of hypovitaminosis D, defined as a 25‑hydroxyvitamin D [25(OH)D] level below the desirable level of 20 ng/ml, ranged between 12-96% in children and adolescents, and 54-90% in pregnant women. In adults, it ranged between 44 and 96%, and the mean 25(OH)D varied between 11 and 20 ng/ml. In general, significant predictors of low 25(OH)D levels were female gender, increasing age and body mass index, veiling, winter season, use of sun screens, lower socioeconomic status, and higher latitude.We retrieved 14 RCTs comparing supplementation to control or placebo, published during the period 2015-2017: 2 in children, 8 in adults, and 4 in pregnant women. In children and adolescents, a vitamin D dose of 1000-2000 IU/d was needed to maintain serum 25(OH)D level at target. In adults and pregnant women, the increment in 25(OH)D level was inversely proportional to the dose, ranging between 0.9 and 3 ng/ml per 100 IU/d for doses ≤2000 IU/d, and between 0.1 and 0.6 ng/ml per 100 IU/d for doses ≥3000 IU/d. While the effect of vitamin D supplementation on glycemic indices is still controversial in adults, vitamin D supplementation may be protective against gestational diabetes mellitus in pregnant women. In the only identified study in the elderly, there was no significant difference between 600 IU/day and 3750 IU/day doses on bone mineral density. We did not identify any fracture studies.The available vitamin D guidelines in the region are based on expert opinion, with recommended doses between 400 and 2000 IU/d, depending on the age category, and country.

CONCLUSION

Hypovitaminosis D is prevalent in the MENA region, and doses of 1000-2000 IU/d may be necessary to reach a desirable 25(OH)D level of 20 ng/ml. Studies assessing the effect of such doses of vitamin D on major outcomes, and confirming their long term safety, are needed.

Worldwide Fracture Prediction

The substantial increase in the burden of non-communicable diseases in general and osteoporosis in particular, necessitates the establishment of efficient and targeted diagnosis and treatment strategies. This chapter reviews and compares different tools for osteoporosis screening and diagnosis; it also provides an overview of different treatment guidelines adopted by countries worldwide. While access to dual-energy X-ray absorptiometry to measure bone mineral density (BMD) is limited in most areas in the world, the introduction of risk calculators that combine risk factors, with or without BMD, have resulted in a paradigm shift in osteoporosis screening and management. To-date, forty eight risk assessment tools that allow risk stratification of patients are available, however only few are externally validated and tested in a population-based setting. These include Osteoporosis Self-Assessment Tool; Osteoporosis Risk Assessment Instrument; Simple Calculated Osteoporosis Risk Estimation; Canadian Association of Radiologists and Osteoporosis Canada calculator; Fracture Risk Assessment Calculator (FRAX); Garvan; and QFracture. These tools vary in the number of risk factors incorporated. We present a detailed analysis of the development, characteristics, validation, performance, advantages and limitations of these tools. The World Health Organization proposes a dual-energy X-ray absorptiometry-BMD T-score ≤ -2.5 as an operational diagnostic threshold for osteoporosis, and many countries have also adopted this cut-off as an intervention threshold in their treatment guidelines. With the introduction of the new fracture assessment calculators, many countries chose to include fracture risk as one of the major criteria to initiate osteoporosis treatment. Of the 52 national guidelines identified in 36 countries, 30 included FRAX derived risk in their intervention threshold and 22 were non-FRAX based.  No universal tool or guideline approach will address the needs of all countries worldwide.  Osteoporosis screening and management guidelines are best tailored according to the needs and resources of individual counties. While few countries have succeeded in generating valuable epidemiological data on osteoporotic fractures, to validate their risk calculators and base their guidelines, many have yet to find the resources to assess variations and secular trends in fractures, the performance of various calculators, and ultimately adopt the most convenient care pathway algorithms.

Vitamin D supplementation in obesity and during weight loss: A review of randomized controlled trials

Vitamin D deficiency is common in obese individuals and during weight loss. The recommended vitamin D doses in this specific population are higher than for healthy adults. We reviewed vitamin D supplementation trials in obesity, and during medical or surgical weight loss, and report the effects on 25-hydroxyvitamin D [25(OH)D] concentrations and other relevant outcomes. We conducted a systematic search in PubMed, Medline, Embase and the Cochrane library for relevant randomized controlled trials (RCTs) of oral vitamin D supplementation for at least 3 months in obese individuals without weight loss (OB), and those on medical weight loss (MWL) (2010-2018), and following bariatric surgery (Bar S) (without time restriction). Two reviewers screened the identified citations in duplicate and independently and performed full text screening. One reviewer completed data extraction. We identified 13 RCTs in OB, 6 in MWL and 7 in Bar S. Mean baseline 25(OH)D concentrations ranged between 7 and 27 ng/ml in OB, 15-29 ng/ml in MWL and 15-24 ng/ml in Bar S. In OB (Total N 2036 participants), vitamin D doses of 1600-4000 IU/d increased mean 25(OH)D concentrations to ≥30 ng/ml. Based on three trials during MWL (Total N 359 participants), vitamin D doses of 1200-4600 IU/d for 12 months increased 25(OH)D concentration to ≥30 ng/ml. In Bar S (Total N 615 participants), doses ≥2000 IU/d were needed to reach 30 ng/ml. The change in 25(OH)D concentration was inversely proportional to the administered dose, and to BMI and baseline level with doses of 600-3000 IU/day. With these doses, the change in 25(OH)D concentration [Δ25(OH)D] per 100 IU/d was 0.5-1.2 ng/ml. Three trials assessed bone mineral density as a primary outcome, but only one of them showed a protective effect of vitamin D against bone loss at all sites post-Bar S. There was no effect of vitamin D on weight loss. Data on extra-skeletal parameters, namely glycemic and vascular indices were mostly identified in OB, and findings were inconsistent. In conclusion, Vitamin D doses ≥1600-2000 IU/d may be needed to reach a 25(OH)D concentration of 30 ng/ml in obese individuals and following bariatric surgery. The optimal concentration in this population is unknown, and whether the above doses protect against weight loss induced bone loss and fractures still needs to be confirmed. There is no clear evidence for a beneficial effect of vitamin D supplementation on cardio-metabolic parameters in obese individuals, and data on such parameters with weight loss are very scarce. Well-designed long term RCTs assessing the effect of vitamin D supplementation during weight loss on patient important outcomes are needed.

The role of vitamin d deficiency in the incidence, progression, and complications of type 1 diabetes mellitus

The "nonclassic" role of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been recently widely recognized. In type 1 diabetes mellitus (T1D), it plays an immunomodulatory role through the vitamin D receptor (VDR) present on pancreatic and immune cells. Specific VDR allelic variants have been associated with T1D in many countries. Furthermore, vitamin D deficiency has been prevalent in T1D, and the seasonal and latitude variability in the incidence of T1D can be partly explained by the related variability in vitamin D level. In fact, retrospective studies of vitamin D supplementation during pregnancy or infancy showed a lower incidence of T1D. We will review the different mechanisms of the vitamin D protective effect against insulitis and present the available data on the role of vitamin D deficiency in the control, progression, and complications of T1D.

Classical and Nonclassical Manifestations of Primary Hyperparathyroidism

This narrative review summarizes data on classical and nonclassical manifestations of primary hyperparathyroidism (PHPT). It is based on a rigorous literature search, inclusive of a Medline search for systematic reviews from 1940 to December 2020, coupled with a targeted search for original publications, covering four databases, from January 2013-December 2020, and relevant articles from authors' libraries. We present the most recent information, identify knowledge gaps, and suggest a research agenda. The shift in the presentation of PHPT from a predominantly symptomatic to an asymptomatic disease, with its varied manifestations, has presented several challenges. Subclinical nephrolithiasis and vertebral fractures are common in patients with asymptomatic disease. The natural history of asymptomatic PHPT with no end organ damage at diagnosis is unclear. Some observational and cross-sectional studies continue to show associations between PHPT and cardiovascular and neuropsychological abnormalities, among the different disease phenotypes. Their causal relationship is uncertain. Limited new data are available on the natural history of skeletal, renal, cardiovascular, neuropsychological, and neuromuscular manifestations and quality of life. Normocalcemic PHPT (NPHPT) is often diagnosed without the fulfillment of rigorous criteria. Randomized clinical trials have not demonstrated a consistent long-term benefit of parathyroidectomy (PTX) versus observation on nonclassical manifestations. We propose further refining the definition of asymptomatic disease, into two phenotypes: one without and one with evidence of target organ involvement, upon the standard evaluation detailed in our recommendations. Each of these phenotypes can present with or without non-classical manifestations. We propose multiple albumin-adjusted serum calcium determinations (albumin-adjusted and ionized) and exclusion of all secondary causes of high parathyroid hormone (PTH) when establishing the diagnosis of NPHPT. Refining the definition of asymptomatic disease into the phenotypes proposed will afford insights into their natural history and response to interventions. This would also pave the way for the development of evidence-based guidance and recommendations. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Vitamin D Supplementation and Fractures in Adults: A Systematic Umbrella Review of Meta-Analyses of Controlled Trials

CONTEXT

The growing number of systematic reviews/meta-analyses (SR/MAs) on vitamin D (± calcium) for fracture prevention has led to contradictory guidelines.

OBJECTIVE

This umbrella review aims to assess the quality and explore the reasons for the discrepancy of SR/MAs of trials on vitamin D supplementation for fracture risk reduction in adults.

METHODS

We searched 4 databases (2010-2020), Epistemonikos, and references of included SRs/MAs, and we contacted experts in the field. We used A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR-2) for quality assessment. We compared results and investigated reasons for discordance using matrices and subgroup analyses (PROSPERO registration: CRD42019129540). We included 13 SR/MAs on vitamin D and calcium (Ca/D) and 19 SR/MAs on vitamin D alone, compared to placebo/control.

RESULTS

Only 2 from 10 SRs/MAs on Ca/D were of moderate quality. Ca/D reduced the risk of hip fractures in 8 of 12 SRs/MAs (relative risk [RR] 0.61-0.84), and any fractures in 7 of 11 SR/MAs (RR 0.74-0.95). No fracture risk reduction was noted in SRs/MAs exclusively evaluating community-dwelling individuals or in those on vitamin D alone compared to placebo/control. Discordance in results between SRs/MAs stems from inclusion of different trials, related to search periods and eligibility criteria, and varying methodology (using intention to treat, per-protocol, or complete case analysis from individual trials).

CONCLUSION

Ca/D reduces the risk of hip and any fractures, possibly driven by findings from institutionalized individuals. Individual participant data meta-analyses of patients on Ca/D with sufficient follow-up periods, and subgroup analyses, would unravel determinants for a beneficial response to supplementation.

Bone Health Following Bariatric Surgery: An Update

Obesity rates are increasing rapidly, and bariatric surgery is currently the most effective tool for weight loss. Recently, bariatric surgery induced bone loss has gained attention. Such detrimental effect on bone is multifactorial and causes may include nutrient deficiencies, gut and gonadal hormonal changes, mechanical unloading, loss of lean mass, increased bone marrow fat, and increased risk of fall. This review describes the available evidence on bone loss and fracture risk following bariatric surgery and summarizes the guidelines on the topic. Increased bone resorption starts early postsurgery, and bone markers peak at 1-2 yr. Across studies, the drop in areal bone mineral density is inconsistent at the lumbar spine, while a 2%-5% drop at 6 mo and a 6%-10.5% at 9-12 mo are observed at the total hip. Conversely, studies using quantitative CT showed a 6%-7% decrease in volumetric bone mineral density at the lumbar spine at 6-12 mo postsurgery. These studies also report significant bone loss at the radius and tibia, in addition to alteration in bone microarchitecture. Fracture risk increases 2 yr after surgery, more so following malabsorptive procedures. Fractures were reported at axial, weight bearing sites and at appendicular sites. The available evidence is very heterogeneous, and mostly derived from studies on Roux-en-y gastric bypass in premenopausal women. Data on restrictive procedures is scarce. Our findings suggest that the early postoperative phase represents the "golden window" to intervene and promote bone health. More research is needed to determine the effect of different bariatric procedures on bone, to identify optimal interventions to prevent bone loss and to characterize high risk individuals who should be targeted.

The FRAX-based Lebanese osteoporosis treatment guidelines: rationale for a hybrid model

We describe our approach to develop FRAX-based osteoporosis treatment guidelines in Lebanon, a country with low-moderate fracture rates. A hybrid assessment algorithm that combines a fixed 10 % intervention threshold until age 70 years, and an age-dependent threshold thereafter, was deemed most suitable.

INTRODUCTION

The FRAX risk calculator is used to guide intervention thresholds in several national osteoporosis guidelines. This study aimed to describe the approach in developing FRAX-based osteoporosis treatment guidelines in Lebanon, a country with relatively low fracture rates.

METHODS

We reassessed previous national guidelines combined with an evaluation of age-dependent and fixed FRAX-based intervention threshold models used in the UK, the USA, and Canada. We took into consideration the risk for major osteoporotic fractures (MOF) and the proportions of subjects considered for therapy using such thresholds, before finalizing a model for Lebanon.

RESULTS

The new Lebanese guidelines retained the recommendation to treat individuals with fragility fracture at the hip or spine. A femoral neck T-score ≤-2.5 in subjects without fractures was dropped, since it would imply consideration of therapy for individuals with a 10-year risk for MOF of <10 %, up to age 75 years in women. After considering the impact of both age-dependent and fixed intervention thresholds, we chose a new hybrid algorithm, combining a fixed 10 % treatment threshold until age 70 years and an age-dependent threshold thereafter.

CONCLUSION

The Lebanese FRAX-based hybrid model takes into consideration the risk for MOF and the proportions of subjects considered for treatment. This model avoids consideration of drug therapy in a large proportion of younger subjects at low risk for fracture and targets high risk elderly individuals. It was deemed most suitable for Lebanon and may be an option for other countries with relatively low fracture rates.

Steatotic Liver Disease: Pathophysiology and Emerging Pharmacotherapies

Steatotic liver disease (SLD) displays a dynamic and complex disease phenotype. Consequently, the metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH) therapeutic pipeline is expanding rapidly and in multiple directions. In parallel, noninvasive tools for diagnosing and monitoring responses to therapeutic interventions are being studied, and clinically feasible findings are being explored as primary outcomes in interventional trials. The realization that distinct subgroups exist under the umbrella of SLD should guide more precise and personalized treatment recommendations and facilitate advancements in pharmacotherapeutics. This review summarizes recent updates of pathophysiology-based nomenclature and outlines both effective pharmacotherapeutics and those in the pipeline for MASLD/MASH, detailing their mode of action and the current status of phase 2 and 3 clinical trials. Of the extensive arsenal of pharmacotherapeutics in the MASLD/MASH pipeline, several have been rejected, whereas other, mainly monotherapy options, have shown only marginal benefits and are now being tested as part of combination therapies, yet others are still in development as monotherapies. Although the Food and Drug Administration (FDA) has recently approved resmetirom, additional therapeutic approaches in development will ideally target MASH and fibrosis while improving cardiometabolic risk factors. Due to the urgent need for the development of novel therapeutic strategies and the potential availability of safety and tolerability data, repurposing existing and approved drugs is an appealing option. Finally, it is essential to highlight that SLD and, by extension, MASLD should be recognized and approached as a systemic disease affecting multiple organs, with the vigorous implementation of interdisciplinary and coordinated action plans. SIGNIFICANCE STATEMENT: Steatotic liver disease (SLD), including metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis, is the most prevalent chronic liver condition, affecting more than one-fourth of the global population. This review aims to provide the most recent information regarding SLD pathophysiology, diagnosis, and management according to the latest advancements in the guidelines and clinical trials. Collectively, it is hoped that the information provided furthers the understanding of the current state of SLD with direct clinical implications and stimulates research initiatives.

Vitamin D replacement in children, adolescents and pregnant women in the Middle East and North Africa: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Hypovitaminosis D affects one-third to two-thirds of children and pregnant women from the Middle East and North Africa (MENA) region.

OBJECTIVE

To evaluate in infants, children, adolescents and pregnant women, from the MENA region, the effect of supplementation with different vitamin D doses on the change in 25-hydroxyvitamin D [25(OH)D] level reached, and other skeletal and non-skeletal outcomes.

METHODS

This is a systematic review of randomized controlled trials of vitamin D supplementation conducted in the MENA region. We conducted a comprehensive literature search in 7 databases, without language or time restriction, until November 2016. Two reviewers abstracted data from the included studies, independently and in duplicate. We calculated the mean difference (MD) and 95% CI of 25(OH)D level reached when at least 2 studies were eligible in each comparison (low (<800IU), intermediate (800-2000IU) or high (>2000IU) daily dose of vitamin D, or placebo). We pooled data using RevMan version 5.3.

RESULTS

We identified a total of 15 eligible trials: one in infants, 4 in children and adolescents and 10 in pregnant women. In children and adolescents, an intermediate vitamin D dose (1901IU/d), resulted in a mean difference in 25(OH)D level of 13.5 (95% confidence interval (CI) 8.1-18.8) ng/ml, compared to placebo, favoring the intermediate dose (p<0.001). The proportion of children and adolescents reaching a 25(OH)D level≥ 20ng/ml was 74% in the intermediate dose group. In pregnant women, four trials started supplementation at 12-16weeks of gestation and continued until delivery, and six trials started supplementation at 20-28weeks' gestation and stopped it at delivery. The MD in 25(OH)D level reached was 8.6 (95% CI 5.3-11.9) ng/ml (p<0.001) comparing the high dose (3662IU/d) to the intermediate dose (1836IU/d), and 12.3 (95% CI 6.4-18.2) ng/ml (p<0.001), comparing the high dose (3399IU/d) to the low dose (375IU/d). Comparing the intermediate (1832IU/d) to the low dose (301IU/d), the MD in 25(OH)D level achieved was 7.8 (95% CI 4.5-10.8) ng/ml (p<0.001). The proportion of pregnant women reaching a 25(OH)D level≥20ng/ml was 80%-90%, 73% and 27%-43% in the high, intermediate, and low dose groups, respectively. The risk of bias in the included studies, for children, adolescents and pregnant women, ranged from low to high across all doamins.

CONCLUSION

In children, adolescents and pregnant women from the MENA, an intermediate vitamin D dose of 1000-2000IU daily may be necessary to allow for the majority of the population to reach a desirable 25(OH)D level of 20ng/ml. Further high quality RCTs are required to confirm/refute the beneficial impact of vitamin D supplementation on various clinically important outcomes.

Vitamin D Metabolism in Bariatric Surgery

Hypovitaminosis D is common in obese patients and persists after roux-en-Y gastric bypass and sleeve gastrectomy. Several societies recommend screening for vitamin D deficiency before bariatric surgery, and replacement doses of 3000 IU/d and up to 50,000 IU 1 to 3 times per week, in case of deficiency, with periodic monitoring. These regimens are mostly based on expert opinion. Large trials are needed to assess the vitamin D dose response, by type of bariatric surgery, and evaluate the effect on surrogate markers of skeletal outcomes. Such data are essential to derive desirable vitamin D levels in this population.

Biochemical Markers of Bone Fragility in Patients with Diabetes. A Narrative Review by the IOF and the ECTS

CONTEXT

The risk of fragility fractures is increased in both type 1 and type 2 diabetes. Numerous biochemical markers reflecting bone and/or glucose metabolism have been evaluated in this context. This review summarizes current data on biochemical markers in relation to bone fragility and fracture risk in diabetes.

METHODS

Literature review by a group of experts from the International Osteoporosis Foundation (IOF) and European Calcified Tissue Society (ECTS) focusing on biochemical markers, diabetes, diabetes treatments and bone in adults.

RESULTS

Although bone resorption and bone formation markers are low and poorly predictive of fracture risk in diabetes, osteoporosis drugs seem to change bone turnover markers in diabetics similarly to non-diabetics, with similar reductions in fracture risk. Several other biochemical markers related to bone and glucose metabolism have been correlated with BMD and/or fracture risk in diabetes, including osteocyte-related markers such as sclerostin, HbA1c and advanced glycation end products (AGEs), inflammatory markers and adipokines, as well as IGF-1 and calciotropic hormones.

CONCLUSION

Several biochemical markers and hormonal levels related to bone and/or glucose metabolism have been associated with skeletal parameters in diabetes. Currently, only HbA1c levels seem to provide a reliable estimate of fracture risk, while bone turnover markers could be used to monitor the effects of anti-osteoporosis therapy.

Systematic review of major osteoporotic fracture to hip fracture incidence rate ratios worldwide: implications for Fracture Risk Assessment Tool (FRAX)-derived estimates

The Fracture Risk Assessment Tool (FRAX) is the most widely used tool for fracture prediction. It provides 10-year probabilities for hip and major osteoporotic fracture (MOF). It uses country-specific hip fracture incidence and life expectancy data, and for most countries, MOF/hip fracture incidence rate ratios (IRRs) from Malmo Sweden. However, the risk of MOF varies by age, sex, and geography. The objective is to compare the MOF/hip IRRs across countries, by sex and age. This systematic review targeted observational studies of MOF and hip fractures in individuals >50 years (PROSPERO 2019 CRD42019129259). One reviewer screened potential articles. Two reviewers completed duplicate and independent data abstraction, and assessed study quality based on population representativeness, study design and duration, definition of ethnicity, and fracture characteristics. We calculated the MOF/hip IRRs (95% confidence interval) and Z-values to compare IRRs in various countries to those for Sweden. We included 27 studies, of fair to good quality in the majority, from Europe (15), US and Canada (7), Asia (3), and Australia (2). The IRRs were twofold to 10-fold higher in younger compared to older age categories, and in women compared to men, with few exceptions. Within Europe, and using Sweden as a reference, MOF/Hip IRRs in women 50-54 years from Finland, Italy, Netherlands, Denmark, and UK were significantly lower by 38% to 60%. Findings were similar in men. At older ages, MOF/Hip IRRs were consistently lower in women from European countries compared to Sweden, by 10%-40% and 11%-51%, at 75-79 years and 85-89 years, respectively. Findings were heterogenous in men and in non-European countries. In conclusion, the MOF/hip fracture IRR may vary between countries. The variability at older ages may affect FRAX prediction when country-specific fracture IRRs are not used. Further research is needed to elucidate the implication of our findings to FRAX-derived MOF estimates in various countries. © 2021 American Society for Bone and Mineral Research (ASBMR).

Impact of vitamin D supplementation on falls and fractures-A critical appraisal of the quality of the evidence and an overview of the available guidelines

INTRODUCTION

The beneficial effect of vitamin D supplementation on musculo-skeletal outcomes have been recently questioned and recommendations regarding supplementation vary widely. The aim of this paper is to systematically assess the quality of the evidence evaluating the effect of vitamin D supplementation on falls and fractures.

METHODS

We conducted a systematic search in Medline, PubMed, and Embase and selected systematic reviews (SRs) / meta-analyses (MAs) of randomized controlled trials (RCTs) on vitamin D supplementation and falls or fracture, published between 2012 - 2018. We identified 5 MAs of RCTs on falls, 4 on fractures and 4 on both outcomes. We applied the critical appraisal tool "A MeaSurement Tool to Assess systematic Reviews 2" - AMSTAR 2 - to assess the quality of the identified MAs.

RESULTS

Vitamin D and calcium supplementation (CaD), compared to calcium only or placebo, may reduce the risk of falls, in institutionalized individuals and/or those from the community, but the data is inconsistent. The largest and most consistent evidence for a protective effect of CaD, compared to placebo or control, is in reducing the risk of hip fracture, by 16-33%, and any fracture, by 5-19%. This effect was demonstrated when combining trials in community-dwelling and institutionalized individuals, potentially driven by data from institutionalized individuals as shown in 3 SRs/MAs. Major limitations to the quality of the evidence include variability in the methodology of MAs, but more importantly, differences between trials in terms of subjects' characteristics, vitamin D regimens, outcome definition and ascertainment, risk of bias, trial duration and/or low power. The quality of the included MAs was moderate to critically low.

CONCLUSIONS

While the effect on falls is inconsistent, CaD reduces the risk of fracture (hip and any fracture), as shown in meta-analyses pooling data of studies combining institutionalized and community individuals. The evidence is however limited by major shortcomings and heterogeneity.

Abdominal Visceral Adipose Tissue and All-Cause Mortality: A Systematic Review

Introduction

Increased abdominal visceral adipose tissue (VAT) implies an adverse cardio-metabolic profile. We examined the association of abdominal VAT parameters and all-cause mortality risk.

Methods

We systematically searched four databases. We performed citations/articles screening, data abstraction, and quality assessment in duplicate and independently (CRD42020205021).

Results

We included 12 cohorts, the majority used computed tomography to assess abdominal VAT area. Six cohorts with a mean age ≤ 65 years, examining all-cause mortality risk per increment in VAT area (cm2) or volume (cm3), showed a 11-98% relative risk increase with higher VAT parameters. However, the association lost significance after adjusting for glycemic indices, body mass index, or other fat parameters. In 4 cohorts with a mean age >65 years, the findings on mortality were inconsistent. Conversely, in two cohorts (mean age 73-77 years), a higher VAT density, was inversely proportional to VAT area, and implied a higher mortality risk.

Conclusion

A high abdominal VAT area seems to be associated with increased all-cause mortality in individuals ≤ 65 years, possibly mediated by metabolic complications, and not through an independent effect. This relationship is weaker and may reverse in older individuals, most likely secondary to confounding bias and reverse causality. An individual participant data meta-analysis is needed to confirm our findings, and to define an abdominal VAT area cutoff implying increased mortality risk.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=205021, identifier CRD42020205021.

Bone loss in obesity and obstructive sleep apnea: a review of literature

INTRODUCTION

Obstructive sleep apnea (OSA) is a common sleep-related respiratory disorder. It is associated with many endocrinopathies including hypogonadotropic hypogonadism, hypercortisolism, and glucose intolerance that may lead to bone loss with secondary osteoporosis.

METHODS

We report the case of a 41-year-old man who presented with bilateral 9th rib fractures and was found to have obstructive sleep apnea and osteoporosis. We also present a literature review on this topic.

RESULTS

OSA can lead to bone loss through various mechanisms. Some are shared with obesity, including hypogonadism, altered adrenergic tone, inflammation, oxidative stress, vitamin D deficiency and diabetes mellitus; others are specific to OSA, such as hypoxia and altered glucocorticoids regulation.

CONCLUSION

There are no guidelines on screening for osteoporosis in OSA. Further research is needed to assess the incidence of bone loss and fractures in OSA.

Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis

Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.

Fracture risk following bariatric surgery: a systematic review and meta-analysis

Bariatric surgery may negatively impact bone health. We aimed to compare fracture risk following bariatric surgery by type (malabsorptive, restrictive), or to non-surgical weight loss, or to controls with obesity. We systematically searched four databases from inception until October 2020. We included observational and interventional studies on adults. We screened articles and abstracted data in duplicate and independently and assessed the risk of bias. We conducted random-effects model meta-analyses (Review Manager v5.3), to calculate the relative risk of any or site-specific fracture (CRD42019128536). We identified four trials of unclear-to-high risk of bias and 15 observational studies of fair-to-good quality. Data on fracture risk following bariatric surgery compared to medical weight loss is scarce and limited by the small number of participants. In observational studies, at a mean/median post-operative follow-up > 2 years, the relative risk of any fracture was 45% (p < 0.001) and 61% (p = 0.04) higher following malabsorptive procedures compared to obese controls and restrictive procedures, respectively, with moderate to high heterogeneity. Site-specific relative fracture risk (hip and wrist) was one- to two-folds higher post malabsorptive procedures compared to obese controls or restrictive procedures. The risks of any and of site-specific fracture were not increased following restrictive procedures compared to obese controls. Fracture risk seems to increase following malabsorptive bariatric surgeries, at a mean/median follow-up > 2 years. The risk is not increased with restrictive surgeries. The available evidence has several limitations. A prospective and rigorous long-term follow-up of patients following bariatric surgery is needed for a better assessment of their fracture risk with aging.

Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature

Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.

Impact of vitamin D replacement in adults and elderly in the Middle East and North Africa: a systematic review and meta-analysis of randomized controlled trials

In the Middle East and North Africa (MENA), a vitamin D dose ≥2000 IU/day may be needed to allow to the majority of the population to reach the target 25-hydroxyvitamin D (25(OH)D) level ≥20 ng/ml. Data in the region on the effect of vitamin D supplementation on various skeletal and extra-skeletal effects are scarce.

INTRODUCTION

Hypovitaminosis D is prevalent worldwide, more so in the Middle East and North Africa (MENA). This study aims to determine the effects of vitamin D replacement on the mean difference in 25-hydroxyvitamin D [25(OH)D] level reached and other outcomes, in the MENA.

METHODS

This is a meta-analysis of randomized trials from the MENA, administering vitamin D supplementation for at least 3 months, without language or time restriction. We conducted a comprehensive search in seven databases until July 2015. We abstracted data from published reports, independently and in duplicate. We calculated the mean difference (MD) and 95 % CI of 25(OH)D level reached for eligible comparisons, and pooled data using RevMan version 5.3.

RESULTS

We identified 2 studies in elderly and 17 in adults; for the latter, 11 were included in the meta-analysis. Comparing a high vitamin D dose (>2000 IU/day) to placebo (nine studies), the MD in 25(OH)D level achieved was 18.3 (CI 14.1; 22.5) ng/ml; p value < 0.001; I ² = 92 %. Comparing an intermediate dose (800-2000 IU/day) to placebo (two studies), the MD in 25(OH)D level achieved was 14.7 (CI 4.6; 24.9) ng/ml; p value 0.004; I ² = 91 %. Accordingly, 89 and 71 % of participants, in the high and intermediate dose groups, respectively, reached the desirable level of 20 ng/ml. The risk of bias in the included studies was unclear to high, except for three studies.

CONCLUSION

In the MENA region, vitamin D doses ≥2000 IU/day may be needed to reach the target 25(OH)D level ≥20 ng/ml. The long-term safety and the efficacy of such doses on various outcomes are unknown.