Refining Evaluation of Bone Mass and Adipose Distribution in Dunnigan Syndrome

Familial partial lipodystrophies (FPLD) are rare diseases characterized by selective loss of subcutaneous adipose tissue at different sites. This cross-sectional observational study aimed to estimate adipose tissue in the bone marrow (BMAT), intra (IMCL) and extra-myocyte lipids (EMCL), and define the bone phenotype in the context of FPLD2/Dunnigan syndrome (DS). The subjects comprised 23 controls (C) and 18 DS patients, matched by age, weight and height. Blood samples, dual-energy X-ray absorptiometry for bone mineral density (BMD) and trabecular bone score (TBS) and 1H-spectroscopy using magnetic resonance to estimate BMAT in the lumbar spine, IMCL, EMCL and osteoclastogenesis were assessed. The prevalence of diabetes mellitus was 78% in DS patients. Glucose, HbA1c, triglycerides, insulin and HOMA-IR levels were elevated in DS, whereas HDLc, 25(OH)D, PTH and osteocalcin levels were reduced. BMD was similar between groups at all sites, except 1/3 radius, which was lower in DS group. TBS was reduced in DS. DS presented increased osteoclastogenesis and elevated BMAT, with greater saturation levels and higher IMCL than the C group. HOMA-IR and EMCL were negatively associated with TBS; osteocalcin and EMCL were correlated negatively with BMD. This study contributes to refining the estimation of adipose tissue in DS by showing increased adiposity in the lumbar spine and muscle tissue. DXA detected lower TBS and BMD in the 1/3 radius, suggesting impairment in bone quality and that bone mass is mainly affected in the cortical bone.

Vitamin D deficiency contributes to the diabetic kidney disease progression via increase ZEB1/ZEB2 expressions

BACKGROUND

Diabetic kidney disease (DKD) remains one of the main causes of end-stage renal disease (ESRD) and mortality in diabetic patients worldwide. Vitamin D deficiency (VitDD) is one of the main consequences of different chronic kidney disease (CKD) types and is associated with rapid progression to ESRD. Nevertheless, the mechanisms that lead to this process are poorly understood. This study aimed to characterize a model of diabetic nephropathy progression in VitDD and the epithelial-mesenchymal-transition (EMT) role in these processes.

METHODS

Wistar Hannover rats received a diet with or without VitD before type 1 diabetes (T1D) induction. After this procedure, the rats were accompanied for 12 and 24 weeks after T1D induction and the renal function, structure, cell transdifferentiating markers and zinc finger e-box binding homeobox 1/2 (ZEB1/ZEB2) contribution to kidney damage were evaluated during the DKD progression.

RESULTS

The results showed an increase in glomerular tuft, mesangial and interstitial relative areas and renal function impairment in VitD-deficient diabetic rats compared to diabetic rats that received a VitD-containing diet. These alterations can be associated with increased expression of EMT markers, ZEB1 gene expression, ZEB2 protein expression and TGF-β1 urinary excretion. Decreased miR-200b expression, an important post-transcriptional regulator of ZEB1 and ZEB2 was also observed.

CONCLUSION

Our data demonstrated that VitD deficiency contributes to the rapid development and progression of DKD in diabetic rats induced by increase ZEB1/ZEB2 expressions and miR-200b downregulation.

Contribution of Hip Abductors Muscles on Bone Mineral Density and Functionality in Older Women

BACKGROUND

Despite the well-established role of muscle in maintaining bone mass and physical performance, there are still few studies that assess the relationship between muscle groups and specific bone sites and its contribution to physical function in older people. The aim of the study is to verify the association between hip and knee's muscle strength and bone mineral density of the femoral neck (BMD-FN) and investigated which muscle strength that are related with BMD-FN is associated with physical function in older women.

METHODOLOGY

This is a cross-sectional study of 94 women over the age of 60 years, physically independent. Muscle strength of the hip and knee was evaluated using an isokinetic dynamometer (Biodex, USA) to obtain peak torque (PT). The BMD-FN was obtained using dual-energy x-ray absorption densitometry (DXA). Physical function was evaluated by the Timed Up and Go (TUG), gait speed (GS), five times stand to sit (5TSS) and single-leg stance (SS). To verify the association between muscle strength (independent variable) and the BMD-FN (dependent variable) and the relationship between muscle strength (independent variable) and clinical tests (dependent variable), the multiple linear regression was carried out, adjusted for age, time of menopause, height and level of physical activity. All of the analyses were carried out by the SPSS 17.0 software, with a level of p < 0.05 significance.

RESULTS

We found an association between the hip abductors PT and the BMD-FN and between hip abductors PT and all clinical tests.

CONCLUSION

We observe that hip abductor muscle strength contributes to BMD-FN and to performance in several clinical tests in older women. These findings reinforce the importance of this musculature not only for improving balance and gait, but also it can be a strategy to maintain/improve bone mass in the femoral neck in this population.

Diabetes and bone

Globally, one in 11 adults has diabetes mellitus of which 90% have type 2 diabetes. The numbers for osteoporosis are no less staggering: 1 in 3 women has a fracture after menopause, and the same is true for 1 in 5 men after the age of 50 years. Aging is associated with several physiological changes that cause insulin resistance and impaired insulin secretion, which in turn lead to hyperglycemia. The negative balance between bone resorption and formation is a natural process that appears after the fourth decade of life and lasts for the following decades, eroding the bone structure and increasing the risk of fractures. Not incidentally, it has been acknowledged that diabetes mellitus, regardless of whether type 1 or 2, is associated with an increased risk of fracture. The nuances that differentiate bone damage in the two main forms of diabetes are part of the intrinsic heterogeneity of diabetes, which is enhanced when associated with a condition as complex as osteoporosis. This narrative review addresses the main parameters related to the increased risk of fractures in individuals with diabetes, and the mutual factors affecting the treatment of diabetes mellitus and osteoporosis.

Definition and management of very high fracture risk in women with postmenopausal osteoporosis: a position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Association of Bone Assessment and Metabolism (ABRASSO)

Several drugs are available for the treatment of osteoporosis in postmenopausal women. Over the last decades, most patients requiring pharmacological intervention were offered antiresorptive drugs as first-line therapy, while anabolic agents were considered a last resource for those with therapeutic failure. However, recent randomized trials in patients with severe osteoporosis have shown that anabolic agents reduce fractures to a greater extent than antiresorptive medications. Additionally, evidence indicates that increases in bone mineral density (BMD) are maximized when patients are treated with anabolic agents first, followed by antiresorptive therapy. This evidence is key, considering that greater increases in BMD during osteoporosis treatment are associated with a more pronounced reduction in fracture risk. Thus, international guidelines have recently proposed an individualized approach to osteoporosis treatment based on fracture risk stratification, in which the stratification risk has been refined to include a category of patients at very high risk of fracture who should be managed with anabolic agents as first-line therapy. In this document, the Brazilian Society of Endocrinology and Metabolism and the Brazilian Association of Bone Assessment and Metabolism propose the definition of very high risk of osteoporotic fracture in postmenopausal women, for whom anabolic agents should be considered as first-line therapy. This document also reviews the factors associated with increased fracture risk, trials comparing anabolic versus antiresorptive agents, efficacy of anabolic agents in patients who are treatment naïve versus those previously treated with antiresorptive agents, and safety of anabolic agents.

Bone, fat, and muscle interactions in health and disease

Energy metabolism is a point of integration among the various organs and tissues of the human body, not only in terms of consumption of energy substrates but also because it concentrates a wide interconnected network controlled by endocrine factors. Thus, not only do tissues consume substrates, but they also participate in modulating energy metabolism. Soft mesenchymal tissues, in particular, play a key role in this process. The recognition that high energy consumption is involved in bone remodeling has been accompanied by evidence showing that osteoblasts and osteocytes produce factors that influence, for example, insulin sensitivity and appetite. Additionally, there are significant interactions between muscle, adipose, and bone tissues to control mutual tissue trophism. Not by chance, trophic and functional changes in these tissues go hand in hand from the beginning of an individual's development until aging. Likewise, metabolic and nutritional diseases deeply affect the musculoskeletal system and adipose tissue. The present narrative review highlights the importance of the interaction of the mesenchymal tissues for bone development and maintenance and the impact on bone from diseases marked by functional and trophic disorders of adipose and muscle tissues.

Official position of the Brazilian Association of Bone Assessment and Metabolism (ABRASSO) on the evaluation of body composition by densitometry: part I (technical aspects)—general concepts, indications, acquisition, and analysis

Objective

To review the technical aspects of body composition assessment by dual-energy X-ray absorptiometry (DXA) and other methods based on the most recent scientific evidence.

Materials and methods

This Official Position is a result of efforts by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism (Associação Brasileira de Avaliação Óssea e Osteometabolismo, ABRASSO) and health care professionals with expertise in body composition assessment who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications. In this first part of the Official Position, the authors discuss the different methods and parameters used for body composition assessment, general principles of DXA, and aspects of the acquisition and analysis of DXA scans.

Conclusion

Considering aspects of accuracy, precision, cost, duration, and ability to evaluate all three compartments, DXA is considered the gold-standard method for body composition assessment, particularly for the evaluation of fat mass. In order to ensure reliable, adequate, and reproducible DXA reports, great attention is required regarding quality control procedures, preparation, removal of external artifacts, imaging acquisition, and data analysis and interpretation.

Repetitive stress fracture: a warning sign of genetic susceptibility to fracture? A case report of a heterozygous variant in SERPINF1

The occurrence of fractures in young individuals is frequently overlooked by physicians, especially when associated with exercise or trauma. Nevertheless, multiple fractures should always be investigated since underlying conditions can predispose to such events. We describe here the case of a young, healthy woman who sustained multiple fractures in the lower limbs, which were initially considered to be "stress fractures". Further investigation, including a panel of genes associated with osteogenesis imperfecta, revealed that the patient is a heterozygous carrier of a SERPINF1 variant. According to criteria recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, this variant is classified as likely benign (PM2, PP3, PP4, BP1, and BP4). The patient's mother and brother were also asymptomatic carriers of the variant and had sustained previous minor fractures. The patient had normal biochemical profile and bone density. This condition has been rarely described and is not associated with low bone mineral density or altered bone turnover markers. This case highlights the importance of investigating multiple fractures in young patients who are otherwise healthy since these may be a warning sign of rare genetic conditions associated with fragility fractures.

Ex vivo vibro-acoustography characterization of osteoporosis in an experimental mice model

Background

Osteoporosis is a highly prevalent multifactorial osteometabolic disease, classically diagnosed, in vivo, by dual energy X-ray absorptiometry (DXA). This study evaluated osteoporosis, ex vivo, using vibro-acoustography (VA), an elastographic technique based on ultrasound radiation force.

Methods

Three groups of mice femurs were used: (I) control group (CG), (II) osteoporosis group (OG) and (III) treated osteoporosis group (TOG), in which the animals received pamidronate, an antiresorptive drug. Evaluation was performed in an acoustic tank, using two high frequency focused beams produced by a confocal ultrasonic transducer. A hydrophone registered the low frequency acoustic response (AR) of bone samples. We used micro-computed tomography (microCT) as the reference standard and evaluated the correlation between VA and microCT parameters.

Results

The spectral analyses of the ARs with estimated area under the curve (AUC) values (mean; st. dev.) were, respectively, 1.29e^-07 and 9.32e^-08 for the CG, 3.25e^-08 and 2.16e^-08 for the OG, and 1.50e^-07 and 8.37e^-08 for the TOG. VA differentiated the experimental groups (P<0.01) and the results were reproducible [interclass correlation coefficient (ICC): 0.43 (95% CI: 0.15-0.71)]. There was also a statistically significant association between VA and microCT connectivity (Conn.) (r=0.80; P<0.01) and connectivity density (Conn. D) (r=0.76; P<0.01).

Conclusions

These results encourage further studies aimed at evaluating the potential use of VA for the diagnosis of osteoporosis as a relatively low-cost and radiation-free alternative to DXA.

Population pharmacokinetics of gabapentin in patients with neuropathic pain: Lack of effect of diabetes or glycaemic control

AIMS

Gabapentin (GBP) is widely used to treat neuropathic pain, including diabetic neuropathic pain. Our objective was to evaluate the role of diabetes and glycaemic control on GBP population pharmacokinetics.

METHODS

A clinical trial was conducted in patients with neuropathic pain (n = 29) due to type 2 diabetes (n = 19) or lumbar/cervical disc herniation (n = 10). All participants were treated with a single oral dose GBP. Blood was sampled up to 24 hours after GBP administration. Data were analysed with a population approach using the stochastic approximation expectation maximization algorithm. Weight, body mass index, sex, biomarkers of renal function and diabetes, and genotypes for the main genetic polymorphisms of SLC22A2 (rs316019) and SLC22A4 (rs1050152), the genes encoding the transporters for organic cations OCT2 and OCTN1, were tested as potential covariates.

RESULTS

GBP drug disposition was described by a 1-compartment model with lag-time, first-order absorption and linear elimination. The total clearance was dependent on estimated glomerular filtration rate. Population estimates (between-subject variability in percentage) for lag time, first-order absorption rate, apparent volume of distribution and total clearance were 0.316 h (10.6%), 1.12 h^-1 (10.7%), 140 L (7.7%) and 14.7 L/h (6.97%), respectively. No significant association was observed with hyperglycaemia, glycated haemoglobin, diabetes diagnosis, age, sex, weight, body mass index, SLC22A2 or SLC22A4 genotypes.

CONCLUSION

This population pharmacokinetics model accurately estimated GBP concentrations in patients with neuropathic pain, using estimated glomerular filtrationrate as a covariate for total clearance. The distribution and excretion processes of GBP were not affected by hyperglycaemia or diabetes.

Osteoporosis and Hepatic Steatosis: 2 Closely Related Complications in Short-Bowel Syndrome

BACKGROUND

Osteoporosis has scarcely been prospectively investigated in short-bowel syndrome (SBS). This prospective study was designed to evaluate incretins, adipokines, bone mass, and lipid deposits from marrow adipose tissue (MAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and liver (IHLs).

METHODS

The study comprised 2 groups matched by gender, height, and age: the control group (CG) (9 males, 9 females) and the SBS group (SBSG) (6 males, 5 females). The SBSG was evaluated twice in an interval of 1 year (SBSG₀ and SBSG₁ ). The biochemical evaluation included incretins, leptin, and adiponectin. Dual-energy x-ray absorptiometry and magnetic resonance were, respectively, used to measure BMD and lipid deposits.

RESULTS

Bone mineral density (BMD) was lower in the SBSG than in the CG, but there was no difference between SBSG₀ and SBSG₁ . There was no difference in MAT, SAT, and VAT, but IHL was lower in CG than in SBSG₀ and SBSG₁ . A negative correlation between MAT and third lumbar vertebrae BMD was found in the CG but not in SBSG₀ or SBSG₁ . There was a negative association between IHL and bone mass considering all participants (CG and SBSG₀ ) (R² = 0.38; P < .05).

CONCLUSION

Appropriate nutrition assistance recovers body composition, reverts the relationship of bone mass and MAT, and mitigates bone loss in SBS. In spite of this, osteoporosis seems to be an early and persistent complication in SBS. Curiously, SBS seems to be a highly vulnerable condition for the development of hepatic steatosis and shows an association between bone mass and IHL.

Association of bone mineral density with bone texture attributes extracted using routine magnetic resonance imaging

OBJECTIVE

Dual-energy X-ray absorptiometry (DXA)-derived bone mineral density (BMD) often fails to predict fragility fractures. Quantitative textural analysis using magnetic resonance imaging (MRI) may potentially yield useful radiomic features to predict fractures. We aimed to investigate the correlation between BMD and texture attributes (TAs) extracted from MRI scans and the interobserver reproducibility of the analysis.

METHODS

Forty-nine volunteers underwent lumbar spine 1.5-T MRI and DXA. Three-dimensional (3-D) gray-level co-occurrence matrices were measured from routine sagittal T2 fast spin-echo images using the IBEX software. Twenty-two TAs were extracted from 3-D segmented L3 vertebrae. The estimated concordance coefficient was calculated using linear regression analysis. A Pearson correlation coefficient analysis was performed to evaluate the correlation between BMD and the TAs. Interobserver reproducibility was assessed with the concordance coefficient described by Lin.

RESULTS

The results revealed a fair-to-moderate significant correlation between BMD and 13 TAs (r=-0.20 to 0.39; p<0.05). Eight TAs (autocorrelation, energy, homogeneity 1, homogeneity 1.1, maximum probability, sum average, sum variance, and inverse difference normalized) negatively correlated with BMD (r=-0.20 to -0.38; p<0.05), whereas five TAs (dissimilarity, difference entropy, entropy, sum entropy, and information measure corr 1) positively correlated with BMD (r=0.29-0.39; p<0.05). The interobserver agreement was almost perfect for all significant TAs (95% confidence interval, 0.92-1.00; p<0.05).

CONCLUSION

Specific TAs could be reliably extracted from routine MRI and correlated with BMD. Our results encourage future evaluation of the potential usefulness of quantitative texture measurements from MRI scans for predicting fragility fractures.

Male and female cats have different regional body compositions and energy requirements for weight loss and weight maintenance

Body composition and energy requirements are different between males and females in several species, and both interfere with weight loss. The aim of this study was to compare the total and regional body composition and energy requirements in obese male (n = 8) and female (n = 8) cats, during weight loss and weight maintenance over 17 subsequent weeks after regimen. The total and regional (thoracic and pelvic limbs, and trunk) body composition was assessed by dual-energy X-ray absorptiometry (DXA). Females exhibited a higher fat mass (FM) than males (p < 0.05), and the trunk was the site with greater fat accumulation regardless of gender. A 23.0 ± 2.8% reduction in body weight was followed by a 50.3 ± 9.4% and a 37.0 ± 8.9% reduction in fat in the trunk region in males and females respectively. Lean mass (LM) mobilization was also increased in the trunk (p < 0.05), and the loss of LM was associated with a reduction in bone mass. The energy intake to achieve the same rate of weight loss was 12.9 ± 3.4% higher in males (p < 0.05). The cats exhibited a gradual increase in energy requirements to maintain their body weight after weight loss (p < 0.05). It was concluded that obese cats mainly accumulate fat in the trunk. The reduction in lean mass after the regimen also occurred in the trunk, with no modifications in the skeletal muscle mass of the limbs. Neutered male cats have higher energy requirements than neutered females, and gender should be considered during obesity management in cats.

Body fat redistribution and changes in lipid and glucose metabolism in people living with HIV/AIDS

INTRODUCTION

The HIV lipodystrophy syndrome is characterized by changes in metabolism, and body composition that increase cardiovascular risk of people living with HIV/AIDS (PLWHA) using highly active antiretroviral therapy (HAART).

OBJECTIVE

To assess the prevalence of lipodystrophy and changes in lipid and glucose metabolism in PLWHA in use of HAART.

METHODS

For the anthropometric evaluation we measured weight, height and abdominal circumference (AC). For the lipodystrophy evaluation we conducted physical examination (subjective) and the (objective) examination of absorptiometry with X-ray dual energy (DEXA) by fat mass ratio (FMR). We also conducted lipid profile tests and fasting glucose and used the criteria suggested by The National Cholesterol Education Program III for metabolic disorders classification.

RESULTS

The final sample consisted of 262 patients with a mean age of 44.3 ± 10.2 years. Lipodystrophy, according to the physical examination, was present in 47.7% (95%CI 41.7 - 53.8) of patients, while the prevalence using FMR (DEXA) was 40.8% (95%CI 33.1 - 48.5). Most (53.0%; 95%CI 47.0 - 59.1) of the patients showed increased abdominal adiposity according to AC. The most prevalent metabolic alterations were reduced HDL (67.6%; 95%CI 61.9 - 73.2) and hypertriglyceridemia (55.7%; 95%CI 49.7 - 61.7).

CONCLUSION

The high prevalence of lipodystrophy and changes in lipid and glucose metabolism show the importance of early intervention in this group of patients to prevent cardiovascular complications.

Do all infants need vitamin D supplementation?

A high prevalence of vitamin D deficiency (VDD) in children has been observed worldwide, but there are few studies on the nutritional status of vitamin D (VD) in healthy infants. The main cause of deficiency in healthy children is breastfeeding without supplementation and lack or insufficiency of sun exposure. The aims of this study were to determine serum concentrations of 25(OH)D and verify its association with parathyroid hormone (PTH) concentrations and use of VD supplementation in healthy infants aged ≥ 6 to ≤ 24 months attended at two Primary Health Care Units in Ribeirão Preto city, São Paulo, Brazil. A cross-sectional, observational and analytical study was performed in which serum concentrations of 25(OH)D, PTH, alkaline phosphatase (AP), calcium (Ca), phosphorus (P) and albumin were determined in 155 healthy infants. Information on sun exposure, sociodemographic aspects of mothers and clinical and nutritional characteristics of infants were obtained through interviews with responsible infants’s legal representatives. Ten infants (6%) presented deficient 25(OH)D serum concentration (≤20ng/ml) and 46 (30%), insufficient (21 to 29ng/ml). No changes in serum P, Ca and albumin concentrations were detected. Only one infant had an increase in PTH serum concentrations. 35% (55/155) of infants had high AP e 40% (22/55) presented insufficient serum concentrations of 25(OH)D but none presented deficient ones. There was a weak association between serum concentrations of 25(OH)D and PTH and an association between serum concentrations of 25(OH)D and P when adjusted for sex, age and BMI. There were no associations between inadequate serum concentrations of 25(OH)D (deficient ou insufficient), sun exposure and VD supplementation. This study found a low prevalence of deficient 25(OH)D serum concentration and high prevalence of insufficient ones which was not associated with changes in serum PTH, AP, P, Ca and albumin concentrations, VD supplementation and the formula volume intake.

Diagnosis and treatment of hypoparathyroidism: a position statement from the Brazilian Society of Endocrinology and Metabolism

Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.

High fat diet attenuates hyperglycemia, body composition changes, and bone loss in male streptozotocin-induced type 1 diabetic mice

There is a growing and alarming prevalence of obesity and the metabolic syndrome in type I diabetic patients (T1DM), particularly in adolescence. In general, low bone mass, higher fracture risk, and increased marrow adipose tissue (MAT) are features of diabetic osteopathy in insulin-deficient subjects. On the other hand, type 2 diabetes (T2DM) is associated with normal or high bone mass, a greater risk of peripheral fractures, and no change in MAT. Therefore, we sought to determine the effect of weight gain on bone turnover in insulin-deficient mice. We evaluated the impact of a 6-week high-fat (HFD) rich in medium chain fatty acids or low-fat diet (LFD) on bone mass and MAT in a streptozotocin (STZ)-induced model using male C57BL/6J mice at 8 weeks of age. Dietary intervention was initiated after diabetes confirmation. At the endpoint, lower non-fasting glucose levels were observed in diabetic mice fed with high fat diet compared to diabetic mice fed the low fat diet (STZ-LFD). Compared to euglycemic controls, the STZ-LFD had marked polydipsia and polyphagia, as well as reduced lean mass, fat mass, and bone parameters. Interestingly, STZ-HFD mice had higher bone mass, namely less cortical bone loss and more trabecular bone than STZ-LFD. Thus, we found that a HFD, rich in medium chain fatty acids, protects against bone loss in a T1DM mouse model. Whether this may also translate to T1DM patients who are overweight or obese in respect to maintenance of bone mass remains to be determined through longitudinal studies.

Does the Access to Sun Exposure Ensure Adequate Levels of 25-Hydroxyvitamin D?

Objectives To assess the prevalence of hypovitaminosis D, altered arterial blood pressure, and serum levels of glucose and lipids in community-dwelling women in the city of Ribeirão Preto, in the southeast of Brazil. Methods This was a cross-sectional study of women aged 40-70 years old. Calcium intake and level of sun exposure were assessed by means of a questionnaire. A blood sample was used to determine glucose, lipid profile and 25-hydroxyvitamin D (25[OH]D) concentration. Results Ninety-one women were enrolled (age = 54.2 ± 7.1 years). The mean serum 25(OH)D concentration was 25.7 ± 8.9 ng/mL. A total of 24 (26.4%) women had 25(OH)D levels < 20 ng/mL. Seventy women (76.9%) had 25(OH)D levels < 30 ng/mL. Seventy-five women (90.4%) had inadequate calcium intake, and 61 women (67%) had appropriate sun exposure, 49 of whom (80.3%) had serum 25(OH)D levels < 30 ng/mL. Conclusion This study indicates that even in community-dwelling women, living in a city with high sun exposure, serum levels of 25(OH)D > 30 ng/ml are hardly reached. Thus, it is probable that other intrinsic factors besides sun exposure may regulate the levels of vitamin D.

Bone metabolism dysfunction mediated by the increase of proinflammatory cytokines in chronic HIV infection

Despite the efficacy of antiretroviral therapy (ART) on the control of viral replication, the current challenge is to decrease the chronic inflammatory status and toxicity of the antiretroviral drugs that contribute to increase the risk of metabolic complications. To verify the influence of proinflammatory cytokines on bone metabolism mediated by chronic HIV infection, a cross-sectional study was conducted with 50 HIV-infected adult men treated or not treated with ART. Dual energy X-ray absorptiometry (DXA) was performed to assess bone mineral density. Biochemical analysis were performed of IL-6, TNF-α, osteocalcin, PTH, 25-OH-D, total calcium, albumin, 24 h urinary calcium, and urinary deoxypyridinoline. The participants not treated with ART exhibited higher values of IL-6 and TNF-α than the participants treated with ART for more than 2 years. The TNF-α values were higher in the participants treated with ART for <2 years than in participants treated with ART for more than 2 years (p < 0.05). The increased values of urinary deoxypyridinoline indicated a high reabsorptive activity of bone tissue in all groups, with a significant difference between the participants not treated with ART and the participants treated with ART for <2 years. Through the DXA we found a bone mass reduction in all bone sites in each group. The increase in production of proinflammatory cytokines, most notably in the viremic group, demonstrated the ability to stimulate osteoclast activity and subsequently affect bone mass. The reduction of bone mineral density was observed in all bone sites, principally for the groups receiving antiretroviral treatment.

Relationship Between Adiposity Indices, Lipodystrophy, and Sarcopenia in HIV-Positive Individuals With and Without Lipodystrophy

Metabolism disorders, as well as body shape abnormalities, have been associated with the introduction of antiretroviral therapy. The objective of this study was to compare the diagnostic ability of adiposity indices and to discuss criteria for the classification of lipodystrophy and sarcopenia (SP) in HIV-positive individuals. Anthropometric measurements were determined in 268 individuals of both genders, also submitted to the dual-energy X-ray absorptiometry exam. The adiposity indices calculated were body mass index, body mass index adjusted for fat mass (BMIfat), body adiposity index, body adiposity Index for the Fels Longitudinal Study sample, and The Clínica Universidad de Navarra body adiposity estimator. The presence of lipodystrophy was evaluated using the fat mass ratio (FMR). SP was classified using the appendicular lean mass/height² ratio. The subjects were divided into 3 groups: HIV⁺LIPO⁺ (n = 41), HIV⁺LIPO^- (n = 65), and control (C, HIV-negative individuals; n = 162). Among the adiposity indices assessed, BMIfat showed the strongest correlation with total body fat (in percent) for men (r = 0.87, p < 0.001) and women (r = 0.92, p < 0.001). The frequency of SP was 44.8% and 41.7% in HIV⁺LIPO⁺, 27.8% and 20.7% in HIV⁺LIPO^- and 63.3% and 45.45% in C, for men and women, respectively. The cutoff point suggested for the diagnosis of lipodystrophy according to the FMR was 1.14. The adiposity indices, particularly the BMIfat, have strong correlation with body fat determined by dual-energy X-ray absorptiometry in HIV-positive patients. The implementation of FMR is recommended for more standardized estimates of the frequency of lipodystrophy.

Which equation should be used to measure energy expenditure in HIV-infected patients?

OBJECTIVE: In view of the practical need to use equations for the evaluation of energy expenditure in HIV-infected patients, the objective of the present study was to determine the concordance between the energy expenditure values obtained by indirect calorimetry as the gold standard and those obtained by predictive equations elaborated from data for the healthy population: Harris-Benedict, Schofield and Cunningham, and by equations elaborated from data for HIV-infected patients: Melchior (1991-1993). METHODS: The study was conducted at the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto on 32 HIV-infected men under treatment with highly active antiretroviral therapy. Resting energy expenditure was measured by indirect calorimetry and estimated on the basis of measurement of O2 consumption and CO2 production. RESULTS: Statistical analysis revealed weak concordance for the Harris-Benedict (0.38) and Cunningham (0.34) equations and satisfactory concordance for the Schofield equation (0.47). Only the two Melchior equations (1991 and 1993) showed strong concordance with the values obtained by indirect calorimetry (0.63 and 0.66, respectively) and could be used in practice. CONCLUSION: The best equations seem to be population-specific, such as the Melchior equations elaborated for HIV-infected patients.

Influência do macheamento do orifício piloto nos parafusos cervicais anteriores

OBJETIVO: Analisar experimentalmente a influência do macheamento do orifício piloto nas propriedades mecânicas e na interface osso-implante do parafuso cervical anterior. MÉTODOS: Oito carneiros da raça Santa Inês deslanados foram utilizados no estudo. Nos segmentos vertebrais cervicais de C2-C7 foram realizados orifícios piloto de 2,5mm, de ambos os lados da vértebra. No lado direto da vértebra foi realizado o macheamento previamente a inserção do parafuso cortical de 3,5mm, e no lado esquerdo o implante foi colocado sem o macheamento do orifício piloto. Foram realizados ensaios mecânicos para avaliar a força de arrancamento dos implantes e estudo histomorfométrico da interface osso-implante na fase aguda e oito semanas após a colocação dos implantes. O torque de inserção foi mensurado durante a colocação dos implantes. RESULTADOS: O torque de inserção e a resistência ao arrancamento dos implantes foram maiores nos implantes colocados sem o macheamento do orifício piloto. A interface osso-implante apresentou maior área de contato ósseo e maior área óssea no interior da rosca do implante nos parafusos implantados sem o macheamento prévio. Não foi observado diferença na área óssea fora do passo de rosca do implante. CONCLUSÕES: O macheamento do orifício piloto reduz o torque de inserção e a resistência ao arrancamento do implante na fase aguda e crônica, e reduz a área de contato osso-implante e área de osso no interior do passo de rosca.

Mechanical performance of cylindrical and dual-core pedicle screws after repeated insertion

STUDY DESIGN

Ex vivo study of the mechanical performance of cylindrical and dual-core pedicle screws after insertion, removal, and reinsertion in the same hole.

OBJECTIVE

To evaluate the effect of repeated use of same screw hole on the insertion torque and the retentive strength of the cylindrical and dual-core screws.

SUMMARY OF BACKGROUND DATA

Insertion and removal of pedicle screws is sometimes necessary during surgical procedure to assess the integrity of the pilot-hole wall. However, this maneuver may compromise the implant-holding capacity.

METHODS

Sixty thoracolombar vertebrae (T13–L5), harvested from 10 healthy calves, were used to insert 2 different designs of pedicle screws: cylindrical (5.0-mm outer diameter) and dual-core screws (5.2-mm outer diameter). Three experimental groups were created on the basis of the number of insertions of the screws and 2 subgroups were established according to the core pedicle screw design (dual-core and cylindrical). The insertion torque was measured during initial insertion, second insertion, and third insertion. Pullout screw tests were performed using a universal testing machine to evaluate the pullout strength after initial insertion, second insertion, and third insertion.

RESULTS

Significant reductions of 38% in mean insertion torque and 30% in mean pullout strength of dual-core screw were observed between the initial insertion and the third insertion. The cylindrical screw observed significant reductions of 52.5% in mean insertion torque and 42.3% in mean pullout strength between the initial insertion and the third insertion. A reduction of mean insertion torque and pullout strength between the first insertion and the second insertion but without significance was also observed for both types of screws.

CONCLUSION

Insertions and reinsertion of either cylindrical or dual-core pedicle screws have compromised insertion torque and pullout strength of the implants as measured by mechanical tests.

Hypermetabolism and altered substrate oxidation in HIV-infected patients with lipodystrophy

OBJECTIVE

Human immunodeficiency virus type 1 (HIV)-associated lipodystrophy syndrome compromises body composition and produces metabolic alterations, such as dyslipidemia and insulin resistance. This study aims to determine whether energy expenditure and substrate oxidation are altered due to human HIV-associated lipodystrophy syndrome.

METHODS

We compared energy expenditure and substrate oxidation in 10 HIV-infected men with lipodystrophy syndrome (HIV+LIPO+), 22 HIV-infected men without lipodystrophy syndrome (HIV+LIPO-), and 12 healthy controls. Energy expenditure and substrate oxidation were assessed by indirect calorimetry, and body composition was assessed by dual-energy X-ray absorptiometry. The substrate oxidation assessments were performed during fasting and 30 min after eucaloric breakfast consumption (300 kcal).

RESULTS

The resting energy expenditure adjusted for lean body mass was significantly higher in the HIV+LIPO+ group than in the healthy controls (P = 0.02). HIV-infected patients had increased carbohydrate oxidation and lower lipid oxidation when compared to the control group (P < 0.05) during fasting conditions. After the consumption of a eucaloric breakfast, there was a significant increase in carbohydrate oxidation only in the HIV+LIPO- and control groups (P < 0.05), but there was no increase in the HIV+LIPO+ group.

CONCLUSION

Hypermetabolism and alteration in substrate oxidation were observed in the HIV+LIPO+ group.

Força muscular e densidade mineral óssea em idosos eutróficos e desnutridos

OBJETIVO: Este estudo teve como objetivo avaliar a associação do estado nutricional com a força muscular de preensão manual e a densidade mineral óssea em idosos do sexo masculino. MÉTODOS: Participaram do estudo 41 idosos do sexo masculino, sendo 20 eutróficos (peso: M=69,6, DP=8,4; índice de massa corporal: M=25,7, DP=2,2) e 21 desnutridos (peso: M=50,9, DP=6,1; índice de massa corporal: M=18,7, DP=1,8), classificados subjetivamente segundo a Mini Avaliação Nutricional. A avaliação antropométrica incluiu peso corporal, altura, circunferência do braço e da panturrilha. A composição corporal foi avaliada pelo método de absorciometria por dupla emissão de Raios X, e a ocorrência de osteoporose foi definida de acordo com os critérios estabelecidos pela Organização Mundial da Saúde. A força muscular foi avaliada pelo dinamômetro de mão. RESULTADOS: O grupo desnutrido apresentou valores expressivamente menores dos parâmetros antropométricos e de com-posição corporal em relação ao grupo eutrófico (p<0,005). Além disso, a ocorrência de osteoporose foi signifi-cativamente maior (p<0,01) no grupo desnutrido em todas as regiões estudadas: colo do fêmur, quadril total e coluna. A força muscular de preensão manual dos idosos desnutridos foi significativamente menor que a dos idosos eutróficos (M=23,1, DP=6,8 e M=30,3, DP=8,4, respectivamente; p<0,005). CONCLUSÃO: A desnutrição está associada à menor força muscular e à diminuição da densidade mineral óssea em idosos do sexo masculino.

Primary hyperparathyroidism as the first clinical manifestation of multiple endocrine neoplasia type 2A in a 5-year-old child

BACKGROUND

Primary hyperparathyroidism occurs in only 10%-30% of patients with multiple endocrine neoplasia type 2A (MEN2A), rarely as the sole clinical manifestation, and is usually diagnosed after the third decade of life.

SUMMARY

A 5-year-old girl was referred for prophylactic thyroidectomy as she carried the p.C634R RET mutation. She was clinically asymptomatic, with a normally palpable thyroid and with the cervical region free of lymphadenopathy or other nodules. Preoperative tests revealed hypercalcemia associated with elevation of parathyroid hormone (PTH) (calcium = 11.2 mg/dL, calcium ion = 1.48 mmol/L, phosphorus = 4.0 mg/dL, alkaline phosphatase = 625 U/L, parathyroid hormone (PTH) PTH = 998 pg/mL). A thyroid ultrasound was normal and parathyroid scintigraphy with (99m)Tc-Sestamibi revealed an area of radioconcentration in the upper half of the left thyroid lobe suggesting hyperfunctioning parathyroid tissue. She underwent total thyroidectomy and parathyroidectomy and developed hypocalcemia. The anatomopathological examination showed no histopathological changes in the thyroid tissue and an adenoma of the parathyroid gland, confirming the diagnosis of hyperparathyroidism.

CONCLUSIONS

Primary hyperparathyroidism can be a precocious manifestation of MEN2A. This case report highlights that asymptomatic hypercalcemia should be scrutinized in children related to patients with MEN2A who carry a mutation in the RET proto-oncogene, especially mutations in the codon 634, before the currently recommended age of 8 years.

TAPPING PILOT HOLE: MECHANICAL ANALYSIS OF SHEEP VERTEBRA AND THE ARTIFICIAL BONE MODEL

Objective: To determine the effect of pilot hole tapping, together with other variables such as pilot hole diameter, in relation to inner screw diameter and preparation method, on the insertion torque and pullout resistance of the screws used for anterior fixation of the cervical spine. Method: Twenty polyurethane test bodies and 30 thoracic vertebrae (T1-T5) were tested. Four holes were drilled into each test body: two of them with a diameter of 2.0 mm and two with a diameter of 2.5 mm. The holes were drilled using a bit or probe, according to the experimental group. Each experimental group was divided into two equal subgroups, with and without pilot hole tapping. In all, there were eight experimental groups: four using polyurethane specimens and four using sheep vertebrae. Cortical screws of 3.5 mm in outer diameter and 14 mm in length were inserted into the pilot holes. The insertion torque was measured during screw implantation and mechanical pullout tests were then performed using an Emic^® universal testing machine, with the Tesc 3.13 software, load cells of 1000 N, force application rate of 0.2 mm/min, preloading of 5 N and accommodation time of 10 seconds. The property evaluated in the mechanical tests was the maximum pullout force. Results and Conclusion: Pilot hole tapping significantly decreased the insertion torque and pullout force of the screws in all the experimental groups.

Parafusos automacheantes: comparação mecânica no modelo artificial de osso e na vértebra cervical de carneiro

OBJETIVO: comparar o novo parafuso travado na placa cervical (CSLP) automacheante com o parafuso convencional cortical automacheante utilizado na fixação da placa cervical anterior, por meio da análise do torque de inserção e da resistência ao arrancamento dos implantes. MÉTODOS: 15 parafusos corticais automacheantes e 15 parafusos CSLP automacheantes foram inseridos em 15 modelos artificiais de osso (poliuretana) e 15 vértebras cervicais de carneiro. Os parâmetros estudados foram o torque de inserção e a força de arrancamento. Foram formados dois grupos experimentais, de acordo com o tipo de parafuso utilizado: Grupo I, com parafuso cortical automacheante; Grupo II, com parafuso CSLP automacheante. O orifício-piloto foi perfurado com 10,0 mm de profundidade, por meio de broca com diâmetro de 2,5 mm (Grupo I) e 3,0 mm (Grupo II). O torque de inserção foi mensurado durante a implantação dos parafusos e, em seguida, foram realizados ensaios mecânicos em máquina universal de testes, para avaliar a força de arrancamento dos implantes. RESULTADOS: os parafusos automacheantes CSLP apresentaram valores do torque de inserção e resistência ao arrancamento maiores que os parafusos corticais automacheantes. CONCLUSÃO: o desenho do parafuso CSLP influencia o seu torque de inserção e resistência ao arrancamento, sendo a avaliação desses parâmetros superiores aos parafusos corticais automacheantes.

The effect of repetitive pilot-hole use on the insertion torque and pullout strength of vertebral system screws

STUDY DESIGN

In vitro biomechanical investigation of the screw-holding capacity.

OBJECTIVE

To evaluate the effect of repetitive screw-hole use on the insertional torque and retentive strength of vertebral system screws.

SUMMARY AND BACKGROUND DATA

Placement and removal of vertebral system screws is sometimes necessary during the surgical procedures in order to assess the walls of the pilot hole. This procedure may compromise the holding capacity of the implant.

METHODS

Screws with outer diameter measuring 5, 6, and 7 mm were inserted into wood, polyurethane, polyethylene, and cancellous bone cylindrical blocks. The pilot holes were made with drills of a smaller, equal, or wider diameter than the inner screw diameter. Three experimental groups were established based on the number of insertions and reinsertions of the screws and subgroups were created according to the outer diameter of the screw and the diameter of the pilot hole used.

RESULTS

A reduction of screw-holding capacity was observed between the first and the following insertions regardless the anchorage material. The pattern of reduction of retentive strength was not similar to the pattern of torque reduction. The pullout strength was more pronounced between the first and the last insertions, while the torque decreased more proportionally from the first to the last insertions.

CONCLUSION

Insertion and reinsertion of the screws of the vertebral fixation system used in the present study reduced the insertion torque and screw purchase.

Impairment of bone mass development in children with chronic cholestatic liver disease

OBJECTIVE

To analyse aspects of mineral metabolism, bone mineral density (BMD), bone remodelling activity and serum IGF-1 levels in children with chronic cholestatic disease (CCLD).

PATIENTS AND MEASUREMENTS

A total of 13 children with chronic cholestatic liver disease (CCLD; mean age 7.2 +/- 4.8 years) and 22 control subjects (mean age 7.6 +/- 4.5 years) were studied. Serum osteocalcin, bone alkaline phosphatase (BAP), 25-hydroxyvitamin D, PTH and IGF-1 levels and urinary deoxypyridinoline were determined. BMD was measured by dual-energy X-ray absorptiometry in the lumbar spine, total hip and whole body. Lumbar spine areal BMD was converted mathematically to apparent volumetric BMD (aBMD) and corrected for the bone age of the patient.

RESULTS

Z-score of lumbar spine BMD was lower in CCLD patients than in controls and the difference was maintained when BMD was expressed as aBMD (control = 0.107 +/- 0.02 vs. CCLD = 0.092 +/- 0.02 g/cm(3), P < 0.05) and after conversion for bone age. All participants showed normal 25-hydroxyvitamin D levels, with no significant differences in serum levels of 25-hydroxyvitamin D and PTH between groups. IGF-1 levels were significantly lower in the CCLD group (control = 19.6 +/- 16.8 vs. CCLD = 6.4 +/- 7.6 nmol/l, P < 0.05) and a positive correlation was observed between whole body BMD and IGF-1 in this group.

CONCLUSIONS

These results indicate that CCLD limits bone mass gain in children. A reduction in hepatic IGF-1 production might be responsible, at least in part, for the low bone mass of these patients.

Mönckeberg's sclerosis - is the artery the only target of calcification?

BACKGROUND

Since its first description, Mönckeberg's sclerosis has only been related to arterial media calcification, being listed among the primary diseases of the vessels.

CASE PRESENTATION

We report here a clinically and histologically confirmed case of Mönckeberg's sclerosis in which the patient presented with massive areas of soft tissue calcifications in the pharynx and larynx. Polysomnographic parameters showed severe obstructive apnea refractory to nasal continuous positive airway pressure. Clinical and laboratory findings excluded concomitant endocrine or rheumatological diseases.

CONCLUSION

Our data provide a new insight about Mönckeberg's sclerosis, i.e., the fact that the etiopathogenic process involved in the phenomenon of calcification may not be restricted only to the arteries, but may occur in the entire organism. Further studies of the etiopathogenesis of this disease are needed.

Familial association of pseudohypoparathyroidism and psoriasis: case report

CONTEXT

The association between psoriasis and hypoparathyroidism has been reported by several authors, and it has been suggested that abnormalities in calcium homeostasis may be involved in the development or exacerbation of psoriasis. However, so far there have only been two reports of pseudohypoparathyroidism associated with psoriasis.

OBJECTIVE

To describe the familial occurrence of this association for the first time.

CASE REPORTS

Two siblings with psoriasis associated with pseudohypoparathyroidism were presented. The first patient was a 24-year-old white male with disseminated erythrodermic pustular psoriasis that began 2 months before admission. He had had a history of mental retardation, recurrent otitis, seizures and arthralgia from the age of 11 years onwards. He presented the characteristic phenotype of Albright osteodystrophy: short stature, obesity, round facies, broad forehead, short neck and brachydactylia. He adopted a position of flexed limbs and showed proximal muscle weakness and a positive Trousseau sign. He had clinical signs of hypocalcemia (0.69 mmol/l ionized calcium and 3.2 mg/dl total calcium), hyperphosphatemia (6.6 mg/dl), hypomagnesemia (1.0 mEq/l), hypoalbuminemia (3.1 g/dl), normal serum intact PTH levels (45.1 pg/ml), primary hypothyroidism (13.2 mU/ml TSH, and 4.7 mg/dl total T(4)), hypergonadotrophic hypogonadism (116.0 ng/ml LH, 13.2 mU/ml FSH and 325.0 ng/dl testosterone), osteoporosis, and diffuse calcifications in soft tissues and in the central nervous system. The second case was a 14-year-old white girl with a history of psoriasis vulgaris from the age of five years onwards, and antecedents of mental retardation. She presented signs of Albright osteodystrophy (short stature, round facies, obesity, short neck, brachydactylia), hypocalcemia (ionized calcium of 1.08 mmol/l and total calcium of 6.7 mg/dl) hyperphosphatemia (9.4 mg/dl), elevated serum PTH levels (223.0 pg/ml), osteoporosis, and hypergonadotrophic hypogonadism (7.0 mU/ml LH, 9.3 mU/ml FSH and undetectable estradiol levels).