Background: Vitamin D insufficiency and higher testosterone are common in obese girls and may adversely affect glucose homeostasis and cardiovascular risk. Data are conflicting regarding the impact of parathyroid hormone (PTH) on these factors. Our objective was to determine associations of 25-hydroxyvitamin D (25-OHD), PTH, and testosterone with measures of glucose homeostasis and cardiovascular risk in adolescent girls after controlling for regional adiposity, with the hypothesis that lower 25-OHD, a higher PTH or PTH/25-OHD ratio, and higher testosterone would be associated with lower insulin sensitivity and greater cardiovascular risk.
View Article and Find Full Text PDFBackground: HIV lipodystrophy - characterized by peripheral lipoatrophy, with or without central fat accumulation - confers increased metabolic risk. However, the functional activity of HIV lipodystrophic tissue in relation to metabolic risk has yet to be fully explored in vivo through the use of non-invasive imaging techniques. This study assesses the relationship between FDG uptake in various fat depots and metabolic/immune parameters among subjects with HIV lipodystrophy.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
November 2012
Context: Recent studies have suggested that obesity in men is associated with increased fracture risk. Obesity in men is also associated with dysregulation of the GH/IGF-I and gonadal steroid axes, important regulators of bone homeostasis.
Objective: The aim of the study was to investigate body composition and endocrine determinants of bone microarchitecture and mechanical properties in obese men.
Objective: Hyperinsulinaemia is an important determinant of the polycystic ovarian syndrome (PCOS). In addition to lifestyle measures, therapeutic strategies include the use of oestrogen-progesterone combination pills (EP), and insulin sensitizers such as metformin, either alone or in combination. Data are limited regarding the impact of metformin alone vs metformin with EP on cardiometabolic risk in overweight adolescents with PCOS.
View Article and Find Full Text PDFPurpose: Patients with neurofibromatosis 1 (NF1), NF2, and schwannomatosis are at risk for multiple nerve sheath tumors and premature mortality. Traditional magnetic resonance imaging (MRI) has limited ability to assess disease burden accurately. The aim of this study was to establish an international cohort of patients with quantified whole-body internal tumor burden and to correlate tumor burden with clinical features of disease.
View Article and Find Full Text PDFWomen with anorexia nervosa (AN) have elevated marrow fat mass despite low visceral and subcutaneous fat depots, which is inversely associated with bone mineral density (BMD). Whether marrow fat mass remains persistently elevated or decreases with recovery from AN is currently unknown. In this study, we investigated changes in marrow fat in women who have recovered from AN (AN-R).
View Article and Find Full Text PDFIntroduction: The purpose of this study was to report the MRI findings that can be encountered in successfully treated bacterial septic arthritis.
Materials And Methods: The study included 12 patients (8 male and 4 female; mean age 38 years, range 9-85) with 13 proven cases of bacterial septic arthritis. The joints involved were hip (n = 3), knee (n = 3), shoulder (n = 2), sacroiliac (n = 2), ankle (n = 1), wrist (n = 1), and elbow (n = 1).
Objective: Enchondromas are benign lesions that may present with nonspecific features on imaging in children. Correlation of histology with imaging findings is often required to make the final diagnosis of a benign lesion. The aim of this study was to review imaging and pathological findings of enchondromas in children.
View Article and Find Full Text PDFObjective: Abdominal adiposity is associated with increased cardiovascular risk and decreased GH secretion. The objective of our study was to determine the effects of GH on body composition and cardiovascular risk markers in abdominally obese women.
Materials And Methods: In this randomized, double-blind, placebo-controlled study, 79 obese premenopausal women received GH vs placebo for 6 months.
Context: Anorexia nervosa (AN) is associated with depletion of body fat, loss of bone mineral density (BMD), and impaired thermogenesis. Brown adipose tissue (BAT) is lower in obese individuals and decreases during aging. Recent studies have suggested a link between BAT and bone metabolism.
View Article and Find Full Text PDFContext: The pathogenesis and function of dorsocervical sc adipose tissue (DSAT) accumulation in HIV-infected patients is not known. Previous investigations using either UCP-1 expression or positron emission tomography have been inconclusive as to whether this depot represents brown adipose tissue (BAT). We investigated DSAT gene expression, including DIO2, a deiodinase that contributes to increased thermogenesis in brown fat, and simultaneously determined [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake in lipodystrophic HIV and healthy control subjects.
View Article and Find Full Text PDFObjective: To demonstrate incidental findings and scoliosis on whole-body MRI (WBMRI) in patients with neurofibromatosis type 1 and 2 (NF1 & NF2, respectively), and schwannomatosis.
Materials And Methods: Institutional review board approval and written informed consent were obtained for this prospective HIPAA-compliant study. A total of 247 subjects (141 with NF1, 55 with NF2, 51 with schwannomatosis; 132 women (53.
Purpose: To develop a modular MR-compatible lower leg exercise device for muscle testing using a clinical 3 T MR scanner.
Materials And Methods: An exercise device to provide isotonic resistance to plantar- or dorsiflexion was constructed from nonferrous materials and designed for easy setup and use in a clinical environment. Validation tests were performed during dynamic MR acquisitions.
Despite being a risk factor for cardiovascular disease and diabetes mellitus, obesity has been thought to protect against osteoporosis. However, recent studies have demonstrated a differential impact of specific fat compartments on bone mineral density (BMD) with visceral adipose tissue (VAT) having potential detrimental effects on BMD. Visceral obesity is also associated with dysregulation of the GH/IGF-1 axis, an important regulator of bone homeostasis.
View Article and Find Full Text PDFAdiponectin, an adipokine secreted by adipocytes, exerts beneficial effects on glucose and lipid metabolism and has been found to improve insulin resistance by decreasing triglyceride content in muscle and liver in obese mice. Adiponectin is found in several isoforms and the high-molecular weight (HMW) form has been linked most strongly to the insulin-sensitizing effects. Fat content in skeletal muscle (intramyocellular lipids, IMCL) and liver (intrahepatic lipids, IHL) can be quantified noninvasively using proton magnetic resonance spectroscopy ((1)H-MRS).
View Article and Find Full Text PDFBiomechanics are central in understanding the pathophysiology and magnetic resonance (MR) imaging of overhead throwing athlete injuries. Repetitive excessive valgus forces at the elbow result in characteristic injuries due to medial joint distraction, lateral joint compression, and rotatory forces at the olecranon. MR imaging is useful for assessment of the throwing elbow in adults.
View Article and Find Full Text PDFPurpose: To use finite element modeling based on flat-panel volume computed tomography (CT) and bone mineral density (BMD) provided by dual-energy x-ray absorptiometry (DXA) to compare bone failure load, stiffness, and trabecular structure in women with anorexia nervosa (AN) and age-matched normal-weight control subjects.
Materials And Methods: The study was approved by the institutional review board and complied with HIPAA guidelines. Informed consent was obtained.
Purpose: This paper assesses interscan, interreader, and intrareader variability of C-arm CT and compares it to that of flat-panel volume-CT (fpVCT) and high-definition multi-detector-CT (HD-MDCT).
Methods: Five cadaver knee specimens were imaged using C-arm-CT, fpVCT, and HD-MDCT. Apparent (app.
Objective: To compare breath-hold 1H-magnetic resonance spectroscopy (1H-MRS) with respiratory-gated 1H-MRS and computed tomography (CT) for quantification of hepatic lipid content.
Methods: Twenty-three premenopausal women underwent breath-hold point-resolved single-voxel 1H-MRS of the liver followed by respiratory-gated 1H-MRS at 3 Tesla and CT slice through the liver. Interscan variability for 1H-MRS was assessed in 6 volunteers.
Recent studies have demonstrated an important physiologic link between bone and fat. Bone and fat cells arise from the same mesenchymal precursor cell within bone marrow, capable of differentiation into adipocytes or osteoblasts. Increased BMI appears to protect against osteoporosis.
View Article and Find Full Text PDFAccurate methods for assessing body composition in subjects with obesity and anorexia nervosa (AN) are important for determination of metabolic and cardiovascular risk factors and to monitor therapeutic interventions. The purpose of our study was to assess the accuracy of dual-energy X-ray absorptiometry (DXA) for measuring abdominal and thigh fat, and thigh muscle mass in premenopausal women with obesity, AN, and normal weight compared to computed tomography (CT). In addition, we wanted to assess the impact of hydration on DXA-derived measures of body composition by using bioelectrical impedance analysis (BIA).
View Article and Find Full Text PDFContext: Despite having low visceral and sc fat depots, women with anorexia nervosa (AN) have elevated marrow fat mass, which is inversely associated with bone mineral density (BMD). Adipocytes and osteoblasts differentiate from a common progenitor cell, the human mesenchymal stem cell. Therefore, understanding factors that regulate this differentiation process may provide insight into bone loss in AN.
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