Background: The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.
View Article and Find Full Text PDFBackground: The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age-sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development.
View Article and Find Full Text PDFLancet
September 2014
Background: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration.
Methods: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART).
Background: The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100,000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery.
Methods: We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013.
Background: Remarkable financial and political efforts have been focused on the reduction of child mortality during the past few decades. Timely measurements of levels and trends in under-5 mortality are important to assess progress towards the Millennium Development Goal 4 (MDG 4) target of reduction of child mortality by two thirds from 1990 to 2015, and to identify models of success.
Methods: We generated updated estimates of child mortality in early neonatal (age 0-6 days), late neonatal (7-28 days), postneonatal (29-364 days), childhood (1-4 years), and under-5 (0-4 years) age groups for 188 countries from 1970 to 2013, with more than 29,000 survey, census, vital registration, and sample registration datapoints.
Both bone mass by densitometry and speed of sound (SOS) from quantitative ultrasound of the bone (QUS) are directly related to bone strength. However, reports of lower bone mass but higher SOS in neonates with intrauterine growth deficit lead to apparent contradictory conclusions on bone strength. Three groups of infants were studied: small for gestation (SGA) with birth weights ≤10th percentile for gestation and 2 control groups with appropriate birth weights (11th to 90th percentile) for gestation (AGA): matched to SGA group for gestation and birth weight, respectively.
View Article and Find Full Text PDFBone quantitative ultrasound generated speed of sound (SOS) is a marker of bone strength. However, critical evaluation of its validity for use in small bones is extremely limited, and SOS data may not be consistent with data obtained from dual energy x ray absorptiometry, another marker of bone strength. We report the SOS values pre and postinjection of s.
View Article and Find Full Text PDFBackground: Factors that affect quantitative ultrasound (QUS) bone measurements have not been clearly defined for all clinical populations.
Objective: To determine some technical and clinical aspects that may affect QUS bone measurement in the neonate-maternal dyad.
Materials And Methods: Speed of sound (SOS) was measured at the radius and tibia using a commercial multisite axial transmission QUS instrument and three manufacturer-provided probes (CS, CR and CM).
Objective: To study the relationship between anthropometric measurements and living conditions in infants and children living in refugee camps.
Design: Cross-sectional study.
Setting: Four Palestinian refugee camps in Lebanon.
Background: Leptin and its soluble receptor (sOB-R) are important to regulation of body composition but there are no data on the developmental variations in these plasma variables and their relationship with body composition measurements,
Methods: Weight, length, and body composition (bone, fat and lean mass) by dual energy absorptiometry, and plasma variables were measured in healthy infants at 2, 4, 8 and 12 months.
Results: 15 whites and 29 African Americans (21 males and 23 females) with mean birth weight 3357 +/- 45 (SEM) g and gestation of 39.3 +/- 0.
Objectives: A piglet model was used to determine the variations in measurements from different software algorithms used in the same type of dual energy X ray absorptiometry (DXA) instruments from the same manufacturer.
Methods: Forty-one piglets (6190 +/- 5856g, mean +/- SD) were scanned in duplicate with a fan-beam densitometer (Hologic QDR4500A, Hologic Inc, Bedford, MA) in the infant whole body scan mode. The same scans were analyzed with two software versions: vKH6 (validated with carcass chemical measurement) and v11.
Background: A piglet model was used to determine the influence of frequently encountered situations in clinical studies of infants and young children on fan-beam dual-energy x-ray absorptiometry (DXA) measurements.
Methods: DXA scans of piglets (640 g to 21,100 g) were acquired in the infant and adult mode and were analyzed with 1 infant, 1 pediatric, and 3 versions of adult software.
Results: The effect of repositioning of the piglets from the center to the periphery of the scanning table on DXA measurements included an average difference of up to 0.
Objective: To document the clinical and experimental situations that may affect DXA measurements in small subjects.
Methods: 49 piglets (886g to 21100g) had measurements with either of two pencil beam densitometers (QDR 1000W and QDR 2000 Plus, Hologic Inc, Waltham, MA) using commercial infant (IWB) and adult whole body (AWB) software v5.71p and v5.
Objective: To validate the most widely reported dual energy X-ray absorptiometry (DXA) technique for the measurement of bone mass and body composition in human infants with a piglet model.
Methods: Duplicate scans were obtained in 13 piglets (1950g to 21100g) using a whole body densitometer (Hologic QDR 2000 plus, Hologic Inc., Waltham, MA) operated in the pencil-beam mode on a two platform (aluminum platform overlying a foam table pad) system.
JPEN J Parenter Enteral Nutr
April 2004
Background: Fan beam dual energy x-ray absorptiometry (FB DXA) has recently been validated for the measurement of body composition in small subjects. This study represents the first report of body composition (bone mineral content, fat mass, and lean mass) in human neonates measured by FB DXA.
Methods: FB DXA measurements were performed in 73 healthy singleton neonates with mean +/- SD birth weights 3354 +/- 316 g (range, 2720 to 3982 g) and gestational ages 39.
Objectives: A piglet model was used to validate and cross validate the fan-beam (FB) dual energy X-ray absorptiometry (DXA) software vKH6 and to determine the predictive values of physiologic parameters (weight, length, age and gender) on body composition.
Methods: Nineteen piglets (Group A: 600 to 21100 g) were used to validate the FB-DXA measurements of body composition based on chemical analysis of the carcass. An additional 22 piglets (Group B: 640 g to 17660 g) had FB-DXA measurements, and these values were compared to the predicted values generated from regression equations computed from group A piglets.
Background: Compared with the older pencil-beam (PB) dual-energy X-ray absorptiometry (DXA), the newer fan-beam (FB) DXA has the advantage of faster scan acquisition and greater accuracy of body-composition measurement in small subjects. However, no data exist on the relation between the measurements obtained with these techniques.
Objective: The objective of the study was to investigate whether PB and FB DXA measurements in small subjects are interchangeable.
Objective: Palm and palm olein (PO) oils are used in some infant formula fat blends to match the fatty acid profile of human milk, but their presence has been shown to lower calcium and fat absorption. We aimed to determine if the reported differences in calcium absorption could affect skeletal development by comparing bone mineral accretion in healthy term infants fed a milk-based formula with (PMF) or without PO.
Methods: Whole body bone mineralization was evaluated in healthy term infants fed 1 of 2 coded, commercially available, ready-to-feed infant formulas in a randomized, double-blind, parallel study.
Objective: To test the suitability of phantoms to cross-calibrate body composition measurements in small subjects among different dual energy X-ray absorptiometry (DXA) instruments.
Methods: A set of four phantoms with total weights 1520g, 3140g, 4650g and 7490g were made with low cost and easily available materials. Each phantom was made from assembling polyethylene bottles (100 to 1000 mL) filled with either pure olive oil or electrolyte solution in different combinations, and borosilicate tubes (3 and 5 mL) and flexible polypropylene tubing filled with calcium carbonate.
A piglet model was used to determine whether the fan beam dual energy X-ray absorptiometry technique (DXA) could be adapted for the measurement of body composition of small subjects. Commercial domestic swine piglets (n = 14) with weights between 1.95 and 21.
View Article and Find Full Text PDFAvailability of software delineation of the lumbar spine region from infant whole-body (IWB) dual energy X-ray absorptiometry scan offers an opportunity to gain additional information at the lumbar spine without a separate scan, although the validity of this technique has never been tested. Lumbar spine measurements derived from IWB scans using software-delineated first to fourth lumbar vertebrae, and from specific infant spine (IS) scans, were determined in 111 infants using two pencil-beam densitometers. Intraoperator repeatability determined by reanalysis of 10 pairs of IWB and IS scans from each densitometer.
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