Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: Comparison with dual-energy x-ray absorptiometry

© 2014 Wan et al.; licensee BioMed Central Ltd.Background: There is a need for a practical, inexpensive method to assess body composition in obese adolescents. This study aimed to 1) compare body composition parameters estimated by a stand-on, multi-frequency bioelectrical impendence (BIA) device, using a) the manufacturers' equations, and b) published and derived equations with body composition measured by dual-energy x-ray absorptiometry (DXA) and 2) assess percentage body fat (%BF) change after a weight loss intervention.Methods: Participants were 66 obese adolescents, mean age (SD) 12.9 (2.0) years. Body composition was measured by Tanita BIA MC-180MA (Tanita BIA8) and DXA (GE-Lunar Prodigy). BIA resistance and reactance data at frequencies of 5, 50, 250 and 500 kHz, were used in published equations, and to generate a new prediction equation for fat-free mass (FFM) using a split-sample method. Approximately half (n = 34) of the adolescents had their body composition measured by DXA and BIA on two occasions, three to nine months apart.Results: The correlations between FFM (kg), fat mass (kg) and %BF measured by BIA and DXA were 0.92, 0.93 and 0.78, respectively. The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA. The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM). After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement.Conclusion: The Tanita BIA8 could be a valuable clinical tool to measure body composition at the group level, but is inaccurate for the individual obese adolescent.Link_to_subscribed_fulltex

Solar cycle and seasonal behaviour of quasi two and rive day oscillations in the time variations of fOF2

Seasonal and solar cycle variations of the quasi-two- and five-day oscillation amplitudes off f0F2 are evaluated by moving periodogram analysis. The 23 year time series (1964-1986) of fOF2 hourly values of Kaliningrad (54.7°N, 20.62°E), covering the solar cycles 20 and 21, is used for the analysis. Long term variations of these amplitudes are modulated by the 11-year solar cycle and are simultaneously influenced by the geomagnetic activity. The annual variation of the quasi-two- and five-day oscillation amplitudes has very clear maxima near the equinoxes. The mechanism of the influence of the travelling planetary waves in the meteor wind region by vertical plasma drift to the F2-layer electron density maximum is discussed

The long-term effects of switching from active intravenous bisphosphonate treatment to low-dose maintenance therapy in children with osteogenesis imperfecta

Background/Aims: Intravenous bisphosphonate therapy is the first-line treatment in moderate-to-severe osteogenesis imperfecta (OI), but there are varied treatment protocols with little data on long-term efficacy. This study evaluates the clinical outcomes when transitioning from active bisphosphonate treatment to maintenance therapy. Methods: A retrospective review was conducted on 17 patients before treatment, following active treatment (zoledronate 0.05 mg/kg 6-monthly or pamidronate 6-9 mg/kg/year) and after establishment on maintenance treatment for more than 2 years (zoledronate 0.025 mg/kg 6-monthly or pamidronate <4 mg/kg/year). Results: There was a significant reduction in mean fracture rate from 1.5 +/- 1.1 fractures/year at baseline to 0.7 +/- 0.7 fractures/year on active treatment. Z-scores for lumbar spine bone mineral density, bone mineral content, volumetric bone mineral density and bone mineral content for lean tissue mass increased during active treatment. These improvements were maintained during the period of maintenance treatment. Vertebral height improved in fractured thoracic vertebrae from pre-treatment to active therapy and improved further during maintenance treatment. Metacarpal cortical thickness and relative cortical area also increased over the treatment periods. Conclusion: Maintenance intravenous bisphosphonate therapy preserved the beneficial effects of active treatment at the doses stated above. Further studies are required to determine the optimal bisphosphonate treatment regimen in the management of children with OI

British waterborne domestic freight (BWDF) : the waterborne freight alternative to road transport in the UK, and its role in sustainable mobility

Increasingly it has been recognised that there are many problems associated with the over-dependence on road haulage, and that along with the reality of congestion and gridlock on the EU road network, the external costs of road haulage in terms of the pollution roads inflict on society is now considered unsustainable in the long term. In response to this reality, both the EU and UK governments have developed policy advocating a transfer of freight from roads to the more environmentally friendly transport modes of water and rail. In essence this is an investigation and analysis of the economic, environmental and political issues which affect the diversion of freight from roads to water in the 21st century. Packer's 1994 "Roads to water" study examined the prospect of the viability of a significant modal switch from roads to water and highlighted a numbe of issues which he felt would adversley affect modal transfer. This thesis tests a number of these conclusions to see if they are still a barrier to conversion in 2004 as Packer suggested they were ten years earlier. This is achieved by the analysis of six different case studies, where it is felt that the traditional road haulage element could be transferred to water transport. An analysis of the pollution and external costs imposed on society by the road halulage element within these studies has been compared to an alternative BWDF option, and the results clearly show that water, in every case is considerably more environmentally friendly than road. In addition to this, the research has established a number of other results pertaining to these studies. These include the compariosn of the operation costs of both modes, the number of LGV kilometres eradicated by the modal transfer and the reduction of fuel used. The conclusion of this analysis is that, in one year, 33,594 long distance road haulage journeys could be eradicated from UK roads. It also concluded that the distance generated by long distance road haulage would reduce from 6,084,091 kms to 422,837 kms local (short distance) haulage, a reduction of 5,661,254 kms. In addition, 2,055 tonnes of fuel would be reduced to 139 tonnes saving 1,916 tonnes per annum, and road halulage pollution would fall from 9,051 tonnes per annum to 630 tonnes eradicating 8,421 tonnes of land based pollution. In terms of external costs it also concluded that the external costs imposed on society would reduce by £751,520 per annum.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

La virtù segreta. La presidenza di Bartolomeo Bressan al Liceo "A. Pigafetta (1866-1877)"

AbstractBackgroundA suboptimal bone accrual in young individuals with cystic fibrosis (CF) may be related to the development of a premature CF-related bone disease. Dual energy X-ray absorptiometry (DXA) is the mainstream measure of bone health; however, the influence of body size and lean tissue mass (LTM) on bone data is poorly interpreted.MethodsTotal body dual-energy X-ray absorptiometry (DXA) measurements of bone mineral content (BMC) and LTM in 53 individuals with CF (7.00–17.99years) were compared to 53 sex-matched controls. BMC, height, and LTM in relation to height and BMC Z-scores were calculated and used in a 4-step algorithm.ResultsPubertal females with CF had less total body BMC for age (p=0.02); pre-pubertal males (p=0.05) and pubertal females with CF (p=0.03) were shorter; and pubertal females with CF showed less total body BMC for LTM (p=0.01).ConclusionsThe algorithm showed the following: (1) prior to puberty lowered total body BMC was primarily due to short stature, (2) LTM was appropriate for body size, and (3) pubertal females with CF had significantly less total body BMC for their LTM. Longer controlled trials are needed to clinically interpret CF-related bone disease using DXA derived data that considers patient size and body composition

Cystic fibrosis-related bone disease in children: Examination of peripheral quantitative computed tomography (pQCT) data

Background: The investigation of skeletal health data beyond dual X-ray absorptiometry (DXA) is limited in young individuals with CF. We assessed volumetric bone mineral densities (BMD), and bone and muscle parameters using peripheral quantitative computed tomography (pQCT) in individuals with CF and controls, 7.00-17.99 years