3 results
Sex differences in association of protein intake with loss of appendicular lean mass in older adults
- Liset Elstgeest, Laura Schaap, Martijn Heymans, Linda Hengeveld, Denise Houston, Elke Naumann, Eleanor Simonsick, Marjolein Visser, Hanneke Wijnhoven
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- Journal:
- Proceedings of the Nutrition Society / Volume 79 / Issue OCE2 / 2020
- Published online by Cambridge University Press:
- 10 June 2020, E481
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A lower dietary protein intake has been associated with muscle mass loss, a decline in physical performance and more mobility limitations over time in old age. Current guidelines for protein intake advise ≥ 0.8 g/kg body weight (BW)/d, while experts propose a higher intake for older adults (1.0–1.2 g/kg BW/d), irrespective of sex. It is unknown whether the association between protein intake and loss of muscle mass is different for men and women, and whether there is an optimal protein intake to prevent this loss. Therefore, we investigated the shape of the association between protein intake and change in appendicular lean mass (aLM) over 3 years in community-dwelling older adults, separately for men and women. Data of men (n = 935) and women (n = 1061) aged 70–81 years and participating in the Health, Aging and Body Composition study were used. Dietary protein intake, measured in 1998/1999 using a food frequency questionnaire, was expressed in daily grams of protein per kg adjusted BW (g/kg aBW/d) by using healthy instead of actual BW. aLM was assessed by dual-energy X-ray absorptiometry at baseline and after 3 years. Restricted cubic spline functions with 3 knots in linear regression models were used as well as linear regression analyses. The fit of both models was compared using the likelihood ratio test. All analyses were stratified by sex and adjusted for demographics, lifestyle factors, chronic conditions, height and baseline aLM. Mean (SD) protein intake was 70.8 (26.2) g in men and 61.0 (22.5) g in women, or 0.93 (0.36) and 0.95 (0.36) g/kg aBW/d, respectively. Over 3 years, mean loss of aLM was 0.61 (1.16) kg in men and 0.35 (0.95) kg in women. In both men and women, the likelihood ratio was not significant (P = 0.57 and 0.67, respectively), indicating that the spline regression model did not fit the data better than the linear regression model. In men, the linear model showed no association between protein intake and change in aLM (adjusted B per 0.1 g/kg aBW/d = 18.1, P = 0.34). In women, a higher protein intake was associated with a smaller loss of aLM (adjusted B per 0.1 g/kg aBW/d = 34.5, P = 0.017). This study suggests a linear association between protein intake and 3-year loss of aLM in older women; however, no association was found in older men. Future studies into sex differences in associations with other physical outcomes are needed. For both sexes, an optimal protein intake could not be detected.
19 - Nitrogen as a threat to the European greenhouse balance
- from Part IV - Managing nitrogen in relation to key societal threats
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- By Klaus Butterbach-Bahl, Karlsruhe Institute of Technology, Eiko Nemitz, Centre for Ecology and Hydrology, Sönke Zaehle, Max Planck Institute for Biogeochemistry, Gilles Billen, University Pierre & Marie Curie, Pascal Boeckx, Ghent University, Jan Willem Erisman, Energy Research Centre of the Netherlands, Josette Garnier, UMR Sisyphe UPMC & CNRS, Rob Upstill-Goddard, UMR Sisyphe UPMC & CNRS, Michael Kreuzer, ETH Zurich Institute of Plant, Animal and Agroecosystem Science, Oene Oenema, Wageningen University and Research Centre, Stefan Reis, Centre for Ecology and Hydrology, Martijn Schaap, TNO Built Environment and Geosciences, David Simpson, Norwegian Meteorological Institute, Wim de Vries, Wageningen University and Research Centre, Wilfried Winiwarter, International Institute for Applied Systems Analysis, Mark A. Sutton, Centre for Ecology and Hydrology
- Edited by Mark A. Sutton, NERC Centre for Ecology and Hydrology, UK, Clare M. Howard, NERC Centre for Ecology and Hydrology, UK, Jan Willem Erisman, Gilles Billen, Albert Bleeker, Peringe Grennfelt, Hans van Grinsven, Bruna Grizzetti
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- Book:
- The European Nitrogen Assessment
- Published online:
- 16 May 2011
- Print publication:
- 14 April 2011, pp 434-462
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Summary
Executive summary
Nature of the problem
Reactive nitrogen (Nr) is of fundamental importance in biological and chemical processes in the atmosphere–biosphere system, altering the Earth's climate balance in many ways. These include the direct and indirect emissions of nitrous oxide (N2O), atmospheric Nr deposition and tropospheric ozone formation (O3), both of which alter the biospheric CO2 sink, Nr supply effects on CH4 emissions, and the formation of secondary atmospheric aerosols resulting from the emissions of nitrogen oxides (NOx) and ammonia (NH3).
Human production and release of Nr into the environment is thus expected to have been an important driver of European greenhouse balance. Until now, no assessment has been made of how much of an effect European Nr emissions are having on net warming or cooling.
Approaches
This chapter summarizes current knowledge of the role of Nr for global warming. Particular attention is given to the consequences of atmospheric Nr emissions. The chapter draws on inventory data and review of the literature to assess the contribution of anthropogenic atmospheric Nr emissons to the overall change in radiative forcing (between 1750 and 2005) that can be attributed to activities in Europe.
The use of Nr fertilizers has major additional effects on climate balance by allowing increased crop and feed production and larger populations of livestock and humans, but these indirect effects are not assessed here.
14 - Atmospheric transport and deposition of reactive nitrogen in Europe
- from Part III - Nitrogen flows and fate at multiple spatial scales
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- By David Simpson, Norwegian Meteorological Institute, Wenche Aas, NILU, Norwegian Institute for Air Research, Jerzy Bartnicki, Norwegian Meteorological Institute, Haldis Berge, Norwegian Meteorological Institute, Albert Bleeker, Energy Research Centre of the Netherlands, Kees Cuvelier, Frank Dentener, European Commission Joint Research Centre, Tony Dore, Centre for Ecology and Hydrology, Jan Willem Erisman, Energy Research Centre of the Netherlands, Hilde Fagerli, Norwegian Meteorological Institute, Chris Flechard, Soils, Agro-hydro systems and Spatialization, Ole Hertel, University of Aarhus, Hans van Jaarsveld, Netherlands Environmental Assessment Agency, Mike Jenkin, Atmospheric Chemistry Services, Martijn Schaap, TNO Built Environment and Geosciences, Valiyaveetil Shamsudheen Semeena, Norwegian Meteorological Institute, Philippe Thunis, European Commission Joint Research Centre, Robert Vautard, LSCE/IPSL laboratoire CEA/CNRS/VSQ, Massimo Vieno, University of Edinburgh
- Edited by Mark A. Sutton, NERC Centre for Ecology and Hydrology, UK, Clare M. Howard, NERC Centre for Ecology and Hydrology, UK, Jan Willem Erisman, Gilles Billen, Albert Bleeker, Peringe Grennfelt, Hans van Grinsven, Bruna Grizzetti
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- Book:
- The European Nitrogen Assessment
- Published online:
- 16 May 2011
- Print publication:
- 14 April 2011, pp 298-316
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Summary
Executive summary
Nature of the problem
Observations of atmospheric reactive nitrogen (Nr) deposition are severely restricted in spatial extent and type. The chain of processes leading to atmospheric deposition emissions, atmospheric dispersion, chemical transformation and eventual loss from the atmosphere is extremely complex and therefore currently, observations can only address part of this chain.
Approaches
Modelling provides a way of estimating atmospheric transport and deposition of Nr at the European scale. A description of the different model types is provided.
Current deposition estimates from models are compared with observations from European air chemistry monitoring networks.
The main focus of the chapter is at the European scale; however, both local variability and and intercontinental Nr transfers are also addressed.
Key findings/state of knowledge
Atmospheric deposition is a major input of Nr for European terrestrial and freshwater ecosystems as well as coastal sea areas.
Models are key tools to integrate our understanding of atmospheric chemistry and transport, and are essential for estimating the spatial distribution of deposition, and to support the formulation of air pollution control strategies.
Our knowledge of the reliability of models for deposition estimates is, however, limited, since we have so few observational constraints on many key parameters.
Total Nr deposition estimates cannot be directly assessed because of a lack of measurements, especially of the Nr dry deposition component. Differences among European regional models can be significant, however, e.g. 30% in some areas, and substantially more than this for specific locations.