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The predictors of interpregnancy change in body mass index
- Ciara Reynolds, Brendan Egan, Eimer O'Malley, Sharon Sheehan, Michael Turner
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- Journal:
- Proceedings of the Nutrition Society / Volume 79 / Issue OCE2 / 2020
- Published online by Cambridge University Press:
- 10 June 2020, E444
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Introduction
Pregnancy is a time when weight increases as part of a physiological process to aid fetal growth. However, when excess weight is gained during pregnancy, and retained thereafter, the risk of obesity in the future increases. Increasing BMI between pregnancies and maternal obesity are associated with several adverse pregnancy outcomes. Although the risks of increasing BMI on future pregnancies is well defined, the predictors of this weight gain are not. This study aimed to investigate the predictors of interpregnancy BMI change.
Materials and methodsThis study was conducted in one of Europe's largest maternity hospitals delivering approximately 8000 infants per annum. Women's sociodemographic and clinical data were self-reported at the first antenatal visit and computerised to an electronic recording system by trained midwives. Weight and height were measured at the first antenatal visits of both pregnancies, and body mass index was calculated. Data was extracted and analysed for women who delivered their first and second singleton infants between 2009–2018.
ResultsA total of 12,056 women delivered their first and second baby over the 10-year period. The mean interval between pregnancies was 32.3months (SD15.9) and the median BMI change was 0.6units (IQR1.3). From the first to the second pregnancy the rate of obesity increased from 11.6% to 16.0%. Between pregnancies 46.1% of women maintained their BMI (-1 to + 1units), 13.3% lost > 1 BMI unit(s), whereas 15.5% gained 1–2unit(s), 9.9% gained 2–3units and 12.0% gained > 3units. Overall, 5.8% became obese by the second pregnancy. On multinomial regression analysis, having a pregnancy interval of > 3years (aOR2.1, 95%CI 1.9–2.5, p < 0.001), artificial feeding after the first pregnancy (aOR1.8, 1.5–2.0, p < 0.001), postnatal depression after the first pregnancy (aOR1.6, 1.3–2.1, p < 0.001) and taking prescribed anxiolytics or antidepressants (aOR1.6, 1.1–2.5, p = 0.013) were predictors of gaining > 3 BMI units between pregnancies after adjusting for maternal occupation and age. The predictors of becoming obese in the second pregnancy also included a pregnancy interval of > 3years (aOR1.5, 1.2–1.8, p < 0.001), artificial feeding after the first pregnancy (aOR2.1, 1.8–2.6, p < 0.001), postnatal depression after the first pregnancy (aOR1.7, 1.2–2.3, p = 0.001) and taking prescribed anxiolytics or antidepressants (aOR1.8, 1.1–3.1, p = 0.016) following the same adjustments.
ConclusionLonger pregnancy interval, not breastfeeding and psychological health disorders are predictors of BMI increase between pregnancies and becoming obese in the second pregnancy. Interventions provided following women's first delivery should aim to promote breastfeeding, manage weight and improve mental health.
Towards a Mechanical Model of Skin: Insights into Stratum Corneum Mechanical Properties from Hierarchical Models of Lipid Organisation
- Brendan O'Malley, David J. Moore, Massimo Noro, Jamshed Anwar, Becky Notman, Reinhold Dauskhardt, Eilidh Bedford
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- Journal:
- MRS Online Proceedings Library Archive / Volume 844 / 2004
- Published online by Cambridge University Press:
- 01 February 2011, Y5.7
- Print publication:
- 2004
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The stratum corneum (SC), the outermost layer of the skin, provides the body with a physiologically essential barrier to unregulated water loss and the influx of exogenous substances. Furthermore, the 10–20 micron thick SC, composed of overlapping protein-rich corneocytes surrounded by a heterogeneous multilamellar lipid matrix, displays tremendous mechanical cohesion and thermal integrity. To understand the contribution of these components to SC mechanical properties requires building a complete mechanical model of the skin. In this study we focus on modelling the hierarchical microstructure of the lipid phase and its relation to mechanical properties using a combination of atomistic and mesoscale simulations. The modelling approaches are parameterised with experimental data from FT-IR spectroscopy, X-ray scattering and, in the case of the mesoscale simulations, with detailed density profiles derived from atomic models. The atomistic models are used to probe the role of specific lipid species in maintaining the thermal and structural stability of the SC extracellular lipid matrix and to investigate the role of hydrogen bonding networks in SC lipid cohesion. Mesoscale models are used to investigate domain formation and lipid bilayer organisation on length and time scales inaccessible with atomistic models. These coarse grained models display transitions between ordered hexagonal gel phases and fluid phases, reproducing the experimentally observed ordering of the hydrophilic and hydrophobic regions.