Healthy eating and lifestyle in pregnancy (HELP): a protocol for a cluster randomised trial to evaluate the effectiveness of a weight management intervention in pregnancy.

BACKGROUND: Approximately 1 in 5 pregnant women in the United Kingdom are obese. In addition to being associated generally with poor health, obesity is known to be a contributing factor to pregnancy and birth complications and the retention of gestational weight can lead to long term obesity.This paper describes the protocol for a cluster randomised trial to evaluate whether a weight management intervention for obese pregnant women is effective in reducing women's Body Mass Index at 12 months following birth. METHODS/DESIGN: The study is a cluster randomised controlled trial involving 20 maternity units across England and Wales. The units will be randomised, 10 to the intervention group and 10 to the control group. 570 pregnant women aged 18 years or over, with a Body Mass Index of +/=30 (kg/m2) and between 12 and 20 weeks gestation will be recruited. Women allocated to the control group will receive usual care and two leaflets giving advice on diet and physical activity. In addition to their usual care and the leaflets, women allocated to the intervention group will be offered to attend a weekly 1.5 hour weight management group, which combines expertise from Slimming World with clinical advice and supervision from National Health Service midwives, until 6 weeks postpartum.Participants will be followed up at 36 weeks gestation and at 6 weeks, 6 months and 12 months postpartum. Body Mass Index at 12 months postpartum is the primary outcome. Secondary outcomes include pregnancy weight gain, quality of life, mental health, waist-hip ratio, child weight centile, admission to neonatal unit, diet, physical activity levels, pregnancy and birth complications, social support, self-regulation and self-efficacy. A cost effectiveness analysis and process evaluation will also be conducted. DISCUSSION: This study will evaluate the effectiveness of a theory-based intervention developed for obese pregnant women. If successful the intervention will equip women with the necessary knowledge and skills to enable them to make healthier choices for themselves and their unborn child. TRIAL REGISTRATION: Current Controlled Trials: ISRCTN25260464 Date of registration: 16th April 2010.

'Healthy Eating and Lifestyle in Pregnancy (HELP)' trial: Process evaluation framework.

INTRODUCTION: We developed and tested in a cluster RCT a theory-driven group-based intervention for obese pregnant women. It was designed to support women to moderate weight gain during pregnancy and reduce BMI one year after birth, in addition to targeting secondary health and wellbeing outcomes. In line with MRC guidance on developing and evaluating complex interventions in health, we conducted a process evaluation alongside the trial. This paper describes the development of the process evaluation framework. METHOD: This cluster RCT recruited 598 pregnant women. Women in the intervention group were invited to attend a weekly weight-management group. Following a review of relevant literature, we developed a process evaluation framework which outlined key process indicators that we wanted to address and how we would measure these. Central to the process evaluation was to understand the mechanism of effect of the intervention. We utilised a logic-modelling approach to describe the intervention which helped us focus on what potential mediators of intervention effect to measure, and how. RESULTS: The resulting process evaluation framework was designed to address 9 core elements; context, reach, exposure, recruitment, fidelity, recruitment, retention, contamination and theory-testing. These were assessed using a variety of qualitative and quantitative approaches. The logic model explained the processes by which intervention components bring about change in target outcomes through various mediators and theoretical pathways including self-efficacy, social support, self-regulation and motivation. CONCLUSION: Process evaluation is a key element in assessing the effect of any RCT. We developed a process evaluation framework and logic model, and the results of analyses using these will offer insights into why the intervention is or is not effective.

Human parainfluenza type 3 virus impairs the efficacy of glucocorticoids to limit allergy-induced pulmonary inflammation in guinea-pigs.

Viral exacerbations of allergen-induced pulmonary inflammation in pre-clinical models reportedly reduce the efficacy of glucocorticoids to limit pulmonary inflammation and airways hyper-responsiveness to inhaled spasmogens. However, exacerbations of airway obstruction induced by allergen challenge have not yet been studied. hPIV-3 (human parainfluenza type 3 virus) inoculation of guinea-pigs increased inflammatory cell counts in BAL (bronchoalveolar lavage) fluid and caused hyper-responsiveness to inhaled histamine. Both responses were abolished by treatment with either dexamethasone (20 mg/kg of body weight, subcutaneous, once a day) or fluticasone propionate (a 0.5 mg/ml solution aerosolized and inhaled over 15 min, twice a day). In ovalbumin-sensitized guinea-pigs, allergen (ovalbumin) challenge caused two phases of airway obstruction [measured as changes in sGaw (specific airways conductance) using whole body plethysmography]: an immediate phase lasting between 4 and 6 h and a late phase at about 7 h. The late phase, airway hyper-responsiveness to histamine and inflammatory cell counts in BAL were all significantly reduced by either glucocorticoid. Inoculation of guinea-pigs sensitized to ovalbumin with hPIV-3 transformed the allergen-induced airway obstruction from two transient phases into a single sustained response lasting up to 12 h. This exacerbated airway obstruction and airway hyper-responsiveness to histamine were unaffected by treatment with either glucocorticoid whereas inflammatory cell counts in BAL were only partially inhibited. Virus- or allergen-induced pulmonary inflammation, individually, are glucocorticoid-sensitive, but in combination generate a phenotype where glucocorticoid efficacy is impaired. This suggests that during respiratory virus infection, glucocorticoids might be less effective in limiting pulmonary inflammation associated with asthma.

Inhaled extended-release microparticles of heparin elicit improved pulmonary pharmacodynamics against antigen-mediated airway hyper-reactivity and inflammation.

Inhaled heparin appears to provide benefit in the management of airway hyper-reactivity and inflammation. The pharmacodynamics of inhaled heparin are however transient. Providing sustained heparin concentrations in the respiratory tract should provide for an extended duration of action. We examined the in-vivo efficacy of a nebulised controlled-release microparticle formulation of heparin in modifying antigen-induced airway hyper-reactivity (AHR) and lung inflammation. Heparin-loaded biodegradable poly (D,L-lactide-co-glycolide) microparticles were prepared by spray-drying. Aerosol properties for both nebulised heparin solution and heparin microparticles displayed characteristics consistent with heparin delivery to the respiratory tract. In vitro release assays showed heparin to be released from the microparticles over 8-12 h and for the heparin to remain functional. Temporal pharmacodynamic responses were studied in an ovalbumin-sensitised in vivo model exhibiting AHR and airway inflammation. Despite a reduced total dose of heparin deposited in the airways following nebulisation with heparin microparticles, this treatment led to a more sustained inhibitory effect upon AHR and airway inflammation than equivalent doses of nebulised heparin solution. The work supports extended-release heparin as an inhalation dosing strategy in experimental therapeutic applications aimed at improving the pharmacodynamics of heparin in the treatment of AHR and lung inflammation.