Dietary intervention in gestational diabetes: a qualitative study of the acceptability and feasibility of a novel whole-diet intervention in healthcare professionals.

Gestational diabetes is treated with medical nutrition therapy, delivered by healthcare professionals; however, the optimal diet for affected women is unknown. Randomised controlled trials, such as the DiGest (Dietary Intervention in Gestational Diabetes) trial, will address this knowledge gap, but the acceptability of whole-diet interventions in pregnancy is unclear. Whole-diet approaches reduce bias but require high levels of participant commitment and long intervention periods to generate meaningful clinical outcomes. We aimed to assess healthcare professionals' views on the acceptability of the DiGest dietbox intervention for women with gestational diabetes and to identify any barriers to adherence which could be addressed to support good recruitment and retention to the DiGest trial. Female healthcare professionals (n 16) were randomly allocated to receive a DiGest dietbox containing 1200 or 2000 kcal/d including at least one weeks' food. A semi-structured interview was conducted to explore participants' experience of the intervention. Interviews were audio-recorded, transcribed verbatim and analysed thematically using NVivo software. Based on the findings of qualitative interviews, modifications were made to the dietboxes. Participants found the dietboxes convenient and enjoyed the variety and taste of the meals. Factors which facilitated adherence included participants having a good understanding of study aims and sufficient organisational skills to facilitate weekly meal planning in advance. Barriers to adherence included peer pressure during social occasions and feelings of deprivation or hunger (affecting both standard and reduced calorie groups). Healthcare professionals considered random allocation to a whole-diet replacement intervention to be acceptable and feasible in a clinical environment and offered benefits to participants including convenience.

Pregnancy glucagon-like peptide 1 predicts insulin but not glucose concentrations.

AIMS: Incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP) cause increased insulin secretion in non-pregnant adults, but their role in pregnancy, where there are additional metabolically-active hormones from the placenta, is less clear. The aim of the present study was to assess if fasting and post-load incretin concentrations were predictive of pregnancy insulin and glucose concentrations. METHODS: Pregnant women (n = 394) with one or more risk factors for gestational diabetes were recruited at 28 weeks for a 75 g oral glucose tolerance test (OGTT). Glucose, insulin, GLP-1 and GIP were measured in the fasting state and 120 min after glucose ingestion. RESULTS: Fasting plasma GLP-1 concentrations were associated with plasma insulin (standardised ß' 0.393 (0.289-0.498), p = 1.3 × 10-12; n = 306), but not with glucose concentrations (p = 0.3). The association with insulin was still evident when adjusting for BMI (ß' 0.271 (0.180-0.362), p = 1.1 × 10-8; n = 297). Likewise, at 120 min the OGTT GLP-1 concentrations were associated with plasma insulin concentrations (ß' 0.216 (0.100-0.331), p = 2.7 × 10-4; n = 306) even after adjusting for BMI (ß' 0.178 (0.061-0.294), p = 2.9 × 10-3; n = 296), but not with glucose (p = 0.9). GIP concentrations were not associated with insulin or glucose concentrations at either time point (all p > 0.2). In pregnancy plasma GLP-1, but not GIP, concentrations appear to be predictive of circulating insulin concentrations, independently of associations with BMIs. CONCLUSIONS: These results suggest that the relationship between insulin and incretins is preserved in pregnancy, but that other factors, such as placental hormones or counter-regulatory hormones, may be more important determinants of glycaemia and gestational diabetes aetiology.

Genetic mapping reveals Pou2af2/OCA-T1-dependent tuning of tuft cell differentiation and intestinal type 2 immunity.

Chemosensory epithelial tuft cells contribute to innate immunity at barrier surfaces, but their differentiation from epithelial progenitors is not well understood. Here, we exploited differences between inbred mouse strains to identify an epithelium-intrinsic mechanism that regulates tuft cell differentiation and tunes innate type 2 immunity in the small intestine. Balb/cJ (Balb) mice had fewer intestinal tuft cells than C57BL/6J (B6) mice and failed to respond to the tuft cell ligand succinate. Most of this differential succinate response was determined by the 50- to 67-Mb interval of chromosome 9 (Chr9), such that congenic Balb mice carrying the B6 Chr9 interval had elevated baseline numbers of tuft cells and responded to succinate. The Chr9 locus includes Pou2af2, which encodes the protein OCA-T1, a transcriptional cofactor essential for tuft cell development. Epithelial crypts expressed a previously unannotated short isoform of Pou2af2 predicted to use a distinct transcriptional start site and encode a nonfunctional protein. Low tuft cell numbers and the resulting lack of succinate response in Balb mice were explained by a preferential expression of the short isoform and could be rescued by expression of full-length Pou2af2. Physiologically, Pou2af2 isoform usage tuned innate type 2 immunity in the small intestine. Balb mice maintained responsiveness to helminth pathogens while ignoring commensal Tritrichomonas protists and reducing norovirus burdens.

Towards Novel Nutritional Strategies in Gestational Diabetes: Eating Behaviour and Obesity in Women with Gestational Diabetes Compared with Non-Pregnant Adults.

BACKGROUND: Gestational diabetes is associated with increased risk of obesity, type 2 diabetes and cardiovascular disease. Effective nutritional strategies are needed to reduce BMI and improve long-term maternal cardiometabolic health, but the relative contribution of maternal eating behaviour, a potential barrier to dietary change, has not been explored. We compared eating behaviour in women with gestational diabetes with that of men and non-pregnant women with comparable risk factors, and tested associations between eating behaviour traits and BMI in women with gestational diabetes. We hypothesized that eating behaviour would be unfavourable in gestational diabetes and would be associated with BMI. METHODS: Participants (n = 417) including 53 men, 164 non-pregnant women and 200 women with gestational diabetes (singleton pregnancy; 29 weeks' gestation) were recruited into three prospective studies assessing weight loss interventions, with similar entry criteria. The three-factor eating questionnaire (TFEQ-R18) assessed uncontrolled eating, emotional eating and cognitive restraint at study enrolment. Associations between BMI at study enrolment and TFEQ-R18 (% maximum score) were assessed using linear regression. RESULTS: Women with gestational diabetes had significantly lower uncontrolled eating scores vs. men (53% vs. 65%; p < 0.001) and non-pregnant women (53% vs. 66%; p < 0.001), lower emotional eating scores vs. non-pregnant women (60% vs. 71%; p < 0.001) and higher cognitive restraint (p < 0.001 vs. men and non-pregnant women). In women with gestational diabetes, emotional eating scores were positively associated with BMI at study enrolment (beta coefficient 7.8 (95% CI 3.9 to 11.7), p < 0.001). CONCLUSIONS: Women with gestational diabetes have favourable eating behaviour compared with other population groups. Because BMI at study enrolment was associated with emotional eating, nutritional strategies which reduce emotional eating may provide new opportunities to improve long-term maternal health after gestational diabetes.