Diabetes disrupts one in six pregnancies, bestowing immediate and long-term health risks to mother and child. Diet and exercise are commonly prescribed to control dysglycemia, but their effectiveness across sub-populations and types of diabetes (type-1; type-2; or gestational diabetes mellitus, GDM) is uncertain. Therefore, a systematic review and meta-analysis on the effect of diet and/or exercise on glycemia in pregnant women with diabetes was conducted. Random effects models were used to evaluate effect sizes across studies and anticipated confounders (e.g., age, ethnicity, BMI). Of the 4845 records retrieved, 26 studies (8 nutritional supplements, 12 dietary, and 6 exercise interventions) were included. All studies were conducted in patients with GDM. Overall, supplement- and exercise-based interventions reduced fasting glucose (−0.30 mmol/L; 95% CI = −0.55, −0.06; p = 0.02; and 0.10 mmol/L; 95% CI = −0.20, −0.01; p = 0.04); and supplement- and diet-based interventions reduced HOMA-IR (−0.40; 95% CI = −0.58, −0.22; p < 0.001; and −1.15; 95% CI = −2.12, −0.17; p = 0.02). Subgroup analysis by confounders only confirmed marginal changed effect sizes. Our results suggest a favorable role of certain nutritional supplements, diet, and exercise practices on glycemia in women with GDM and underline a lack of evidence in ~20% of other diabetes-related pregnancies (i.e., women with pre-existing diabetes).

ObjectivesStudies that use continuous glucose monitoring (CGM) to monitor women with gestational diabetes (GDM), highlight the importance of managing dysglycemia over a 24-hour period. However, the effect of current treatment methods on dysglycemia over 24-hrs are currently unknown. This study aimed to characterise CGM metrics over 24-hrs in women with GDM and the moderating effect of treatment strategy.MethodsRetrospective analysis of CGM data from 128 women with GDM in antenatal diabetes clinics. CGM was measured for 7-days between 30-32 weeks gestation. Non-parametric tests were used to evaluate differences of CGM between periods of day (morning, afternoon, evening, and overnight) and between treatment methods (i.e., diet alone or diet+metformin). Exploratory analysis in a subgroup of 34 of participants was performed to investigate the association between self-reported macronutrient intake and glycaemic control.ResultsGlucose levels significantly differed during the day (i.e., morning to evening; P&lt;0.001) and were significantly higher (i.e., mean blood glucose and area under the curve [AUC]) and more variable (i.e., SD and CV) than overnight glucose levels. Morning showed the highest amount of variability (CV; 8.4% vs 6.5%, P&lt;0.001 and SD; 0.49 mmol/L vs 0.38 mmol/L, P&lt;0.001). When comparing treatment methods, mean glucose (6.09 vs 5.65 mmol/L; P&lt;0.001) and AUC (8760.8 vs 8115.1 mmol/L.hr; P&lt;0.001) were significantly higher in diet+metformin compared to diet alone. Finally, the exploratory analysis revealed a favourable association between higher protein intake (+1SD or +92 kcal/day) and lower mean glucose (-0.91 mmol/L p, P=0.02) and total AUC (1209.6 mmol/L.h, P=0.021).ConclusionsGlycemia varies considerably across a day, with morning glycemia demonstrating greatest variability. Additionally, our work supports that individuals assigned to diet+metformin have greater difficulty managing glycemia and results suggest that increased dietary protein may assist with management of dysglycemia. Future work is needed to investigate the benefit of increased protein intake on management of dysglycemia.

Aim: To assess whether postprandial glucose responses (PPGRs) are individual in people with type 1 diabetes (T1DM) and influenced by personal physiological and clinical parameters. Methods: We assessed physiological and clinical parameters of one-hundred and twenty individuals with type 1 diabetes (mean±SD: Age 31±7years, BMI 26.9±2.3kg.m2, HbA1c 7.6±0.8% [55.8±8.2mmol/moL]) and captured postprandial interstitial glucose responses via continuous glucose monitoring (CGM) in response to two carbohydrate-based standardised meals (shredded wheat [SW] or millet oat-porridge [OP]), twice, on four separate occasions. Each meal was matched for energy, fibre, and macronutrient composition, glycaemic index (GI), and insulin administration. Results: Despite identical energy, fibre, and macronutrient content, GI, and prandial insulin administration, the average PPGR differed significantly between OP and SW, respectively (IG AUC: 1807±588 vs. 1678±533 mmol.L.min-1; p=0.05). PPGRs to each meal type showed a high degree of reproducibility within individuals (OP r=0.994, p&lt;0.001 vs. SW r=0.987 p&lt;0.001), but large interpersonal variation within each meal type (CV%: OP 32.5% vs. SW 31.7%). Higher PPGR was positively associated with PPGR variability (r=0.698, p&lt;0.001), HbA1c (r=0.223, p=0.014), BMI (r=0.316, p&lt;0.001), and age (r=0.277, p&lt;0.001). Conclusions: Using a total of 19,200 glucose measurements, we show that PPGR in individuals with type 1 diabetes is interpersonal and influenced by BMI, age, and HbA1c. We show that identification of personal characteristics is a promising means for designing effective nutritional interventions to predict and control glycaemic responses to food in this population. Disclosure C.F.B. Dingena: None. A. Marsh: None. R. Ajjan: Advisory Panel; Self; Eli Lilly and Company, Merck Sharp & Dohme Corp., Novo Nordisk Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; Abbott. M. Campbell: None.

Objectives Globally, 1 in 7 of all pregnancies are disrupted by diabetes, bestowing immediate and long-term health risks to mother and child. While diet and exercise are commonly prescribed in clinical practise to manage dysglycemia during pregnancy, the independent and combined effectiveness of diet and exercise across populations and types of diabetes (type-1, type-2, or gestational diabetes mellitus) is uncertain. To inform prevention strategies, the effects of distinct independent and combined diet and exercise strategies on gestational dysglycemia were synthesised and evaluated. Methods A systematic search for randomised controlled trials (published after 2000) that investigated the effect of diet and/or exercise interventions on glycemia in pregnant women diagnosed with diabetes was designed for AMED, EMBASE, MEDLINE (via OVID), PubMed, and Scopus. Random effects models were used to test the generalizability of results across studies and within key subgroups stratified by known confounders of gestational dysglycemia (e.g., age, ethnicity, BMI). This project is registered on PROSPERO (CRD42021268977). Results Following title-abstract screening of 4803 abstracts, 59 RCTs were included for full-text screening. and 16 studies with 1034 participants were suitable for quantitative analysis. Of these 16 studies, 9 were supplementation-based, 3 were dietary interventions, and 4 were exercise interventions. Furthermore, all studies identified via the systematic search strategy were conducted in patients diagnosed with gestational diabetes mellitus (GDM). Conclusions We identified numerous studies that evaluated and supported the use of lifestyle interventions for women with GDM; however, there is a lack of research examining lifestyle interventions in pre-existing diabetes in pregnancy. Funding Sources University of Leeds School of Food Science and Nutrition.

IntroductionDiabetes in pregnancy presents a unique physiological challenge to manage glycaemia while maintaining adequate nourishment for the growing fetus. Women with diabetes who become pregnant are at greater risk of adverse maternal and newborn outcomes, compared with women without diabetes. Evidence suggests that control of (postprandial) glycaemia is key to manage maternal and offspring health but it is not yet clear (1) how diet and lifestyle moderate these shifts across the full duration of pregnancy or (2) what aspects of maternal and offspring health are associated with dysglycaemia.Methods and analysisTo investigate these gaps, a cross-over randomised clinical trial has been embedded within routine clinical care. Seventy-six pregnant women in their first trimester with type 1 or type 2 diabetes (with or without medication) attending their routine antenatal appointments at National Health Service (NHS) Leeds Teaching Hospitals will be recruited. Following informed consent, data on women’s health, glycaemia, pregnancy and delivery will be shared by the NHS with researchers. At each visit in the first (10–12 weeks), second (18–20 weeks) and third (28–34 weeks) trimester, participants will be asked for consent to: (1) lifestyle and diet questionnaires, (2) blood for research purposes and (3) analysis of urine collected at clinical visits. Additionally, participants will be asked to consume two blinded meals in duplicate in second and third trimester. Glycaemia will be assessed by continuous glucose monitoring as part of routine care. The primary outcome is the effect of experimental meals (high vs low protein) on postprandial glycaemia. Secondary outcomes include (1) the association between dysglycaemia and maternal and newborn health, and (2) the association between maternal metabolic profiles in early pregnancy with dysglycaemia in later pregnancy.Ethics and disseminationThe Leeds East Research Ethics Committee and NHS (REC: 21/NE/0196) approved the study. Results will be published in peer-reviewed journals and disseminated to participants and the wider public.Trial registration numberISRCTN57579163.