Metformin: A promising option for the management of gestational diabetes mellitus - Exploring the benefits, challenges and clinical needs in the current management of gestational diabetes mellitus.

The incidence of gestational diabetes mellitus (GDM) is increasing. One in three women require insulin to achieve glycaemic targets in GDM. However, it is unclear whether insulin therapy alone is the most effective treatment for all women in achieving glycaemic control and preventing adverse pregnancy outcomes. Although no oral hypoglycaemic agents are approved for pregnancy in Australia, recent research indicates that metformin is effective in preventing adverse perinatal outcomes and may even have possible benefits in the long term. Furthermore, there appears to be a specific role for both metformin and insulin among the GDM population. Metformin provides an option to offer an individualised approach to treat GDM.

Genome wide association study of response to interval and continuous exercise training: the Predict-HIIT study.

BACKGROUND: Low cardiorespiratory fitness (V̇O2peak) is highly associated with chronic disease and mortality from all causes. Whilst exercise training is recommended in health guidelines to improve V̇O2peak, there is considerable inter-individual variability in the V̇O2peak response to the same dose of exercise. Understanding how genetic factors contribute to V̇O2peak training response may improve personalisation of exercise programs. The aim of this study was to identify genetic variants that are associated with the magnitude of V̇O2peak response following exercise training. METHODS: Participant change in objectively measured V̇O2peak from 18 different interventions was obtained from a multi-centre study (Predict-HIIT). A genome-wide association study was completed (n = 507), and a polygenic predictor score (PPS) was developed using alleles from single nucleotide polymorphisms (SNPs) significantly associated (P < 1 × 10-5) with the magnitude of V̇O2peak response. Findings were tested in an independent validation study (n = 39) and compared to previous research. RESULTS: No variants at the genome-wide significance level were found after adjusting for key covariates (baseline V̇O2peak, individual study, principal components which were significantly associated with the trait). A Quantile-Quantile plot indicates there was minor inflation in the study. Twelve novel loci showed a trend of association with V̇O2peak response that reached suggestive significance (P < 1 × 10-5). The strongest association was found near the membrane associated guanylate kinase, WW and PDZ domain containing 2 (MAGI2) gene (rs6959961, P = 2.61 × 10-7). A PPS created from the 12 lead SNPs was unable to predict V̇O2peak response in a tenfold cross validation, or in an independent (n = 39) validation study (P > 0.1). Significant correlations were found for beta coefficients of variants in the Predict-HIIT (P < 1 × 10-4) and the validation study (P < × 10-6), indicating that general effects of the loci exist, and that with a higher statistical power, more significant genetic associations may become apparent. CONCLUSIONS: Ongoing research and validation of current and previous findings is needed to determine if genetics does play a large role in V̇O2peak response variance, and whether genomic predictors for V̇O2peak response trainability can inform evidence-based clinical practice. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR), Trial Id: ACTRN12618000501246, Date Registered: 06/04/2018, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374601&isReview=true .

Impact of whole-body resistance exercise timing on mitigating hyperglycaemia-induced vascular dysfunction.

NEW FINDINGS: What is the central question of this study? Is the estrous cycle affected during disuse atrophies and if so, how do estrous cycle changes relate to musculoskeletal outcomes? What is the main finding and its importance? Rodent estrous cycles are altered during disuse atrophy, which corresponds to musculoskeletal outcomes. However, the estrous cycle does not appear changed in Lewis Lung Carcinoma, which corresponded to no differences in muscle size compared to healthy controls. These findings suggest a relationship between estrous cycle and muscle size during atrophic pathologies. ABSTRACT: Hyperglycemia can cause disruptions in vascular function, whereas exercise has been shown to restore vascular function. The primary aim of this study is to investigate the effect of performing whole-body resistance exercise, 30-min before, immediately following, or 30- or 60-min after a high carbohydrate meal, on endothelial function, measured by flow-mediated dilation (FMD). Healthy adults will be recruited to this randomized crossover trial to compare the postprandial glycaemic and vascular responses to four different exercise timing conditions and a control: i) C- control, high carbohydrate meal/no exercise, ii) 30Pre- 30 min of resistance exercises (~30% of 1RM [Repetition Maximum]), 30 min before a high carbohydrate meal, iii) IP- 30 min of resistance exercises (~30% of 1RM), immediately following a high carbohydrate meal, iv) 30Post- 30 min of resistance exercises, 30 min after a high carbohydrate meal and v) 60Post- 30 min of resistance exercises, 60 min after a high carbohydrate meal. Measures of metabolic and vascular function will be assessed at baseline and for two hours following the carbohydrate-based breakfast meal.

Carbohydrate restriction with postmeal walking effectively mitigates postprandial hyperglycemia and improves endothelial function in type 2 diabetes.

Postprandial hyperglycemia has deleterious effects on endothelial function. Restricting carbohydrate intake and postmeal walking have each been shown to reduce postprandial hyperglycemia, but their combination and subsequent effects on endothelial function have not been investigated. Here, we sought to examine the effect of blunting postprandial hyperglycemia by following a low-carbohydrate diet, with or without postmeal walking exercise, on markers of vascular health in type 2 diabetes (T2D). In a randomized crossover design, individuals with T2D ( n = 11) completed three 4-day controlled diet interventions consisting of 1) low-carbohydrate diet alone (LC), 2) low-carbohydrate diet with 15-min postmeal walks (LC + Ex), and 3) low-fat control diet (CON). Fasting blood samples and brachial artery flow-mediated dilation (%FMD) were measured before and after each intervention. Total circulating microparticles (MPs), endothelial MPs, platelet MPs, monocyte-platelet aggregates, and adhesion molecules were assessed as biomarkers of vascular health. There was a significant condition × time interaction for %FMD ( P = 0.01), with post hoc tests revealing improved %FMD after LC + Ex (+0.8 ± 1.0%, P = 0.02), with no change after LC or CON. Endothelial MPs were significantly reduced with the LC diet by ~45% (from 99 ± 60 to 44 ± 31 MPs/µl, P = 0.02), with no change after LC + Ex or CON (interaction: P = 0.04). Total MPs were lower (main effect time: P = 0.02), whereas monocyte-platelet aggregates were higher (main effect time: P < 0.01) after all interventions. Plasma adhesion molecules and C-reactive protein were unaltered. Attenuating postprandial hyperglycemic excursions using a low-carbohydrate diet combined with postmeal walking appears to be an effective strategy to improve endothelial function in individuals with T2D. NEW & NOTEWORTHY Carbohydrate restriction and postmeal walking lower postprandial hyperglycemia in individuals with type 2 diabetes. Here, we show that the combination significantly improved endothelial function and that carbohydrate restriction alone reduced circulating endothelial microparticles in individuals with type 2 diabetes. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/low-carb-diet-and-exercise-improve-endothelial-health/ .

Physiological responses to a five-day adventure race: Continuous blood glucose, hemodynamics and metabolites the 2012 GODZone field-study.

BACKGROUND/OBJECTIVE: Adventure racing is an ultra-endurance activity that imposes a unique multifaceted stress on the human body. The purpose of this field study was to examine the physiological responses to a 5-day adventure race. METHODS: Eight competitors, two teams (1 female each) in the 2012 GODZone adventure race volunteered. Competitors trekked, cycled and paddled ∼326 km in ∼116 hours. Continuous glucose was measured the day before and throughout. Body mass, urinary solutes, and blood pressure and heart rate during resting, standing, and repeated squat-stand conditions, were assessed pre and post. RESULTS: Despite no changes in mean blood glucose levels, there was increased glycemic variability (Standard deviation glucose; Pre: 0.5 ±â€¯0.1 vs Race: 1.0 ±â€¯0.2 mmol/L, p = 0.02) and periods of hypoglycemia (i.e., Min glucose Pre: 4.1 ±â€¯0.3 vs Race: 3.6 ±â€¯0.5 mmol/L, p = 0.05) during the race. After the race, the blood pressure during resting, standing and squat-stand conditions was significantly lower, by 14 ±â€¯14 mmHg, 16 ±â€¯15 mmHg and 18 ±â€¯15 mmHg (all p < 0.05), respectively, with no change in heart rate. During five-days of adventure racing there is increased glycemic variability and more frequent periods of low blood glucose levels. Additionally, following the race pronounced hypotension is observed in competitors. CONCLUSION: We observed more frequent glucose fluctuations, lower glucose levels and significant perturbations in blood pressure control. Further research is warranted to examine the long-term impact of adventure racing on metabolic and cardiovascular function.

The impact of acute high-intensity interval exercise on biomarkers of cardiovascular health in type 2 diabetes.

PURPOSE: High-intensity interval training (HIIT) interventions improve cardiovascular health, yet the acute effects on circulating and functional biomarkers of cardiovascular function are unclear in individuals with type 2 diabetes (T2D). To explore this, we conducted two investigations to examine the acute response to HIIT in individuals with T2D. METHODS: Study 1 measured blood pressure, endothelial-dependent dilation, circulating measures of endothelial activation, and troponin T, 30 min and 2 h after HIIT (7 × 1-min intervals) in T2D (n = 8) and age-matched normoglycemic controls (CTL; n = 8). Study 2 assessed circulating measures of endothelial activation and troponin T, 30 min, and 24 h after HIIT (10 × 1-min intervals) in ten previously trained T2D men. RESULTS: In study 1, markers of endothelial function and activation within the first 2 h after HIIT did not differ from baseline between T2D and CTL participants, except at 30 min after HIIT for glucose, which was reduced more in T2D than CTL (by -0.8 ± 1.2 mmol/L, p = 0.04), and VCAM-1, which was reduced more 30 min after HIIT in CTL compared to T2D (by -187 ± 221 ng/mL, p = 0.05). Study 2 saw no significant difference in any circulating markers of endothelial activation and troponin T, 30 min, and 24 h after HIIT in trained T2D males. CONCLUSION: Exploratory findings from these two studies suggest that acute HIIT does not substantially alter circulating and functional markers of cardio(vascular) health in individuals with T2D who are unaccustomed (study 1) and accustomed to HIIT (study 2).

Resistance-based interval exercise acutely improves endothelial function in type 2 diabetes.

Different modes of exercise, disease, and training status can modify endothelial shear stress and result in distinct effects on endothelial function. To date, no study has examined the influence of type 2 diabetes (T2D) and training status on the acute endothelial response to different modes of interval exercise (INT). We examined the effect of a single session of resistance- and cardio-based INT compared with a time-matched control on endothelial function in 12 age-matched T2D participants, 12 untrained, and 11 trained adults (aged 56 ± 7 yr). Flow-mediated dilation (%FMD) of the brachial artery was assessed at baseline and immediately, 1, and 2 h after an acute bout of cardio interval (C-INT), resistance interval (R-INT), and seated control (CTL); these interventions were randomized and separated by >2 days. C-INT involved seven 1-min cycling intervals at 85% of peak power with 1-min recovery between. R-INT involved the same pattern of seven 1-min intervals using leg resistance exercises. Endothelial function (%FMD) was improved after R-INT in all groups (Condition × Time interaction, P < 0.01), an effect that was most robust in T2D where %FMD was higher immediately (+4.0 ± 2.8%), 1 h (+2.5 ± 2.5%), and 2 h (+1.9 ± 1.9%) after R-INT compared with CTL (P < 0.01 for all). C-INT improved %FMD in T2D at 1-h postexercise (+1.6 ± 2.2%, P = 0.03) compared with CTL. In conclusion, R-INT acutely improves endothelial function throughout the 2-h postexercise period in T2D patients. The long-term impact of resistance exercise performed in an interval pattern is warranted.

Effectiveness and safety of high-intensity interval training in patients with type 2 diabetes.

IN BRIEF Recent research has shown that high-intensity interval training (HIIT) can promote improvements in glucose control and cardiovascular health in individuals with type 2 diabetes. This article summarizes the evidence and highlights the ways in which HIIT might be safely implemented as an adjunct to more traditional exercise approaches.

'Exercise snacks' before meals: a novel strategy to improve glycaemic control in individuals with insulin resistance.

AIMS/HYPOTHESIS: The aim of this study was to investigate whether small doses of intense exercise before each main meal ('exercise snacks') would result in better blood glucose control than a single bout of prolonged, continuous, moderate-intensity exercise in individuals with insulin resistance. METHODS: Nine individuals completed three exercise interventions in randomised order. Measures were recorded across 3 days with exercise performed on the middle day, as either: (1) traditional continuous exercise (CONT), comprising 30 min moderate-intensity (60% of maximal heart rate [HRmax]) incline walking before dinner; (2) exercise snacking (ES), consisting of 6 × 1 min intense (90% HRmax) incline walking intervals 30 min before each meal; or (3) composite exercise snacking (CES), encompassing 6 × 1 min intervals alternating between walking and resistance-based exercise, 30 min before meals. Meal timing and composition were controlled within participants for exercise interventions. RESULTS: ES attenuated mean 3 h postprandial glucose concentration following breakfast (by 1.4 ± 1.5 mmol/l, p = 0.02) but not lunch (0.4 ± 1.0 mmol/l, p = 0.22), and was more effective than CONT following dinner (0.7 ± 1.5 mmol/l below CONT; p = 0.04). ES also reduced 24 h mean glucose concentration by 0.7 ± 0.6 mmol/l (p = 0.01) and this reduction persisted for the subsequent 24 h (lower by 0.6 ± 0.4 mmol/l vs CONT, relative to their baselines; p = 0.01). CES was just as effective as ES (p > 0.05 for all glycaemic variables) at improving glycaemic control. CONCLUSIONS/INTERPRETATION: Dosing exercise as brief, intense 'exercise snacks' before main meals is a time-efficient and effective approach to improve glycaemic control in individuals with insulin resistance.

Diagnosis to Delivery: A Randomized Clinical Trial of Postmeal Walking in Women with Gestational Diabetes.

PURPOSE: The aim of this study was to determine whether advice to perform postmeal walking could be an effective and feasible alternate to standard care continuous walking for the management of gestational diabetes (GDM). METHODS: Forty women with GDM were randomized between 28 and 30 wk of gestation into either standard care (CTL; 30-min continuous walking, most days per week) or standard care with advice to PMW (daily 10-min walks after three main meals) for ~7 wk. The primary outcome for this randomized controlled trial was postprandial glucose assessed by continuous glucose monitors. Continuous glucose monitor and ActivPAL inclinometers (physical activity parameters) were each worn for 7 d at ~28 and ~35 wk gestation. Delivery outcomes were also collected. A linear mixed model compared the changes across time between groups. RESULTS: Twenty-six women (PMW: n = 12, CTL: n = 14; age 34 ± 5 y) completed the trial. Mean 3 h postprandial glucose at dinner was higher in the PMW versus CTL group at baseline and across the intervention (main effect group, P = 0.04). Twenty-four hours, nocturnal, and fasting glucose were similar between groups. The PMW group spent ~57 min·d -1 more time sedentary and ~11 min·d -1 less time stepping versus CTL (main effect group: P = 0.02 and 0.05). Adherence to the prescribed 30 min·d -1 of physical activity was high, regardless of whether accumulated as 3 × 10-min or one single bout of walking. CONCLUSIONS: Distributing activity as 10-min bouts after main meals did not improve postprandial glucose outcomes compared with standard-care control. More research on the optimal duration and intensity of postmeal walks to improve postprandial responses are needed. Strategies that mitigate sedentary time and increase the minutes of physical activity accumulated across the day in pregnancy are also warranted.

Timing of Moderate to Vigorous Physical Activity, Mortality, Cardiovascular Disease, and Microvascular Disease in Adults With Obesity.

OBJECTIVE: To assess the association between timing of aerobic moderate to vigorous physical activity (MVPA) and risk of cardiovascular disease (CVD), microvascular disease (MVD), and all-cause mortality in adults with obesity and a subset with obesity and type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: Participants included adults with obesity (BMI ≥30 kg/m2) and a subset of those with T2D from the UK Biobank accelerometry substudy. Aerobic MVPA was defined as bouts of MVPA lasting ≥3 continuous minutes. Participants were categorized into morning, afternoon, or evening MVPA based on when they undertook the majority of their aerobic MVPA. The reference group included participants with an average of less than one aerobic MVPA bout per day. Analyses were adjusted for established and potential confounders. RESULTS: The core sample included 29,836 adults with obesity, with a mean age of 62.2 (SD 7.7) years. Over a mean follow-up period of 7.9 (SD 0.8) years, 1,425 deaths, 3,980 CVD events, and 2,162 MVD events occurred. Compared with activity in the reference group, evening MVPA was associated with the lowest risk of mortality (hazard ratio [HR] 0.39; 95% CI 0.27, 0.55), whereas afternoon (HR 0.60; 95% CI 0.51, 0.71) and morning MVPA (HR 0.67; 95% CI 0.56, 0.79) demonstrated significant but weaker associations. Similar patterns were observed for CVD and MVD incidence, with evening MVPA associated with the lowest risk of CVD (HR 0.64; 95% CI 0.54, 0.75) and MVD (HR 0.76; 95% CI 0.63, 0.92). Findings were similar in the T2D subset (n = 2,995). CONCLUSIONS: Aerobic MVPA bouts undertaken in the evening were associated with the lowest risk of mortality, CVD, and MVD. Timing of physical activity may play a role in the future of obesity and T2D management.

Assessing the effect of anthocyanins through diet and supplementation on cognitive function in older adults at risk for dementia: protocol for a randomised controlled trial.

INTRODUCTION: Promising evidence is emerging for the procognitive, anti-inflammatory and neuroprotective properties of dietary flavonoids, particularly anthocyanins that provide red, purple and blue plant pigments. METHODS AND ANALYSIS: The 'Food for Thought' study is a multicentre, 6-month randomised, parallel 3-arm clinical trial. Its primary aim is to investigate whether anthocyanin consumption, either through diet or supplementation, can prevent memory loss progression and improve inflammatory and cardiovascular health in older adults at risk for dementia. Eligible participants will include those aged 60-85 years with a diagnosis of amnestic mild cognitive impairment or with a self-referral of memory concerns and scoring ≤13 on the Memory Index Score within the Telephone Montreal Cognitive Assessment screening test. Participants will be randomised to one of three arms: High anthocyanin ('purple foods') diet (aiming for a target of 250 mg anthocyanins/day); freeze-dried product derived from blackcurrants (250 mg anthocyanins/day); or control (coloured maltose powder). The primary outcome is auditory anterograde memory functioning assessed by the Buschke and Grober Free and Cued Selective Reminding Test-Immediate Recall. Secondary outcomes are additional cognitive functions including processing speed, working memory, aspects of executive functioning (attentional shifting and word generativity) and premorbid estimate as well as subjective memory problems and self-reported depression symptoms. Additional secondary outcomes are blood pressure, inflammatory biomarkers, brain-derived neurotrophic factor, fatty acid profile, apolipoprotein E and polyphenol metabolites, gut microbiota composition and function and vascular and microvascular endothelial function tests. Repeated measures analysis of variance and/or mixed linear modelling will evaluate changes over time, with the inclusion of covariates. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Greater Western Human Research Ethics Committee (2021/ETH12083). A Consumer Advisory Group was established to guide and review the protocol and dissemination strategy. The results of this trial are intended to be published in a peer-reviewed journal. TRIAL SPONSOR: National Health and Medical Research Centre Dementia Collaborative Research Centre.Start date of clinical trial: 02 September 2022.Expected end date: 11 October 2024. TRIAL REGISTRATION NUMBER: ACTRN12622000065796.

Using Continuous Glucose Monitoring to Prescribe a Time to Exercise for Individuals with Type 2 Diabetes.

This study examines the potential utility of using continuous glucose monitoring (CGM) to prescribe an exercise time to target peak hyperglycaemia in people with type 2 diabetes (T2D). The main aim is to test the feasibility of prescribing an individualised daily exercise time, based on the time of CGM-derived peak glucose, for people with T2D. Thirty-five individuals with T2D (HbA1c: 7.2 ± 0.8%; age: 64 ± 7 y; BMI: 29.2 ± 5.2 kg/m2) were recruited and randomised to one of two 14 d exercise interventions: i) ExPeak (daily exercise starting 30 min before peak hyperglycaemia) or placebo active control NonPeak (daily exercise starting 90 min after peak hyperglycaemia). The time of peak hyperglycaemia was determined via a two-week baseline CGM. A CGM, accelerometer, and heart rate monitor were worn during the free-living interventions to objectively measure glycaemic control outcomes, moderate-to-vigorous intensity physical activity (MVPA), and exercise adherence for future translation in a clinical trial. Participation in MVPA increased 26% when an exercise time was prescribed compared to habitual baseline (p < 0.01), with no difference between intervention groups (p > 0.26). The total MVPA increased by 10 min/day during the intervention compared to the baseline (baseline: 23 ± 14 min/d vs. intervention: 33 ± 16 min/d, main effect of time p = 0.03, no interaction). The change in peak blood glucose (mmol/L) was similar between the ExPeak (-0.44 ± 1.6 mmol/L, d = 0.21) and the NonPeak (-0.39 ± 1.5 mmol/L, d = 0.16) intervention groups (p = 0.92). Prescribing an exercise time based on CGM may increase daily participation in physical activity in people with type 2 diabetes; however, further studies are needed to test the long-term impact of this approach.

The Effect of Exercise on Quality of Life in Type 2 Diabetes: A Systematic Review and Meta-analysis.

BACKGROUND: Exercise is a proven therapy for managing cardiometabolic risk factors in type 2 diabetes (T2D). However, its effects on patient-reported outcome measures such as quality of life (QoL) in people with T2D remain unclear. Consequently, the primary aim of this study was to determine the effect of regular exercise on QoL in adults with T2D. A secondary aim was to determine the effect of different exercise modalities on QoL. The third aim was to determine whether improvements in QoL were associated with improvements in gly'cated hemoglobin (A1C). METHODS: Relevant databases were searched to May 2022. Eligible studies included randomized trials involving ≥2 wk of aerobic and/or resistance exercise and assessed QoL using a purpose-specific tool. Mean differences and 95% confidence intervals (CI) were calculated as standardized mean difference (SMD) or weighted mean difference. A regression analysis was undertaken to examine the interaction between change in QoL with change in A1C. RESULTS: Of the 12,642 studies retrieved, 29 were included involving 2354 participants. Exercise improved QoL when compared with control (SMD, 0.384; 95% CI, 0.257 to 0.512; P < 0.001). Aerobic exercise, alone (SMD, 0.475; 95% CI, 0.295 to 0.655; P < 0.001) or in combination with resistance training (SMD, 0.363; 95% CI, 0.179 to 0.548; P < 0.001) improved QoL, whereas resistance training alone did not. Physical components of health-related QoL (HRQoL) improved with all exercise modalities, but mental components of HRQoL remained unchanged. Exercise improved A1C (mean difference, -0.509%; 95% CI, -0.806% to -0.212%; P = 0.001), and this change was associated with improvements in HRQoL ( ß = -0.305, SE = 0.140, Z = -2.18, P = 0.030). CONCLUSIONS: These results provide robust evidence that regular aerobic exercise alone or in combination with resistance training is effective for improving QoL in adults with T2D. Such improvements seem to be mediated by improvements in physical components of HRQoL and are associated with improved blood glucose control. Further studies should be undertaken to determine the relative importance of exercise duration, intensity, and frequency on patient-reported outcomes such as QoL.

Physical Activity, but Not Glycaemic Load, Is Associated with Lower Real-Time Glycaemic Control in Free-Living Women with Gestational Diabetes Mellitus.

Maintaining blood glucose within the target range is the primary treatment goal for women with gestational diabetes mellitus (GDM). Foods with low glycaemic loads are recommended in clinical practice; however, the relative importance of other key lifestyle variables is unexplored. This pilot study explored the associations of glycaemic load, carbohydrates and physical activity parameters on blood glucose concentrations in free-living women with GDM. Twenty-nine women (28-30 weeks gestation, 34 ± 4 years) with GDM were enrolled. Continuous glucose monitoring, physical activity (ActivPAL inclinometer) and dietary intake and dietary quality were measured concurrently for 3 days. Pearson correlation analyses determined the association between glucose levels and lifestyle variables. Despite all receiving the same nutrition education, only 55% of women were following a low glycaemic load diet with a large range of carbohydrate intakes (97-267 g/day). However, the glycaemic load did not correlate with 3-hr postprandial glucose (r2 = 0.021, p = 0.56) or 24-h glucose iAUC (r2 = 0.021, p = 0.58). A significant relationship between total stepping time and lower 24-h glucose iAUC (r2 = 0.308, p = 0.02) and nocturnal glucose (r2 = 0.224, p = 0.05) was found. In free-living women with diet-controlled GDM, more physical activity, i.e., steps accumulated across the day, may be a simple and effective strategy for improving maternal blood glucose concentrations.

Impact of a Low-Carbohydrate Compared with Low-Fat Breakfast on Blood Glucose Control in Type 2 Diabetes: A Randomized Trial.

BACKGROUND: In type 2 diabetes (T2D), consuming carbohydrates results in a rapid and large increase in blood glucose, particularly in the morning when glucose intolerance is highest. OBJECTIVES: We investigated if a low-carbohydrate (LC) breakfast (∼465 kcal: 25 g protein, 8 g carbohydrates, and 37 g fat) could improve glucose control in people with T2D when compared with a low-fat control (CTL) breakfast (∼450 kcal:20 g protein, 56 g carbohydrates, and 15 g fat). METHODS: Participants with T2D (N = 121, 53% women, mean age 64 y) completed a remote 3-month parallel-group randomized controlled trial comparing a LC with standard low-fat guideline CTL breakfast. The change in HbA1c was the prespecified primary outcome. Continuous glucose monitoring, self-reported anthropometrics, and dietary information were collected for an intention-to-treat analysis. RESULTS: HbA1c was reduced (-0.3%; 95% CI: -0.4%, -0.1%) after 12 wks of a LC breakfast, but the between-group difference in HbA1c was of borderline statistical significance (-0.2; 95% CI: -0.4, 0.0; P = 0.06). Self-reported total daily energy (-242 kcal; 95% CI: -460, -24 kcal; P = 0.03) and carbohydrate (-73 g; 95% CI: -101, -44 g; P < 0.01) intake were lower in the LC group but the significance of this difference is unclear. Mean and maximum glucose, area under the curve, glycemic variability, standard deviation, and time above range were all significantly lower, and time in the range was significantly higher, in the LC group compared with CTL (all P < 0.05). CONCLUSIONS: Advice and guidance to consume a LC breakfast appears to be a simple dietary strategy to reduce overall energy and carbohydrate intake and improve several continuous glucose monitoring variables when compared with a CTL breakfast in persons living with T2D. The trial was registered at clinicaltrials.gov as NCT04550468.

Supports and Barriers to Lifestyle Interventions in Women with Gestational Diabetes Mellitus in Australia: A National Online Survey.

BACKGROUND: Gestational diabetes mellitus (GDM) affects approximately one in six pregnancies, causing a significant burden on maternal and infant health. Lifestyle interventions are first-line therapies to manage blood glucose levels (BGLs) and prevent future cardiometabolic complications. However, women with GDM experience considerable barriers to lifestyle interventions; thus, the aim of this study was to determine how women with GDM manage their condition and to identify the primary supports and barriers to lifestyle intervention participation. METHODS: An online cross-sectional survey of women in Australia with a history of GDM was conducted. Questions included participant demographics, strategies used to manage BGLs, physical activity and dietary habits, and barriers and supports to lifestyle interventions. RESULTS: A total of 665 individuals consented and responded to the advertisement, of which 564 were eligible and provided partial or complete responses to the survey questions. Most respondents were between 35 and 39 years of age (35.5%), not pregnant (75.4%), working part-time (26.7%), university-educated (58.0%), and had only one child (40.1%). Most respondents managed their BGLs through diet (88.3%), with "low-carbohydrate" diets being the most popular (72.3%), and 46.2% of respondents were undertaking insulin therapy. Only 42.2% and 19.8% of respondents reported meeting the aerobic and strengthening exercise recommendations, respectively. Women with one child or currently pregnant expecting their first child were 1.51 times more likely (95% CI, 1.02, 2.25) to meet the aerobic exercise recommendations than those with two or more children. The most common reported barriers to lifestyle intervention participation were "lack of time" (71.4%) and "childcare" commitments (57.7%). Lifestyle interventions delivered between 6 and 12 months postpartum (59.0%), involving an exercise program (82.6%), and delivered one-on-one were the most popular (64.9%). CONCLUSION: Most women report managing their GDM with lifestyle strategies. The most common strategies reported involve approaches not currently included in the clinical practice guidelines such as reducing carbohydrate consumption. Furthermore, despite being willing to participate in lifestyle interventions, respondents report significant barriers, including lack of time and childcare commitments, whereas mentioned supports included having an online format. Lifestyle interventions for women with a history of GDM should be designed in a manner that is both tailored to the individual and considerate of existing barriers and supports to participation.

Three short postmeal walks as an alternate therapy to continuous walking for women with gestational diabetes.

The purpose of this study was to determine whether postmeal walking (PMW, breaking up exercise into short bouts after meals) is an effective and feasible alternative to continuous walking for the management of gestational diabetes. Forty-one women with gestational diabetes were randomised between weeks 28-30 gestation to either standard care (30 minutes continuous exercise) or standard care with PMW (10 minutes of walking after breakfast, lunch, and dinner). Continuous glucose and activity monitors were worn to measure glycaemic control and adherence during 3 days of standard care (baseline) followed by 3 days of postmeal or continuous walking. A linear mixed model analysed the changes from baseline between postmeal and continuous walking, as an average of the 3-day periods. Thirty-two women (PMW n = 17: control n = 15, 33 ± 5 years, body mass index 25 ± 4 kg·m-2) completed the trial. Postprandial and overnight glucose concentrations were similar between PMW and control; both interventions improved from baseline. There was no difference in adherence between groups; however, PMW completed more minutes of prescribed physical activity across baseline and intervention days compared to the continuous walking standard-care group. Preliminary findings from this proof-of-concept study suggest PMW could be a promising alternative to, and work interchangeably with, traditional advice to perform continuous moderate-intensity physical activity in women with gestational diabetes. Novelty: Three 10-minute postmeal walks may be comparable to 30 minutes continuous walking for glucose control in women with gestational diabetes. Accumulating activity in short bouts after meals is a feasible alternate to continuous exercise for women with gestational diabetes.

Systematic literature review: should a bedtime snack be used to treat hyperglycemia in type 2 diabetes?

BACKGROUND: Consuming a bedtime snack is often recommended for people with type 2 diabetes. OBJECTIVE: This systematic review aims to evaluate the evidence from intervention studies to determine whether consuming a bedtime snack improves fasting hyperglycemia and/or overall glycemic control in individuals with type 2 diabetes. METHODS: PubMed, Medline (EBSCO), Cochrane Library, and CINAHL Plus (EBSCO) databases were searched until 20 July, 2022. We included prospective studies in people with type 2 diabetes or prediabetes that included the intervention of a bedtime snack, consumed >30 min after dinner and <2 h before bed and reported glycemic outcomes. RESULTS: The systematic review included 16 studies. There was no consistent relationship between consumption of a bedtime snack and improved glycemic control, especially when a no-snack control was included. Of the 4 studies that included the use of corn starch, a low dose seemed to have benefits over high-dose corn starch in terms of improved nocturnal and fasting glucose concentrations. CONCLUSIONS: Current advice to consume a bedtime snack is based on a limited number of intervention studies that often do not include a no-snack control, nor have used a feasible bedtime snack option that could be translated into everyday clinical practice. Further research is needed in type 2 diabetes patients treated with or without insulin. This review was registered at the Prospective Register of Systematic Reviews (PROSPERO) as CRD42020182523.

Personalising activity to target peak hyperglycaemia and improve cardiometabolic health in people with type 2 diabetes: protocol for a randomised controlled trial.

INTRODUCTION: The benefits of physical activity for glycaemic control in type 2 diabetes (T2D) are well-known. However, whether established glycaemic and cardiovascular benefits can be maximised by exercising at a certain time of day is unknown. Given postprandial glucose peaks contribute to worsening glycated haemoglobin (HbA1c) and cardiovascular risk factors, and that exercise immediately lowers blood glucose, prescribing exercise at a specific time of day to attenuate peak hyperglycaemia may improve glycaemic control and reduce the burden of cardiovascular disease in people with T2D. METHODS AND ANALYSIS: A single-centre randomised controlled trial will be conducted by the University of Wollongong, Australia. Individuals with T2D (n=70, aged 40-75 years, body mass index (BMI): 27-40 kg/m2) will be recruited and randomly allocated (1:1), stratified for sex and insulin, to one of three groups: (1) exercise at time of peak hyperglycaemia (ExPeak, personalised), (2) exercise not at time of peak hyperglycaemia (NonPeak) or (3) waitlist control (WLC, standard care). The trial will be 5 months, comprising an 8-week intervention and 3-month follow-up. Primary outcome is the change in HbA1c preintervention to postintervention. Secondary outcomes include vascular function (endothelial function and arterial stiffness), metabolic control (blood lipids and inflammation) and body composition (anthropometrics and dual-energy X-ray absorptiometry (DEXA)). Tertiary outcomes will examine adherence. ETHICS AND DISSEMINATION: The joint UOW and ISLHD Ethics Committee approved protocol (2019/ETH09856) prospectively registered at the Australian New Zealand Clinical Trials Registry. Written informed consent will be obtained from all eligible individuals prior to commencement of the trial. Study results will be published as peer-reviewed articles, presented at national/international conferences and media reports. TRIAL REGISTRATION NUMBER: ACTRN12619001049167.