The metabolic consequences of 'yo-yo' dieting are markedly influenced by genetic diversity.

BACKGROUND: Weight loss can improve the metabolic complications of obesity. However, it is unclear whether insulin resistance persists despite weight loss and whether any protective benefits are preserved following weight regain (weight cycling). The impact of genetic background on weight cycling is undocumented. We aimed to investigate the effects of weight loss and weight cycling on metabolic outcomes and sought to clarify the role of genetics in this relationship. METHOD: Both C57BL/6 J and genetically heterogeneous Diversity Outbred Australia (DOz) mice were alternately fed high fat Western-style diet (WD) and a chow diet at 8-week intervals. Metabolic measures including body composition, glucose tolerance, pancreatic beta cell activity, liver lipid levels and adipose tissue insulin sensitivity were determined. RESULTS: After diet switch from WD (8-week) to chow (8-week), C57BL/6 J mice displayed a rapid normalisation of body weight, adiposity, hyperinsulinemia, liver lipid levels and glucose uptake into adipose tissue comparable to chow-fed controls. In response to the same dietary intervention, genetically diverse DOz mice conversely maintained significantly higher fat mass and insulin levels compared to chow-fed controls and exhibited much more profound interindividual variability than C57BL/6 J mice. Weight cycled (WC) animals were re-exposed to WD (8-week) and compared to age-matched controls fed 8-week WD for the first time (LOb). In C57BL/6 J but not DOz mice, WC animals had significantly higher blood insulin levels than LOb controls. All WC animals exhibited significantly greater beta cell activity than LOb controls despite similar fat mass, glucose tolerance, liver lipid levels and insulin-stimulated glucose uptake in adipose tissue. CONCLUSION: Following weight loss, metabolic outcomes return to baseline in C57BL/6 J mice with obesity. However, genetic diversity significantly impacts this response. A period of weight loss does not provide lasting benefits after weight regain, and weight cycling is detrimental and associated with hyperinsulinemia and elevated basal insulin secretion.

Maternal and neonatal outcomes of women with gestational diabetes and without specific medical conditions: an Australian population-based study comparing induction of labor with expectant management.

BACKGROUND/AIMS: To evaluate maternal birth and neonatal outcomes among women with gestational diabetes mellitus (GDM), but without specific medical conditions and eligible for vaginal birth who underwent induction of labour (IOL) at term compared with those who were expectantly managed. MATERIALS AND METHODS: Population-based cohort study of women with GDM, but without medical conditions, who had a singleton, cephalic birth at 38-41 completed weeks gestation, in New South Wales, Australia between January 2010 and December 2016. Women who underwent IOL at 38, 39, 40 weeks gestation (38-, 39-, 40-induction groups) were compared with those who were managed expectantly and gave birth at and/or beyond the respective gestational age group (38-, 39-, 40-expectant groups). Multivariable logistic regression analysis was used to assess the association between IOL and adverse maternal birth and neonatal outcomes taking into account potential confounding by maternal age, country of birth, smoking, residential location, residential area of socioeconomic disadvantage and birth year. RESULTS: Of 676 762 women who gave birth during the study period, 66 606 (10%) had GDM; of these, 34799 met the inclusion criteria. Compared with expectant management, those in 38- (adjusted odds ratio (aOR) 1.11; 95% CI, 1.04-1.18), 39- (aOR 1.21; 95% CI, 1.14-1.28) and 40- (aOR 1.50; 95% CI, 1.40-1.60) induction groups had increased risk of caesarean section. Women in the 38-induction group also had an increased risk of composite neonatal morbidity (aOR 1.10; 95% CI, 1.01-1.21), which was not observed at 39- and 40-induction groups. We found no difference between groups in perinatal death or neonatal intensive care unit admission for births at any gestational age. CONCLUSION: In women with GDM but without specific medical conditions and eligible for vaginal birth, IOL at 38, 39, 40 weeks gestation is associated with an increased risk of caesarean section.

Muscle and adipose tissue insulin resistance: malady without mechanism?

Insulin resistance is a major risk factor for numerous diseases, including type 2 diabetes and cardiovascular disease. These disorders have dramatically increased in incidence with modern life, suggesting that excess nutrients and obesity are major causes of "common" insulin resistance. Despite considerable effort, the mechanisms that contribute to common insulin resistance are not resolved. There is universal agreement that extracellular perturbations, such as nutrient excess, hyperinsulinemia, glucocorticoids, or inflammation, trigger intracellular stress in key metabolic target tissues, such as muscle and adipose tissue, and this impairs the ability of insulin to initiate its normal metabolic actions in these cells. Here, we present evidence that the impairment in insulin action is independent of proximal elements of the insulin signaling pathway and is likely specific to the glucoregulatory branch of insulin signaling. We propose that many intracellular stress pathways act in concert to increase mitochondrial reactive oxygen species to trigger insulin resistance. We speculate that this may be a physiological pathway to conserve glucose during specific states, such as fasting, and that, in the presence of chronic nutrient excess, this pathway ultimately leads to disease. This review highlights key points in this pathway that require further research effort.

Utility of the Hospital Admission Risk Programme diabetes risk calculator in identifying patients with type 2 diabetes at risk of unplanned hospital presentations.

BACKGROUND: Prevention of hospitalisation is an important aspect of type 2 diabetes (T2D) management. AIMS: We retrospectively determined the utility of the Hospital Admission Risk Programme (HARP) diabetes risk calculator (HARP tool) in identifying patients with T2D more likely to have unplanned hospital presentations. METHODS: The HARP tool includes a clinical assessment score (Part A) and a psychosocial and self-management impact score (Part B), and categorises patients into low, medium, high or urgent risk of acute hospitalisation. It was completed for T2D patients attending Royal North Shore Hospital, Sydney, in 2013. RESULTS: Within the cohort of 278 patients (age 65.3 ± 10.5 years; 62.9% male; diabetes duration 10.7 ± 6.6 years), 67.3% were classified as low risk, 32.7% as medium risk and none as high or urgent risk. Following adjustment for confounders, a medium HARP score was associated with a 3.1-fold increased risk of unplanned hospital presentations in the subsequent 12 months (95% confidence interval: 1.35-7.31; P = 0.008). Part A scores were significantly higher for patients that presented to hospital compared to those that did not (14.2 ± 6.8 vs 11.4 ± 5.5; P = 0.034), whereas there was no difference in Part B scores (P = 0.860). CONCLUSIONS: In patients with low and medium HARP scores, clinical features were more predictive of hospital presentations than certain psychosocial or self-management factors in the present cohort. Further studies are required to characterise unplanned hospitalisation in patients with higher HARP scores, or whether additional psychosocial assessments could improve the tool's predictability.

Identification of Patients With Diabetes Who Benefit Most From a Health Coaching Program in Chronic Disease Management, Sydney, Australia, 2013.

INTRODUCTION: Chronic disease management programs (CDMPs) that include health coaching can facilitate and coordinate diabetes management. The aim of this study was to assess changes in patients' general knowledge of diabetes, self-reported health status, diabetes distress, body mass index (BMI), and glycemic control after enrollment in a face-to-face CDMP group health coaching session (with telephone follow-up) compared with participation in telephone-only health coaching, during a 12-month period. METHODS: Patients with diabetes were enrolled in a health coaching program at Royal North Shore Hospital, Sydney, Australia, in 2013. Questionnaires were administered at baseline and at 3, 6, and 12 months, and the results were compared with baseline. Glycemic control, measured with glycated hemoglobin A1c (HbA1c) and BMI, were measured at baseline and 12 months. RESULTS: Overall, 238 patients attended a face-to-face CDMP session with telephone follow-up (n = 178) or participated in telephone-only health coaching (n = 60). We found no change in BMI in either group; however, HbA1c levels in patients with baseline above the current recommended target (>7%) decreased significantly from 8.5% (standard deviation [SD], 1.0%) to 7.9% (SD, 1.0%) (P = .03). Patients with the lowest self-reported health status at baseline improved from 4.4 (SD, 0.5) to 3.7 (SD, 0.9) (P = .001). Diabetes knowledge improved in all patients (24.4 [SD, 2.4] to 25.2 [SD, 2.4]; P < .001), and diabetes distress decreased among those with the highest levels of distress at baseline (3.0 [SD, 0.4] vs 3.8 [SD, 0.6]; P = .003). CONCLUSION: Diabetes health coaching programs can improve glycemic control and reduce diabetes distress in patients with high levels of these at baseline.

Impact of obesity and epicardial fat on early left atrial dysfunction assessed by cardiac MRI strain analysis.

BACKGROUND: Diastolic dysfunction is a major cause of morbidity in obese individuals. We aimed to assess the ability of magnetic resonance imaging (MRI) derived left atrial (LA) strain to detect early diastolic dysfunction in individuals with obesity and type 2 diabetes, and to explore the association between cardiac adipose tissue and LA function. METHODS: Twenty patients with obesity and T2D (55 ± 8 years) and nineteen healthy controls (48 ± 13 years) were imaged using cine steady state free precession and 2-point Dixon cardiovascular magnetic resonance. LA function was quantified using a feature tracking technique with definition of phasic longitudinal strain and strain rates, as well as radial motion fraction and radial velocities. RESULTS: Systolic left ventricular size and function were similar between the obesity and type 2 diabetes and control groups by MRI. All patients except four had normal diastolic assessment by echocardiography. In contrast, measures of LA function using magnetic resonance feature tracking were uniformly altered in the obesity and type 2 diabetes group only. Although there was no significant difference in intra-myocardial fat fraction, Dixon 3D epicardial fat volume(EFV) was significantly elevated in the obesity and type 2 diabetes versus control group (135 ± 31 vs. 90 ± 30 mL/m2, p < 0.001). There were significant correlations between LA functional indices and both BMI and EFV (p ≤ 0.007). CONCLUSIONS: LA MRI-strain may be a sensitive tool for the detection of early diastolic dysfunction in individuals with obesity and type 2 diabetes and correlated with BMI and epicardial fat supporting a possible association between adiposity and LA strain. Trials Registration Australian New Zealand Clinical Trials Registry No. ACTRN12613001069741.

Subcutaneous fat transplantation alleviates diet-induced glucose intolerance and inflammation in mice.

AIMS/HYPOTHESIS: Adipose tissue (AT) distribution is a major determinant of mortality and morbidity in obesity. In mice, intra-abdominal transplantation of subcutaneous AT (SAT) protects against glucose intolerance and insulin resistance (IR), but the underlying mechanisms are not well understood. METHODS: We investigated changes in adipokines, tissue-specific glucose uptake, gene expression and systemic inflammation in male C57BL6/J mice implanted intra-abdominally with either inguinal SAT or epididymal visceral AT (VAT) and fed a high-fat diet (HFD) for up to 17 weeks. RESULTS: Glucose tolerance was improved in mice receiving SAT after 6 weeks, and this was not attributable to differences in adiposity, tissue-specific glucose uptake, or plasma leptin or adiponectin concentrations. Instead, SAT transplantation prevented HFD-induced hepatic triacylglycerol accumulation and normalised the expression of hepatic gluconeogenic enzymes. Grafted fat displayed a significant increase in glucose uptake and unexpectedly, an induction of skeletal muscle-specific gene expression. Mice receiving subcutaneous fat also displayed a marked reduction in the plasma concentrations of several proinflammatory cytokines (TNF-α, IL-17, IL-12p70, monocyte chemoattractant protein-1 [MCP-1] and macrophage inflammatory protein-1ß [ΜIP-1ß]), compared with sham-operated mice. Plasma IL-17 and MIP-1ß concentrations were reduced from as early as 4 weeks after transplantation, and differences in plasma TNF-α and IL-17 concentrations predicted glucose tolerance and insulinaemia in the entire cohort of mice (n = 40). In contrast, mice receiving visceral fat transplants were glucose intolerant, with increased hepatic triacylglycerol content and elevated plasma IL-6 concentrations. CONCLUSIONS/INTERPRETATION: Intra-abdominal transplantation of subcutaneous fat reverses HFD-induced glucose intolerance, hepatic triacylglycerol accumulation and systemic inflammation in mice.

Intensive Lifestyle Intervention for Remission of Early Type 2 Diabetes in Primary Care in Australia: DiRECT-Aus.

OBJECTIVE: We aimed to assess whether remission of type 2 diabetes (T2D) could be achieved with a low-energy total diet replacement (TDR) in an Australian primary care setting. RESEARCH DESIGN AND METHODS: Individuals aged 20-65 years with T2D duration up to 6 years, BMI >27.0 kg/m2, and not treated with insulin were prescribed a 13-week low-energy TDR (Optifast; Nestlé Health Science) followed by 8-week structured food reintroduction and 31-week supported weight maintenance. The primary outcome was T2D remission at 12 months. RESULTS: A total of 155 participants comprised the intention-to-treat population. At 12 months, T2D remission was achieved in 86 (56%) participants, with a mean adjusted weight loss of 8.1% (95% CI 7.2-9.1). Two serious adverse events requiring hospitalization related to the study intervention were reported. CONCLUSIONS: At 12 months T2D remission was achieved for one in two Australian adults in a primary care setting.

The impact of weight cycling on health outcomes in animal models: A systematic review and meta-analysis.

The pattern of weight loss and regain, termed "weight cycling," is common in overweight individuals. It is unclear whether the well-established benefits of weight loss persist following weight regain or whether weight cycling is harmful. Human studies of weight cycling have conflicting results reflecting limitations of the observational designs of these studies. By controlling the macronutrient content of diets in animal studies, weight cycling can be studied in a highly controlled manner, thereby overcoming the limitations of human studies. We conducted a systematic review and meta-analysis of animal studies which assessed the health consequences of weight cycling. Studies were classified into those which compared weight cycling to lifelong obesity and those which compared weight cycling to later onset obesity. There were no differences in health outcomes between weight cycled animals and those with lifelong obesity, highlighting that weight regain reverses health benefits achieved by weight loss. In comparison with animals with later onset obesity, weight cycled animals had higher fasting glucose levels and more impaired glucose tolerance following weight regain. Our review of animal studies suggests that health benefits of diet-induced weight loss do not persist after weight regain and weight cycling results in adverse metabolic outcomes.

Systems-level analysis of insulin action in mouse strains provides insight into tissue- and pathway-specific interactions that drive insulin resistance.

Skeletal muscle and adipose tissue insulin resistance are major drivers of metabolic disease. To uncover pathways involved in insulin resistance, specifically in these tissues, we leveraged the metabolic diversity of different dietary exposures and discrete inbred mouse strains. This revealed that muscle insulin resistance was driven by gene-by-environment interactions and was strongly correlated with hyperinsulinemia and decreased levels of ten key glycolytic enzymes. Remarkably, there was no relationship between muscle and adipose tissue insulin action. Adipocyte size profoundly varied across strains and diets, and this was strongly correlated with adipose tissue insulin resistance. The A/J strain, in particular, exhibited marked adipocyte insulin resistance and hypertrophy despite robust muscle insulin responsiveness, challenging the role of adipocyte hypertrophy per se in systemic insulin resistance. These data demonstrate that muscle and adipose tissue insulin resistance can occur independently and underscore the need for tissue-specific interrogation to understand metabolic disease.

Large-for-Gestational-Age Neonates in Type 1 Diabetes and Pregnancy: Contribution of Factors Beyond Hyperglycemia.

Despite significant reductions in serious adverse perinatal outcomes for women with type 1 diabetes in pregnancy, the opposite effect has been observed for fetal overgrowth and associated complications, such as neonatal hypoglycemia, shoulder dystocia, and admission to the neonatal intensive care unit. In addition, infants born large for gestational age (LGA) have an increased lifetime risk of obesity, diabetes, and chronic disease. Although exposure to hyperglycemia plays an important role, women who seemingly achieve adequate glycemic control in pregnancy continue to experience a greater risk of excess fetal growth, leading to LGA neonates and macrosomia. We review potential contributors to excess fetal growth in pregnancies complicated by type 1 diabetes. In addition to hyperglycemia, we explore the role of glycemic variability, prepregnancy overweight and obesity, gestational weight gain, and maternal lipid levels. Greater understanding of the stimuli that drive excess fetal growth could lead to targeted management strategies in pregnant women with type 1 diabetes, potentially reducing the incidence of LGA neonates and the inherent risk of acute and long-term complications.

Outcomes for Women with Gestational Diabetes Treated with Metformin: A Retrospective, Case-Control Study.

Metformin is increasingly being used a therapeutic option for the management of gestational diabetes mellitus (GDM). The aim of this study was to compare the maternal characteristics and perinatal outcomes of women with GDM treated with metformin (with or without supplemental insulin) with those receiving other management approaches. A retrospective, case-control study was carried out and 83 women taking metformin were matched 1:1 with women receiving insulin or diet and lifestyle modification alone. Women managed with diet and lifestyle modification had a significantly lower fasting plasma glucose (p < 0.001) and HbA1c (p < 0.01) at diagnosis of GDM. Furthermore, women managed with metformin had a higher early pregnancy body mass index (BMI) compared to those receiving insulin or diet and lifestyle modification (p < 0.001). There was no difference in mode of delivery, birth weight or incidence of large- or small-for-gestational-age neonates between groups. Women receiving glucose lowering therapies had a higher rate of neonatal hypoglycaemia (p < 0.05). The incidence of other adverse perinatal outcomes was similar between groups. Despite their greater BMI, women with metformin-treated GDM did not have an increased risk of adverse perinatal outcomes. Metformin is a useful alternative to insulin in the management of GDM.

Evaluation of Blood Glucose Meter Efficacy in an Antenatal Diabetes Clinic.

BACKGROUND: The optimal treatment of diabetes in pregnancy requires accurate measurement of blood glucose levels, in order to minimize adverse outcomes for both mother and neonate. Self-monitoring of blood glucose is routinely used to measure glycemic control and to assess whether treatment targets are being met; however, the accuracy of blood glucose meters in pregnancy is unclear. MATERIALS AND METHODS: Pregnant women with gestational, type 1, or type 2 diabetes mellitus were eligible to participate. Nonfasting capillary blood glucose levels were measured in duplicate using the BGStar(®) (Sanofi, Sydney, Australia) and FreeStyle Lite(®) (Abbott, Sydney) blood glucose meters. Venous blood samples were collected and analyzed for plasma glucose, hematocrit, and glycated hemoglobin. Capillary blood glucose was compared with plasma glucose and further assessed according to International Organization for Standardization (ISO) 15197:2013 standards. RESULTS: One hundred ten women were recruited, providing 96 samples suitable for analysis. The mean ± SD laboratory plasma glucose level was 4.6 ± 1.4 mmol/L; the BGStar and FreeStyle Lite capillary blood glucose values were 5.3 ± 1.4 mmol/L and 5.0 ± 1.3 mmol/L, respectively. Both meters showed a positive bias (0.42 mmol/L for the FreeStyle Lite and 0.65 mmol/L for the BGStar). Furthermore, neither meter fulfilled the ISO 15197:2013 standards, and there was a nonsignificant improvement in meter performance at blood glucose levels of ≤4.2 mmol/L. Hematocrit did not affect the results of either blood glucose meter. Clarke Error Grid analysis demonstrated that approximately 70% of the results of both meters would lead to appropriate clinical action. CONCLUSIONS: The BGStar and FreeStyle Lite blood glucose meters did not meet ISO 15197:2013 recommendations for blood glucose monitoring systems when assessed in a population of women with diabetes in pregnancy. Clinicians should consider this difference in blood glucose readings when making diabetes-related treatment decisions.

Rationale and design of Short-Term EXenatide therapy in Acute ischaemic Stroke (STEXAS): a randomised, open-label, parallel-group study.

INTRODUCTION: Both hyperglycaemia and hypoglycaemia in acute ischaemic stroke (AIS) are associated with increased infarct size and worse functional outcomes. Thus, therapies that can maintain normoglycaemia during stroke are clinically important. Glucagon-like peptide 1 (GLP-1) analogues, including exenatide, are routinely used in the treatment of hyperglycaemia in type 2 diabetes, but data on the usefulness of this class of agents in the management of elevated glucose levels in AIS are limited. Owing to their glucose-dependent mechanism of action, GLP-1 analogues are associated with a low risk of hypoglycaemia, which may give them an advantage over intensive insulin therapy in the acute management of hyperglycaemia in this setting. METHODS AND ANALYSIS: The Short-Term EXenatide therapy in Acute ischaemic Stroke study is a randomised, open-label, parallel-group pilot study designed to investigate the efficacy of exenatide at lowering blood glucose levels in patients with hyperglycaemia with AIS. A total of 30 patients presenting with AIS and blood glucose levels >10 mmol/L will be randomised to receive the standard therapy (intravenous insulin) or intravenous exenatide for up to 72 h. Outcomes including blood glucose levels within the target range (5-10 mmol/L), the incidence of hypoglycaemia and the feasibility of administering intravenous exenatide in this patient population will be assessed. A follow-up visit at 3 months will facilitate evaluation of neurological outcomes post-stroke. ETHICS AND DISSEMINATION: This study has been approved by the local Institutional Review Board (Northern Sydney Local Health District Human Research Ethics Committee). The study results will be communicated via presentations at scientific conferences and through publication in peer-reviewed journals. CONCLUSIONS: As GLP-1 analogues require elevated glucose levels to exert their insulin potentiating activity, the use of exenatide in the management of hyperglycaemia in AIS may reduce the incidence of hypoglycaemia, thereby conferring a benefit in morbidity and mortality for patients in the long term. TRIAL REGISTRATION NUMBER: ACTRN12614001189617.

Pharmacotherapy for the treatment of obesity.

The recognition of the complex counter-regulatory hormonal, metabolic and neurochemical mechanisms that promote weight regain following weight loss and the conceptualisation of obesity as a chronic disease requiring long-term management has led to increasing focus on the role of adjunctive therapies for obesity, particularly pharmacotherapy. Currently available pharmacotherapy achieves a weight loss intermediate between that commonly attained by lifestyle intervention and bariatric surgery, however its accessibility, compared to bariatric surgery increases its appeal. Despite the poor history of obesity pharmacotherapy, novel agents that are in development appear to have several advantages over predecessors. They are generally more selective in their mechanism of action, thereby potentially minimising adverse sequelae and improving the risk-benefit ratio of pharmacotherapy. Another approach has been to use combined pharmacotherapy to better counteract the multiple counter-regulatory neuroendocrine mechanisms which promote weight regain, as well as allowing lower constituent doses of the combined monotherapy agents, which improves the safety and tolerability of these agents that are usually required long-term for chronic weight maintenance. This review will provide an overview of past, present and future pharmacotherapy for obesity. The efficacy and safety profile of currently available pharmacotherapy will be discussed in the setting of stringent regulatory review processes now in place given the fraught history of pharmacological interventions for obesity. Potential novel therapies that seek to better target the multiple complex counter-regulatory mechanisms promoting weight regain while improving the efficacy/safety profile, will also be examined.

Intrinsic depot-specific differences in the secretome of adipose tissue, preadipocytes, and adipose tissue-derived microvascular endothelial cells.

OBJECTIVE: Visceral adipose tissue (VAT) is more closely linked to insulin resistance than subcutaneous adipose tissue (SAT). We conducted a quantitative analysis of the secretomes of VAT and SAT to identify differences in adipokine secretion that account for the adverse metabolic consequences of VAT. RESEARCH DESIGN AND METHODS: We used lectin affinity chromatography followed by comparison of isotope-labeled amino acid incorporation rates to quantitate relative differences in the secretomes of VAT and SAT explants. Because adipose tissue is composed of multiple cell types, which may contribute to depot-specific differences in secretion, we isolated preadipocytes and microvascular endothelial cells (MVECs) and compared their secretomes to those from whole adipose tissue. RESULTS: Although there were no discrete depot-specific differences in the secretomes from whole adipose tissue, preadipocytes, or MVECS, VAT exhibited an overall higher level of protein secretion than SAT. More proteins were secreted in twofold greater abundance from VAT explants compared with SAT explants (59% versus 21%), preadipocytes (68% versus 0%), and MVECs (62% versus 15%). The number of proteins in the whole adipose tissue secretome was greater than the sum of its cellular constituents. Finally, almost 50% of the adipose tissue secretome was composed of factors with a role in angiogenesis. CONCLUSIONS: VAT has a higher secretory capacity than SAT, and this difference is an intrinsic feature of its cellular components. In view of the number of angiogenic factors in the adipose tissue secretome, we propose that VAT represents a more readily expandable tissue depot.