Danish Diabetes Birth Registry 2: a study protocol of a national prospective cohort study to monitor outcomes of pregnancies of women with pre-existing diabetes

INTRODUCTION

Despite technological developments and intensified care, pregnancies in women with pre-existing diabetes are still considered high-risk pregnancies. The rate of adverse outcomes in pregnancies affected by diabetes in Denmark is currently unknown, and there is a limited understanding of mechanisms contributing to this elevated risk. To address these gaps, the Danish Diabetes Birth Registry 2 (DDBR2) was established. The aims of this registry are to evaluate maternal and fetal-neonatal outcomes based on 5 years cohort data, and to identify pathophysiology and risk factors associated with short-term and long-term outcomes of pregnancies in women with pre-existing diabetes.

METHODS AND ANALYSIS

The DDBR2 registry is a nationwide 5-year prospective cohort with an inclusion period from February 2023 to February 2028 of pregnancies in women with all types of pre-existing diabetes and includes registry, clinical and questionnaire data and biological samples of mother-partner-child trios. Eligible families (parents age ≥18 years and sufficient proficiency in Danish or English) can participate by either (1) basic level data obtained from medical records (mother and child) and questionnaires (partner) or (2) basic level data and additional data which includes questionnaires (mother and partner) and blood samples (all). The primary maternal outcome is Hemoglobin A1c (HbA1c) levels at the end of pregnancy and the primary offspring endpoint is the birth weight SD score. The DDBR2 registry will be complemented by genetic, epigenetic and metabolomic data as well as a biobank for future research, and the cohort will be followed through data from national databases to illuminate possible mechanisms that link maternal diabetes and other parental factors to a possible increased risk of adverse long-term child outcomes.

ETHICS AND DISSEMINATION

Approval from the Ethical Committee is obtained (S-20220039). Findings will be sought published in international scientific journals and shared among the participating hospitals and policymakers.

TRIAL REGISTRATION NUMBER

NCT05678543.

Clinical and Metabolic Characterization of Women With Gestational Diabetes Mellitus Within the First Year Postpartum

Context

Women with gestational diabetes mellitus (GDM) have an increased risk of long-term complications, including impaired glucose metabolism, type 2 diabetes (T2DM), cardiovascular disease, and obesity. In current clinical practice, a 1 size fits all approach to GDM is applied, although heterogeneity among women with GDM has been recognized.

Objective

To give the most adequate preventive care and postpartum (PP) guidance, we aimed to make a metabolic characterization and identify subgroups of women with previous GDM within the first year PP.

Methods

In this prospective cohort study, we collected data in gestational week 34-38, at 3 months, and 1 year PP on women with GDM who participated in a PP follow-up program in Central Region Denmark from April 2019 to December 2022.

Results

In total, 1270 women were included in the program in late pregnancy. Of the 768 women participating in either the oral glucose tolerance test 3 months PP (n = 545) or the 1-year follow-up (n = 493) or both (n = 261), 608 (79.2%) were normoglycemic, 137 (17.8%) had prediabetes, 20 (2.6%) had T2DM, and 3 (.4%) had developed T1DM. More than 40% of the women gained weight in the first year PP compared with their pregestational weight.

Conclusion

Our study shows that 20.8% of women with GDM who volunteered to participate in a clinical follow-up program developed prediabetes or diabetes (T1DM and T2DM) within the first year PP. The GDM diagnosis encompasses a heterogenetic group of women and a deeper characterization may provide an opportunity for a more personalized risk assessment to prevent the progression to T2DM.

Advances in extracellular vesicles as mediators of cell-to-cell communication in pregnancy

Cell-to-cell communication mediated by Extracellular Vesicles (EVs) is a novel and emerging area of research, especially during pregnancy, in which placenta derived EVs can facilitate the feto-maternal communication. EVs comprise a heterogeneous group of vesicle sub-populations with diverse physical and biochemical characteristics and originate by specific biogenesis mechanisms. EVs transfer molecular cargo (including proteins, nucleic acids, and lipids) between cells and are critical mediators of cell communication. There is growing interest among researchers to explore into the molecular cargo of EVs and their functions in a physiological and pathological context. For example, inflammatory mediators such as cytokines are shown to be released in EVs and EVs derived from immune cells play key roles in mediating the immune response as well as immunoregulatory pathways. Pregnancy complications such as gestational diabetes mellitus, preeclampsia, intrauterine growth restriction and preterm birth are associated with altered levels of circulating EVs, with differential EV cargo and bioactivity in target cells. This implicates the intriguing roles of EVs in reprogramming the maternal physiology during pregnancy. Moreover, the capacity of EVs to carry bioactive molecules makes them a promising tool for biomarker development and targeted therapies in pregnancy complications. This review summarizes the physiological and pathological roles played by EVs in pregnancy and pregnancy-related disorders and describes the potential of EVs to be translated into clinical applications in the diagnosis and treatment of pregnancy complications.

Insulin Signaling Is Preserved in Skeletal Muscle During Early Diabetic Ketoacidosis

BACKGROUND AND AIMS

During diabetic ketoacidosis (DKA), muscle tissue develops a profound insulin resistance that complicates reversal of this potentially lethal condition. We have investigated mediators of insulin action in human skeletal muscle during total insulin withdrawal in patients with type 1 diabetes, under the hypothesis that initial phases of DKA are associated with impaired postreceptor signaling.

MATERIALS AND METHODS

Muscle biopsies were obtained during a randomized, controlled, crossover trial involving 9 patients with type 1 diabetes. The subjects were investigated during a high-dose insulin clamp preceded by either: (1) insulin-controlled euglycemia (control) or (2) total insulin withdrawal for 14 hours. Insulin action in skeletal muscle and whole-body substrate metabolism were investigated using western blot analysis and indirect calorimetry respectively.

RESULTS

During insulin withdrawal, insulin-stimulated dephosphorylation of glycogen synthase decreased by ∼30% (P < .05) compared with the control situation. This was associated with a decrease in glucose oxidation by ∼30% (P < .05). Despite alterations in glucose metabolism, insulin transduction to glucose transport and protein synthesis (Akt, AS160, mammalian target of rapamycin, and eukaryotic translation initiation factor 4E binding protein) was intact, and glucose transporter (GLUT4) and mitochondrial proteins (succinate dehydrogenase complex, subunit A and prohibitin 1) protein expression were unaffected by the intervention.

CONCLUSION

DKA impairs insulin-stimulated activation of glycogen synthase, whereas insulin signal transduction to glucose transport and protein synthesis remains intact. Reversal of insulin resistance during treatment of DKA should target postreceptor mediators of glucose uptake.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02077348.

Nutrient sensing: LEAP2 concentration in response to fasting, glucose, lactate, and β-hydroxybutyrate in healthy young males

BACKGROUND

The appetite-suppressing potential of liver-expressed antimicrobial peptide 2 (LEAP2), and its antagonistic effects on the hunger-inducing hormone ghrelin have attracted scientific interest. It is unclear how LEAP2 is influenced by fasting and how it responds to specific nutrients.

OBJECTIVES

The purpose of this investigation was to assess whether LEAP2 concentration 1) decreases after fasting, 2) increases postprandially, and 3) is regulated by nutrient sensing in the splanchnic bed.

METHODS

Plasma LEAP2 concentration was measured in blood samples from 5 clinical cross-over trials, following 1) 36 h of fasting (n = 8), 2) 10 h of fasting (n = 37, baseline data pooled from 4 of the clinical trials), 3) Oral and intravenous glucose administration (n = 11), 4) Oral and intravenous Na-lactate administration (n = 10), and 5) Oral and intravenous Na-β-hydroxybutyrate (BHB) administration (n = 8). All 5 trials included healthy males.

RESULTS

Compared with a 10-h fasting period, the median LEAP2 concentration was 38% lower following 36 h of fasting (P < 0.001). Oral administration of glucose elevated, whereas intravenous glucose administration lowered LEAP2 concentration (intervention x time, P = 0.001), resulting in a mean difference of 9 ng/mL (95% confidence interval [CI]: 1, 17) after 120 min. Oral lactate increased, and intravenous lactate decreased LEAP2 (intervention x time, P = 0.007), with a mean difference between interventions of 10 ng/mL (95% CI: 6, 15) after 120 min. In contrast, oral and intravenous administration of BHB reduced the LEAP2 concentration (main effect of time, P < 0.001).

CONCLUSIONS

Our investigations show that LEAP2 concentration was lower after a 36-h fast than an overnight fast and that oral delivery of glucose and lactate elevated LEAP2 concentration compared with intravenous administration, whereas LEAP2 concentrations decreased with both oral and intravenous BHB. This indicates that the LEAP2 concentration is sensitive to intestinal exposure to specific substrates, highlighting the need for future studies exploring the relationship between nutrients and LEAP2. This trial was registered at clinicaltrials.gov as NCT01840098, NCT03204877, NCT04299815, NCT03935841, and NCT01705782.

Health promotion intervention among women with recent gestational diabetes mellitus: penetration, participation, and baseline findings from the Face-it randomized controlled trial

INTRODUCTION

Face-it is a randomized controlled trial for women with recent gestational diabetes mellitus (GDM) and their families designed to evaluate the effect of a health promotion intervention on type 2 diabetes mellitus (T2DM) risk and quality of life. This study examined (1) the penetration and participation rates for the Face-it trial, (2) the characteristics of the participating women and the potential differences in characteristics according to partner participation status, and (3) representativity of the women at baseline.

RESEARCH DESIGN AND METHODS

We identified women with GDM during pregnancy and invited them and their partners to a baseline examination 10-14 weeks after delivery. Representativity was assessed by comparing the baseline participants with non-participating women, the general population of women with GDM delivering in Denmark, and populations from other intervention trials.

RESULTS

The penetration rate was 38.0% (867/2279) and the participation rate was 32.9% (285/867). The 285 women who attended baseline had a mean age of 32.7 (±4.8) years and body mass index (BMI) of 28.1 (±5.4) kg/m2, and 69.8% had a partner who participated. The women participating with a partner were more often primiparous, born in Denmark (82.8% vs 68.2%), were younger, and more often had a BMI ≤24.9 kg/m2 (35.7% vs 21.2%) compared with women without a partner. Compared with the general population of women with GDM in Denmark, these women broadly had similar degree of heterogeneity, but had higher rates of primiparity and singleton deliveries, and lower rates of preterm delivery and prepregnancy obesity.

CONCLUSIONS

The penetration and participation rates were acceptable. We found a high rate of partner participation. Overall, women participating with a partner were comparable with those participating without a partner. Participating women were broadly similar to the general national GDM population, however with prepregnancy obesity, multiparity, preterm delivery, and multiple pregnancy being less represented.

TRIAL REGISTRATION NUMBER

NCT03997773.

Whey Protein Premeal Lowers Postprandial Glucose Concentrations in Adults Compared with Water-The Effect of Timing, Dose, and Metabolic Status: a Systematic Review and Meta-analysis

BACKGROUND

Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly understood but may involve stimulation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin secretion together with a slower gastric emptying rate.

OBJECTIVES

The objective of this systematic review and meta-analysis was to review all randomized clinical trials investigating premeals with whey protein in comparison with a nonactive comparator (control) that evaluated plasma glucose, GLP-1, GIP, insulin, and/or gastric emptying rate. Secondary aims included subgroup analyses on the timing and dose of the premeal together with the metabolic state of the participants [lean, obese, and type 2 diabetes mellitus (T2DM)].

METHODS

We searched EMBASE, CENTRAL, PUBMED, and clinicaltrials.gov and found 16 randomized crossover trials with a total of 244 individuals. The last search was performed on 9 August, 2022.

RESULTS

Whey protein premeals lowered peak glucose concentration by -1.4 mmol/L [-1.9 mmol/L; -0.9 mmol/L], and the area under the curve for glucose was -0.9 standard deviation (SD) [-1.2 SD; -0.6 SD] compared with controls (high certainty). In association with these findings, whey protein premeals elevated GLP-1 (low certainty) and peak insulin (high certainty) concentrations and slowed gastric emptying rate (high certainty) compared with controls. Subgroup analyses showed a more pronounced and prolonged glucose-lowering effect in individuals with T2DM compared with participants without T2DM. The available evidence did not elucidate the role of GIP. The protein dose used varied between 4 and 55 g, and meta-regression analysis showed that the protein dose correlated with the glucose-lowering effects.

CONCLUSIONS

In conclusion, whey protein premeals lower postprandial blood glucose, reduce gastric emptying rate, and increase peak insulin. In addition, whey protein premeals may elevate plasma concentrations of GLP-1. Whey protein premeals may possess clinical potential, but the long-term effects await future clinical trials.

Breastfeeding and insulin requirements in women with Type 1 diabetes mellitus in the first year postpartum

AIMS

To explore whether breastfeeding affects postpartum insulin requirements, HbA1c levels, and pregnancy weight retention in women with Type 1 Diabetes Mellitus (T1DM).

METHODS

This prospective study included 66 women with T1DM. The women were divided into two groups based on whether they were breastfeeding (BF) at 6 months postpartum (BF_yes, n = 32) or not (BF_no, n = 34). Mean daily insulin requirement (MDIR), HbA1c levels, and pregnancy weight retention at 5 time-points from discharge to 12 months postpartum were compared.

RESULTS

MDIR increased by 35% from 35.7 IU at discharge to 48.1 IU at 12 months postpartum (p < 0.001). MDIR in BF_yes and BF_no were comparable, however in BF_yes, MDIR were continuously lower compared to BF_no. Postpartum HbA1c increased rapidly from 6.8% at 1 month to 7.4% at 3 months postpartum and settled at 7.5% at 12 months postpartum. The increase in HbA1c during the first 3 months postpartum was most pronounced in BF_no (p < 0.001). Although neither were statistically significant, from 3 months postpartum HbA1c levels were highest in the BF_no and BF_no had a higher pregnancy weight retention compared to BF_yes (p = 0.31).

CONCLUSION

In women with T1DM, breastfeeding did not significantly affect postpartum insulin requirements, HbA1c levels or pregnancy weight retention in the first year after delivery.

Hyperglycemia in Pregnancy and Women's Health in the 21st Century

Hyperglycemia is the commonest medical condition affecting pregnancy and its incidence is increasing globally in parallel with the twin epidemics of diabetes and obesity. Both pre-pregnancy diabetes and gestational diabetes are associated with short term pregnancy complications, with the risk of immediate complications generally broadly rising with more severe hyperglycemia. In this article we firstly consider these risks and their optimal management during pregnancy and then broaden our scope to consider the long-term implications of hyperglycemia in pregnancy as it relates to overall maternal and offspring health in a life course perspective.

Three months of melatonin treatment reduces insulin sensitivity in patients with type 2 diabetes-A randomized placebo-controlled crossover trial

The use of the sleep-promoting hormone melatonin is rapidly increasing as an assumed safe sleep aid. During the last decade, accumulating observations suggest that melatonin affects glucose homeostasis, but the precise role remains to be defined. We investigated the metabolic effects of long-term melatonin treatment in patients with type 2 diabetes including determinations of insulin sensitivity and glucose-stimulated insulin secretion. We used a double-blinded, randomized, placebo-controlled, crossover design. Seventeen male participants with type 2 diabetes completed (1) 3 months of daily melatonin treatment (10 mg) 1 h before bedtime (M) and (2) 3 months of placebo treatment 1 h before bedtime (P). At the end of each treatment period, insulin secretion was assessed by an intravenous glucose tolerance test (0.3 g/kg) (IVGTT) and insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp (insulin infusion rate 1.5 mU/kg/min) (primary endpoints). Insulin sensitivity decreased after melatonin (3.6 [2.9-4.4] vs. 4.1 [3.2-5.2] mg/(kg × min), p = .016). During the IVGTT, the second-phase insulin response was increased after melatonin (p = .03). In conclusion, melatonin treatment of male patients with type 2 diabetes for 3 months decreased insulin sensitivity by 12%. Clinical use of melatonin treatment in dosages of 10 mg should be reserved for conditions where the benefits will outweigh the potential negative impact on insulin sensitivity.

[Pregnancy after simultaneouspancreasandkidney transplantation]

In this case report, a 41-year-old nullipara obtained pregnancy one and a half year after a simultaneous pancreas and kidney transplantation (SKP). After SKP, the woman had no need for insulin and no hypertension. Her kidney function was stable during pregnancy and no insulin was needed. During the last weeks of pregnancy, increased blood pressure was seen. Biochemically, there were no signs of preeclampsia and no proteinuria. An elective cesarean section was performed in gestational week 37+5 and a healthy boy, 2,710 g. (-1.2 standarddeviation) was born. Pregnancy after SKP is possible and can have a good prognosis.

The Arg82Cys polymorphism of the protein nepmucin implies a role in HDL metabolism

Context

Blood lipid levels are linked to the risk of cardiovascular disease and regulated by genetic factors. A low-frequency polymorphism Arg82Cys (rs72836561) in the membrane protein nepmucin, encoded by CD300LG, is associated with lower fasting concentration of high-density lipoprotein cholesterol (HDLc) and higher fasting triglycerides. However, whether the variant is linked to postprandial lipids and glycemic status remains elusive.

Objective

Here, we augment the genetic effect of Arg82Cys on fasting plasma concentrations of HDL subclasses, postprandial lipemia after a standardized high-fat meal, and glycemic status to further untangle its role in HDL metabolism.

Methods

We elucidated fasting associations with HDL subclasses in a population-based cohort study (Oxford BioBank, OBB), including 4522 healthy men and women. We investigated fasting and postprandial consequences on HDL metabolism in recall-by-genotype (RbG) studies (fasting: 20 carrier/20 noncarrier; postprandial: 7 carrier/17 noncarrier), and shed light on the synergistic interaction with glycemic status.

Results

A lower fasting plasma concentration of cholesterol in large HDL particles was found in healthy male carriers of the Cys82 polymorphism compared to noncarriers, both in the OBB (P = .004) and RbG studies (P = .005). In addition, the Cys82 polymorphism was associated with low fasting plasma concentrations of ApoA1 (P = .008) in the OBB cohort. On the contrary, we did not find differences in postprandial lipemia or 2-hour plasma glucose levels.

Conclusion

Taken together, our results indicate an association between the Arg82Cys variant and a lower concentration of HDL particles and HDLc, especially in larger HDL subclasses, suggesting a link between nepmucin and HDLc metabolism or maturation.

Ambivalence and moral dilemmas in women's lived experiences of obesity and pregnancy: Qualitative insights for maternal lifestyle interventions

BACKGROUND

Maternal obesity is a global health concern that is associated with significant effects on both short- and long-term health of both mother and child. However, maternal lifestyle interventions tend to focus solely on diet and physical activity in ways that disembody and disengage the social context in which women live their lives.

AIMS

The aim of this study was to explore the lived experiences of maternal obesity and delve into how experiences of the body and motherhood affect women's motivation for participating in a postpartum lifestyle intervention.

METHOD

A qualitative study using in-depth semi-structured interviews based on participant-generated photographs was used to allow the women to openly express their lived experiences of maternal obesity. The study emanated from a gynaecological department of a major Danish hospital, and five pregnant or postpartum women living with obesity participated. Interviews were audio recorded, transcribed and analysed using an Interpretive Phenomenological Approach.

RESULTS

The analysis identified an overall theme of ambivalence and four subthemes among the participating women. The themes reflected contrasting feelings where the obese body was simultaneously an arena for aesthetic failure, functional success and moral dilemmas. Experiences of weight stigma and moral accusations in healthcare settings further increased the women's sense of ambivalence and challenged their strong desire to lose weight.

CONCLUSION

This study highlights an ambivalent and vulnerable situation of maternal obesity which makes moral sensitivity towards weight and body concerns crucial to consider in future maternal health interventions. Our data suggest that an emphasis on functionality and capability rather than aesthetics and measured ideals would be useful in providing care and support in postpartum lifestyle interventions for women living with obesity.

The Effect of Melatonin on Incretin Hormones: Results From Experimental and Randomized Clinical Studies

CONTEXT

Glucose homeostasis is under circadian control through both endocrine and intracellular mechanisms, with several lines of evidence suggesting that melatonin affects glucose homeostasis.

OBJECTIVE

To evaluate the acute in vivo and in situ effects of melatonin on secretion of the incretin hormones, glucagon-like-peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), and their impact on β-cell insulin secretion.

DESIGN

A human randomized, double-blinded, placebo-controlled crossover study combined with a confirmatory in situ study of perfused rat intestines.

SETTING

Aarhus University Hospital.

METHODS

Fifteen healthy male participants were examined 2 × 2 times: an oral glucose tolerance test (OGTT) was performed on day 1 and an isoglycemic IV glucose infusion replicating the blood glucose profile of the OGTT day was performed on day 2. These pairs of study days were repeated on treatment with melatonin and placebo, respectively. For the in situ study, 6 rat intestines and 4 rat pancreases were perfused arterially with perfusion buffer ± melatonin. The intestines were concomitantly perfused with glucose through the luminal compartment.

RESULTS

In humans, melatonin treatment resulted in reduced GIP secretion compared with placebo (ANOVA P = 0.003), an effect also observed in the perfused rat intestines (ANOVA P = 0.003), in which GLP-1 secretion also was impaired by arterial melatonin infusion (ANOVA P < 0.001). Despite a decrease in GIP levels, the in vivo glucose-stimulated insulin secretion was unaffected by melatonin (P = 0.78).

CONCLUSION

Melatonin reduced GIP secretion during an oral glucose challenge in healthy young men but did not affect insulin secretion. Reduced GIP secretion was confirmed in an in situ model of the rat intestine.

Human skeletal muscle CD90+ fibro-adipogenic progenitors are associated with muscle degeneration in type 2 diabetic patients

Type 2 diabetes mellitus (T2DM) is associated with impaired skeletal muscle function and degeneration of the skeletal muscles. However, the mechanisms underlying the degeneration are not well described in human skeletal muscle. Here we show that skeletal muscle of T2DM patients exhibit degenerative remodeling of the extracellular matrix that is associated with a selective increase of a subpopulation of fibro-adipogenic progenitors (FAPs) marked by expression of THY1 (CD90)-the FAP^CD90+. We identify platelet-derived growth factor (PDGF) as a key FAP regulator, as it promotes proliferation and collagen production at the expense of adipogenesis. FAPs^CD90+ display a PDGF-mimetic phenotype, with high proliferative activity, clonogenicity, and production of extracellular matrix. FAP^CD90+ proliferation was reduced by in vitro treatment with metformin. Furthermore, metformin treatment reduced FAP content in T2DM patients. These data identify a PDGF-driven conversion of a subpopulation of FAPs as a key event in the fibrosis development in T2DM muscle.

Effects of daily administration of melatonin before bedtime on fasting insulin, glucose and insulin sensitivity in healthy adults and patients with metabolic diseases. A systematic review and meta-analysis

BACKGROUND

Melatonin is increasingly used as a pharmacological sleep aid but it is also emerging as a regulator of glucose homoeostasis. Yet, previous research has been ambiguous with reports of both positive and negative effects of melatonin on glucose metabolism.

OBJECTIVES

To assess the effect of daily treatment with melatonin on fasting glucose, insulin, insulin sensitivity and haemoglobin A1c (HbA1c) levels.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL, clinicaltrials.gov and clinicaltrialsregister.eu were systematically searched.

ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

All randomized, placebo-controlled studies with melatonin treatment were assessed. We included studies with daily melatonin treatment (≥2 weeks) of healthy adults or patients with metabolic diseases.

METHODS

Hedges' g differences were calculated for the metabolic parameters of the included studies, heterogeneity was assessed with χ² and I² tests and meta-analyses were performed with the random-effects model.

RESULTS

Long-term treatment with melatonin did not change fasting glucose significantly compared with placebo (g: -0.07 [-0.22 to 0.08], n = 603) but it reduced fasting insulin levels slightly (g: -0.27 [-0.50 to -0.04], n = 278) and trended towards reduced insulin resistance (HOMA-IR) (g: -0.20 [-0.44 to 0.03], n = 278). HbA1c levels were largely unaffected by melatonin treatment compared with placebo (g: 0.14 [-0.19 to 0.46], n = 142).

CONCLUSIONS

With the available literature, melatonin seems to be a glucose-metabolic safe sleep aid in patients with metabolic diseases and in healthy adults. It may even have beneficial glucose-metabolic effects as fasting insulin levels were reduced in this meta-analysis, but the confidence intervals of the meta-analyses are wide, underscoring the need for further research within this field.

Systematically developing a family-based health promotion intervention for women with prior gestational diabetes based on evidence, theory and co-production: the Face-it study

BACKGROUND

Women with prior gestational diabetes mellitus (GDM) are at high risk of developing type 2 diabetes; however, this risk can be reduced by engaging in positive health behaviours e.g. healthy diet and regular physical activity. As such behaviours are difficult to obtain and maintain there is a need to develop sustainable behavioural interventions following GDM. We aimed to report the process of systematically developing a health promotion intervention to increase quality of life and reduce diabetes risk among women with prior GDM and their families. We distil general lessons about developing complex interventions through co-production and discuss our extensions to intervention development frameworks.

METHODS

The development process draws on the Medical Research Council UK Development of complex interventions in primary care framework and an adaptation of a three-stage framework proposed by Hawkins et al. From May 2017 to May 2019, we iteratively developed the Face-it intervention in four stages: 1) Evidence review, qualitative research and stakeholder consultations; 2) Co-production of the intervention content; 3) Prototyping, feasibility- and pilot-testing and 4) Core outcome development. In all stages, we involved stakeholders from three study sites.

RESULTS

During stage 1, we identified the target areas for health promotion in families where the mother had prior GDM, including applying a broad understanding of health and a multilevel and multi-determinant approach. We pinpointed municipal health visitors as deliverers and the potential of using digital technology. In stage 2, we tested intervention content and delivery methods. A health pedagogic dialogue tool and a digital health app were co-adapted as the main intervention components. In stage 3, the intervention content and delivery were further adapted in the local context of the three study sites. Suggestions for intervention manuals were refined to optimise flexibility, delivery, sequencing of activities and from this, specific training manuals were developed. Finally, at stage 4, all stakeholders were involved in developing realistic and relevant evaluation outcomes.

CONCLUSIONS

This comprehensive description of the development of the Face-it intervention provides an example of how to co-produce and prototype a complex intervention balancing evidence and local conditions. The thorough, four-stage development is expected to create ownership and feasibility among intervention participants, deliverers and local stakeholders.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03997773 , registered retrospectively on 25 June 2019.

The Impact of Lifestyle, Diet and Physical Activity on Epigenetic Changes in the Offspring-A Systematic Review

Aims: This systematic review examines the association between maternal lifestyle, diet and physical activity, and epigenetic changes in the offspring. Methods: A literature search was conducted using multiple science databases: PubMed, Embase and Cochrane Library, on 10 March 2021. RCT and Cohort studies in English or Scandinavian languages were included. Exposure variables included diet, lifestyle, meal patterns or physical activity. Studies using dietary supplements as exposure variables were excluded. Outcome variables included were DNA methylation, microRNA or histone changes in placenta, cord blood or offspring. Two independent authors screened, read and extracted data from the included papers. The Cochrane risk-of-bias tool for randomized trials (RoB2) and The Critical Appraisal Skills Program (CASP) Cohort Study Checklist were used to assess risk of bias in the included studies. A qualitative approach was employed due to heterogeneity of exposures and results of the studies. Results: 16 studies and 3617 participants were included in the final analysis. The exposure variables included physical activity, carbohydrate, low glycemic index diet, added sugar, fat, Mediterranean diet and pro-inflammatory diet. The outcome variables identified were differences in DNA methylation and microRNA. Most studies described epigenetic changes in either placenta or cord blood. Genes reported to be methylated were GR, HSD2, IGF-2, PLAG1, MEG-3, H19 and RXRA. However, not all studies found epigenetic changes strong enough to pass multiple testing, and the study quality varied. Conclusion: Despite the variable quality of the included studies, the results in this review suggest that there may be an association between the mother’s lifestyle, diet and level of physical activity during pregnancy and epigenetic changes in the offspring.

Intrahepatic cholestasis of pregnancy: Association with glycaemic control in gestational diabetes

AIMS

The aim of this study was to determine whether the metabolic glucose profile, based on glycaemic control and insulin requirements, was different in women with gestational diabetes mellitus (GDM) and intrahepatic cholestasis of pregnancy (ICP) compared to women with only GDM.

METHODS

This retrospective cohort study comprised women with GDM and ICP matched with women with only GDM was undertaken at Aarhus University hospital, Denmark, from 2012 to 2019. A total of 46 cases and 184 controls were compared in relation to glycaemic control during pregnancy. Women with GDM and ICP were further divided into subgroups according to the severity of ICP: mild ICP (fasting bile salts 10-39 μmol/L) and moderate/severe ICP (bile salts ≥40 μmol/L).

RESULTS

No statistically significant differences were observed in baseline 2-h oral glucose tolerance test values, second and third trimester HbA_1c values, or maximum insulin requirements during pregnancy between women with GDM with and without ICP. Significantly more women with ICP developed preeclampsia during pregnancy: 23.9% (11/46) versus 7.6% (14/184); p = 0.003.

CONCLUSIONS

This study is the first to address the course of pregnancy in women with GDM with and without ICP in a clinical setting. Under the current treatment guidelines, ICP is not associated with clinically significant changes in glycaemic control in GDM. Significantly more women with both GDM and ICP developed preeclampsia.

Extreme insulin resistance during pregnancy: a therapeutic challenge

SUMMARY

During pregnancy, maternal tissues become increasingly insensitive to insulin in order to liberate nutritional supply to the growing fetus, but occasionally insulin resistance in pregnancy becomes severe and the treatment challenging. We report a rare and clinically difficult case of extreme insulin resistance with daily insulin requirements of 1420 IU/day during pregnancy in an obese 36-year-old woman with type 2 diabetes (T2D) and polycystic ovary syndrome (PCOS). The woman was referred to the outpatient clinic at gestational week 12 + 2 with a hemoglobin A1c (HbA1c) at 59 mmol/mol. Insulin treatment was initiated immediately using Novomix 30, and the doses were progressively increased, peaking at 1420 units/day at week 34 + 4. At week 35 + 0, there was an abrupt fall in insulin requirements, but with no signs of placental insufficiency. At week 36 + 1 a, healthy baby with no hypoglycemia was delivered by cesarean section. Blood samples were taken late in pregnancy to search for causes of extreme insulin resistance and showed high levels of C-peptide, proinsulin, insulin-like growth factor (IGF-1), mannan-binding-lectin (MBL) and leptin. CRP was mildly elevated, but otherwise, levels of inflammatory markers were normal. Insulin antibodies were undetectable, and no mutations in the insulin receptor (INSR) gene were found. The explanation for the severe insulin resistance, in this case, can be ascribed to PCOS, obesity, profound weight gain, hyperleptinemia and inactivity. This is the first case of extreme insulin resistance during pregnancy, with insulin requirements close to 1500 IU/day with a successful outcome, illustrating the importance of a close interdisciplinary collaboration between patient, obstetricians and endocrinologists.

LEARNING POINTS

This is the first case of extreme insulin resistance during pregnancy, with insulin requirements of up to 1420 IU/day with a successful outcome without significant fetal macrosomia and hypoglycemia. Obesity, PCOS, T2D and high levels of leptin and IGF-1 are predictors of severe insulin resistance in pregnancy. A close collaboration between patient, obstetricians and endocrinologists is crucial for tailoring the best possible treatment for pregnant women with diabetes, beneficial for both the mother and her child.

Trans-ethnic gut microbiota signatures of type 2 diabetes in Denmark and India

Background

Type 2 diabetes (T2D), a multifactorial disease influenced by host genetics and environmental factors, is the most common endocrine disease. Several studies have shown that the gut microbiota as a close-up environmental mediator influences host physiology including metabolism. The aim of the present study is to examine the compositional and functional potential of the gut microbiota across individuals from Denmark and South India with a focus on T2D. Many earlier studies have investigated the microbiome aspects of T2D, and it has also been anticipated that such microbial associations would be dependent on diet and ethnic origin. However, there has been no large scale trans-ethnic microbiome study earlier in this direction aimed at evaluating any “universal” microbiome signature of T2D.

Methods

16S ribosomal RNA gene amplicon sequencing was performed on stool samples from 279 Danish and 294 Indian study participants. Any differences between the gut microbiota of both populations were explored using diversity measures and negative binomial Wald tests. Study samples were stratified to discover global and country-specific microbial signatures for T2D and treatment with the anti-hyperglycemic drug, metformin. To identify taxonomical and functional signatures of the gut microbiota for T2D and metformin treatment, we used alpha and beta diversity measures and differential abundances analysis, comparing metformin-naive T2D patients, metformin-treated T2D patients, and normoglycemic individuals.

Results

Overall, the gut microbial communities of Danes and Indians are compositionally very different. By analyzing the combined study materials, we identify microbial taxonomic and functional signatures for T2D and metformin treatment. T2D patients have an increased relative abundance of two operational taxonomic units (OTUs) from the Lachnospiraceae family, and a decreased abundance of Subdoligranulum and Butyricicoccus. Studying each population per se, we identified T2D-related microbial changes at the taxonomic level within the Danish population only.

Alpha diversity indices show that there is no significant difference between normoglycemic individuals and metformin-naive T2D patients, whereas microbial richness is significantly decreased in metformin-treated T2D patients compared to metformin-naive T2D patients and normoglycemic individuals. Enrichment of two OTUs from Bacteroides and depletion of Faecalibacterium constitute a trans-ethnic signature of metformin treatment.

Conclusions

We demonstrate major compositional differences of the gut microbiota between Danish and South Indian individuals, some of which may relate to differences in ethnicity, lifestyle, and demography. By comparing metformin-naive T2D patients and normoglycemic individuals, we identify T2D-related microbiota changes in the Danish and Indian study samples. In the present trans-ethnic study, we confirm that metformin changes the taxonomic profile and functional potential of the gut microbiota.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00856-4.

Acute metabolic effects of melatonin-A randomized crossover study in healthy young men

Melatonin regulates circadian rhythm, but may also have effects on glucose homeostasis. A common G-allele in the MTNR1B locus has been associated with an increased risk of type 2 diabetes (T2DM). We aimed to examine acute effects of high doses of melatonin on glucose metabolism with attention to MTNR1B genotype. Twenty men were examined in a double-blinded, randomized crossover study on two nonconsecutive days with four doses of 10 mg oral melatonin or placebo. Insulin sensitivity and insulin secretion were assessed by an intravenous glucose tolerance test (IVGTT) and a hyperinsulinaemic-euglycaemic clamp (HEC). Blood samples were drawn to determine the metabolic profile and MTNR1B rs10830963 genotype. Indirect calorimetry and blood pressure measurements were also performed. Insulin sensitivity index was significantly reduced on the melatonin day (P = .028) in the whole group and in homozygous carriers of the rs10830963 C-allele (P = .041). Glucose during the IVGTT was unaffected, but there was a tendency towards lower insulin and C-peptide levels in the first minutes after glucose administration in G-allele carriers. Systolic blood pressure decreased and lipid oxidation increased significantly on the melatonin day in rs10830963 G-allele carriers. Overall, our study reports that acute administration of melatonin in supra-physiological doses may have a negative impact on insulin sensitivity. Clinical trial registration number (clinicaltrial.gov): NCT03204877.

"High prepregnancy HbA1c is challenging to improve and affects insulin requirements, gestational length, and birthweight"

BACKGROUND

The aim of this study was to explore how prepregnancy glycosylated hemoglobin (HbA1c) affects the course of HbA1c and insulin requirements during pregnancy, the gestational length, and birthweight.

METHODS

An observational cohort study was conducted consisting of 380 women with type 1 diabetes who gave birth 530 times from 2004 to 2014. The participants were divided into four groups according to prepregnancy HbA1c.

RESULTS

HbA1c was significantly different between the groups at all time intervals from week 5 to 10 to week 33 to 36 (P ≤ .01). In group 1, with the lowest prepregnancy HbA1c (<6.5% [48 mmol/mol]), HbA1c stayed at the same level throughout pregnancy. In the other groups (group 2: 6.5% [48 mmol/mol]-7.9% [63 mmol/mol], group 3: 8% [64 mmol/mol]-9.9% [86 mmol/mol], and group 4: > 10% [86 mmol/mol]) a decrease in HbA1c was seen in early pregnancy but stabilized from midpregnancy onward. Group 1 had the lowest daily insulin requirements throughout pregnancy among the four groups (P = .001). The relationship between birthweight and prepregnancy HbA1c was found to be inversely U-shaped. Mean gestational length in group 4 was significantly shorter than in group 1 (P = .001).

CONCLUSIONS

In this very large cohort, we found that a poor prepregnancy HbA1c is a predictor for poor glycemic control during pregnancy and that HbA1c decreases until midpregnancy and then plateaus. A very poor prepregnancy HbA1c is associated with shorter gestational length and lower birthweight, which is contrary to the common assumption that poor glycemic control leads to higher birthweight.

Changes in insulin sensitivity and insulin secretion during pregnancy and post partum in women with gestational diabetes

INTRODUCTION

The metabolic abnormalities underlying gestational diabetes mellitus (GDM) include increased insulin resistance and beta cell defects, but it is essential to clarify how insulin resistance and insulin secretion develop post partum in order to decide when and how to screen for type 2 diabetes. The purpose of the present study was to characterize and compare changes in insulin sensitivity, insulin secretion and hormonal status around parturition and 6 months post partum in women with gestational diabetes.

RESEARCH DESIGN AND METHODS

A longitudinal experimental study was performed at Aarhus University Hospital, Denmark. Eight women with GDM were examined at three identical visits: in late pregnancy (LP) between gestational age 34+0 and 36+6, early post partum (EPP) between 12 and 34 days post partum, and late post partum (LPP) 6 months post partum. An intravenous glucose tolerance test was performed, followed by a hyperinsulinemic euglycemic clamp. Blood samples were collected to assess metabolic, hormonal and inflammatory markers at each visit.

RESULTS

First and second phase insulin secretion and C-peptide concentrations were higher in late pregnancy than post partum (p<0.001). Insulin sensitivity index (ISI) was different at all three visits: ISI_LP=0.03±0.004, ISI_EPP=0.09±0.008 and ISI_LPP=0.07±0.008) (p<0.001). Also, significant changes in lipids, leptin, glucagon, growth hormone and insulin-like growth factor-1 were seen when comparing the visits.

CONCLUSIONS

Insulin sensitivity improves immediately after delivery in women with GDM but seems to deteriorate within the first 6 months post partum. Our findings underline the importance of having an increased awareness of the profound risk of developing type 2 diabetes after GDM.

TRIAL REGISTRATION NUMBER

NCT02770079.

Efficacy and Safety of Glimepiride With or Without Linagliptin Treatment in Patients With HNF1A Diabetes (Maturity-Onset Diabetes of the Young Type 3): A Randomized, Double-Blinded, Placebo-Controlled, Crossover Trial (GLIMLINA)

OBJECTIVE

Sulfonylureas are first-line treatment of hepatocyte nuclear factor 1-α (HNF1A) diabetes (maturity-onset diabetes of the young type 3), but many patients do not achieve optimal glycemic control without episodes of hypoglycemia. We investigated the combination of the sulfonylurea glimepiride and the dipeptidyl peptidase 4 inhibitor linagliptin versus glimepiride monotherapy with respect to glycemic variability, glycemic control, and risk of hypoglycemia.

RESEARCH DESIGN AND METHODS

In a randomized, double-blinded, crossover trial, patients with HNF1A diabetes (n = 19; mean ± SD age 43 ± 14 years, BMI 24.8 ± 2.8 kg/m², and glycated hemoglobin [HbA_1c] 7.4 ± 0.2% [57.1 ± 7.3 mmol/mol]) were randomly assigned to treatment with glimepiride + linagliptin 5 mg (16 weeks), washout (4 weeks), and glimepiride + placebo (16 weeks) (or vice versa). Glimepiride was titrated targeting a fasting plasma glucose of 4.5-6.0 mmol/L without hypoglycemia. Treatments were evaluated by continuous glucose monitoring (CGM), HbA_1c, and meal test.

RESULTS

Compared with glimepiride + placebo, glimepiride + linagliptin did not significantly improve the primary end point, mean amplitude of glycemic excursions (MAGE) (mean difference -0.7 mmol/L, P = 0.1540), but displayed significant reductions in coefficient of variation on CGM (-3.6%, P = 0.0401), HbA_1c (-0.5%, P = 0.0048), and glimepiride dose (-0.7 mg/day, P = 0.0099). β-cell glucose sensitivity (assessed as C-peptide-to-glucose ratio) during meal test improved with glimepiride + linagliptin. Incidences of hypoglycemia were similar with both treatments.

CONCLUSIONS

Linagliptin as add-on treatment to glimepiride improved glycemic variability and control without increasing risk of hypoglycemia in patients with HNF1A diabetes.

Protocol for a randomised controlled trial of a co-produced, complex, health promotion intervention for women with prior gestational diabetes and their families: the Face-it study

Background

Gestational diabetes mellitus (GDM) is associated with an increased risk of future diabetes in both mother, father and offspring. More knowledge is needed about how to effectively reduce the risk of diabetes through sustained behavioural interventions in these families. The Face-it intervention is a complex health promotion intervention embedded in multi-level supportive environments. The aim of the intervention is to reduce type 2 diabetes risk and increase quality of life among families in the first year following a GDM-affected pregnancy by promoting physical activity, healthy dietary behaviours and breastfeeding through a focus on social support, motivation, self-efficacy, risk perception and health literacy.

Methods

This national multicentre study is a two-arm randomised controlled trial including 460 women with GDM in a ratio of 2 (intervention):1 (usual care). The Face-it intervention consists of three main components: 1) additional visits from municipal health visitors, 2) digital health coaching tailored to family needs and 3) a structured cross-sectoral communication system in the health care system. The intervention runs from 3 to 12 months after delivery. The primary outcome is maternal body mass index at 12 months after delivery as a proxy for diabetes risk.

The women will be examined at baseline and at follow-up, and this examination will include blood tests, oral glucose tolerance test (OGTT), anthropometrics, blood pressure, self-reported diet and physical activity, breastfeeding, quality of life, health literacy, physical and mental health status, risk perception and social support. Aside from those data collected for OGTT and breastfeeding and offspring parameters, the same data will be collected for partners. Data on offspring anthropometry will also be collected. Information on pregnancy- and birth-related outcomes will be derived from the medical records of the woman and child.

Discussion

This randomised controlled trial seeks to demonstrate whether the Face-it intervention, addressing the individual, family and health care system levels, is superior to usual care in reducing diabetes risk for mothers and their families. Coupled with a process evaluation and an economic analysis, the study will provide evidence for policymakers and health services about health promotion among families affected by GDM and the potential for reducing risk of type 2 diabetes and associated conditions.

Trial registration

ClinicalTrials.gov NCT03997773. Registered June 25, 2019 – Retrospectively registered.

Substrate metabolism, hormone and cytokine levels and adipose tissue signalling in individuals with type 1 diabetes after insulin withdrawal and subsequent insulin therapy to model the initiating steps of ketoacidosis

AIMS/HYPOTHESIS

Lack of insulin and infection/inflammation are the two most common causes of diabetic ketoacidosis (DKA). We used insulin withdrawal followed by insulin administration as a clinical model to define effects on substrate metabolism and to test whether increased levels of counter-regulatory hormones and cytokines and altered adipose tissue signalling participate in the early phases of DKA.

METHODS

Nine individuals with type 1 diabetes, without complications, were randomly studied twice, in a crossover design, for 5 h followed by 2.5 h high-dose insulin clamp: (1) insulin-controlled euglycaemia (control) and (2) after 14 h of insulin withdrawal in a university hospital setting.

RESULTS

Insulin withdrawal increased levels of glucose (6.1 ± 0.5 vs 18.6 ± 0.5 mmol/l), NEFA, 3-OHB (127 ± 18 vs 1837 ± 298 μmol/l), glucagon, cortisol and growth hormone and decreased HCO₃^- and pH, without affecting catecholamine or cytokine levels. Whole-body energy expenditure, endogenous glucose production (1.55 ± 0.13 vs 2.70 ± 0.31 mg kg^-1 min^-1), glucose turnover, non-oxidative glucose disposal, lipid oxidation, palmitate flux (73 [range 39-104] vs 239 [151-474] μmol/min), protein oxidation and phenylalanine flux all increased, whereas glucose oxidation decreased. In adipose tissue, Ser473 phosphorylation of Akt and mRNA levels of G0S2 decreased, whereas CGI-58 (also known as ABHD5) mRNA increased. Protein levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase phosphorylations were unaltered. Insulin therapy decreased plasma glucose concentrations dramatically after insulin withdrawal, without any detectable effect on net forearm glucose uptake.

CONCLUSIONS/INTERPRETATION

Release of counter-regulatory hormones and overall increased catabolism, including lipolysis, are prominent features of preacidotic ketosis induced by insulin withdrawal, and dampening of Akt insulin signalling and transcriptional modulation of ATGL activity are involved. The lack of any increase in net forearm glucose uptake during insulin therapy after insulin withdrawal indicates muscle insulin resistance.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02077348 FUNDING: This study was supported by Aarhus University and the KETO Study Group/Danish Agency for Science Technology and Innovation.

Determinants of Maternal Insulin Resistance during Pregnancy: An Updated Overview

Insulin resistance changes over time during pregnancy, and in the last half of the pregnancy, insulin resistance increases considerably and can become severe, especially in women with gestational diabetes and type 2 diabetes. Numerous factors such as placental hormones, obesity, inactivity, an unhealthy diet, and genetic and epigenetic contributions influence insulin resistance in pregnancy, but the causal mechanisms are complex and still not completely elucidated. In this review, we strive to give an overview of the many components that have been ascribed to contribute to the insulin resistance in pregnancy. Knowledge about the causes and consequences of insulin resistance is of extreme importance in order to establish the best possible treatment during pregnancy as severe insulin resistance can result in metabolic dysfunction in both mother and offspring on a short as well as long-term basis.

Prevalence and geographical distribution of insulin pump therapy in the Central Denmark Region and its association with metabolic parameters

AIMS

Insulin treatment in type 1 diabetes encompasses multiple daily insulin injections (MDI) or continuous subcutaneous insulin infusion (CSII). Both population-based studies and comparative studies regarding CSII use are sparse. The aim of the current study was to describe the prevalence and distribution of CSII use among adults with type 1 diabetes in the Central Denmark Region and to compare metabolic control in CSII-treated patients to those treated with MDI.

METHODS

A database was constructed using the Danish Adult Diabetes Registry in 2014/2015 in combination with an audit of the patients' medical records.

RESULTS

3909 adults with type 1 diabetes patients were included. The proportion of patients treated with CSII differed significantly between the 8 regional hospitals from 12.0% to 31.1%. CSII users had a significantly lower HbA1c compared to MDI treated patients (7.6% (60 mmol/mol) versus 8.0% (64 mmol/mol)) in unadjusted analyses. After adjustment for clinically relevant characteristics the difference between CSII and MDI-treated patients was attenuated, but remained statistically significant.

CONCLUSION

The distribution of CSII differed markedly between hospitals and CSII users had better glycemic control, even after adjustment for sex, age, BMI, diabetes duration, smoking, use of lipid-lowering and blood pressure-lowering medication.

Parity Increases Insulin Requirements in Pregnant Women With Type 1 Diabetes

CONTEXT

Tight glycemic control throughout pregnancy in women with type 1 diabetes is crucial, and knowledge about which factors that affect insulin sensitivity could improve the outcome for both mother and offspring.

OBJECTIVE

To evaluate insulin requirements in women with type 1 diabetes during pregnancy and test whether parity affects insulin requirements.

DESIGN

Observational cohort study consisting of women with type 1 diabetes who gave birth at Aarhus University Hospital, Denmark, from 2004 to 2014.

MAIN OUTCOME MEASURE

Daily insulin requirement (the hypothesis that parity could affect insulin resistance was formulated before data collection).

RESULTS

A total of 380 women with a total of 536 pregnancies were included in the study. Mean age was 31.1 years, and prepregnancy hemoglobin A1c was 60 mmol/mol. Parity was as follows: P0, 43%; P1, 40%; P2, 14%; and P3+4, 3%. Insulin requirements from weeks 11 to 16 decreased significantly by 4% (P = 0.0004) and rose from week 19 to delivery with a peak of 70% (P < 0.0005) at weeks 33 to 36. Overall, insulin requirements increased significantly with parity. The unadjusted differences between P0 and P1, P2, and P3+4 were 9% (P < 0.0005), 12% (P < 0.0005), and 23% (P < 0.0011), respectively. After adjustment for confounders, differences were 13% (P < 0.0005), 20% (P < 0.0005), and 36% (P < 0.0005). We also observed an adjusted difference between P1 and P3+4 of 20% (P < 0.0012).

CONCLUSIONS

The data show changes in insulin requirements from week to week in pregnancy and indicate that insulin requirements increase with parity. This suggests that the patient's parity probably should be considered in choosing insulin dosages for pregnant women with type 1 diabetes.

Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial

BACKGROUND

Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP.

METHOD

We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA).

RESULTS

We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ± 12 mmHg (RDN) and 159 ± 14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [-6.2 ± 18.8 mmHg (RDN) vs. -6.0 ± 13.5 mmHg (SHAM)] and at 6 months [-6.1 ± 18.9 mmHg (RDN) vs. -4.3 ± 15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ± 2.7 (RDN) vs. 7.0 ± 2.5 (SHAM)].RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial.

CONCLUSION

Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques.

Acute Hypoglycemia in Healthy Humans Impairs Insulin-Stimulated Glucose Uptake and Glycogen Synthase in Skeletal Muscle: A Randomized Clinical Study

Hypoglycemia is the leading limiting factor in glycemic management of insulin-treated diabetes. Skeletal muscle is the predominant site of insulin-mediated glucose disposal. Our study used a crossover design to test to what extent insulin-induced hypoglycemia affects glucose uptake in skeletal muscle and whether hypoglycemia counterregulation modulates insulin and catecholamine signaling and glycogen synthase activity in skeletal muscle. Nine healthy volunteers were examined on three randomized study days: 1) hyperinsulinemic hypoglycemia (bolus insulin), 2) hyperinsulinemic euglycemia (bolus insulin and glucose infusion), and 3) saline control with skeletal muscle biopsies taken just before, 30 min after, and 75 min after insulin/saline injection. During hypoglycemia, glucose levels reached a nadir of ∼2.0 mmol/L, and epinephrine rose to ∼900 pg/mL. Hypoglycemia impaired insulin-stimulated glucose disposal and glucose clearance in skeletal muscle, whereas insulin signaling in glucose transport was unaffected by hypoglycemia. Insulin-stimulated glycogen synthase activity was completely ablated during hyperinsulinemic hypoglycemia, and catecholamine signaling via cAMP-dependent protein kinase and phosphorylation of inhibiting sites on glycogen synthase all increased.

Metabolic effects of insulin in a human model of ketoacidosis combining exposure to lipopolysaccharide and insulin deficiency: a randomised, controlled, crossover study in individuals with type 1 diabetes

AIMS/HYPOTHESIS

Diabetic ketoacidosis (DKA) is often caused by concomitant systemic inflammation and lack of insulin. Here we used an experimental human model to test whether and how metabolic responses to insulin are impaired in the early phases of DKA with a specific focus on skeletal muscle metabolism.

METHODS

Nine individuals with type 1 diabetes from a previously published cohort were investigated twice at Aarhus University Hospital using a 120 min infusion of insulin (3.0/1.5 mU kg^-1 min^-1) after an overnight fast under: (1) euglycaemic conditions (CTR) or (2) hyperglycaemic ketotic conditions (KET) induced by an i.v. bolus of lipopolysaccharide and 85% reduction in insulin dosage. The primary outcome was insulin resistance in skeletal muscle. Participants were randomly assigned to one of the two arms at the time of screening using www.randomizer.org . The study was not blinded.

RESULTS

All nine volunteers completed the 2 days and are included in the analysis. Circulating concentrations of glucose and 3-hydroxybutyrate increased during KET (mean ± SEM 17.7 ± 0.6 mmol/l and 1.6 ± 0.2 mmol/l, respectively), then decreased after insulin treatment (6.6 ± 0.7 mmol/l and 0.1 ± 0.07 mmol/l, respectively). Prior to insulin infusion (KET vs CTR) isotopically determined endogenous glucose production rates were 17 ± 1.7 μmol kg^-1 min^-1 vs 8 ± 1.3 μmol kg^-1 min^-1 (p = 0.003), whole body phenylalanine fluxes were 2.9 ± 0.5 μmol kg^-1 min^-1 vs 3.1 ± 0.4 μmol kg^-1 min^-1 (p = 0.77) and urea excretion rates were 16.9 ± 2.4 g/day vs 7.3 ± 1.7 g/day (p = 0.01). Insulin failed to stimulate forearm glucose uptake and glucose oxidation in KET compared with CTR (p < 0.05). Glycogen synthase phosphorylation was impaired in skeletal muscle.

CONCLUSIONS/INTERPRETATION

In KET, hyperglycaemia is primarily driven by increased endogenous glucose production. Insulin stimulation during early phases of DKA is associated with reduced glucose disposal in skeletal muscle, impaired glycogen synthase function and lower glucose oxidation. This underscores the presence of muscle insulin resistance in the pathogenesis of DKA. Trial registration www.clinicaltrials.gov (ID number: NCT02157155). Funding This work was funded by the Danish Council for Strategic Research (grant no. 0603-00479B).

Altered gene expression and repressed markers of autophagy in skeletal muscle of insulin resistant patients with type 2 diabetes

This case-control study was designed to investigate the gene expression profile in skeletal muscle from severely insulin resistant patients with long-standing type 2 diabetes (T2D), and to determine associated signaling pathways. Gene expression profiles were examined by whole transcriptome, strand-specific RNA-sequencing and associated signaling was determined by western blot. We identified 117 differentially expressed gene transcripts. Ingenuity Pathway Analysis related these differences to abnormal muscle morphology and mitochondrial dysfunction. Despite a ~5-fold difference in plasma insulin, we did not observe any difference in phosphorylation of AKT or AS160, although other insulin-sensitive cascades, as mTOR/4EBP1, had retained their sensitivity. Autophagy-related gene (ATG14, RB1CC1/FIP200, GABARAPL1, SQSTM1/p62, and WIPI1) and protein (LC3BII, SQSTM1/p62 and ATG5) expression were decreased in skeletal muscle from the patients, and this was associated with a trend to increased phosphorylation of the insulin-sensitive regulatory transcription factor FOXO3a. These data show that gene expression is highly altered and related to mitochondrial dysfunction and abnormal morphology in skeletal muscle from severely insulin resistant patients with T2D, and that this is associated with decreased expression of autophagy-related genes and proteins. We speculate that prolonged treatment with high doses of insulin may suppress autophagy thereby generating a vicious cycle maintaining insulin resistance.

Effects of Renal Denervation on Insulin Sensitivity and Inflammatory Markers in Nondiabetic Patients with Treatment-Resistant Hypertension

Increased sympathetic activity is important in the pathogenesis of hypertension and insulin resistance. Afferent signaling from the kidneys elevates the central sympathetic drive. We investigated the effect of catheter-based renal sympathetic denervation (RDN) on glucose metabolism, inflammatory markers, and blood pressure in nondiabetic patients with treatment-resistant hypertension. Eight subjects were included in an open-labelled study. Each patient was studied before and 6 months after RDN. Endogenous glucose production was assessed by a 3-³H glucose tracer, insulin sensitivity was examined by hyperinsulinemic euglycemic clamp, hormones and inflammatory markers were analyzed, and blood pressure was measured by office blood pressure readings and 24-hour ambulatory blood pressure monitoring. Insulin sensitivity (M-value) increased nonsignificantly from 2.68 ± 0.28 to 3.07 ± 0.41 (p = 0.12). A significant inverse correlation between the increase in M-value and BMI 6 months after RDN (p = 0.03) was found, suggesting beneficial effects on leaner subjects. Blood pressure decreased significantly, but there were no changes in hormones, inflammatory markers, or endogenous glucose production. Our results indicate that RDN may improve insulin sensitivity in some patients with treatment-resistant hypertension, albeit confirmation of these indications of beneficial effects on leaner subjects awaits the outcome of larger randomized controlled studies.

Effects of insulin-induced hypoglycaemia on lipolysis rate, lipid oxidation and adipose tissue signalling in human volunteers: a randomised clinical study

AIMS/HYPOTHESIS

The aims of this study were to determine the role of lipolysis in hypoglycaemia and define the underlying intracellular mechanisms.

METHODS

Nine healthy volunteers were randomised to treatment order of three different treatments (crossover design). Treatments were: (1) saline control; (2) hyperinsulinaemic hypoglycaemia (HH; i.v. bolus of 0.1 U/kg insulin); and (3) hyperinsulinaemic euglycaemia (HE; i.v. bolus of 0.1 U/kg insulin and 20% glucose). Inclusion criteria were that volunteers were healthy, aged >18 years, had a BMI between 19 and 26 kg/m², and provided both written and oral informed consent. Exclusion criteria were the presence of a known chronic disease (including diabetes mellitus, epilepsy, ischaemic heart disease and cardiac arrhythmias) and regular use of prescription medication. The data was collected at the medical research facilities at Aarhus University Hospital, Denmark. The primary outcome was palmitic acid flux. Participants were blinded to intervention order, but caregivers were not.

RESULTS

Adrenaline (epinephrine) and glucagon concentrations were higher during HH than during both HE and control treatments. NEFA levels and lipid oxidation rates (determined by indirect calorimetry) returned to control levels after 105 min. Palmitate flux was increased to control levels during HH (p = NS) and was more than twofold higher than during HE (overall mean difference between HH vs HE, 114 [95% CI 64, 165 μmol/min]; p < 0.001). In subcutaneous adipose tissue biopsies, we found elevated levels of hormone-sensitive lipase (HSL) and perilipin-1 phosphorylation 30 min after insulin injection during HH compared with both control and HE. There were no changes in the levels of adipose triglyceride lipase (ATGL), comparative gene identification-58 (CGI-58) or G₀/G₁ switch gene 2 (G0S2) proteins. Insulin-stimulated phosphorylation of Akt and mTOR were unaffected by hypoglycaemia. Expression of the G0S2 gene increased during HE and HH compared with control, without changes in ATGL (also known as PNPLA2) or CGI-58 (also known as ABHD5) mRNA levels.

CONCLUSIONS/INTERPRETATION

These findings suggest that NEFAs become a major fuel source during insulin-induced hypoglycaemia and that lipolysis may be an important component of the counter-regulatory response. These effects appear to be mediated by rapid stimulation of protein kinase A (PKA) and HSL, compatible with activation of the β-adrenergic catecholamine signalling pathway.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01919788 FUNDING: : The study was funded by Aarhus University, the Novo Nordisk Foundation and the KETO Study Group/Danish Agency for Science Technology and Innovation (grant no. 0603-00479, to NM).

The solitary sellar plasmacytoma: a diagnostic challenge

Solitary sellar plasmacytomas are exceedingly rare and difficult to distinguish from other pituitary tumors. We report a case of a 62-year-old woman presenting with blurred vision of the right eye and tenderness of the right temporal region, which was interpreted as temporal arteritis. MRI revealed a pituitary mass lesion (20mm×14mm×17mm) without compression of the optic chiasm and her pituitary function was normal. Pituitary surgery was undertaken due to growth of the lesion, and histopathological examination showed a highly cellular neoplasm composed of mature monoclonal plasma cells. Subsequent examinations revealed no evidence of extrasellar myeloma. The patient received pituitary irradiation and has remained well and free of symptoms apart from iatrogenic central diabetes insipidus. Until now, only eight cases of solitary sellar plasmacytoma have been reported. Most frequent symptoms stem from compression of the cranial nerves in the cavernous sinus (III, IV, V), whereas the anterior pituitary function is mostly intact.

LEARNING POINTS

A solitary plasmacytoma is a rare cause of a sellar mass lesion.The radiological and clinical features are nonspecific, but cranial nerve affection and intact pituitary function are usually present.The diagnosis is made histologically and has important therapeutic implications.

Combined Insulin Deficiency and Endotoxin Exposure Stimulate Lipid Mobilization and Alter Adipose Tissue Signaling in an Experimental Model of Ketoacidosis in Subjects With Type 1 Diabetes: A Randomized Controlled Crossover Trial

Most often, diabetic ketoacidosis (DKA) in adults results from insufficient insulin administration and acute infection. DKA is assumed to release proinflammatory cytokines and stress hormones that stimulate lipolysis and ketogenesis. We tested whether this perception of DKA can be reproduced in an experimental human model by using combined insulin deficiency and acute inflammation and tested which intracellular mediators of lipolysis are affected in adipose tissue. Nine subjects with type 1 diabetes were studied twice: 1) insulin-controlled euglycemia and 2) insulin deprivation and endotoxin administration (KET). During KET, serum tumor necrosis factor-α, cortisol, glucagon, and growth hormone levels increased, and free fatty acids and 3-hydroxybutyrate concentrations and the rate of lipolysis rose markedly. Serum bicarbonate and pH decreased. Adipose tissue mRNA contents of comparative gene identification-58 (CGI-58) increased and G0/G1 switch 2 gene (G0S2) mRNA decreased robustly. Neither protein levels of adipose triglyceride lipase (ATGL) nor phosphorylations of hormone-sensitive lipase were altered. The clinical picture of incipient DKA in adults can be reproduced by combined insulin deficiency and endotoxin-induced acute inflammation. The precipitating steps involve the release of proinflammatory cytokines and stress hormones, increased lipolysis, and decreased G0S2 and increased CGI-58 mRNA contents in adipose tissue, compatible with latent ATGL stimulation.

Parity and type 2 diabetes mellitus: a study of insulin resistance and β-cell function in women with multiple pregnancies

OBJECTIVE

Increasing parity may be a risk factor for the development of type 2 diabetes mellitus and the metabolic alterations during a normal pregnancy induces a prediabetic state; thus, multiple pregnancies may act as a risk factor for development of type 2 diabetes if these physiological alterations in glucose homeostasis are not reversed postpartum. We hypothesize that multiple pregnancies may lead to β-cell exhaustion and that the insulin resistance that occurs during pregnancy may persist after multiple births.

RESEARCH DESIGN AND MEASURES

A total of 28 healthy premenopausal women were recruited: 15 high parity women (≥4 children) and 13 body mass index (BMI)-matched and age-matched low parity women (1 and 2 children). The study consisted of an intravenous glucose tolerance test for assessment of β-cell function followed by a hyperinsulinemic euglycemic clamp for assessment of insulin sensitivity. Dual-energy X-ray absorptiometry was performed to assess body composition.

RESULTS

All anthropometric measures, measures of body composition and baseline blood samples were comparable between the 2 groups. Neither first phase insulin release (0-10 min, p=0.92) nor second phase insulin release (10-60 min, p=0.62), both measured as area under the curve, differed between the 2 groups. The M-value, calculated as the mean glucose infusion rate during the last 30 min of the clamp period, was 8.66 (7.70 to 9.63) mg/kg/min in the high parity group compared with 8.41 (7.43 to 9.39) mg/kg/min in the low parity group (p=0.69).

CONCLUSIONS

We did not detect any effects of increasing parity on insulin sensitivity or β-cell function.

Gestational diabetes: A clinical update

Gestational diabetes mellitus (GDM) is increasing in prevalence in tandem with the dramatic increase in the prevalence of overweight and obesity in women of childbearing age. Much controversy surrounds the diagnosis and management of gestational diabetes, emphasizing the importance and relevance of clarity and consensus. If newly proposed criteria are adopted universally a significantly growing number of women will be diagnosed as having GDM, implying new therapeutic challenges to avoid foetal and maternal complications related to the hyperglycemia of gestational diabetes. This review provides an overview of clinical issues related to GDM, including the challenges of screening and diagnosis, the pathophysiology behind GDM, the treatment and prevention of GDM and the long and short term consequences of gestational diabetes for both mother and offspring.

Circulating acylghrelin levels are suppressed by insulin and increase in response to hypoglycemia in healthy adult volunteers

OBJECTIVE

Ghrelin has glucoregulatory and orexigenic actions, but its role in acute hypoglycemia remains uncertain. We aimed to investigate circulating levels of acylghrelin (AG) and unacylated ghrelin (UAG) in response to hyperinsulinemia and to hypoglycemia.

DESIGN

A randomized, single-blind, placebo-controlled crossover study including 3 study days was performed at a university hospital clinical research center.

METHODS

Nine healthy men completed 3 study days: i) saline control (CTR), ii) hyperinsulinemic euglycemia (HE) (bolus insulin 0.1 IE/kg i.v. and glucose 20% i.v. for 105 min, plasma glucose ≈5 mmol/l), and iii) hyperinsulinemic hypoglycemia (HH) (bolus insulin 0.1 IE/kg i.v.).

RESULTS

HH and HE suppressed AG concentrations at t=45-60 min as compared with CTR (P<0.05). At t=90 min, a rebound increase in AG was observed in response to HH as compared with both HE and CTR (P<0.05). UAG also decreased during HH and HE at t=45 min (P<0.05), whereas the AG-to-UAG ratio remained unaffected.

CONCLUSIONS

This study demonstrates that AG and UAG are directly suppressed by hyperinsulinemia and that AG concentrations increase after a latency of ≈1 h in response to hypoglycemia, suggesting a potential counterregulatory role of AG.

Complete recovery after severe myxoedema coma complicated by status epilepticus

We report a case of life-threatening myxoedema presenting with hypothermia, hypotension, bradycardia, pericardial effusion and deep coma. The condition was complicated by prolonged status epilepticus. The optimal treatment strategy has been debated over the years and the literature is briefly reviewed. Treatment with l-thyroxine (LT4) monotherapy without initial loading dose and with no l-triiodothyronine (LT3) treatment was successful with full recovery after hospitalisation for more than a month. Myxoedema coma is a rare, reversible condition with a high mortality and should be considered as a differential diagnosis in medical emergencies.

Reduced CD300LG mRNA tissue expression, increased intramyocellular lipid content and impaired glucose metabolism in healthy male carriers of Arg82Cys in CD300LG: a novel genometabolic cross-link between CD300LG and common metabolic phenotypes

BACKGROUND

CD300LG rs72836561 (c.313C>T, p.Arg82Cys) has in genetic-epidemiological studies been associated with the lipoprotein abnormalities of the metabolic syndrome. CD300LG belongs to the CD300-family of membrane-bound molecules which have the ability to recognize and interact with extracellular lipids. We tested whether this specific polymorphism results in abnormal lipid accumulation in skeletal muscle and liver and other indices of metabolic dysfunction.

METHODS

40 healthy men with a mean age of 55 years were characterized metabolically including assessment of insulin sensitivity by the hyperinsulinemic euglycemic clamp, intrahepatic lipid content (IHLC) and intramyocellular lipid content (IMCL) by MR spectroscopy, and β-cell function by an intravenous glucose tolerance test. Changes in insulin signaling and CD300LG mRNA expression were determined by western blotting and quantitative PCR in muscle and adipose tissue.

RESULTS

Compared with the 20 controls (CC carriers), the 20 CT carriers (polymorphism carriers) had higher IMCL (p=0.045), a reduced fasting forearm glucose uptake (p=0.011), a trend toward lower M-values during the clamp; 6.0 mg/kg/min vs 7.1 (p=0.10), and higher IHLC (p=0.10). CT carriers had lower CD300LG mRNA expression and CD300LG expression in muscle correlated with IMCL (β=-0.35, p=0.046), forearm glucose uptake (β=0.37, p=0.03), and tended to correlate with the M-value (β=0.33, p=0.06), independently of CD300LG genotype. β-cell function was unaffected.

CONCLUSIONS

The CD300LG polymorphism was associated with decreased CD300LG mRNA expression in muscle and adipose tissue, increased IMCL, and abnormalities of glucose metabolism. CD300LG mRNA levels correlated with IMCL and forearm glucose uptake. These findings link a specific CD300LG polymorphism with features of the metabolic syndrome suggesting a role for CD300LG in the regulation of common metabolic traits.

TRIAL REGISTRATION NUMBER

NCT01571609.

Effects of 12 weeks high dose vitamin D3 treatment on insulin sensitivity, beta cell function, and metabolic markers in patients with type 2 diabetes and vitamin D insufficiency - a double-blind, randomized, placebo-controlled trial

OBJECTIVES

Vitamin D insufficiency is common in subjects with type 2 diabetes. Observational studies suggest that vitamin D plays a role in the pathogenesis of type 2 diabetes. However, results of intervention studies have been inconsistent. We investigated the effects of improving vitamin D status on insulin sensitivity, insulin secretion, and inflammatory markers in patients with type 2 diabetes.

MATERIALS/METHODS

A double blind, randomized, placebo controlled trial was conducted. Sixteen patients with type 2 diabetes and hypovitaminosis D were recruited. Eight patients received colecalciferol and (280 μg daily for 2 weeks, 140 μg daily for 10 weeks) and 8 patients received identical placebo tablets for 12 weeks. Before and after intervention, patients underwent IVGTT, hyperinsulinemic euglycemic clamp, assessment of baseline high-frequency insulin pulsatility, glucose-entrained insulin pulsatility, DXA scans, 24-hour-ambulatory blood pressure monitorings, and fasting blood samples.

RESULTS

Serum-25(OH) vitamin D and serum-1,25(OH)₂ vitamin D increased significantly after 12 weeks in the intervention group (p=0.01, p=0.004). Serum-25(OH) vitamin D was also significantly higher in the vitamin D group compared to the placebo group (p=0.02) after intervention. Although no significant changes in insulin sensitivity, inflammation, blood pressure, lipid profile, or HbA1c were found, we observed borderline (p between 0.05 and 0.10) improvements of insulin secretion, in terms of c-peptide levels, first phase incremental AUC insulin and insulin secretory burst mass.

CONCLUSIONS

Improvement in vitamin D status does not improve insulin resistance, blood pressure, inflammation or HbA1c, but might increase insulin secretion in patients with established type 2 diabetes.

Effects of vitamin D supplementation on body fat accumulation, inflammation, and metabolic risk factors in obese adults with low vitamin D levels - results from a randomized trial

BACKGROUND

Low plasma 25-hydroxy-vitamin D (25OHD) is associated with obesity. Vitamin D (VD) may be implicated in obesity and its complications such as insulin resistance, hypertension, and low-grade inflammation. We investigated the effects of VD supplementation on fat distribution and on obesity complications in obese adults with low plasma levels of 25OHD.

METHODS

In a double-blind design 52 subjects aged 18 to 50years with BMI>30kg/m(2) and plasma 25OHD <50nmol/l were randomized to 26weeks of treatment with 7000IU of VD daily or placebo. Body composition was assessed by DXA and subcutaneous (SAT) and visceral adipose tissue (VAT), intrahepatic (IHL) and intramyocellular lipids (IMCL) were evaluated by magnetic resonance imaging and magnetic resonance spectroscopy. Insulin resistance (HOMA-IR), blood pressure, plasma lipids, and circulating inflammatory markers were also investigated.

RESULTS

VD treatment increased mean plasma levels of 25OHD from 33nmol/l to 110nmol/l (P<0.0001) and decreased median parathyroid hormone levels from 5.3 to 4.5pmol/l (P<0.01) in the intervention group. Treatment did not change body fat, SAT, VAT, IHL, or IMCL compared with placebo. Neither did treatment affect HOMA, blood pressure, plasma lipids or any of several inflammatory markers investigated including hsCRP.

CONCLUSION

Increasing 25OHD levels by VD treatment for 26weeks have no effects on obesity complications in obese adults with low baseline plasma 25OHD.

Failing heart of patients with type 2 diabetes mellitus can adapt to extreme short-term increases in circulating lipids and does not display features of acute myocardial lipotoxicity

BACKGROUND

Circulating lipid levels and myocardial lipid content (MyLC) is increased in type 2 diabetes mellitus. This may cause a state of lipotoxicity that compromises left ventricular function and aggravate heart failure. We investigated the relationship among circulating lipid levels, MyLC, and cardiac function together with the acute cardiac effects of high as opposed to low circulating free fatty acid (FFA) and triglyceride levels in patients with type 2 diabetes mellitus and heart failure.

METHODS AND RESULTS

Eighteen patients underwent 8-hour intralipid/heparin-infusion (high FFA) and hyperinsulinemic-euglycemic clamping (low FFA) in a randomized crossover-designed study. We applied magnetic resonance proton spectroscopy to measure MyLC. Cardiac function was assessed by advanced echocardiography, cardiopulmonary exercise, and MRI. MyLC correlated positively with circulating triglyceride (r=0.47; r(2)=0.22; P=0.003) and FFA (r=0.45; r(2)=0.20; P=0.001) levels and inversely with left ventricular ejection fraction (r=-0.54; r(2)=0.29; P=0.004). Circulating FFA concentrations differed between study arms (0.05 ± 0.04 mmol/L [low FFA] versus 1.04 ± 0.27 mmol/L [high FFA]; P<0.001) and MyLC increased from 0.78 ± 0.59% (low FFA) to 1.16 ± 0.73% (high FFA; P<0.01). Resting left ventricular ejection fraction and global strain did not differ between high and low FFA, whereas resting systolic mitral plane velocity (S'max) was highest during high FFA (3.6±0.8 cm/s [low FFA] versus 3.8±0.7 cm/s [high FFA]; P=0.02). Peak exercise capacity and oxygen consumption did not differ between the study arms, and neither did postexercise measurements of left ventricular ejection fraction, global strain, and S'max.

CONCLUSIONS

Our findings indicate that the failing heart of patients with type 2 diabetes mellitus can adapt to short-term extreme changes in circulating substrates and does not display features of acute myocardial lipotoxicity. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01192373.

Effect of acute hyperglycemia on left ventricular contractile function in diabetic patients with and without heart failure: two randomized cross-over studies

BACKGROUND

It is unknown whether changes in circulating glucose levels due to short-term insulin discontinuation affect left ventricular contractile function in type 2 diabetic patients with (T2D-HF) and without (T2D-nonHF) heart failure.

MATERIALS AND METHODS

In two randomized cross-over-designed trials, 18 insulin-treated type 2 diabetic patients with (Ejection Fraction (EF) 36 ± 6%, n = 10) (trial 2) and without systolic heart failure (EF 60 ± 3%, n = 8) (trial 1) were subjected to hyper- and normoglycemia for 9-12 hours on two different occasions. Advanced echocardiography, bicycle exercise tests and 6-minute hall walk distance were applied.

RESULTS

Plasma glucose levels differed between study arms (6.5 ± 0.8 mM vs 14.1 ± 2.6 mM (T2D-HF), 5.8 ± 0.4 mM vs 9.9 ± 2.1 mM (T2D-nonHF), p<0.001). Hyperglycemia was associated with an increase in several parameters: maximal global systolic tissue velocity (Vmax) (p<0.001), maximal mitral annulus velocity (S'max) (p<0.001), strain rate (p = 0.02) and strain (p = 0.05). Indices of increased myocardial systolic contractile function were significant in both T2D-HF (Vmax: 14%, p = 0.02; S'max: 10%, p = 0.04), T2D-nonHF (Vmax: 12%, p<0.01; S'max: 9%, p<0.001) and in post exercise S'max (7%, p = 0.049) during hyperglycemia as opposed to normoglycemia. LVEF did not differ between normo- and hyperglycemia (p = 0.17), and neither did peak exercise capacity nor catecholamine levels. Type 2 diabetic heart failure patients' 6-minute hall walk distance improved by 7% (p = 0.02) during hyperglycemia as compared with normoglycemia.

CONCLUSIONS

Short-term hyperglycemia by insulin discontinuation is associated with an increase in myocardial systolic contractile function in type 2 diabetic patients with and without heart failure and with a slightly prolonged walking distance in type 2 diabetic heart failure patients. (Clinicaltrials.gov identifier NCT00653510).

Reduced mRNA and protein expression of perilipin A and G0/G1 switch gene 2 (G0S2) in human adipose tissue in poorly controlled type 2 diabetes

CONTEXT

Increased lipolysis and free fatty acid (FFA) levels contribute significantly to the pathogenesis of chronic and acute insulin resistance in type 2 diabetes, but the underlying mechanisms are uncertain.

OBJECTIVE

Our objective was to test whether increased lipolysis and FFA levels induced by insulin withdrawal are accompanied by increased adipose tissue (AT) contents of adipose triglyceride lipase (ATGL) and/or altered intracellular ATGL regulation.

DESIGN AND PARTICIPANTS

Nine patients with type 2 diabetes were examined twice in a randomized crossover design after 16 h of 1) hyperglycemia/insulin withdrawal and 2) euglycemia/insulin infusion. Blood samples were drawn and a sc abdominal AT biopsy was obtained.

SETTING

The study was conducted at a university hospital research unit.

RESULTS

Circulating glucose (7.2 ± 0.3 vs. 11.2 ± 0.8 mmol/liter) and FFA (0.51 ± 0.05 vs. 0.65 ± 0.04 mmol/liter) were increased and insulin levels decreased after insulin withdrawal. AT ATGL protein tended to be increased (P = 0.075) after insulin withdrawal; by contrast, AT protein and mRNA content of perilipin A (Plin) and G(0)/G(1) switch gene 2 (G0S2), known negative regulators of ATGL activity, were decreased by 20-30% (all P values <0.03). All measured parameters related to hormone-sensitive lipase remained unaffected.

CONCLUSIONS

We found reduced mRNA and protein content of Plin and G0S2 and borderline increased ATGL protein in sc AT from poorly controlled type 2 diabetic subjects. This suggests that increased ATGL activity may contribute to the elevated lipolysis and circulating FFA levels in acute insulin withdrawal and metabolic dysregulation in type 2 diabetic patients and that this mechanism may be modifiable.