Comparative impact of Roux-en-Y gastric bypass, sleeve gastrectomy or diet alone on beta-cell function in insulin-treated type 2 diabetes patients

Although bariatric surgery is an effective treatment for type 2 diabetes by inducing weight loss and augmenting gut hormone secretion, the immediate effect on beta-cell function itself remains to be elucidated in type 2 diabetes. Therefore, a prospective, randomized trial was performed in 30 patients with insulin-treated type 2 diabetes and a body mass index ≥ 35 kg/m2. Patients were randomly assigned (1:1:1) to Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in combination with protein-sparing modified fast (PSMF), or to PSMF alone. Eu- and hyperglycemic clamps were performed before and 3 weeks after surgery and/or PSMF initiation. The primary outcome was the evolution of insulin sensitivity and beta-cell function after surgery, calculated using the composite measures of glucose disposal rate, insulin secretion rate, and disposition index (DI). Results revealed that markers of insulin sensitivity increased similarly in all arms (p = 0.43). A higher marker for maximal beta-cell function was observed when comparing SG to PSMF (p = 0.007). The DI showed a clear positive evolution after RYGB and SG, but not after PSMF alone. Altogether, these findings indicate that bariatric surgery results in an immediate beta-cell function recovery in insulin-treated type 2 diabetes.

A retrospective study of people with familial hypercholesterolaemia in a Belgian lipid clinic

BACKGROUND

Familial hypercholesterolaemia (FH) is a genetic disease characterised by hypercholesterolaemia and premature cardiovascular events. Early diagnosis and treatment can reduce the cardiovascular burden. We describe the characteristics of patients with heterozygous FH followed in a tertiary hospital in Belgium.

METHODS

We retrospectively studied a population of 321 patients with definite heterozygous FH who visited the UZ Leuven lipid clinic at least once between 1 January 2016 and 31 December 2020. Data are represented as mean ± SD.

RESULTS

The age at time of diagnosis of FH was 39 ± 18 years. Patients with atherosclerotic disease (secondary prevention) were older (p < .001), more often male (p < .001), had a higher body mass index (p < .001), prevalence of (pre)diabetes (p < .001) and hypertension (p < .001) and had lower levels of low-density lipoprotein-cholesterol (LDL-C) (p < .001) than individuals without atherosclerotic disease (primary prevention). The average LDL-C in both primary (109 ± 53 mg/dL) and secondary (81 ± 63 mg/dL) prevention did not meet the targets of LDL-C as proposed by the 2019 ESC/EAS guidelines for the management of dyslipidaemias. However, LDL-C levels in the subgroup of patients treated with PCSK9 inhibition therapy, and especially in the triple therapy group (combination of statin, ezetimibe and PCSK9 inhibitor), were markedly lower (p < .001).

CONCLUSIONS

In this Belgian population, people with heterozygous FH remain undertreated. Reaching treatment targets in FH seems possible, although this requires combination treatment (with PCSK9-targeted therapy) in most patients. Earlier diagnosis of FH, more extensive lipid-lowering treatment and reimbursement options and a more holistic approach are needed to lower LDL-C and cardiovascular risk in patients with FH.

Hypoglycaemia after Initiation of CFTR Modulator Therapy in a Cystic Fibrosis Patient without Diabetes

Introduction

Cystic fibrosis transmembrane regulator (CFTR) modulator therapies improve respiratory function and glycaemic control in patients with cystic fibrosis (CF). The direct effect of CFTR modulator therapies on pancreatic function in patients without preexisting diabetes remains unclear. Case Presentation. An 18-year-old female with CF caused by F508del/F508del mutation, who had no diabetes, developed postprandial hypoglycaemias 6 months after initiation of elexacaftor, tezacaftor, and ivacaftor combination therapy (ETI). Symptoms were persisted after brief discontinuation of ETI, but her symptoms and time-in-hypoglycaemia had improved remarkably by avoiding high glycaemic index-foods. Discussion. This case of hypoglycaemia associated with CFTR modulator therapy in a patient without preexisting diabetes suggests that CFTR modulator therapy has the potential to directly affect glucose homeostasis. There might be an improvement in insulin secretion as well as a reduction in systemic insulin resistance.

Conclusion

Treatment of CF patients without diabetes with CFTR modulator therapies can cause recurrent hypoglycaemic episodes which resolve with dietary measures.

Designing Mobile Phone Text Messages Using the Behavior Change Wheel Framework to Influence Food Literacy in Adults With Type 2 Diabetes in Kenya: Protocol for a Systematic Development Study

BACKGROUND

The worldwide prevalence of type 2 diabetes (T2D) has increased in the past decade, and it is projected to increase by 126% by 2045 in Africa. At the same time, mobile phone use has increased in Africa, providing a potential for innovative mobile health interventions to support diabetes care.

OBJECTIVE

This study aimed to apply the Behavior Change Wheel (BCW) framework to develop text messages to influence food literacy in adults with T2D in urban Kenya.

METHODS

The 8 steps of the BCW framework guided the development of text messages: (1) Define the problem in behavioral terms; (2) select target behaviors; (3) specify the target behaviors based on who needs to perform the behaviors, what needs to change, and when, where, how often, and with whom; (4) identify what needs to change; (5) identify intervention functions; (6) select policy categories; (7) select behavior change techniques (BCTs); and (8) select the mode of delivery. Recent exploratory studies in Kenya and other low- and middle-income countries provided information that was used to contextualize the intervention.

RESULTS

In step 1, the behavioral problem was defined as unhealthy dietary patterns among adults with T2D. In step 2, based on a qualitative study in the target population, the target behavior was selected to be evaluation of reliable sources of information, and selection and preparation of healthy food. In step 3, unhealthy dietary patterns were selected. In step 4, 10 domains of the Theoretical Domains Framework were identified, and in step 5, 5 intervention functions were linked to the domains and unhealthy dietary patterns were specified. In step 6, communication and regulations were identified as policy categories, while in step 7, 9 BCTs were selected from the Behavior Change Technique Taxonomy version 1. In step 8, the most suitable mode of delivery was determined to be mobile text messages. A total of 36 mobile text messages were developed based on the 9 BCTs.

CONCLUSIONS

This study shows the step-by-step application of the BCW framework to develop mobile text messages to influence food literacy in adults with T2D.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/48271.

STE20 kinase TAOK3 regulates type 2 immunity and metabolism in obesity

Healthy adipose tissue (AT) contains ST2+ Tregs, ILC2s, and alternatively activated macrophages that are lost in mice or humans on high caloric diet. Understanding how this form of type 2 immunity is regulated could improve treatment of obesity. The STE20 kinase Thousand And One amino acid Kinase-3 (TAOK3) has been linked to obesity in mice and humans, but its precise function is unknown. We found that ST2+ Tregs are upregulated in visceral epididymal white AT (eWAT) of Taok3-/- mice, dependent on IL-33 and the kinase activity of TAOK3. Upon high fat diet feeding, metabolic dysfunction was attenuated in Taok3-/- mice. ST2+ Tregs disappeared from eWAT in obese wild-type mice, but this was not the case in Taok3-/- mice. Mechanistically, AT Taok3-/- Tregs were intrinsically more responsive to IL-33, through higher expression of ST2, and expressed more PPARγ and type 2 cytokines. Thus, TAOK3 inhibits adipose tissue Tregs and regulates immunometabolism under excessive caloric intake.

Change in carbohydrate intake one year after Roux-en-Y gastric bypass: A prospective study

Background and objectives: To investigate the effect of carbohydrate intake before laparoscopic Roux-en-Y gastric bypass (LRYGB) on body weight, body composition and glycaemic status after surgery. Methods: In a tertiary centre cohort study, dietary habits, body composition and glycaemic status were evaluated before and 3, 6 and 12 months after LRYGB. Detailed dietary food records were processed by specialized dietitians on the basis of a standard protocol. The study population was subdivided according to relative carbohydrate intake before surgery. Results: Before surgery, 30 patients had a moderate relative carbohydrate intake (26%-45%, M-CHO), a mean body mass index (BMI) of 40.4 ± 3.9 kg/m² and a mean glycated haemoglobin A1c (A1C) of 6.5 ± 1.2% compared to 20 patients with a high relative carbohydrate intake (> 45%, H-CHO), mean BMI of 40.9 ± 3.7 kg/m² (non-significant, NS) and a mean A1C of 6.2% (NS). One year after surgery, body weight, body composition and glycaemic status were similar in the M-CHO (n = 25) and H-CHO groups (n = 16), despite less caloric intake in the H-CHO group (1317 ± 285 g vs. 1646 ± 345 g in M-CHO, p < 0.01). Their relative carbohydrate intake converged to 46% in both groups, but the H-CHO group reduced the absolute total carbohydrate consumption more than the M-CHO group (190 ± 50 g in M-CHO vs. 153 ± 39 g in H-CHO, p < 0.05), and this was especially pronounced for the mono- and disaccharides (86 ± 30 g in M-CHO vs. 65 ± 27 g in H-CHO, p < 0.05). Conclusion: A high relative carbohydrate intake before LRYGB, did not influence the change in body composition or diabetes status after surgery, despite a significantly lower total energy intake and less mono- and disaccharide consumption after surgery.

Effect of sleeve gastrectomy and Roux-en-Y gastric bypass on gastrointestinal physiology

BACKGROUND

Knowledge regarding the gastrointestinal physiology after sleeve gastrectomy and Roux-en-Y gastric bypass is urgently needed to understand, prevent and treat the nutritional and pharmacological complications of bariatric surgery.

AIM

To investigate the effect of sleeve gastrectomy and Roux-en-Y gastric bypass on gastrointestinal motility (e.g., transit and pressure), pH, and intestinal bile acid concentration.

MATERIAL AND METHODS

An exploratory cross-sectional study was performed in six participants living with obesity, six participants who underwent sleeve gastrectomy, and six participants who underwent Roux-en-Y gastric bypass. During the first visit, a wireless motility capsule (SmartPill©) was ingested after an overnight fast to measure gastrointestinal transit, pH, and pressure. During the second visit, a gastric emptying scintigraphy test of a nutritional drink labeled with ^99mTc-colloid by a dual-head SPECT gamma camera was performed to measure gastric emptying half-time (GET_1/2). During the third visit, two customized multiple lumen aspiration catheters were positioned to collect fasting and postprandial intestinal fluids to measure bile acid concentration.

RESULTS

Immediate pouch emptying (P = 0.0007) and a trend for faster GET_1/2 (P = 0.09) were observed in both bariatric groups. There was a tendency for a shorter orocecal transit in participants with sleeve gastrectomy and Roux-en-Y gastric bypass (P = 0.08). The orocecal segment was characterized by a higher 25th percentile pH (P = 0.004) and a trend for a higher median pH in both bariatric groups (P = 0.07). Fasting total bile acid concentration was 7.5-fold higher in the common limb after Roux-en-Y gastric bypass (P < 0.0001) and 3.5-fold higher in the jejunum after sleeve gastrectomy (P = 0.009) compared to obesity. Postprandial bile acid concentration was 3-fold higher in the jejunum after sleeve gastrectomy (P = 0.0004) and 6.5-fold higher in the common limb after Roux-en-Y gastric bypass (P < 0.0001) compared to obesity.

CONCLUSION

The anatomical alterations of sleeve gastrectomy and Roux-en-Y gastric bypass have an important impact on gastrointestinal physiology. This data confirms changes in transit and pH and provides the first evidence for altered intraluminal bile acid concentration.

Patients with a History of Bariatric Surgery Are 8 Years Younger at Presentation with Severe Alcoholic Hepatitis

PURPOSE

Patients with prior bariatric surgery (BS) are at risk to develop alcohol use disorder (AUD) and alcohol-related liver disease (ALD). Severe alcoholic hepatitis (sAH) is one of the most severe manifestations of ALD with a 28-day mortality of 20-50%. The impact of prior BS on patients presenting with sAH was assessed.

METHODS

From 01/2008 to 04/2021, consecutive patients admitted to a tertiary referral center with biopsy-proven sAH were included in a database.

RESULTS

One hundred fifty-eight sAH patients of which 28 patients had a history of BS (BS group) were identified. Of this BS group, 24 patients underwent a Roux-en-Y gastric bypass (RYGB), 3 a biliopancreatic diversion, 1 an adjustable gastric band, and no patients a sleeve gastrectomy. The proportion of patients with BS increased threefold over time during the study period. Patients in the BS group were significantly younger at diagnosis of sAH (44.3 years vs 52.4 years), were more frequently female, and had a higher body mass index and a higher grade of steatosis on liver biopsy. The correlation between BS and a younger age at diagnosis remained significant in a multivariate regression analysis. There were no differences in disease severity between both groups. Furthermore, there were no differences in corticosteroid response, 28-day, 90-day, or 1-year survival.

CONCLUSION

Prior BS is independently associated with a younger age of presentation with sAH, but is not independently associated with a different disease severity or outcome. These findings support the need for early detection of AUD in patients who underwent BS, in particular RYGB.

Perceived facilitators and barriers to healthy dietary behaviour in adults with type 2 diabetes mellitus in Kenya: A qualitative study

OBJECTIVE

This study aimed to explore the facilitators and barriers to healthy dietary behaviour in adults with type 2 diabetes mellitus (T2DM) in Kenya.

DESIGN

A qualitative descriptive design using telephone interviews was applied. An interview guide was developed through a modified theoretical framework.

SETTING

This study was conducted in selected hospitals in Nakuru County, located in west-central Kenya.

PARTICIPANTS

A two-step sampling strategy was used to select hospitals and study participants. Adult participants aged 30 to 85 years old, with T2DM from six hospitals were selected based on their ability to openly elaborate on the theme of dietary behaviour.

RESULTS

Thirty respondents were interviewed (mean age 62 years; 43.3% females). The average duration of the interviews was 32:02 minutes (SD 17.07). The highest-ranking internal facilitators of healthy dietary behaviour were knowledge of healthy food choices, gardening, self-efficacy, food preparation skills and eating at home. External facilitators included inaccurate beliefs and information on food and diet, education by healthcare workers, food availability, proximity to food selling points and family support. Internal barriers included tastes and preferences, health conditions barring intake of certain foods, and random eating of unhealthy foods. External barriers included socioeconomic factors, seasonal unavailability of fruits and food safety concerns.

CONCLUSIONS

Facilitators and barriers to healthy dietary behaviour among Kenyan adults with T2DM are related to food literacy and include selection, preparation and eating. Interventions to enhance healthy dietary behaviour should target context-specific knowledge, skills and self-efficacy.

Pharmacokinetics of Oral Rebaudioside A in Patients with Type 2 Diabetes Mellitus and Its Effects on Glucose Homeostasis: A Placebo-Controlled Crossover Trial

Background and Objectives

Rebaudioside A, a steviol glycoside, is deglycosylated by intestinal microflora prior to the absorption of steviol and conjugation to steviol glucuronide. While glucose-lowering properties are observed for rebaudioside A in mice, they have been attributed to the metabolites steviol and steviol glucuronide. We aimed to characterize the pharmacokinetic and pharmacodynamic properties of rebaudioside A and its metabolites in patients with early-onset type 2 diabetes mellitus (T2DM).

Methods

This randomized, placebo-controlled, open-label, two-way crossover trial was performed in subjects with T2DM on metformin or no therapy at the University Hospitals Leuven, Belgium. Following oral rebaudioside A (3 g), plasma concentrations of rebaudioside A, steviol and steviol glucuronide were determined. The effect on glucose homeostasis was examined by an oral glucose tolerance test (OGTT) performed 19 h following rebaudioside A administration, i.e. the presumed time of maximal steviol and steviol glucuronide concentrations. The primary pharmacodynamic endpoint was the difference in area under the blood glucose concentration–time curve during the first 2 h of the OGTT (AUC_{Glucose(0–2h)}) for rebaudioside A vs. placebo.

Results

In total, 30 subjects [63.5 (57.8–69.0) years of age, 86.7% male] completed the trial. Rebaudioside A was detected as early as 1 h after administration in nearly all subjects. As expected, steviol and steviol glucuronide reached their maximal concentrations at 19.5 h following rebaudioside A administration. Rebaudioside A did not lower the AUC_{Glucose(0–2h)} compared to placebo (− 0.7 (95% CI − 22.3; 20.9) h·mg/dL, P = 0.95). Insulin and C-peptide concentrations were also comparable between both conditions (P > 0.05).

Conclusion

Rebaudioside A is readily absorbed after oral administration and metabolized to steviol and steviol glucuronide. However, no effect on glucose nor insulin or C-peptide excursion was observed during the OGTT at the time of maximal metabolite concentrations. Thus, no antidiabetic properties of rebaudioside A could be observed in patients with T2DM after single oral use.

Clinical Trial Registration

Registered on ClinicalTrials.gov (NCT03510624).

Supplementary Information

The online version contains supplementary material available at 10.1007/s13318-022-00792-7.

Offering Guidance and Learning to Prescribers to Initiate Parenteral Nutrition using a Validated Electronic Decision TREE (OLIVE TREE)

Parenteral nutrition (PN) is recommended in patients nutritionally at risk and unable to receive oral or enteral nutrition. A standardized electronic PN order format could enhance appropriate PN prescribing. We developed the OLIVE TREE (Offering guidance and Learning to prescribers to Initiate PN using a Validated Electronic decision TREE), embedded in our electronic health record. We aimed to evaluate its validity and impact on physicians' prescribing behavior. A non-randomized before-after study was carried out in a tertiary care center. The OLIVE TREE comprises 120 individual items. A process validation was performed to determine interrater agreement between a pharmacist and the treating physician. To estimate the proportion of patients for whom the OLIVE TREE had an effective and potential impact on physicians' prescribing behavior, a proof of concept study was conducted. The proportion of patients for whom PN was averted and the proportion of decisions not in line with the recommendation were also calculated. The process validation in 20 patients resulted in an interrater agreement of 95.0%. The proof of concept in 73 patients resulted in an effective and potential impact on prescribing behavior in 50.7% and 79.5% of these patients, respectively. Initiation of PN was not averted and recommendations of the OLIVE TREE were overruled in 42.5% of the patients. Our newly developed OLIVE TREE has a good process validity. A substantial impact on prescribing behavior was observed, although initiation of PN was not avoided. In the next phase, the decision tree will be implemented hospital-wide.

Clinical and patient-centered implementation outcomes of mHealth interventions for type 2 diabetes in low-and-middle income countries: a systematic review

BACKGROUND

The prevalence of Type 2 Diabetes is rising in Low- and Middle-Income Countries (LMICs), affecting all age categories and resulting in huge socioeconomic implications. Mobile health (mHealth) is a potential high-impact approach to improve clinical and patient-centered outcomes despite the barriers of cost, language, literacy, and internet connectivity. Therefore, it is valuable to examine the clinical and implementation outcomes of mHealth interventions for Type 2 Diabetes in LMICs.

METHODS

The Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines were applied in framing and reporting the review criteria. A systematic search of Cochrane Library, Web of Science, PubMed, Scopus, and Ovid databases was performed through a combination of search terms. Randomized Controlled Trials (RCTs) and cohort studies published in English between January 2010 and August 2021 were included. Risk of bias for missing results in the included studies was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2). Quantitative and qualitative methods were used to synthesize the results.

RESULTS

The search identified a total of 1161 articles. Thirty studies from 14 LMICs met the eligibility criteria. On clinical outcomes, 12 and 9 studies reported on glycated hemoglobin (HbA1c )and fasting blood glucose (FBG) respectively. Text messages was the most commonly applied mHealth approach, used in 19 out of the 30 studies. Ten out of the 12 studies (83.3%) that reported on HbA1c had a percentage difference of <0.3% between the mHealth intervention and the comparison group. Additionally, studies with longer intervention periods had higher effect size and percentage difference on HbA1c (1.52 to 2.92%). Patient-centred implementation outcomes were reported variedly, where feasibility was reported in all studies. Acceptability was reported in nine studies, appropriateness in six studies and cost in four studies. mHealth evidence reporting and assessment (mERA) guidelines were not applied in all the studies in this review.   CONCLUSION: mHealth interventions in LMICs are associated with clinically significant effectiveness on HbA1 but have low effectiveness on FBG. The application of mERA guidelines may standardize reporting of patient-centered implementation outcomes in LMICs.

TRIAL REGISTRATION

PROSPERO: Registration ID 154209.

Liraglutide for Weight Management in the Real World: Significant Weight Loss Even if the Maximal Daily Dose Is Not Achieved

INTRODUCTION

Obesity is a global health challenge, and pharmacologic options are emerging. Once daily subcutaneous administration of 3 mg liraglutide, a glucagon like peptide-1 analogue, has been shown to induce weight loss in clinical trials, but real-world effectiveness data are scarce.

METHODS

It is a single-centre retrospective cohort study of patients who were prescribed liraglutide on top of lifestyle adaptations after multidisciplinary evaluation. In Belgium, liraglutide is only indicated for weight management if the BMI is >30 kg/m2 or ≥27 kg/m2 with comorbidities such as dysglycaemia, dyslipidaemia, hypertension, or obstructive sleep apnoea. No indication is covered by the compulsory health care insurance. Liraglutide was started at 0.6 mg/day and uptitrated weekly until 3 mg/day or the maximum tolerated dose. Treatment status and body weight were evaluated at the 4-month routine visit.

RESULTS

Between June 2016 and January 2020, liraglutide was prescribed to 115 patients (77% female), with a median age of 47 (IQR 37.7-54.0) years, a median body weight of 98.4 (IQR 90.0-112.2) kg, a BMI of 34.8 (IQR 32.2-37.4) kg/m2, and an HbA1c level of 5.6%. Five (4%) patients did not actually initiate treatment, 9 (8%) stopped treatment, and 8 (7%) were lost to follow-up. At the 4-month visit, the median body weight had decreased significantly by 9.2% to 90.8 (IQR 82.0-103.5) kg (p < 0.001). Patients using 3.0 mg/day (n = 60) had lost 8.0 (IQR 5.8-10.4) kg. The weight loss was similar (p = 0.9622) in patients that used a lower daily dose because of intolerance: 7.4 (IQR 6.2-9.6) kg for 1.2 mg (n = 3), 7.8 (IQR 4.1-7.8) kg for 1.8 mg (n = 16), and 9.0 (IQR 4.8-10.7) kg for 2.4 mg/day (n = 14). Weight loss was minimal if liraglutide treatment was not started or stopped prematurely (median 3.0 [IQR 0.3-4.8] kg, p < 0.001, vs. on treatment). Further analysis showed an additional weight reduction of 1.8 kg in the patients that had started metformin <3 months before the start of liraglutide (p < 0.001). The main reasons for liraglutide discontinuation were gastrointestinal complaints (n = 5/9) and drug cost (n = 2/9).

CONCLUSION

In this selected group of patients, the majority complied with liraglutide treatment over the initial 4-month period and achieved a significant weight loss, irrespective of the maximally tolerated maintenance dose. Addition of metformin induced a small but significant additional weight loss.

Belgian data of ODYSSEY APPRISE: stringent LDL-c targets are in reach when using all available tools

BACKGROUND

As lipid targets became more stringent in the latest ESC/EAS guidelines, many patients on statin monotherapy are left above their risk-based target, increasing the need for lipid-lowering therapies. The results of the ODYSSEY APPRISE study were recently published by Gaudet et al In this trial, alirocumab (a PCSK9 inhibitor) was investigated in high cardiovascular risk patients in a real-life setting.

OBJECTIVE

We aim at analysing the characteristics, safety and efficacy of alirocumab in the Belgian population of the ODYSSEY APPRISE trial and, based on literature research, we aim to evaluate the importance and the need for the add-on, non-statin lipid-lowering therapy in clinical practice.

METHODS AND RESULTS

ODYSSEY APPRISE is a multicentric, prospective, single-arm, Phase 3b open-label trial. A total of 68 Belgian patients were enrolled, 63 patients had heterozygous familial hypercholesterolaemia (HeFH). Baseline mean LDL-c was 188.7 mg/dL (SD ± 51.8). At week 12, 65 patients had an evaluable efficacy end point with a mean LDL-c reduction of 59.9% from baseline. The overall incidence of treatment-emergent adverse events (TEAEs) was 75.0%. The most frequent TEAE was back pain (10.3%), nasopharyngitis (10.3%) and injection site erythema (8.8%). Based on the literature, a majority of patients do not reach their risk-based lipid target despite statin therapy alone.

CONCLUSION

In a real-life setting, alirocumab is both well-tolerated, safe and very effective in reducing LDL-c in this Belgian cohort. In clinical practice, more patients should be initiated on the add-on, non-statin lipid-lowering therapy in order to reach their risk-based lipid target.

One hundred years of insulin therapy

At the time of its first clinical application 100 years ago, insulin was presented as the cure for people with diabetes mellitus. That transpired to be an overstatement, yet insulin has proven to be the lifesaver for people with type 1 diabetes mellitus and an essential therapy for many with type 2 diabetes mellitus or other forms of diabetes mellitus. Since its discovery, insulin (a molecule of only 51 amino acids) has been the subject of pharmaceutical research and development that has paved the way for other protein-based therapies. From purified animal-extracted insulin and human insulin produced by genetically modified organisms to a spectrum of insulin analogues, pharmaceutical laboratories have strived to tailor the preparations to the needs of patients. Nonetheless, overall glycaemic control often remains poor as exogenous insulin is still not able to mimic the physiological insulin profile. Circumventing subcutaneous administration and the design of analogues with profiles that mimic that of physiological insulin are ongoing areas of research. Novel concepts, such as once-weekly insulins or glucose-dependent and oral insulins, are on the horizon but their real-world effectiveness still needs to be proven. Until a true cure for type 1 diabetes mellitus is found and the therapeutic arsenal for other forms of diabetes mellitus is expanded, insulin will remain central in the treatment of many people living with diabetes mellitus.

Psychosocial Consequences of Bariatric Surgery: Two Sides of a Coin: a Scoping Review

This scoping review summarizes current evidence with regard to the impact of bariatric surgery on psychological health in adults with obesity. While a large body of evidence reports major metabolic benefit and improved quality of life, there is also ample evidence suggesting an increased incidence of self-harming behavior, a greater likelihood of developing an alcohol problem and higher rates of completed suicide among bariatric patients. Being able to identify the "at risk" patient population requires more longitudinal research into the risk factors for psychological complications after bariatric surgery. Bariatric surgery remains an extremely valuable long-term treatment option for managing obesity; however, there is a need to invest in mitigating psychological complications after the surgery, such as depression, alcohol consumption, and other self-harming behaviors.

A multicenter propensity score matched analysis in 73,843 patients of an association of nutritional risk with mortality, length of stay and readmission rates

BACKGROUND

The reported prevalences and effects of nutritional risk vary widely in the literature because of both methodological differences (e.g., screening tools and statistical analyses) and different patient populations.

OBJECTIVE

In this study the authors analyzed in-hospital mortality, 30-d mortality, readmission within 4 mo, and justified length of stay (jLoS) (determined by governmental assessment to justify financial compensation) in hospitalized patients nutritionally at risk compared with hospitalized patients not at risk.

DESIGN

This was a multicenter retrospective cohort study in 6 Belgian hospitals among inpatients in 2018. Propensity score matching was applied, including comorbidity score and exact matching for hospital, age group, sex, type of admission, living situation, and medical specialty.

RESULTS

In total, 73,843 of 85,677 patients were screened at admission, with 16,141 found to have nutritional risk (prevalence of 21.9%). Oncology patients had the highest risk prevalence of 38.3%, whereas patients receiving plastic or reconstructive surgery had a prevalence of 5.2%. Patients nutritionally at risk had higher odds of dying in the hospital (5.1% compared with 3.3%; OR: 1.56; 95% CI: 1.37, 1.76), dying within 30 d of admission (6.8% compared with 4.3%; OR: 1.62; 95% CI: 1.45, 1.81) and being readmitted within 4 mo after discharge (35.5% compared with 32.9%; OR: 1.12; 95% CI: 1.07, 1.18). These differences were consistent across hospitals. The association between being nutritionally at risk and jLoS was ambiguous.

CONCLUSIONS

One out of 5 patients included in this study was nutritionally at risk. Using propensity score matching, higher odds of in-hospital mortality, readmission, and 30-d mortality were observed. In contrast to oft-reported increased length of stay with poor nutrition, propensity matched data for jLoS suggested that this association was less pronounced in this cohort.

Effect of obesity on gastrointestinal transit, pressure and pH using a wireless motility capsule

BACKGROUND

Despite the increasing prevalence and medical burden of obesity, the understanding of gastrointestinal physiology in obesity is scarce, which hampers drug development.

AIM

To investigate the effect of obesity and food intake on gastrointestinal transit, pressure and pH.

MATERIAL AND METHODS

An exploratory cross-sectional study using a wireless motility capsule (SmartPill©) was performed in 11 participants with obesity and 11 age- and gender-matched participants with normal weight (group) in fasted and fed state (visit). During the first visit, the capsule was ingested after an overnight fast. During a second visit, the capsule was ingested after a nutritional drink to simulate fed state. Linear mixed models were constructed to compare segmental gastrointestinal transit, pressure and pH between groups (obesity or control) and within every group (fasted or fed).

RESULTS

Food intake slowed gastric emptying in both groups (both P < 0.0001), though food-induced gastric contractility was higher in participants with obesity compared to controls (P = 0.02). In the small intestine, a higher contractility (P = 0.001), shorter transit (P = 0.04) and lower median pH (P = 0.002) was observed in participants with obesity compared to controls. No differences were observed for colonic measurements.

CONCLUSION

Obesity has a profound impact on gastrointestinal physiology, which should be taken into account for drug development.

ZBTB32 performs crosstalk with the glucocorticoid receptor and is crucial in glucocorticoid responses to starvation

The hypothalamic-pituitary-adrenal (HPA) axis forms a complex neuroendocrine system that regulates the body’s response to stress such as starvation. In contrast with the glucocorticoid receptor (GR), Zinc finger and BTB domain containing 32 (ZBTB32) is a transcription factor with poorly described functional relevance in physiology. This study shows that ZBTB32 is essential for the production of glucocorticoids (GCs) in response to starvation, since ZBTB32^−/− mice fail to increase their GC production in the absence of nutrients. In terms of mechanism, GR-mediated upregulation of adrenal Scarb1 gene expression was absent in ZBTB32^−/− mice, implicating defective cholesterol import as the cause of the poor GC synthesis. These lower GC levels are further associated with aberrations in the metabolic adaptation to starvation, which could explain the progressive weight gain of ZBTB32^−/− mice. In conclusion, ZBTB32 performs a crosstalk with the GR in the metabolic adaptation to starvation via regulation of adrenal GC production.

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ZBTB32 is involved in the glucocorticoid production in response to starvation

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GR-mediated upregulation of adrenal Scarb1 regulates cholesterol import

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The weight gain of ZBTB32^−/− mice is associated with aberrant metabolic adaptations

Testosterone Reduces Body Fat in Male Mice by Stimulation of Physical Activity Via Extrahypothalamic ERα Signaling

Testosterone (T) reduces male fat mass, but the underlying mechanisms remain elusive, limiting its clinical relevance in hypogonadism-associated obesity. Here, we subjected chemically castrated high-fat diet-induced adult obese male mice to supplementation with T or the nonaromatizable androgen dihydrotestosterone (DHT) for 20 weeks. Both hormones increased lean mass, thereby indirectly increasing oxygen consumption and energy expenditure. In addition, T but not DHT decreased fat mass and increased ambulatory activity, indicating a role for aromatization into estrogens. Investigation of the pattern of aromatase expression in various murine tissues revealed the absence of Cyp19a1 expression in adipose tissue while high levels were observed in brain and gonads. In obese hypogonadal male mice with extrahypothalamic neuronal estrogen receptor alpha deletion (N-ERαKO), T still increased lean mass but was unable to decrease fat mass. The stimulatory effect of T on ambulatory activity was also abolished in N-ERαKO males. In conclusion, our work demonstrates that the fat-burning action of T is dependent on aromatization into estrogens and is at least partially mediated by the stimulation of physical activity via extrahypothalamic ERα signaling. In contrast, the increase in lean mass upon T supplementation is mediated through the androgen receptor and indirectly leads to an increase in energy expenditure, which might also contribute to the fat-burning effects of T.

Metabolic effects of duodenojejunal bypass surgery in a rat model of type 1 diabetes

BACKGROUND

Metabolic surgery has beneficial metabolic effects, including remission of type 2 diabetes. We hypothesized that duodenojejunal bypass (DJB) surgery can protect against development of type 1 diabetes (T1D) by enhancing regulation of cellular and molecular pathways that control glucose homeostasis.

METHODS

BBDP/Wor rats, which are prone to develop spontaneous autoimmune T1D, underwent loop DJB (n = 15) or sham (n = 15) surgery at a median age of 41 days, before development of diabetes. At T1D diagnosis, a subcutaneous insulin pellet was implanted, oral glucose tolerance test was performed 21 days later, and tissues were collected 25 days after onset of T1D. Pancreas and liver tissues were assessed by histology and RT-qPCR. Fecal microbiota composition was analyzed by 16S V4 sequencing.

RESULTS

Postoperatively, DJB rats weighed less than sham rats (287.8 vs 329.9 g, P = 0.04). In both groups, 14 of 15 rats developed T1D, at similar age of onset (87 days in DJB vs 81 days in sham, P = 0.17). There was no difference in oral glucose tolerance, fasting and stimulated plasma insulin and c-peptide levels, and immunohistochemical analysis of insulin-positive cells in the pancreas. DJB rats needed 1.3 ± 0.4 insulin implants vs 1.9 ± 0.5 in sham rats (P = 0.002). Fasting and glucose stimulated glucagon-like peptide 1 (GLP-1) secretion was elevated after DJB surgery. DJB rats had reduced markers of metabolic stress in liver. After DJB, the fecal microbiome changed significantly, including increases in Akkermansia and Ruminococcus, while the changes were minimal in sham rats.

CONCLUSION

DJB does not protect against autoimmune T1D in BBDP/Wor rats, but reduces the need for exogenous insulin and facilitates other metabolic benefits including weight loss, increased GLP-1 secretion, reduced hepatic stress, and altered gut microbiome.

Fat Induces Glucose Metabolism in Nontransformed Liver Cells and Promotes Liver Tumorigenesis

Hepatic fat accumulation is associated with diabetes and hepatocellular carcinoma (HCC). Here, we characterize the metabolic response that high-fat availability elicits in livers before disease development. After a short term on a high-fat diet (HFD), otherwise healthy mice showed elevated hepatic glucose uptake and increased glucose contribution to serine and pyruvate carboxylase activity compared with control diet (CD) mice. This glucose phenotype occurred independently from transcriptional or proteomic programming, which identifies increased peroxisomal and lipid metabolism pathways. HFD-fed mice exhibited increased lactate production when challenged with glucose. Consistently, administration of an oral glucose bolus to healthy individuals revealed a correlation between waist circumference and lactate secretion in a human cohort. In vitro, palmitate exposure stimulated production of reactive oxygen species and subsequent glucose uptake and lactate secretion in hepatocytes and liver cancer cells. Furthermore, HFD enhanced the formation of HCC compared with CD in mice exposed to a hepatic carcinogen. Regardless of the dietary background, all murine tumors showed similar alterations in glucose metabolism to those identified in fat exposed nontransformed mouse livers, however, particular lipid species were elevated in HFD tumor and nontumor-bearing HFD liver tissue. These findings suggest that fat can induce glucose-mediated metabolic changes in nontransformed liver cells similar to those found in HCC. SIGNIFICANCE: With obesity-induced hepatocellular carcinoma on a rising trend, this study shows in normal, nontransformed livers that fat induces glucose metabolism similar to an oncogenic transformation.

Presence of Liver Steatosis Is Associated With Greater Diabetes Remission After Gastric Bypass Surgery

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance (IR) and β-cell dysfunction. Ectopic fat accumulation in liver and muscle causes IR. Since bariatric and metabolic surgery significantly improves fatty liver disease, we hypothesized that coexistence of liver steatosis (i.e., when hepatic IR contributes in T2DM) would be associated with greater diabetes improvement after surgery.

RESEARCH DESIGN AND METHODS

A total of 519 patients with T2DM who underwent Roux-en-Y gastric bypass and simultaneous liver biopsy and had a minimum 5-year follow-up were analyzed to assess the independent association between biopsy-proven liver steatosis and postoperative long-term diabetes remission (glycated hemoglobin <6.5% [48 mmol/mol] off medications).

RESULTS

Of the 407 patients with biopsy-proven liver steatosis, long-term diabetes remission was achieved in 211 (52%) patients compared with remission in 44 out of 112 (39%) patients without steatosis (P = 0.027). In multivariable analysis, presence of liver steatosis was an independent predictor of long-term diabetes remission (odds ratio 1.96 [95% CI 1.04-3.72]; P = 0.038). Hepatocyte ballooning, lobular inflammation, or fibrosis at baseline did not predict diabetes remission.

CONCLUSIONS

This study, for the first time, suggests that in patients with T2DM who are considering bariatric and metabolic surgery, coexistence of liver steatosis is associated with better long-term glycemic outcomes. Furthermore, our data suggest that there are distinct variants of T2DM in which metabolic responses to surgical weight loss are different. A subgroup of patients whose T2DM is characterized by the presence of hepatic steatosis (presumably associated with worse IR) experience better postoperative metabolic outcomes.

Effects of gastric bypass surgery on expression of glucose transporters and fibrotic biomarkers in kidney of diabetic fatty rats

BACKGROUND

Diabetic nephropathy is the leading cause of chronic kidney disease. Observational studies suggest Roux-en-Y gastric bypass (RYGB) reduces progression of diabetic nephropathy.

OBJECTIVES

To unravel the mechanisms by which RYGB is beneficial and protective for diabetic nephropathy.

SETTING

Academic laboratories.

METHODS

Forty-eight Zucker diabetic fatty rats were randomized to RYGB, sham surgery (SHAM), or pair-fed (PF) groups. An oral glucose tolerance test was performed at 25 days post intervention and kidneys were harvested at 30 days. Primary outcome measures included expression of key genes and proteins in the glucose transport, oxidative stress, inflammation, and fibrosis pathways.

RESULTS

Thirty days post intervention, RYGB rats weighed 349 ± 8 g, which was lower than SHAM (436 ± 14 g, P < .001), but not PF (374 ± 18 g) rats. RYGB rats had lower fasting glucose than PF animals and improved homeostatic model assessment of insulin resistance compared with PF and SHAM groups. These enhanced metabolic outcomes were accompanied by reduced sodium-glucose co-transporter 1 (Sglt1) gene expression (-23% versus PF, P = .01) in the kidney of RYGB rats. Expression of Sglt2, Glut1, or Glut2 mRNA, or oxidative stress and inflammation markers did not differ significantly. However, RYGB surgery induced a 19% lower expression of transforming growth factor (Tgfβ) mRNA (P = .004) compared with SHAM treated animals. Notably, adenosine monophosphate-activated protein kinase phosphorylation was increased (P = .04) in kidneys of the RYGB surgery animals.

CONCLUSIONS

Improvement of hyperglycemia after RYGB may reduce the glucose load on the kidney leading to a downregulation of specific glucose transporters. RYGB surgery may also attenuate kidney fibrosis through the adenosine monophosphate-activated protein kinase/TGFβ pathway.

The curious fate of bone following bariatric surgery: bone effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) in mice

BACKGROUND

Bone loss and increased fracture risk following bariatric surgery has been reported. We investigated whether the two most commonly performed surgeries, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), lead to bone loss. In addition, we examined whether fortification of the diet with calcium citrate prevents bone loss.

METHODS

We used mouse models for SG and RYGB and compared bone loss with a group of sham mice with similar weight loss. All groups were switched at the time of surgery to a low-fat diet (LFD). We also examined whether fortification of the diet with calcium citrate and vitamin D was able to prevent bone loss.

RESULTS

At 2 weeks we observed no major bone effects. However, at 8 weeks, both trabecular and cortical bone were lost to the same extent after SG and RYGB, despite increased calcium absorption and adequate serum levels of calcium, vitamin D, and parathyroid hormone (PTH). Diet fortification with calcium citrate and vitamin D was able to partially prevent bone loss.

CONCLUSIONS

Both SG and RYGB lead to excess bone loss, despite intestinal adaptations to increase calcium absorption. Fortifying the diet with calcium citrate and vitamin D partly prevented the observed bone loss. This finding emphasizes the importance of nutritional support strategies after bariatric surgery, but also affirms that the exact mechanisms leading to bone loss after bariatric surgery remain elusive and thus warrant further research.

Does Colectomy Improve Type 2 Diabetes?

Gastrectomy and gastric bypass improve type 2 diabetes (T2DM), potentially through alterations in intestinal hormones and the microbiome. The aim of this study was to analyze whether colorectal resections result in improvement of T2DM. A total of 171 patients with T2DM who underwent colectomy for benign diseases were studied with a median postoperative follow-up of 3 years (interquartile range [IQR] 1-5). The median BMI and glycated hemoglobin (HbA_1c) at baseline and post-colectomy were 30.3 kg/m² (IQR 26.6-34.6) versus 30.4 kg/m² (IQR 26.2-35) (p = 0.1), and 6.7% (IQR 6.2-7.5) versus 6.5% (IQR 6.5-7.1) (p = 0.5), respectively. The proportion of patients taking diabetes medications at baseline versus post-colectomy did not differ significantly. Changes in BMI, HbA_1c, and status of diabetes medications were not statistically different between the subtypes of colorectal resection. Our experience suggests that colectomy for benign colorectal diseases is not associated with long-term changes in body weight or glycemic control.

Vhl deletion in osteoblasts boosts cellular glycolysis and improves global glucose metabolism

The skeleton has emerged as an important regulator of systemic glucose homeostasis, with osteocalcin and insulin representing prime mediators of the interplay between bone and energy metabolism. However, genetic evidence indicates that osteoblasts can influence global energy metabolism through additional, as yet unknown, mechanisms. Here, we report that constitutive or postnatally induced deletion of the hypoxia signaling pathway component von Hippel-Lindau (VHL) in skeletal osteolineage cells of mice led to high bone mass as well as hypoglycemia and increased glucose tolerance, not accounted for by osteocalcin or insulin. In vitro and in vivo data indicated that Vhl-deficient osteoblasts displayed massively increased glucose uptake and glycolysis associated with upregulated HIF-target gene expression, resembling the Warburg effect that typifies cancer cells. Overall, the glucose consumption by the skeleton was increased in the mutant mice, as revealed by 18F-FDG radioactive tracer experiments. Moreover, the glycemia levels correlated inversely with the level of skeletal glucose uptake, and pharmacological treatment with the glycolysis inhibitor dichloroacetate (DCA), which restored glucose metabolism in Vhl-deficient osteogenic cells in vitro, prevented the development of the systemic metabolic phenotype in the mutant mice. Altogether, these findings reveal a novel link between cellular glucose metabolism in osteoblasts and whole-body glucose homeostasis, controlled by local hypoxia signaling in the skeleton.

Long-term effects of gastric bypass surgery on psychosocial well-being and eating behavior: not all that glitters is gold

OBJECTIVES

The aim of this pilot study was to evaluate long-term effects of Roux-en-Y gastric bypass (RYGB) on physical and psychosocial health as well as eating behavior of obese patients.

METHODS

We compared 23 patients 7 years after RYGB to 23 body mass index (BMI), sex, and age matched obese control patients by means of self-reporting questionnaires: Hospital Anxiety and Depression Scale (HADS), Quality of Life Enjoyment and Satisfaction Questionnaire - Short Form (Q-LES-Q SF), Dutch Eating Behavior Questionnaire (DEBQ), and Alcohol Use Disorders Identification Test (AUDIT). Data are presented as median ± interquartile rage.

RESULTS

Physical health had improved and body image (80 ± 25% vs. 20 ± 49%, p < 0.001) was better in post-RYGB patients when compared to controls. HADS-depression score (4 ± 8 vs. 11 ± 9; p = 0.005) was lower post-RYGB. Satisfaction with physical health (2 ± 2 vs. 2 ± 1, p = 0.037), daily life functioning (4 ± 2 vs. 2 ± 2, p = 0.050), and hobbies (4 ± 1 vs. 2 ± 2, p = 0.011) was higher post-RYGB, but social relationships and sexual performance were not perceived as superior. In addition, post-RYGB patients were more prone to eat on external cues (13 ± 7 vs. 19 ± 13; p = 0.007).

CONCLUSION

Seven years post-RYGB, patients reported a significant improvement of physical health and higher satisfaction with daily life, but not with social relationships or sexual performance. Eating behavior post-RYGB was more influenced by external cues.

Effect of a transcriptional inactive or absent vitamin D receptor on beta-cell function and glucose homeostasis in mice

Vitamin D deficiency is associated with beta-cell dysfunction and a higher risk of diabetes, but mice and humans with an absence of the vitamin D receptor (VDR) display normal glucose tolerance. Here, we investigated the direct effects of absence of VDR or absence of ligand activation of VDR on beta-cell function. For this purpose, we generated mice, with a mutation in the AF2 domain of Vdr (VDRΔAF2), preventing ligand-driven transcriptional activation of vitamin D responsive genes. VDRΔAF2 mice were compared to Vdr full knockout (VDR^-/-) and wild type (WT) mice. In order to avoid hypocalcemia, which has a direct effect on beta-cell function, mice were fed a high calcium, high lactose diet yielding comparable serum calcium in all mice. While VDR^-/- mice developed extensive alopecia by the age of 24 weeks, the fur of VDRΔAF2 remained normal. All VDRΔAF2 mice weighed significantly less than WT, while male but not female VDR^-/- mice had a lower body weight than WT mice. Dual-energy X-ray absorptiometry showed that both VDRΔAF2 (17.2% (females) and 16.6% (males)) and VDR^-/- (15.7% and 14.8%) mice have a lower percentage of body fat (vs 19.3% and 22.2% in WT). Serum 25(OH)D₃ concentrations were lower for both VDRΔAF2 (-4.55 fold, P<0.001) and VDR^-/- (-3.7 fold, P<0.001) as compared to 12 week old WT mice, while serum 1,25(OH)₂D₃ was increased for both strains 94.5 fold (P<0.01) and 92.8 fold (P<0.001) for VDRΔAF2 and VDR^-/- vs WT, respectively). In vivo glucose tolerance tests performed at 12 and 24 weeks of age, as well as ex vivo glucose stimulated insulin secretion on freshly isolated islets, revealed no major differences between the three strains. Microarray analysis on freshly isolated islets showed only 1 differentially expressed gene, phosphodiesterase 10a (Pde10a), which was 2.16 and 1.75 fold up-regulated in VDRΔAF2 and VDR^-/- islets as compared to WT islets, respectively (P≤0.001). We conclude that in the presence of normocalcemia, absence of VDR or its ligand-activated transcription of genes has no direct regulatory effect on murine glucose homeostasis or gene expression in islets of Langerhans.

Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography

High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging.

The microRNA-29 Family Dictates the Balance Between Homeostatic and Pathological Glucose Handling in Diabetes and Obesity

The microRNA-29 (miR-29) family is among the most abundantly expressed microRNA in the pancreas and liver. Here, we investigated the function of miR-29 in glucose regulation using miR-29a/b-1 (miR-29a)-deficient mice and newly generated miR-29b-2/c (miR-29c)-deficient mice. We observed multiple independent functions of the miR-29 family, which can be segregated into a hierarchical physiologic regulation of glucose handling. miR-29a, and not miR-29c, was observed to be a positive regulator of insulin secretion in vivo, with dysregulation of the exocytotic machinery sensitizing β-cells to overt diabetes after unfolded protein stress. By contrast, in the liver both miR-29a and miR-29c were important negative regulators of insulin signaling via phosphatidylinositol 3-kinase regulation. Global or hepatic insufficiency of miR-29 potently inhibited obesity and prevented the onset of diet-induced insulin resistance. These results demonstrate strong regulatory functions for the miR-29 family in obesity and diabetes, culminating in a hierarchical and dose-dependent effect on premature lethality.

Cereulide food toxin, beta cell function and diabetes: Facts and hypotheses

The incidence of both type 1 and type 2 diabetes is increasing and although environmental pollutants are believed to be potential culprits, the extent to which they can be held responsible remains uncertain. Some bacterial strains of the Bacillus cereus produce a toxin, cereulide, which is frequently found in starchy meals and which is difficult to eradicate from the food chain as it is highly resistant to heat, acidity and proteolysis. While cereulide is well known to cause acute emetic toxicity when ingested at high doses, several in vitro studies have shown that also extremely low doses of cereulide can be toxic, with beta cells being particularly sensitive. Mechanistically, such low doses impair the mitochondrial activity of the beta cells thereby leading to hampered insulin secretion and cell death, both key traits in the pathophysiology of diabetes. In vivo studies of chronic or repeated low dose exposure to cereulide are currently lacking, but should be performed to further clarify the true relevance of cereulide as a potential environmental contributor to the ongoing diabetes epidemic.

Low cytochrome oxidase 4I1 links mitochondrial dysfunction to obesity and type 2 diabetes in humans and mice

OBJECTIVES

Cytochrome oxidase (COX) dysfunction is associated with mitochondrial oxidative stress. We determined the association between COX expression, obesity and type 2 diabetes.

SUBJECTS/METHODS

COX4I1 and COX10 genes were measured in monocytes of 24 lean controls, 31 glucose-tolerant and 67 diabetic obese patients, and 17 morbidly obese patients before and after bariatric surgery. We investigated the effect of caloric restriction and peroxisome proliferator-activated receptor (PPAR) agonist treatment on Cox in obese diabetic mice, and that of diet-induced insulin resistance in Streptozotocin-treated mice.

RESULTS

Low COX4I1 was associated with type 2 diabetes in obese patients, adjusting for age, gender, smoking, interleukin-6 and high-sensitivity C-reactive protein, all related to metabolic syndrome (MetS; odds ratio: 6.1, 95% confidence interval: 2.3-16). In contrast, COX10 was low in glucose-tolerant and diabetic obese patients. In morbidly obese patients, COX4I1 was lower in visceral adipose tissue collected at bariatric surgery. In their monocytes, COX4I1 decreased after bariatric surgery, and low COX4I1 at 4 months was associated with MetS at 7 years. In leptin-deficient obese diabetic mice, Cox4i1 was low in white visceral adipose tissue (n=13; P<0.001) compared with age-matched lean mice (n=10). PPARγ-agonist treatment (n=13), but not caloric restriction (n=11), increased Cox4i1 (P<0.001). Increase in Cox4i1 depended on the increase in glucose transporter 4 (Glut4) expression and insulin sensitivity, independent of the increase in blood adiponectin. In streptozotocin-treated mice (three groups of seven mice, diet-induced insulin resistance decreased Cox4i1 and Glut4 (P<0.001 for both).

CONCLUSION

COX4I1 depression is related to insulin resistance and type 2 diabetes in obesity. In peripheral blood monocytes, it may be a diagnostically useful biomarker.

Foodborne cereulide causes beta-cell dysfunction and apoptosis

Aims/Hypothesis

To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function.

Methods

Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6) and rat (INS-1E) beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1). Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS). Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests.

Results

24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05). Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05) and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein). Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05) and reactive oxygen species increased by more than twofold (P<0.05) following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively.

Conclusions/Interpretation

Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell.

GLP1 and cancer: friend or foe?

The new incretin-based therapies, dipeptidyl peptidase-4 (DPP4) inhibitors and glucagon like peptide 1 (GLP1) receptor agonists are widely used for the treatment of type 2 diabetes because of their glucose-lowering capacity with low risk of hypoglycemia. As they are weight neutral or induce weight loss in this mostly overweight population, they are popular among clinicians and patients alike. Nonetheless, concerns have been raised about GLP1's trophic effects. While increased β cell mass observed in rodents sounds appealing for treatment of diabetes, there was also an increased incidence of medullary thyroid cancer (MTC) in some species. We reviewed literature available in the Medline database until March 2012. Safety signals have emerged for MTC and pancreatic carcinoma from adverse event databases in the United States and Europe. Considering the relatively short duration of these studies, it is more likely that premalignant lesions are stimulated in presence of GLP1, rather than new neoplasms induced. Moreover, interpreting results of animal studies is difficult because of species-specific differences in presence and density of GLP1 receptors. Furthermore, data are emerging suggesting beneficial effects of GLP1 on colon and breast cancer. In conclusion, presently, the benefits of using DPP4 inhibitors or GLP1 receptor agonists for treatment of type 2 diabetes outweigh the risks. Nonetheless, their safety profile should be monitored and their indications should be widened cautiously. At present they remain contra-indicated in patients with a personal or family history of MTC or multiple endocrine neoplasia type 2.

Whipple's disease. A classic case report and review of the literature

We report the case of a 43-year-old carpenter with abdominal complaints and progressive weight loss. The HLA-B27 positive male had been suffering migratory arthropathy for five years, only partially under control with corticosteroids and methotrexate therapy. Endoscopic investigation showed dark staining of the duodenal mucosa and the ileal mucosa had an erythematous aspect with multiple white spots. Abundant periodic acid Schiff positive macrophages were seen on histologic examination of biopsy samples. This is a classic presentation of Whipple's disease, a rare multisystemic disease caused by the Tropheryma whipplei. Typical symptoms are arthropathy, weight loss, abdominal pain and diarrhea, but also systemic and neurological manifestations may occur. The otherwise lethal disease can be treated with long term antibiotics.