COVID-19 and diabetes: understanding the interrelationship and risks for a severe course

The relationship between COVID-19 and diabetes mellitus is complicated and bidirectional. On the one hand, diabetes mellitus is considered one of the most important risk factors for a severe course of COVID-19. Several factors that are often present in diabetes mellitus are likely to contribute to this risk, such as older age, a proinflammatory and hypercoagulable state, hyperglycemia and underlying comorbidities (hypertension, cardiovascular disease, chronic kidney disease and obesity). On the other hand, a severe COVID-19 infection, and its treatment with steroids, can have a specific negative impact on diabetes itself, leading to worsening of hyperglycemia through increased insulin resistance and reduced beta-cell secretory function. Worsening hyperglycemia can, in turn, adversely affect the course of COVID-19. Although more knowledge gradually surfaces as the pandemic progresses, challenges in understanding the interrelationship between COVID-19 and diabetes remain.Diabetes mellitus: pathophysiological changes and therap

Fasting parameters for estimation of stimulated beta cell function in islet transplant recipients with or without basal insulin treatment

In order to assess beta cell secretory capacity after islet transplantation, standardized mixed meal stimulation tests are often used. But these tests are cumbersome and the effect of exogenous insulin on the test results is unclear. The aim of our study was to determine to what extent fasting glycemic indices can estimate stimulated beta cell function in islet transplant recipients with and without basal insulin. In total 100 mixed meal stimulation tests, including 31 with concurrent basal insulin treatment, were performed in 36 islet transplant recipients. In a multivariate model, fasting C-peptide and fasting glucose together estimated peak C-peptide withR(2) = .87 and area under the curve (AUC) C-peptide with aR(2) = .93. There was a larger increase of glucose during tests in which exogenous insulin was used (+7.9 vs +5.3 mmol/L,P < .001) and exogenous insulin use was associated with a slightly lower estimated peak C-peptide (relative change: -15%,P = .02). In islet transplant recipients the combination of fasting C-peptide and glucose can be used to accurately estimate stimulated beta cell function after a mixed meal stimulation test, whether exogenous basal insulin is present or not. These data indicate that graft function can be reliably determined during exogenous insulin treatment and that regular islet graft stimulation tests can be minimized.Analysis and support of clinical decision makin

Clinical use of donation after circulatory death pancreas for islet transplantation

Due to a shortage of donation after brain death (DBD) organs, donation after circulatory death (DCD) is increasingly performed. In the field of islet transplantation, there is uncertainty regarding the suitability of DCD pancreas in terms of islet yield and function after islet isolation. The aim of this study was to investigate the potential use of DCD pancreas for islet transplantation. Islet isolation procedures from 126 category 3 DCD and 258 DBD pancreas were performed in a 9-year period. Islet yield after isolation was significantly lower for DCD compared to DBD pancreas (395 515 islet equivalents [IEQ] and 480 017 IEQ, respectively; p = .003). The decrease in IEQ during 2 days of culture was not different between the two groups. Warm ischemia time was not related to DCD islet yield. In vitro insulin secretion after a glucose challenge was similar between DCD and DBD islets. After islet transplantation, DCD islet graft recipients had similar graft function (AUC C-peptide) during mixed meal tolerance tests and Igls score compared to DBD graft recipients. In conclusion, DCD islets can be considered for clinical islet transplantation.Diabetes mellitus: pathophysiological changes and therap

Oxidative stress leads to beta-cell dysfunction through loss of beta-cell identity

Pancreatic beta-cell failure is a critical event in the onset of both main types of diabetes mellitus but underlying mechanisms are not fully understood. beta-cells have low anti-oxidant capacity, making them more susceptible to oxidative stress. In type 1 diabetes (T1D), reactive oxygen species (ROS) are associated with pro-inflammatory conditions at the onset of the disease. Here, we investigated the effects of hydrogen peroxide-induced oxidative stress on human beta-cells. We show that primary human beta-cell function is decreased. This reduced function is associated with an ER stress response and the shuttling of FOXO1 to the nucleus. Furthermore, oxidative stress leads to loss of beta-cell maturity genes MAFA and PDX1, and to a concomitant increase in progenitor marker expression of SOX9 and HES1. Overall, we propose that oxidative stress-induced beta-cell failure may result from partial dedifferentiation. Targeting antioxidant mechanisms may preserve functional beta-cell mass in early stages of development of T1D.Nephrolog

The association of glucose metabolism and kidney function in middle-aged adults

Background. Previous clinical studies have shown that various measures of glucose metabolism are associated with a risk of chronic kidney disease in different populations, but results were not consistent. In this study we assessed measures of glucose metabolism and their association with kidney function in a population-based study.Methods. The Netherlands Epidemiology of Obesity study is a population-based cohort study of middle-aged men and women. We categorized the study population according to glycaemic levels into normoglycaemia (reference group), pre-diabetes mellitus (pre-DM), known DM and newly diagnosed DM. Outcome variables were serum creatinine, estimated glomerular filtration rate (eGFR), glomerular hyperfiltration (defined as an eGFR >90th percentile; >102mL/min/1.73m(2)) and micro-albuminuria. We examined the association between measures of glucose metabolism [fasting glucose, haemoglobin A1c (HbA1c), fasting insulin, glucose area under the curve (AUC), insulin AUC, Homoeostatic Model Assessment of Insulin Resistance (HOMA-IR), HOMA of beta-cell function (HOMA-B) and disposition index] and measures of kidney function.Results. Of the total population (N=6338), 55% of participants were classified as normoglycaemic (reference), 35% as pre-DM, 7% as DM and 4% as newly diagnosed DM. Compared with the reference group, diagnosed and newly diagnosed DMs were associated with a slightly higher trend in eGFR {+2.1mL/min/1.73m(2) [95% confidence interval (CI) -0.2-4.4] and +2.7mL/min/1.73m(2) [95% CI -0.3-5.7], respectively}. A 1% higher HbA1c was associated with increased odds of hyperfiltration [odds ratio (OR) 1.41 (95% CI 1.06-1.88)]. Higher levels of fasting plasma glucose, AUC glucose and HOMA-B were associated with hyperfiltration. Fasting insulin, AUC insulin and HOMA-IR were not associated with hyperfiltration. The OR of microalbuminuria was 1.21 (95% CI 1.04-1.42) per mmol/L higher fasting glucose concentrations.Conclusions. Both fasting and post-prandial glucose and HOMA-B, but not measures of insulin resistance, were associated with glomerular hyperfiltration, while fasting glucose was also associated with microalbuminuria.Nephrolog

Pancreas Transplantation With Grafts From Donors Deceased After Circulatory Death: 5 Years Single-Center Experience

Transplant surger

Increased stress, weight gain and less exercise in relation to glycemic control in people with type 1 and type 2 diabetes during the COVID-19 pandemic

Introduction Lockdown measures have a profound effect on many aspects of daily life relevant for diabetes self-management. We assessed whether lockdown measures, in the context of the COVID-19 pandemic, differentially affect perceived stress, body weight, exercise and related this to glycemic control in people with type 1 and type 2 diabetes. Research design and methods We performed a short-term observational cohort study at the Leiden University Medical Center. People with type 1 and type 2 diabetes >= 18 years were eligible to participate. Participants filled out online questionnaires, sent in blood for hemoglobin A1c (HbA1c) analysis and shared data of their flash or continuous glucose sensors. HbA1c during the lockdown was compared with the last known HbA1c before the lockdown. Results In total, 435 people were included (type 1 diabetes n=280, type 2 diabetes n=155). An increase in perceived stress and anxiety, weight gain and less exercise was observed in both groups. There was improvement in glycemic control in the group with the highest HbA1c tertile (type 1 diabetes: -0.39% (-4.3 mmol/mol) (p<0.0001 and type 2 diabetes: -0.62% (-6.8 mmol/mol) (p=0.0036). Perceived stress was associated with difficulty with glycemic control (p<0.0001). Conclusions An increase in perceived stress and anxiety, weight gain and less exercise but no deterioration of glycemic control occurs in both people with relatively well-controlled type 1 and type 2 diabetes during short-term lockdown measures. As perceived stress showed to be associated with glycemic control, this provides opportunities for healthcare professionals to put more emphasis on psychological aspects during diabetes care consultations.Diabetes mellitus: pathophysiological changes and therap

Oxidative stress in pancreatic alpha and beta cells as a selection criterion for biocompatible biomaterials

The clinical success rate of islet transplantation, namely independence from insulin injections, is limited by factors that lead to graft failure, including inflammation, acute ischemia, acute phase response, and insufficient vascularization. The ischemia and insufficient vascularization both lead to high levels of oxidative stress, which are further aggravated by islet encapsulation, inflammation, and undesirable cell-biomaterial interactions. To identify biomaterials that would not further increase damaging oxidative stress levels and that are also suitable for manufacturing a beta cell encapsulation device, we studied five clinically approved polymers for their effect on oxidative stress and islet (alpha and beta cell) function. We found that 300 poly(ethylene oxide terephthalate) 55/poly(butylene terephthalate) 45 (PEOT/PBT300) was more resistant to breakage and more elastic than other biomaterials, which is important for its immunoprotective function. In addition, it did not induce oxidative stress or reduce viability in the MIN6 beta cell line, and even promoted protective endogenous antioxidant expression over 7 days. Importantly, PEOT/PBT300 is one of the biomaterials we studied that did not interfere with insulin secretion in human islets.Diabetes mellitus: pathophysiological changes and therap

DNA methylation and transcriptional trajectories during human development and reprogramming of isogenic pluripotent stem cells

Diabetes mellitus: pathophysiological changes and therap