Genetics of Type 2 Diabetes: association, interaction, prediction

Type 2 Diabetes is a common chronic disease that results from an imbalance between the bodies insulin need and the production of insulin. It is a heterogeneous disorder in which the relative contributions of insulin resistance and defects in insulin secretion are highly variable between patients. Insulin is produced by beta cells located in the islets of Langerhans in the pancreas. It is a hormone with an extensive range of effects on metabolism. One of its main functions is to facilitate glucose uptake in various body tissues to allow glycogen storage. Besides a number of internal and external stimuli, the primary stimulus for insulin secretion are elevated glucose levels. When a relative lack of insulin remains untreated, this will eventually result in hyperglycaemia, i.e. diabetes. Besides short term symptoms of hyperglycaemia, the main burden of type 2 diabetes are its long term complications; retinopathy, nephropathy, neuropathy and cardiovascular disease, which account for most of the morbidity and mortality of the disease. Worldwide type 2 diabetes is a rapidly growing health care issue, with an estimated 171 million patients worldwide in 2000 and the expectancy that this number will be more than doubled by 2030. Although many researchers in the past decennia have devoted their research to type 2 diabetes, much

The (cost) effectiveness of a very low-energy diet intervention with the use of eHealth in patients with type 2 diabetes and obesity:study protocol for a randomised controlled non-inferiority trial (E-diet trial)

BACKGROUND: Despite preventive measures, the number of people with type 2 diabetes and obesity is increasing. Obesity increases morbidity and mortality in people with type 2 diabetes, making weight loss a cornerstone of treatment. We previously developed a very low energy diet (VLED) intervention that effectively reduced weight in people with type 2 diabetes in the long term. However, this intervention requires considerable time and manpower, which reduces the number of people who can benefit from it. eHealth offers more efficient solutions but has proven to be less effective than face-to-face interventions. Therefore, we want to investigate whether a blended version of our VLED intervention (in which face-to-face contact is partly replaced by an eHealth (mobile) application (E-VLED)) would be more cost-effective than the current face-to-face intervention. METHODS: We will conduct a randomised, controlled trial with non-inferiority design in patients with type 2 diabetes and obesity (BMI &gt; 30 kg/m2), aged 18-75 years. The control group will receive the usual care VLED intervention, while the intervention group will receive the E-VLED intervention for 1 year, where face-to-face contact will be partly replaced by an eHealth (mobile) application. The main study endpoint is the difference in weight (% change) between the control and intervention group after 1 year, plus the difference between the total costs (euro) of the treatment in the control and intervention groups. The secondary aims are to investigate the effectiveness of the E-VLED diet intervention regarding cardiovascular risk factors, quality of life, patient satisfaction, compliance, and to study whether there is a difference in effectiveness in pre-specified subgroups. General linear models for repeated measurements will be applied for the statistical analysis of the data. DISCUSSION: We hypothesise that the E-VLED intervention will be equally effective compared to the usual care VLED but lower in costs due to less time invested by the dietician. This will enable to help more people with type 2 diabetes and obesity to effectively lose weight and improve their health-related quality of life. TRIAL REGISTRATION: Netherlands Trial Register, NL7832, registered on 26 June 2019.</p

Mining treatment patterns of glucose-lowering medications for type 2 diabetes in the Netherlands

Rationale and objectives Different classes of glucose-lowering medications are used for patients with type 2 diabetes mellitus (T2DM) management. It is unclear how often these medications are prescribed in clinical practice. In this study, we aimed to describe treatment patterns of glucose-lowering medications in patients with T2DM in the Netherlands. Methods We studied a cohort of 73 819 patients with T2DM, aged ≥45 years with a first prescription for oral glucose-lowering medication between 2011 and 2017. We used the NControl database with dispensing data from 800 pharmacies in the Netherlands. Prevalence of each glucose-lowering medication class during 6 years after the index date was calculated. Using SQL Server, we identified stepwise patterns of medication prescription in this population. Findings During the study period, prevalence of biguanides (BIGU) decreased from 95.6% to 80.8% and use of sulfonylureas (SU) increased from 27.3% to 42.3%. 55.2% of all patient

The clinical value of metabolic syndrome and risks of cardiometabolic events and mortality in the elderly: The Rotterdam study

Background: To evaluate the clinical value of metabolic syndrome based on different definitions [American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI), International Diabetes Federation (IDF) and European Group for the Study of Insulin Resistance (EGIR)] in middle-aged and elderly populations. Methods: We studied 8643 participants from the Rotterdam study (1990-2012; mean age 62.7; 57.6% female), a large prospective population-based study with predominantly elderly participants. We performed cox-proportional hazards models for different definitions, triads within definitions and each separate component for the risk of incident type 2 diabetes mellitus, coronary heart disease, stroke, cardiovascular- and all-cause mortality. Results: In our population of 8643 subjects, metabolic syndrome was highly prevalent (prevalence between 19.4 and 42.4%). Metabolic syndrome in general was associated with incident type 2 diabetes mellitus (median follow-up of 6.8years, hazard ratios 3.13-3.78). The associations with coronary heart disease (median follow-up of 7.2years, hazard ratios 1.08-1.32), stroke (median follow-up of 7.7years, hazard ratios 0.98-1.32), cardiovascular mortality (median follow-up of 8.2years, ratios 0.95-1.29) and all-cause mortality (median follow-up of 8.7years, hazard ratios 1.05-1.10) were weaker. AHA/NHLBI- and IDF-definitions showed similar associations with clinical endpoints compared to the EGIR, which was only significantly associated with incident type 2 diabetes mellitus. All significant associations disappeared after correcting metabolic syndrome for its individual components. Conclusions: Large variability exists between and within definitions of the metabolic syndrome with respect to risk of clinical events and mortality. In a relatively old population the metabolic syndrome did not show an additional predictive value on top of its individual components. So, besides as a manner of easy identification of high risk patients, the metabolic syndrome does not seem to add any predictive value for clinical practice

Sex difference in the incidence of microvascular complications in patients with type 2 diabetes mellitus: a prospective cohort study

Aims: Type 2 diabetes mellitus is a major cause of death and disability due to its long-term macro- and microvascular diseases. Although women with type 2 diabetes have more macrovascular diseases, it is unclear whether there are sex differences in the occurrence of microvascular disease. The aim of our study was to investigate sex differences in the incidence of microvascular complications in type 2 diabetes. Methods: Analyses were performed in the DiaGene study, a prospective cohort study for complications of type 2 diabetes, collected in the city of Eindhoven, the Netherlands (n = 1886, mean follow-up time = 6.93 years). Cox proportional hazard models adjusted for risk factors for complications (age, smoking, hypertension, dyslipidemia, HbA1c and duration of type 2 diabetes) were used to analyze the incidence of microvascular complications in men and women. Results: The incidence of microalbuminuria was significantly higher in men (HR microalbuminuria 1.64 [CI 1.21–2.24], p = 0.002). Additionally, men are more likely to develop two or three microvascular complications compared to women (OR 2.42 [CI 1.69–3.45], p < 0.001). Conclusions: This study shows that men with type 2 diabetes are more likely to develop microvascular complications, especially microalbuminuria. Furthermore, men seem to have a higher chance of developing multiple microvascular complications. Our results highlight that men and women may not benefit to a similar extent from current treatment approaches to prevent diabetes-related microvascular diseases

The effect of guideline revisions on vascular complications of type 2 diabetes

Background: The aim of this study was to investigate the impact of implementation and revision of the ‘Diabetes Mellitus type II’ guideline by the Dutch College of General Practitioners (DCGP) on the prevalence and incidence of macrovascular and microvascular complications. Methods: The DiaGene study is a case-control study (n = 1886 patients of type 2 diabetes) with extensive, retrospectively collected complication data, as well as prospective follow up of complications. The study incorporates all lines of diabetes care. Cases were divided into categories according to the date of onset of diabetes and publication dates of the DCGP. Logistic regression models were used to investigate the associations between guideline version and complications. To investigate a possible trend between guideline version and complications, the ‘guideline category’ was also used as a continuous variable. All models were adjusted for clinical covariables. Results: The 1999 and 2006 guidelines versions were associated with significantly lower risk of retinopathy than the group that started without a guideline [OR 0.32 (95% CI 0.14–0.72, p = 0.006) and 0.31 (95% CI 0.11–0.91, p = 0.034), respectively]. A significant trend in reduction of peripheral artery disease (PAD) over the guideline versions was found, adjusted for age, sex and diabetes duration (odds ratio (OR) 0.70, 95% CI 0.51-0.97, p trend = 0.029) and for retinopathy in all models (OR = 0.52, 95% CI 0.37-0.73, p trend < 0.001). Conclusions: The introduction of the first diabetes guideline and subsequent revisions have reduced the risk of macrovascular and microvascular complications of type 2 diabetes, most strongly in diabetic retinopathy. This indicates that real-time diabetes care has improved over time

Apolipoprotein-CIII O-Glycosylation, a Link between GALNT2 and Plasma Lipids

Apolipoprotein-CIII (apo-CIII) is involved in triglyceride-rich lipoprotein metabolism and linked to beta-cell damage, insulin resistance, and cardiovascular disease. Apo-CIII exists in four main proteoforms: non-glycosylated (apo-CIII0a), and glycosylated apo-CIII with zero, one, or two sialic acids (apo-CIII0c, apo-CIII1 and apo-CIII2). Our objective is to determine how apo-CIII glycosylation affects lipid traits and type 2 diabetes prevalence, and to investigate the genetic basis of these relations with a genome-wide association study (GWAS) on apo-CIII glycosylation. We conducted GWAS on the four apo-CIII proteoforms in the DiaGene study in people with and without type 2 diabetes (n = 2318). We investigated the relations of the identified genetic loci and apo-CIII glycosylation with lipids and type 2 diabetes. The associations of the genetic variants with lipids were replicated in the Diabetes Care System (n = 5409). Rs4846913-A, in the GALNT2-gene, was associated with decreased apo-CIII0a. This variant was associated with increased high-density lipoprotein cholesterol and decreased triglycerides, while high apo-CIII0a was associated with raised high-density lipoprotein-cholesterol and triglycerides. Rs67086575-G, located in the IFT172-gene, was associated with decreased apo-CIII2 and with hypertriglyceridemia. In line, apo-CIII2 was associated with low triglycerides. On a genome-wide scale, we confirmed that the GALNT2-gene plays a major role i O-glycosylation of apolipoprotein-CIII, with subsequent associations with lipid parameters. We newly identified the IFT172/NRBP1 region, in the literature previously associated with hypertriglyceridemia, as involved in apolipoprotein-CIII sialylation and hypertriglyceridemia. These results link genomics, glycosylation, and lipid metabolism, and represent a key step towards unravelling the importance of O-glycosylation in health and disease.</p

ADAMTS13 activity as a novel risk factor for incident type 2 diabetes mellitus: a population-based cohort study

Aims/hypothesis: ADAMTS13 is a protease that breaks down von Willebrand factor (VWF) multimers into smaller, less active particles. VWF has been associated with an increased risk of incident type 2 diabetes mellitus. Here, we determine whether ADAMTS13 activity and VWF antigen are associated with incident diabetes. Methods: This study included 5176 participants from the Rotterdam Study, a prospective population-based cohort study. Participants were free of diabetes at baseline and followed up for more than 20 years. Cox proportional hazards models were used to examine the association of ADAMTS13 activity and VWF antigen with incident diabetes. Results: ADAMTS13 activity was associated with an increased risk of incident diabetes (HR 1.17 [95% CI 1.08, 1.27]) after adjus

Lipoprotein(a) plasma levels are not associated with incident microvascular complications in type 2 diabetes mellitus

Aims/hypothesis: Microvascular disease in type 2 diabetes is a significant cause of end-stage renal disease, blindness and peripheral neuropathy. The strict control of known risk factors, e.g. lifestyle, hyperglycaemia, hypertension and dyslipidaemia, reduces the incidence of microvascular complications, but a residual risk remains. Lipoprotein (a) [Lp(a)] is a strong risk factor for macrovascular disease in the general population. We hypothesised that plasma Lp(a) levels and the LPA gene SNPs rs10455872 and rs3798220 are associated with the incident development of microvascular complications in type 2 diabetes. Methods: Analyses were performed of data from the DiaGene study, a prospective study for complications of type 2 diabetes, collected in the city of Eindhoven, the Netherlands (n = 1886 individuals with type 2 diabetes, mean follow-up time = 6.97 years). To assess the relationship between plasma Lp(a) levels and the LPA SNPs with each newly developed microvascular complication (retinopathy n = 223, nephropathy n = 246, neuropathy n = 236), Cox proportional hazards models were applied and adjusted for risk factors for microvascular complications (age, sex, mean arterial pressure, non-HDL-cholesterol, HDL-cholesterol, BMI, duration of type 2 diabetes, HbA1c and smoking). Results: No significant associations of Lp(a) plasma levels and the LPA SNPs rs10455872 and rs3798220 with prevalent or incident microvascular complications in type 2 diabetes were found. In line with previous observations the LPA SNPs rs10455872 and rs3798220 did influence the plasma Lp(a) levels. Conclusions/interpretation: Our data show no association between Lp(a) plasma levels and the LPA SNPs with known effect on Lp(a) plasma levels with the development of microvascular complications in type 2 diabetes. This indicates that Lp(a) does not play a major role in the development of microvascular complications. However, larger studies are needed to exclude minimal effects of Lp(a) on the development of microvascular complications

Association of the IgG N-glycome with the course of kidney function in type 2 diabetes

Introduction Inflammatory processes are thought to be involved in kidney function decline in individuals with type 2 diabetes. Glycosylation of immunoglobulin G (IgG) is an important post-translation process affecting the inflammatory potential of IgG. We investigated the prospective relationship between IgG N-glycosylation patterns and kidney function in type 2 diabetes. Research design and methods In the DiaGene study, an all-lines-of-care case–control study (n=1886) with mean prospective follow-up of 7.0 years, the association between 58 IgG N-glycan profiles and estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR) per year and during total follow-up was analyzed. Models were adjusted for clinical variables and multiple comparisons. Results Eleven traits were significantly associated with eGFR change per year. Bisecting GlcNAc in fucosylated and fucosylated disialylated structures and monosialylation of fucosylated digalactosylated structures were associated with a faster decrease of eGFR. Fucosylation of neutral and monogalactosylated structures was associated with less eGFR decline per year. No significant associations between IgG glycans and ACR were found. Conclusions In type 2 diabetes, we found IgG Nglycosylation patterns associated with a faster decline of kidney function, reflecting a pro-inflammatory state of IgG. eGFR, but not ACR, was associated with IgG glycans, which suggests these associations may represent renal macroangiopathy rather than microvascular disease