Modern Management of Cardiometabolic Continuum: From Overweight/Obesity to Prediabetes/Type 2 Diabetes Mellitus. Recommendations from the Eastern and Southern Europe Diabetes and Obesity Expert Group.

The increasing global incidence of obesity and type 2 diabetes mellitus (T2D) underscores the urgency of addressing these interconnected health challenges. Obesity enhances genetic and environmental influences on T2D, being not only a primary risk factor but also exacerbating its severity. The complex mechanisms linking obesity and T2D involve adiposity-driven changes in ß-cell function, adipose tissue functioning, and multi-organ insulin resistance (IR). Early detection and tailored treatment of T2D and obesity are crucial to mitigate future complications. Moreover, personalized and early intensified therapy considering the presence of comorbidities can delay disease progression and diminish the risk of cardiorenal complications. Employing combination therapies and embracing a disease-modifying strategy are paramount. Clinical trials provide evidence confirming the efficacy and safety of glucagon-like peptide 1 receptor agonists (GLP-1 RAs). Their use is associated with substantial and durable body weight reduction, exceeding 15%, and improved glucose control which further translate into T2D prevention, possible disease remission, and improvement of cardiometabolic risk factors and associated complications. Therefore, on the basis of clinical experience and current evidence, the Eastern and Southern Europe Diabetes and Obesity Expert Group recommends a personalized, polymodal approach (comprising GLP-1 RAs) tailored to individual patient's disease phenotype to optimize diabetes and obesity therapy. We also expect that the increasing availability of dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) agonists will significantly contribute to the modern management of the cardiometabolic continuum.

Consistent glycaemic efficacy and safety of concomitant use of iGlarLixi and sodium-glucose co-transporter-2 inhibitor therapy for type 2 diabetes: A patient-level pooled analysis of three randomised clinical trials.

AIMS: Sodium glucose co-transporter 2 inhibitors (SGLT2is) and/or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with proven cardio- and reno-protective benefits are recommended in people with type 2 diabetes (T2D) at high risk of cardiovascular disease, chronic kidney disease, and/or heart failure. This pooled analysis compared efficacy and safety outcomes of iGlarLixi with or without SGLT2is in people with T2D. METHODS: This post hoc analysis evaluated outcomes in participants who were receiving an SGLT2i when initiating iGlarLixi (SGLT2i users) and those who were not (SGLT2i non-users) in a pooled dataset from three trials: LixiLan-G (advancing from a GLP-1 RA), SoliMix and LixiLan ONE CAN (advancing from basal insulin). RESULTS: Baseline characteristics were generally similar between 219 users and 746 non-users. Least squares mean changes in HbA1c from baseline to Week 26 were similar for users (-1.2 % [95 % confidence intervals: -1.4 %, -1.1 %]) and non-users (-1.2 % [-1.2 %, -1.1 %]). Changes in body weight, fasting glucose and post-prandial glucose were similar between groups, as were hypoglycaemic events. CONCLUSIONS: Pooled results from three studies of adults with T2D demonstrated that iGlarLixi provided similar clinically meaningful improvements in glycaemic control without increased hypoglycaemia risk, regardless of concomitant use of SGLT2is.

Real-world evidence on the use of a fixed-ratio combination of insulin glargine and lixisenatide (iGlarLixi) in people with suboptimally controlled type 2 diabetes in Romania: a prospective cohort study (STAR.Ro).

OBJECTIVES: To assess the effectiveness and safety of insulin glargine and lixisenatide (iGlarLixi) fixed-ratio combination on a cohort of Romanian adults with type 2 diabetes (T2D). DESIGN: Open-label, 24-week, prospective cohort study. SETTING: 65 secondary care diabetes centres in Romania. PARTICIPANTS: The study included 901 adults with T2D suboptimally controlled with previous oral antidiabetic drugs (OADs)±basal insulin (BI) who initiated treatment with iGlarLixi upon the decision of the investigator. Major exclusion criteria were iGlarLixi contraindications and refusal to participate. 876 subjects received at least one dose of iGlarLixi (intention-to-treat/safety population). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint was change in glycated haemoglobin (HbA1c) from baseline to week 24 in the modified intention-to-treat population (study participants with HbA1c available at baseline and week 24). Secondary efficacy outcomes were percentage of participants reaching HbA1c targets and change in fasting plasma glucose (FPG). RESULTS: Mean baseline HbA1c was 9.2% (SD 1.4) and FPG was 10.8 mmol/L (2.9). Mean HbA1c change was -1.3% (95% CI: -1.4% to -1.2%, p<0.0001) at week 24. HbA1c levels ≤6.5%, <7% and<7.5% at week 24 were achieved by 72 (8.9%), 183 (22.6%) and 342 (42.3%) participants, respectively. Mean FPG change was -3.1 mmol/L (95% CI: -3.3 to -2.8, p<0.001) at week 24. Mean body weight change was -1.6 kg (95% CI: -1.9 to -1.3, p<0.001) at 24 weeks. Mean iGlarLixi dose increased from 19.5 U (SD 7.7) and 30.1 U (10.0) to 30.2 U (8.9) (ratio 2/1 pen) and 45.0 U (11.6) (ratio 3/1 pen). Adverse events (AEs) were reported by 43 (4.9%) participants (18 (2.1%) gastrointestinal) with 4 (0.5%) reporting serious AEs. 13 (1.5%) participants reported at least one event of symptomatic hypoglycaemia, with one episode of severe hypoglycaemia reported. CONCLUSIONS: In a real-world setting, 24-week treatment with iGlarLixi provided a significant reduction of HbA1c with body weight loss and low hypoglycaemia risk in T2D suboptimally controlled with OADs±BI treatment.

Evolution of Inflammatory and Oxidative Stress Markers in Romanian Obese Male Patients with Type 2 Diabetes Mellitus after Laparoscopic Sleeve Gastrectomy: One Year Follow-Up.

Geography is one of the key drivers of the significant variation in the etiopathogenic profile and prevalence of type 2 diabetes mellitus (T2DM) and obesity, therefore geographically based data are fundamental for implementing the appropriate interventions. Presently, the selection criteria of T2DM and obesity patients for laparoscopic sleeve gastrectomy (LSG) have not reached a worldwide consensus-highlighting the need for sharing experts' guidance in the preoperative evaluation, choice of the interventional procedure, perioperative management and patient long-term care. The aim of the current study was to evaluate the impact of LSG on T2DM (T2DM) remission in Romanian obese male patients, based on a multiparametric, prospective investigation. We have conducted a randomized controlled study on 41 obese male participants with the body mass index (BMI) ≥ 30 kg/m2, aged 30-65 years, which were randomly divided in two study groups: one receiving conventional treatment and the second undergoing LSG. The clinical and anthropometrical parameters, resting metabolic rate, general biochemical status, adipocytes profile, gastrointestinal hormones levels, proinflammatory, oxidant and antioxidant profiles were determined at three time points: V1 (baseline), V2 (after six months) and V3 (after 12 months). Glycated hemoglobin (HbA1c), blood glucose levels, BMI, weight, visceral fat level, HDL-cholesterol, incretin hormones, proinflammatory and the oxidative stress status were significantly improved in the LSG versus conventional treatment group. This is the first study reporting on the evaluation of metabolic surgery impact on Romanian obese male patients with T2DM. Our results confirm that LSG could contribute to T2DM remission in patients with diabesity, but this beneficial effect seems to be critically influenced by the duration of T2DM rather than by the obesity status. Our results show that, in addition to the parameters included in the prediction algorithm, the proinsulin levels, proinsulin/insulin ratio and the visceral fat percentage could bring added value to the assessment of metabolic status.

Safety and Efficacy of Exenatide Once Weekly in Participants with Type 2 Diabetes and Stage 2/3 Chronic Kidney Disease.

INTRODUCTION: The safety and efficacy of exenatide once weekly (EQW) is overall well established. EQW is primarily renally eliminated. In this study, the efficacy and renal and gastrointestinal tolerability of EQW were summarised in participants with type 2 diabetes and chronic kidney disease stage 3 (CKD3; moderate renal impairment; estimated glomerular filtration rate [eGFR] ≥ 30 to < 60 mL/min/1.73 m2) or CKD stage 2 (CKD2; mild renal impairment; eGFR ≥ 60 to < 90 mL/min/1.73 m2). METHODS: Data on participants with type 2 diabetes and baseline CKD3 or CKD2 from eight phase 3, double-blind or open-label studies with 26- or 28-week controlled treatment periods were pooled. Participants received EQW or a placebo/non-glucagon-like peptide-1 receptor agonist comparator (sitagliptin, metformin, pioglitazone, dapagliflozin and insulin). RESULTS: Participants with baseline CKD3 (N = 182) or CKD2 (N = 772) receiving EQW differed in a number of baseline characteristics, such as age < 65 years, race, mean body mass index and mean type 2 diabetes duration, whereas mean blood pressure and glycated haemoglobin (HbA1c) were similar. Mean reductions in HbA1c, body weight and systolic blood pressure from baseline to week 26/28 in participants receiving EQW were similar between the CKD subgroups. The proportions of participants (CKD3 and CKD2) with any adverse event (AE) were 81% and 72%, respectively, for EQW and 74% and 68%, respectively, for all comparators; those for serious AEs were 2.7% and 3.4%, respectively, for EQW and 6% and 5%, respectively, for all comparators. Gastrointestinal AE rates were higher in the EQW CKD3 subgroup (42.2% of participants) than in the CKD2 (32.8%) subgroup, although rates for nausea and vomiting were similar. There were no dehydration events; one participant in each treatment group had a serious AE of acute kidney injury (EQW with CKD3, n = 1; pioglitazone with CKD2, n = 1). CONCLUSION: Exenatide once weekly was well tolerated and demonstrated similar efficacy in participants with type 2 diabetes with mild and moderate renal impairment. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT00637273, NCT00676338, NCT02229383, NCT02229396, NCT00641056, NCT01652729, NCT00935532, NCT01003184.

Sera of Obese Type 2 Diabetic Patients Undergoing Metabolic Surgery Instead of Conventional Treatment Exert Beneficial Effects on Beta Cell Survival and Function: Results of a Randomized Clinical Study.

BACKGROUND: Pancreatic beta cells are highly sensitive to oxidative and endoplasmic reticulum (ER) stress, commonly occurring in type 2 diabetes (T2D) and obesity. OBJECTIVE: We aimed at investigating cellular responses of human beta cells exposed to sera from obese T2D patients treated differently, namely by conventional therapy or laparoscopic sleeve gastrectomy (LSG). METHODS: Serum samples from obese T2D men randomized to conventional treatment or LSG were taken at baseline and 6 months later. After exposing 1.1B4 cells to study patients' sera, the following were assessed: cellular viability and proliferation (by MTT and xCELLigence assays), reactive oxygen species (ROS) production (with DCFH-DA), and expression of ER stress markers, oxidative- or autophagy-related proteins and insulin (by real-time PCR and Western blot). RESULTS: At 6-month follow-up, patients undergoing LSG achieved an adequate glycemic control, whereas conventionally treated patients did not. As compared to 1.1B4 cells incubated with baseline sera (control), cells exposed to sera from LSG-treated participants exhibited (i) increased viability and proliferation (p < 0.05); (ii) diminished levels of ROS and p53 (p < 0.05); (iii) enhanced protein expression of autophagy-related SIRT1 and p62/SQSTM1 (p < 0.05); (iv) significantly decreased transcript levels of ER stress markers (p < 0.05); and (v) augmented insulin expression (p < 0.05). Conversely, the 6-month conventional therapy appeared not to impact on circulating redox status. Moreover, 1.1B4 cells exposed to sera from conventionally treated patients experienced mild ER stress. CONCLUSION: Circulating factors in patients with improved diabetes after metabolic surgery exerted favorable effects on beta cell function and survival.

Cardiovascular safety of oral semaglutide in patients with type 2 diabetes: Rationale, design and patient baseline characteristics for the PIONEER 6 trial.

AIMS: To assess the cardiovascular (CV) safety of oral semaglutide, the first tablet formulation of a glucagon-like peptide-1 receptor agonist. MATERIALS AND METHODS: PIONEER 6 is a multinational, randomized, placebo-controlled, double-blind trial in patients with type 2 diabetes at high risk of CV events (defined as being aged ≥50 years and having established CV disease [CVD] or moderate [stage 3] chronic kidney disease [CKD], or being aged ≥60 years with ≥1 other CV risk factor). Patients were randomized to once-daily oral semaglutide (up to 14 mg) or placebo added to standard of care. The primary composite endpoint is time to first occurrence of CV death or non-fatal myocardial infarction or non-fatal stroke. The primary hypothesis was to exclude an excess in CV risk with oral semaglutide by assessing non-inferiority versus placebo for the primary endpoint (non-inferiority margin of 1.8 for the upper boundary of the 95% confidence interval of the hazard ratio). PIONEER 6 is event-driven, with follow-up continuing until accrual of at least 122 primary outcome events. There is no pre-defined minimal duration. RESULTS: Overall, 3183 patients have been enrolled (mean age 66.1 years, 31.6% females) in 214 sites across 21 countries. At baseline, the mean duration of diabetes was 14.9 years, mean glycated haemoglobin concentration was 66 mmol/mol (8.2%), and 84.6% of patients had established CVD/moderate CKD. CONCLUSIONS: PIONEER 6 will provide evidence regarding the CV safety of oral semaglutide in patients with type 2 diabetes and high CV risk.

Unrecognised cardiovascular disease in type 2 diabetes: is it time to act earlier?

Cardiovascular disease (CVD) is the most significant prognostic factor in individuals with type 2 diabetes (T2D). However, a significant number of individuals may develop CVD that does not present with the classic angina-related or heart failure symptoms. In these cases, CVD may seem to be 'silent' or 'asymptomatic', but may be more accurately characterised as unrecognised diabetic cardiac impairment. An initial step to raise awareness of unrecognised CVD in individuals with T2D would be to reach a consensus regarding the terminology used to describe this phenomenon. By standardising the terminologies, and agreeing on the implementation of an efficient screening program, it is anticipated that patients will receive an earlier diagnosis and appropriate and timely treatment. Given the availability of anti-diabetic medications that have been shown to concomitantly reduce CV risk and mortality, it is imperative to improve early identification and initiate treatment as soon as possible in order to enable as many patients with T2D as possible to benefit.

Associations of smoking with cardiometabolic profile and renal function in a Romanian population-based sample from the PREDATORR cross-sectional study.

BACKGROUND: The impact of smoking on morbidity is well known, but in Romania, limited data are available regarding the smoking prevalence and relationship with cardiometabolic profile and kidney function. OBJECTIVES: To assess the association of smoking with cardiometabolic traits and kidney function, in a Romanian population-based sample from the PREDATORR study. METHODS: PREDATORR was an epidemiological cross-sectional study. Between 2012 and 2014, participants were randomly selected from the lists of general practitioners and enrolled if they were aged 20 to 79 years, born and living in the past 10 years in Romania. Sociodemographic and lifestyle characteristics were collected through interviewer-administered questionnaires. RESULTS: Overall, 2704 participants were included in the analysis, 18% of them being current smokers and 30.8% former smokers. Current smokers compared to non-smokers had higher total cholesterol (220.6 ± 50.4 versus 213.9 ± 86.8 mg/dl, P = 0.017), LDL-cholesterol (137.8 ± 45.2 versus 130.7 ± 83.7 mg/dl, P = 0.004) and glomerular filtration rate (96.9 ± 16.8 versus 90.7 ± 19.1 ml/min/1.73 m2, P <0.001) in women and higher triglycerides (170.7 ± 129.8 versus 144.3 ± 94.2 mg/dl, P = 0.007), glomerular filtration rate (97.6 ± 17 versus 90.3 ± 18 ml/min/1.73 m2, P < 0.001) and lower HDL-cholesterol (48 ± 15.5 versus 50.4 ± 14.1 mg/dl, P = 0.002) in men. Active smoking was associated with hypercholesterolaemia [OR: 1.40 (95% CI: 1.01-1.96), P = 0.04] and low HDL-cholesterolaemia [OR: 1.39 (95% CI: 1.01-1.91), P = 0.04] and negatively associated with overweight/obesity [OR: 0.67 (95% CI: 0.48-0.94), P = 0.02]. Male former smokers had higher prevalence of abdominal obesity (82.4% versus 76.4%, P = 0.02), hypertriglyceridaemia (43.6% versus 35.6%, P = 0.01), hypertension (64% versus 56.4%, P = 0.01) and ischaemic vascular disease (40.5% versus 30.9%, P = 0.003) than male non-smokers. CONCLUSION: The PREDATORR study showed a high prevalence of smoking in the adult Romanian population providing data on the association of smoking with cardiometabolic traits.

Exenatide once weekly plus dapagliflozin once daily versus exenatide or dapagliflozin alone in patients with type 2 diabetes inadequately controlled with metformin monotherapy (DURATION-8): a 28 week, multicentre, double-blind, phase 3, randomised controlled trial.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce glycaemia and weight, and improve cardiovascular risk factors via different mechanisms. We aimed to compare the efficacy and safety of co-initiation of the GLP-1 receptor agonist exenatide and the SGLT2 inhibitor dapagliflozin with exenatide or dapagliflozin alone in patients with type 2 diabetes inadequately controlled by metformin. METHODS: DURATION-8 was a 28 week, multicentre, double-blind, randomised, active-controlled phase 3 trial done at 109 sites in six countries. Adults (aged ≥18 years) with type 2 diabetes and inadequate glycaemic control (HbA1c 8-12% [64-108 mmol/mol]) despite stable metformin monotherapy (≥1500 mg/day) were randomly assigned (1:1:1), via an interactive voice and web-response system, to receive once-weekly exenatide 2 mg by subcutaneous injection plus once-daily dapagliflozin 10 mg oral tablets, exenatide with dapagliflozin-matched oral placebo, or dapagliflozin with exenatide-matched placebo injections. Randomisation was stratified by baseline HbA1c (<9·0% vs ≥9·0% [<75 mmol/mol vs ≥75 mmol/mol]). The primary endpoint was change in HbA1c from baseline to week 28. Secondary endpoints were the change from baseline in fasting plasma glucose at week 2 and week 28, and 2 h postprandial glucose at week 28; the proportion of patients with an HbA1c less than 7·0% (<53 mmol/mol) at week 28; change in weight at week 28; the proportion of patients with weight loss of 5% or more at week 28; and change in systolic blood pressure at week 28. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02229396. FINDINGS: Between Sept 4, 2014, and Oct 15, 2015, we randomly assigned 695 patients to receive exenatide plus dapagliflozin (n=231), exenatide alone (n=231; n=1 untreated), or dapagliflozin alone (n=233). The intention-to-treat population comprised 685 participants (mean HbA1c 9·3% [SD 1·1]; 78 mmol/mol [12]), of whom 611 (88%) completed the study. After 28 weeks, the change in baseline HbA1c was -2·0% (95% CI -2·1 to -1·8) in the exenatide plus dapagliflozin group, -1·6% (-1·8 to -1·4) in the exenatide group, and -1·4% (-1·6 to -1·2) in the dapagliflozin group. Exenatide plus dapagliflozin significantly reduced HbA1c from baseline to week 28 compared with exenatide alone (-0·4% [95% CI -0·6 to -0·1]; p=0·004) or dapagliflozin alone (-0·6% [-0·8 to -0·3]; p<0·001). Exenatide plus dapagliflozin was significantly superior to either drug alone for all secondary efficacy endpoints, with greater reductions in fasting plasma and postprandial glucose, more patients with an HbA1c less than 7·0% (<53 mmol/mol), greater weight loss, a greater proportion of patients with weight loss of 5% or more, and greater reductions in systolic blood pressure (all p≤0·025). Adverse events were recorded in 131 (57%) of 231 patients in the exenatide plus dapagliflozin group, 124 (54%) of 230 patients in the exenatide group, and 121 (52%) of 233 patients in the dapagliflozin group. The most common adverse events (≥5% of patients in any group) were diarrhoea, injection-site nodules, nausea, and urinary tract infections. No episodes of major hypoglycaemia or minor hypoglycaemia were reported. INTERPRETATION: Co-initiation of exenatide and dapagliflozin improved various glycaemic measures and cardiovascular risk factors in patients with type 2 diabetes inadequately controlled by metformin monotherapy. The dual treatment regimen was well tolerated, with the expected safety profile for this combination. Additional data from an ongoing study (eg, AWARD-10; NCT02597049) will further inform the use of these drug classes in combination. FUNDING: AstraZeneca.

Cancer specific mortality in insulin-treated type 2 diabetes patients.

AIMS: To test the hypothesis that cumulative exposure to insulin and long-acting insulin analogs might be associated with cancer mortality in diabetes patients. METHODS: All consecutive diabetes patients aged over 40 years, residing in a major urban area were screened at their first diabetes outpatient visit between 01/01/2001-12/31/2008 (n = 79869). Exclusion criteria were insulin treatment at screening, no insulin treatment until 12/31/2008, less than 6 months of glucose-lowering treatment alone before insulin initiation, insulin prescription before glargine became available, age <40/≥ 80 years at first insulin prescription, and <6 months of insulin exposure. A total 4990 subjects were followed-up for death based on death certificate, until 12/31/2011. Adjusted time-dependent competing risk regression analysis, with daily updates of treatment modalities was performed. Results are expressed for every 10,000 IU of cumulative dose or one year of cumulative time exposure to insulin. RESULTS: Mean baseline age was 62 ± 9 years, and follow-up 4.7 ± 1.9 years. Glargine cumulative dose was associated with lower cancer mortality risk (subhazard ratio, SHR: 0.94 (95%CI 0.89-0.99, p = 0.033)). Cumulative exposure limited to that attained one year prior to death revealed lower SHRs for cumulative time (0.94 (95%CI 0.89-0.99, p = 0.018)) and cumulative dose of glargine (0.92 (95%CI 0.86-0.98, p = 0.014)). Glargine cumulative time and cumulative dose were significant predictors for lower pancreatic and breast cancer mortality, but not for deaths from lung, colorectal, female genital, liver, and urinary tract cancer. No increased hazards were found for any other subtypes of insulins. CONCLUSIONS: The cumulative dose exposure to insulin glargine was associated with a lower risk of cancer mortality in general, and of breast and pancreatic cancer in particular. This effect remained even after additional "fixed" cohort or propensity score analyses.

Improvements in life expectancy in adult type 2 diabetes patients in the last six decades.

AIM: To investigate the historical changes in survival with diabetes in adult type 2 diabetes patients. METHODS: We analyzed 9066 deaths, 54.2% males, registered at "I. Pavel" Bucharest Diabetes Centre, aged 40-64 years and deceased between 1943 and 2009. We split the analysis in three time periods according to year of death: 1943-1965, 1966-1988 and 1989-2009. RESULTS: The mean age at diabetes onset was 55.5 ± 6.2 years, with mean disease duration at death 12.7 ± 8.2 years and mean age at death 68.2 ± 8.7 years. The mean disease duration at death was 9.9 ± 7.3 years in 1943-1965 period, followed by a significant (p<0.001) rise to 12.2 ± 8.2 years in 1966-1988, and 14 ± 8.1 years (p < 0.001) in 1989-2009. There was a significant increase for coronary heart diseases and cancer and a significant decrease for infections and end-stage renal disease as causes of death. CONCLUSION: We found a significant increase in age at onset and survival with diabetes leading to a significant increase in age at death.

A genome-wide association study of nonsynonymous SNPs identifies a type 1 diabetes locus in the interferon-induced helicase (IFIH1) region.

In this study we report convincing statistical support for a sixth type 1 diabetes (T1D) locus in the innate immunity viral RNA receptor gene region IFIH1 (also known as mda-5 or Helicard) on chromosome 2q24.3. We found the association in an interim analysis of a genome-wide nonsynonymous SNP (nsSNP) scan, and we validated it in a case-control collection and replicated it in an independent family collection. In 4,253 cases, 5,842 controls and 2,134 parent-child trio genotypes, the risk ratio for the minor allele of the nsSNP rs1990760 A --> G (A946T) was 0.86 (95% confidence interval = 0.82-0.90) at P = 1.42 x 10(-10).

Association analysis of the lymphocyte-specific protein tyrosine kinase (LCK) gene in type 1 diabetes.

Prior data associating the expression of lymphocyte-specific protein tyrosine kinase (LCK) with type 1 diabetes, its critical function in lymphocytes, and the linkage of the region to diabetes in the nonobese diabetic (NOD) mouse model make LCK a premier candidate for a susceptibility gene. Resequencing of LCK in 32 individuals detected seven single nucleotide polymorphisms (SNPs) with allele frequencies >3%, including four common SNPs previously reported. These and six other SNPs from dbSNP were genotyped in a two-stage strategy using 2,430 families and were all shown not to be significantly associated with type 1 diabetes. We conclude that a major role for the common LCK polymorphisms in type 1 diabetes is unlikely. However, we cannot rule out the possibility of there being a causal variant outside the exonic, intronic, and untranslated regions studied.

Association of the T-cell regulatory gene CTLA4 with susceptibility to autoimmune disease.

Genes and mechanisms involved in common complex diseases, such as the autoimmune disorders that affect approximately 5% of the population, remain obscure. Here we identify polymorphisms of the cytotoxic T lymphocyte antigen 4 gene (CTLA4)--which encodes a vital negative regulatory molecule of the immune system--as candidates for primary determinants of risk of the common autoimmune disorders Graves' disease, autoimmune hypothyroidism and type 1 diabetes. In humans, disease susceptibility was mapped to a non-coding 6.1 kb 3' region of CTLA4, the common allelic variation of which was correlated with lower messenger RNA levels of the soluble alternative splice form of CTLA4. In the mouse model of type 1 diabetes, susceptibility was also associated with variation in CTLA-4 gene splicing with reduced production of a splice form encoding a molecule lacking the CD80/CD86 ligand-binding domain. Genetic mapping of variants conferring a small disease risk can identify pathways in complex disorders, as exemplified by our discovery of inherited, quantitative alterations of CTLA4 contributing to autoimmune tissue destruction.