Development Of Diabetes In Individuals Research Articles

Assessing the validity of METS-IR for predicting the future onset of diabetes: an analysis using time-dependent receiver operating characteristics

BackgroundThe Metabolic Insulin Resistance Score (METS-IR) is a non-invasive proxy for insulin resistance (IR) that has been newly developed in recent years and has been shown to be associated with diabetes risk. Our aim was to assess the predictive value of METS-IR for the future development of diabetes and its temporal differences in people of different sex, age, and body mass index (BMI).MethodsThe current study included 15,453 baseline non-diabetic subjects in the NAGALA cohort and then grouped according to the World Health Organization’s (WHO) recommended criteria for age and BMI. Multivariate Cox regression and time-dependent receiver operator characteristics (ROC) curves were used to analyze the value of METS-IR in assessing and predicting the risk of diabetes in people of different sexes, ages, and BMIs.Results373 individuals developed diabetes during the observation period. By multivariate COX regression analysis, the development of future diabetes was significantly associated with increased METS-IR, and this positive association was stronger in women than in men and in individuals < 45 years than in individuals ≥ 45 years; while no significant differences were observed between non-obese and overweight/obesity individuals. Using time-dependent ROC analysis we also assessed the predictive value of METS-IR for future diabetes at a total of 11-time points between 2 and 12 years. The results showed that METS-IR had a higher predictive value for the future development of diabetes in women or individuals < 45 years of age compared to men or individuals ≥ 45 years of age for almost the entire follow-up period. Furthermore, across different BMI categories, we also found that in the short term (3–5 years), METS-IR had a higher predictive value for the development of diabetes in individuals with overweight/obesity, while in the medium to long term (6–12 years), METS-IR was more accurate in predicting the development of diabetes in non-obese individuals.ConclusionsOur study showed that METS-IR was independently associated with the development of future diabetes in a non-diabetic population. METS-IR was a good predictor of diabetes, especially for women and individuals < 45 years old for predicting the future risk of developing diabetes at all times.

The Effect of City-Level Sugar-Sweetened Beverage Taxes on Longitudinal HbA1c and Incident Diabetes in Adults With Prediabetes.

Prediabetes, which is a condition characterized by higher-than-normal blood glucose levels that are under the threshold for diabetes, impacts over one-third of U.S. adults. Excise taxes on sugar-sweetened beverages (SSBs) are a proposed policy intervention to lower population consumption of SSBs and generate revenue to support health-related programs, thus potentially delaying or preventing the development of diabetes in individuals with prediabetes. We leveraged data from Kaiser Permanente in California to examine the impact of SSB taxes in California on individual-level mean HbA1c levels and rates of incident diabetes. We compared two outcomes, mean HbA1c levels and rates of incident diabetes, among a matched cohort of adults with prediabetes who lived and did not live in SSB excise tax cities, using outcomes collected in the 6 years prior and 4 years following SSB tax implementation. We used multivariable linear mixed effects models to analyze longitudinal mean HbA1c and discrete-time survival models for incident diabetes. We included 68,658 adults in the analysis. In adjusted models, longitudinal mean HbA1c was 0.007% (95% CI 0.002, 0.011) higher in the tax cities compared with control individuals; while the estimated difference was statistically significant, it was not clinically significant (HbA1c <0.5%). There was no significant difference in the risk of incident diabetes between individuals living in tax and control cities. We found no clinically significant association between SSB taxes and either longitudinal mean HbA1c or incident diabetes among adults with prediabetes in the 4 years following SSB tax implementation.

Predictive value of insulin resistance surrogates for the development of diabetes in individuals with baseline normoglycemia: findings from two independent cohort studies in China and Japan

BackgroundInsulin resistance (IR) plays a crucial role in the occurrence and progression of diabetes. This study aimed to evaluate and compare the predictive value of four IR surrogates, including the triglycerides glucose (TyG) index, TyG and body mass index (TyG-BMI), triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) ratio, and the metabolic score for IR (MetS-IR) for diabetes in two large cohorts.MethodsA total of 116,661 adult participants from the China Rich Healthcare Group and 15,464 adult participants from the Japanese NAGALA cohort were included in the study. Multivariable Cox proportional hazards models were used to assess the standardized hazard ratio (HR) of the TyG index, TyG-BMI, TG/HDL-C ratio, and MetS-IR directly associated with diabetes. Receiver operating characteristic (ROC) curve and time-dependent ROC curve analysis were performed to evaluate and compare the predictive value of the four IR surrogates for diabetes.ResultsIn the two independent cohorts, the average follow-up time was 3.1 years in the China cohort, with 2681(2.30%) incident cases of diabetes recorded, and 6.13 years in the Japan cohort, with 373 incident cases (2.41%) of diabetes recorded. After adjusting for potential confounding factors, we found that among the four IR surrogates, TyG-BMI and MetS-IR showed stronger associations with diabetes. The stronger associations persisted even after further stratification by age, sex, hypertension, and obese subgroups. In terms of diabetes prediction, based on ROC analysis, TyG-BMI demonstrated the highest predictive accuracy for diabetes in the Chinese population, while both TyG-BMI and MetS-IR showed the highest predictive accuracy in the Japanese population. The results of further subgroup ROC analysis confirmed the robustness of these findings. Furthermore, the time-dependent ROC results indicated that among the four IR surrogates, MetS-IR exhibited the highest accuracy in predicting future diabetes at various time intervals in the Japanese population.ConclusionOur findings suggest that evaluating TyG-BMI and MetS-IR as IR surrogates may be the most useful for predicting diabetes events and assessing the risk of developing diabetes in East Asian populations.

Interaction effect between low birthweight and resistin gene rs1862513 variant on insulin resistance and type 2 diabetes mellitus in adulthood: Toon Genome Study.

Gene-environment interactions are considered to critically influence type 2 diabetes mellitus development; however, the underlying mechanisms and specific interactions remain unclear. Given the increasing prevalence of low birthweight (LBW) influenced by the intrauterine environment, we sought to investigate genetic factors related to type 2 diabetes development in individuals with LBW. The interaction between 20 reported type 2 diabetes susceptibility genes and the development of type 2 diabetes in LBW (<2,500 g) individuals in a population-based Japanese cohort (n = 1,021) was examined by logistic regression and stratified analyses. Logistic regression analyses showed that only the G/G genotype at the rs1862513 locus of the resistin gene (RETN), an established initiator of insulin resistance, was closely related to the prevalence of type 2 diabetes in individuals with LBW. Age, sex and current body mass index-adjusted stratified analyses showed a significant interaction effect of LBW and the RETN G/G genotype on fasting insulin, homeostatic model assessment 2-insulin resistance, Matsuda index and the prevalence of type 2 diabetes (all P-values for interaction <0.05). The adjusted odds ratio for type 2 diabetes in the LBW + G/G genotype group was 7.33 (95% confidence interval 2.43-22.11; P = 0.002) compared with the non-LBW + non-G/G genotype group. Similar results were obtained after excluding the influence of malnutrition due to World War II. Simultaneous assessment of LBW and the RETN G/G genotype can more accurately predict the risk of future type 2 diabetes than assessing each of these factors alone, and provide management strategies, including early lifestyle intervention in LBW population.

CT-based measurement of visceral adipose tissue volume as a reliable tool for assessing metabolic risk factors in prediabetes across subtypes

Visceral adipose tissue (VAT) is a well-established risk factor for the development of diabetes in individuals with prediabetes. We aimed to evaluate various adiposity and metabolic indices, including visceral adipose tissue (VAT) volume measured by CT, in individuals with prediabetes, based on their different subtypes. This retrospective study included 78 prediabetes individuals aged ≥ 20 years whose VAT volumes were evaluated by CT. Individuals were classified into prediabetes subtypes: impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG and IGT (C-IFG/IGT). We conducted a comparison of the patients’ adiposity indices and their associations with one other, as well as with insulin resistance, based on the different prediabetes subtypes. Individuals with C-IFG/IGT had higher levels of visceral obesity than those with IFG or IGT. VAT volume was more strongly associated with insulin resistance than other adiposity indices, regardless of prediabetes subtypes. Additionally, VAT volume and liver attenuation index showed a significant correlation with the other indices studied across the prediabetes subtypes. CT-based measurement of VAT volume may be a valuable tool for evaluating metabolic risk factors among individuals with prediabetes.

Proprotein convertase subtilisin/kexin type 9 inhibitors: prospects for cholesterol-lowering therapy in type 2 diabetes

Diabetic dyslipoproteinemia (DLP), characterized by quantitative, qualitative, and kinetic changes in all major circulating lipids, contributes to an increased risk of atherosclerotic cardiovascular disease in patients with type 2 diabetes mellitus (DM). Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) by human monoclonal antibodies is a promising treatment for diabetic DLP. Several drugs differ in their mechanisms of inhibition of PCSK9 activity. The following groups are conditionally distinguished: PCSK9 monoclonal antibodies (anti-PCSK9 monoclonal antibodies): evolocumab, alirocumab, bococizumab (injectable); other injectable medications with different mechanism of actions (inclisiran, SPC4061, SPC5001, adnectin BMS-962476, LIB003, anti-PCSK9 vaccine; anti-PCSK9 vaccine (nanoparticle-based); orally administered drugs (PF-06446846, DS-9001a, SRT3025); cholesteryl ester transfer protein/PCSK9 inhibitors (anacetrapib, evacetrapib, torcetrapib, K-312). This review aims to discuss the role of alirocumab and evolocumab, fully humanized monoclonal antibodies, in the treatment of type 2 DM patients with DLP and to consider their effectiveness and safety. Strategy of search. Scopus, Science Direct (from Elsevier), and PubMed, including the Medline databases, were searched. The following keywords were used: autonomic nervous system, heart rate variability, baroreflex sensitivity, diabetic cardiac autonomic neuropathy, and MeSH terms. A manual search of the bibliography of publications was used to identify research results that could not be found with the online search. Statins are the first line of choice for treating DLP in patients with type 2 DM to reduce the risk of atherosclerotic cardiovascular disease. Ezetimibe is the next drug to be added if patients’ low-density lipoprotein cholesterol levels are higher than acceptable. In cases of failure of the combination of statins with ezetimibe, PCSK9 inhibitor is a reasonable and rational choice. Overall, clinical data suggest that PCSK9 inhibitors are well tolerated and provide a significant reduction in low-density lipoprotein cholesterol levels in type 2 DM patients with DLP in addition to high-intensity statin therapy. The use of PCSK9 inhibitors is not associated with impaired glycemic control or increased risk of diabetes development in individuals without previously diagnosed DM and may prevent or reduce subsequent cardiovascular events.

Stability improvement of polyaniline nanocomposite immunosensor for early detection of insulin receptor antibody as biomarker of type 2 diabetes.

Polyaniline nanocomposite with controllable properties was used to design and fabricate a novel electrochemical immunosensor for the early detection of type 2 diabetes. Insulin receptor antibody is a powerful predictor of type 2 diabetes development in individuals. A systematic study was carried out to investigate the effects of different polyaniline layers and the Nafion layer on the morphological, chemical, and electrochemical properties of nanocomposite immunosensor, especially the stability. The bioengineered Nafion-Au nanoparticles-polyaniline/gold electrode demonstrated outstanding electrocatalytic performance in the detection of insulin receptor antibodies with a high sensitivity (136.21 µA.ng-1.ml.cm-2) in a linear range from 0.001 to 200ng.ml-1 as well as a low detection limit of 1.827pg.ml-1, response time within 10min, remarkable selectivity, and significant stability of 80days. Therefore, the developed immunosensor is a suitable nanocomposite platform for insulin receptor antibody level determination in human plasma.

Metformin Should Not Be Used to Treat Prediabetes.

Based on the results of the Diabetes Prevention Program Outcomes Study (DPPOS), in which metformin significantly decreased the development of diabetes in individuals with baseline fasting plasma glucose (FPG) concentrations of 110-125 vs. 100-109 mg/dL (6.1-6.9 vs. 5.6-6.0 mmol/L) and A1C levels 6.0-6.4% (42-46 mmol/mol) vs. <6.0% and in women with a history of gestational diabetes mellitus, it has been suggested that metformin should be used to treat people with prediabetes. Since the association between prediabetes and cardiovascular disease is due to the associated nonglycemic risk factors in people with prediabetes, not to the slightly increased glycemia, the only reason to treat with metformin is to delay or prevent the development of diabetes. There are three reasons not to do so. First, approximately two-thirds of people with prediabetes do not develop diabetes, even after many years. Second, approximately one-third of people with prediabetes return to normal glucose regulation. Third, people who meet the glycemic criteria for prediabetes are not at risk for the microvascular complications of diabetes and thus metformin treatment will not affect this important outcome. Why put people who are not at risk for the microvascular complications of diabetes on a drug (possibly for the rest of their lives) that has no immediate advantage except to lower subdiabetes glycemia to even lower levels? Rather, individuals at the highest risk for developing diabetes-i.e., those with FPG concentrations of 110-125 mg/dL (6.1-6.9 mmol/L) or A1C levels of 6.0-6.4% (42-46 mmol/mol) or women with a history of gestational diabetes mellitus-should be followed closely and metformin immediately introduced only when they are diagnosed with diabetes.

Relationship between baseline physical activity assessed by pedometer count and new-onset diabetes in the NAVIGATOR trial

ObjectivePhysical activity is related to clinical outcomes, even after adjusting for body mass, but is rarely assessed in randomized clinical trials.Research design and methodsWe conducted an observational analysis of data...

Increased risk of diabetes development in individuals with weight cycling over 4 years: The Kangbuk Samsung Health study

AimsWeight cycling is defined as cyclical loss and gain of weight and recent studies suggest deleterious effects of weight cycling on cardiometabolic health. We aimed to analyze the risk for diabetes development in association with weight cycling over 4 years of follow-up. MethodsA retrospective study performed in 4,818 non-diabetic participants (mean age 43 years, 78.3% men) in a health screening program in whom serial health examinations were performed in 5 consecutive years from 2010 to 2014. Average successive variability of weight (ASVW) was defined by the amount of body weight change in absolute value between the successive years over 5 years summed and divided by four. The subjects were divided into two groups according to body mass index (BMI), normal weight (<23 kg/m2) and overweight (≥23 kg/m2). ResultsOver 4 years, 3.2% developed diabetes. When the subjects were divided into 3 groups according to tertile groups of ASVW, those in the highest tertile showed significantly increased risk for diabetes development compared to those with the lowest tertile {odds ratio (OR) 1.860; 95% CI 1.130–3.063}. When similar analyses were performed according to the 4 groups divided by baseline body weight and ASVW over four years, those who were more than overweight at baseline with high ASVW showed significantly increased risk of diabetes development compared to those had normal weight and low ASVW (OR 2.266; 95% 1.123–4.572). When the subjects were divided into six group according to weight change and ASVW, those with increased weight over 4 years and high ASVW showed the highest risk for diabetes development among the groups compared to those with stable weight and low ASVW over four years (OR 3.660; 95% CI 1.402–9.553). ConclusionsThose with high ASVW showed significantly increased risk for diabetes development over four years compared with those who had low ASVW. Weight cycling was significantly associated with increased risk for diabetes.

Fatty liver index predicts incident diabetes in a Japanese general population with and without impaired fasting glucose.

Fatty liver is associated with the development of diabetes. However, to our knowledge, no study has examined the relationship between the fatty liver index (FLI), calculated scores of hepatic steatosis, and the development of diabetes among individuals without impaired fasting glucose (IFG). We aimed to examine whether FLI predicts the development of diabetes in individuals with and without IFG in a Japanese general population. We selected 1498 men and 2941 women who participated in Specific Health Checkups in Japan. We divided all participants into six groups according to tertiles of FLI (low, moderate, and high) and the presence or absence of IFG, by sex. We calculated hazard ratios for incident diabetes for each group using a Cox proportional hazard model, adjusting for potential confounders. During a mean follow-up period of 3.0years, 176 cases of diabetes in men and 320 cases in women were identified. Compared with the low FLI group without IFG, the high FLI group without IFG was significantly associated with incident diabetes in both men (hazard ratio, 1.90; 95% confidence interval, 1.08-3.36) and women (hazard ratio, 1.72; 95% confidence interval, 1.18-2.51). All IFG groups were significantly associated with incident diabetes regardless of FLI levels. Our results showed that FLI is associated with the development of diabetes regardless of sex and the presence or absence of IFG, and that it may be a useful predictor of future risk of incident diabetes even in individuals without IFG.

A Simple Model for Predicting Two-Year Risk of Diabetes Development in Individuals with Prediabetes.

Given the dramatic rise in the incidence of type 2 diabetes mellitus (T2DM) in recent decades, identifying individuals at increased risk of T2DM and validating methods to reduce their risk of disease progression is important. With more than one-third of US adults having prediabetes, a more precise stratification of absolute risk of T2DM incidence would help in prioritizing prevention efforts. To develop a simple and clinically useful schema to stratify short-term (2-year) absolute risk of T2DM. Observational study of more than 77,000 adult members (age 18-75 years) from 3 Regions of the Kaiser Foundation Health Plan with prediabetes (hemoglobin A1C [HbA1C] = 5.7%-6.4%). The 2-year probability for development of diabetes as a function of baseline HbA1C and body mass index (BMI). The 2-year risk of diabetes diagnosis varied widely by HbA1C and BMI. A small subset (5.2%) had a very high risk of T2DM developing within 2 years. Another 13.3% had a moderate 2-year risk of T2DM, whereas most (81.5%) of the population was at much lower risk. Thus, most Kaiser Foundation Health Plan members with prediabetes have only modest risk of progression to T2DM within 2 years. Using HbA1C and BMI, we created a simple stratification scheme to more precisely estimate risk of T2DM incidence. This will enable more efficient assignment of prevention interventions and clinical and laboratory follow-up to the small subset at highest risk, while minimizing the potentially negative effects of overdiagnosis among the majority with prediabetes who are not at high short-term risk of T2DM.

Additive effect of non-alcoholic fatty liver disease on the development of diabetes in individuals with metabolic syndrome.

Non-alcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of the metabolic syndrome (MetS), with insulin resistance as the common pathophysiology. In a current longitudinal cohort study, we evaluated the separate and combined effects of MetS and NAFLD on incident diabetes risk. Participants were categorized into four groups on the basis of the presence of NAFLD and MetS at baseline (i.e., with NAFLD, with MetS, with both, or without either). We compared the development of diabetes among these four groups. During the mean follow up of 4years, 435 of the 7849 participants (5.5%) developed diabetes. The age, sex, and smoking-adjusted risk of incident diabetes was higher in the NAFLD only group (HR 1.51, 95% CI 1.14-1.99), MetS only group (HR 2.82, 95% CI 2.01-3.95), and both group (HR 5.45, 95% CI 4.32-6.82) compared with the group of neither. When compared with the NAFLD only group, the adjusted HR for incident diabetes was 1.87 (95% CI 1.29-2.72) in the MetS only group and 3.62 (95% CI 2.74-4.77) in both group. Among individuals with MetS, the presence of NAFLD showed a significant increase in risk of incident diabetes even after further adjustment for MetS components including fasting glucose, TG, BMI, systolic BP, and HDL-C (HR 1.53, 95% CI 1.09-2.16). The presence of NAFLD further increased the risk of incident diabetes in individuals with metabolic syndrome. Our results suggest that the coexistence of NAFLD has an additive effect on the development of diabetes in individuals with MetS.

Assessment of plasma glucose cutoff values to predict the development of type 2 diabetes in a Japanese sample: the Funagata Study

The lower cutoff limit used to define impaired fasting glucose (IFG) varies between countries/organizations and is usually 100 or 110 mg/dl. Therefore, we evaluated the cutoff value for IFG that predicted the development of type 2 diabetes among the participants of the Funagata Study, a Japanese population-based, longitudinal study. Overall, 3,413 individuals (age 56.2 ± 12.1 years) without diabetes at baseline and who attended follow-up examinations were included in this analysis. Diabetes was diagnosed based on 75-g oral glucose tolerance tests according to the 1998 World Health Organization criteria. Follow-up visits were completed in 2007 (mean follow-up 147 months). The development of diabetes was used as the endpoint. During the follow-up period, 156 individuals developed diabetes. Life-table method analysis showed significantly decreased diabetes-free survival in individuals with fasting plasma glucose (FPG) ≥ 96 mg/dl (p = 0.002). Cox’s proportional hazard model analyses showed a high risk for the development of diabetes in individuals with FPG ≥ 101 mg/dl. The hazard ratio for patients with an FPG of 101–105 mg/dl was 5.50 (95% confidence interval (CI) 2.12–14.25; p < 0.001). The 5-year incidence of diabetes was also substantially increased in individuals with FPG ≥ 101 mg/dl. The odds ratio for patients with FPG 101–105 mg/dl was 10.9 (95% CI 2.6–46.0; p < 0.001). Receiver operating characteristic curve analysis showed an optimal FPG cutoff value of 100 mg/dl. Based on these results, the optimal FPG cutoff value used to define IFG in Japanese individuals should be 100 mg/dl rather than 110 mg/dl.

Prevention of type 2 diabetes mellitus from the viewpoint of genetics

The prevalence of type 2 diabetes mellitus has increased worldwide over the past decades. The economic and social cost associated with diabetes mellitus and its complications have also increased enormously. Since current methods of treating diabetes is inadequate, the most effective way to reduce the burden associated with type 2 diabetes would be to prevent diabetes itself. Current strategies to prevent type 2 diabetes mellitus are based on efforts to reduce insulin resistance and to preserve or increase pancreatic beta cell function in high risk individuals. Now there is substantial evidence that life style intervention or pharmacologic agents can reduce the development of diabetes in individuals with impaired glucose tolerance. However, it remains to be determined whether the result would be similar in other risk groups for type 2 diabetes. Although development of type 2 diabetes mellitus is influenced by a complex interaction between genetic and environmental factors, current prevention strategies do not reflect contribution of genetic factors. Over the past decade, many investigators tried to find diabetogenic genes by traditional gene discovery methods. It appears that multiple genes with weak effect are involved in the development of type 2 diabetes mellitus which makes searching diabetogenic genes more complicated. In addition to the completion of human genome project, new genetic tools to identify genetic variations and analyze gene to gene or gene to environmental interaction will facilitate the discovery of susceptibility genes for type 2 diabetes mellitus in near future. Once we could identify susceptibility genes and gene to environmental interaction of type 2 diabetes mellitus, we can clarify the role of both environmental and genetic factors in the development of type 2 diabetes mellitus. Moreover, we can identify people who can get more benefit from prevention and also can provide better and personalized preventive measure based on genetic information.

Insulin resistance is a poor predictor of type 2 diabetes in individuals with no family history of disease.

In normoglycemic offspring of two type 2 diabetic parents, low insulin sensitivity (S(I)) and low insulin-independent glucose effectiveness (S(G)) predict the development of diabetes one to two decades later. To determine whether low S(I), low S(G,) or low acute insulin response to glucose are predictive of diabetes in a population at low genetic risk for disease, 181 normoglycemic individuals with no family history of diabetes (FH-) and 150 normoglycemic offspring of two type 2 diabetic parents (FH+) underwent i.v. glucose tolerance testing (IVGTT) between the years 1964-82. During 25 +/- 6 years follow-up, comprising 2,758 person years, the FH- cohort (54 +/- 9 years) had an age-adjusted incidence rate of type 2 diabetes of 1.8 per 1,000 person years, similar to that in other population-based studies, but significantly lower than 16.7 for the FH+ cohort. Even when the two study populations were subdivided by initial values of S(I) and S(G) derived from IVGTT's performed at study entry, there was a 10- to 20-fold difference in age-adjusted incidence rates for diabetes in the FH- vs. FH+ individuals with low S(I) and low S(G). The acute insulin response to glucose was not predictive of the development of diabetes when considered independently or when assessed as a function of S(I), i.e., the glucose disposition index. These data demonstrate that low glucose disposal rates are robustly associated with the development of diabetes in the FH+ individuals, but insulin resistance per se is not sufficient for the development of diabetes in individuals without family history of disease and strongly suggest a familial factor, not detectable in our current measures of the dynamic responses of glucose or insulin to an IVGTT is an important risk factor for type 2 diabetes. Low S(I) and low S(G), both measures of glucose disposal, interact with this putative familial factor to result in a high risk of type 2 diabetes in the FH+ individuals, but not in the FH- individuals.

What's new in … Diabetes prevention and delivery of care

The worldwide prevalence of diabetes mellitus is projected to reach 5.4% (300 million individuals) by 2025, and the evolving pandemic of childhood obesity in Western countries has caused a significant increase in insulin resistance and type 2 diabetes. The potential societal impact is enormous, and growing appreciation of the scale of the problem is reflected in increasingly frequent public pronouncements by Western political leaders. There is an urgent need to develop and deploy systems for preventing the development of diabetes in individuals at risk, and for effective delivery of complex care to those who develop the condition.

Sequence analysis of the diabetes-protective human leukocyte antigen-DQB1*0602 allele in unaffected, islet cell antibody-positive first degree relatives and in rare patients with type 1 diabetes.

The human leukocyte antigen (HLA)-DQA1*0102/DQB1*0602/DRB1*1501 (DR2) haplotype confers strong protection from type 1 diabetes. Growing evidence suggests that such protection may be mostly encoded by the DQB1*0602 allele, and we reported that even first degree relatives with islet cell antibodies (ICA) have an extremely low diabetes risk if they carry DQB1*0602. Recently, novel variants of the DQB1*0602 and *0603 alleles were reported in four patients with type 1 diabetes originally typed as DQB1*0602 with conventional techniques. One inference from this observation is that DQB1*0602 may confer absolute protection and may never occur in type 1 diabetes. By this hypothesis, all patients typed as DQB1*0602 positive with conventional techniques should carry one of the above diabetes-permissive variants instead of the protective DQB1*0602. Such variants could also occur in ICA/DQB1*0602-positive relatives, with the implication that their diabetes risk could be significantly higher than previously estimated. We therefore sequenced the DQB1*0602 and DQA1*0102 alleles in all ICA/DQB1*0602-positive relatives (n = 8) previously described and in six rare patients with type 1 diabetes and DQB1*0602. We found that all relatives and patients carry the known DQB1*0602 and DQA1*0102 sequences, and none of them has the mtDNA A3243G mutation associated with late-onset diabetes in ICA-positive individuals. These findings suggest that diabetes-permissive DQB1*0602/3 variants may be very rare. Thus, although the protective effect associated with DQB1*0602 is extremely powerful, it is not absolute. Nonetheless, the development of diabetes in individuals with DQB1*0602 remains extremely unlikely, even in the presence of ICA, as confirmed by our further evaluation of ICA/DQB1*0602-positive relatives, none of whom has yet developed diabetes.