A plan to improve global type 1 diabetes epidemiology data

Effect of trace elements and nutrients on 21 autoimmune diseases: a Mendelian randomization study

Background

Numerous clinical studies have observed a close relationship between serum trace elements, nutrients, and autoimmune diseases. However, whether there is a genetic causal effect between serum trace elements, nutrients, and autoimmune diseases remains unclear.

Objective

This study aims to investigate the causal effects of serum trace elements and nutrients on 21 autoimmune diseases using Mendelian randomization (MR).

Methods

Single nucleotide polymorphisms for the exposure factors (serum trace elements and vitamins) were obtained from the published UK Biobank database and genome-wide association study (GWAS) public databases. Outcome GWAS data were derived from the FinnGen database. MR was employed to explore the causal relationships between 9 trace elements and 6 vitamins and autoimmune diseases. Causal inference was performed using inverse variance weighted methods, MR Egger, and weighted median methods. Subsequently, heterogeneity tests, horizontal pleiotropy tests, MR-PRESSO tests, and leave-one-out analyses were conducted for sensitivity analysis to evaluate the robustness of the study results. Finally, trace elements and vitamins that were statistically significant in the IVW method and had consistent effect sizes and odds ratios across five methods were selected as exposure factors with a causal relationship to diabetes and its complications. Additionally, multivariable Mendelian randomization was employed to assess the combined effects of multiple exposure factors on autoimmune diseases.

Results

MR analysis indicated that elevated levels of the trace element copper were associated with an increased risk of systemic lupus erythematosus (SLE) and a decreased risk of ulcerative colitis. Carotene was found to have a negative causal relationship with adult-onset Still's disease (AOSD). Elevated levels of copper and selenium were associated with an increased risk of autoimmune hyperthyroidism. Calcium levels showed a negative causal relationship with the risk of polyarteritis nodosa. MVMR results demonstrated that selenium could independently affect the risk of autoimmune hyperthyroidism, separate from copper.

Conclusion

The findings from both univariable and multivariable Mendelian randomization studies support a causal relationship between trace elements, nutrients, and autoimmune diseases. These results have significant clinical implications for developing targeted prevention and treatment strategies for autoimmune diseases.

Fifty years of HLA-associated type 1 diabetes risk: history, current knowledge, and future directions

More than 50 years have elapsed since the association of human leukocyte antigens (HLA) with type 1 diabetes (T1D) was first reported. Since then, methods for identification of HLA have progressed from cell based to DNA based, and the number of recognized HLA variants has grown from a few to tens of thousands. Current genotyping methodology allows for exact identification of all HLA-encoding genes in an individual's genome, with statistical analysis methods evolving to digest the enormous amount of data that can be produced at an astonishing rate. The HLA region of the genome has been repeatedly shown to be the most important genetic risk factor for T1D, and the original reported associations have been replicated, refined, and expanded. Even with the remarkable progress through 50 years and over 5,000 reports, a comprehensive understanding of all effects of HLA on T1D remains elusive. This report represents a summary of the field as it evolved and as it stands now, enumerating many past and present challenges, and suggests possible paradigm shifts for moving forward with future studies in hopes of finally understanding all the ways in which HLA influences the pathophysiology of T1D.

The Burden of Type 1 and Type 2 Diabetes Among Adolescents and Young Adults in 24 Western European Countries, 1990-2019: Results From the Global Burden of Disease Study 2019

Objectives: As little is known about the burden of type 1 (T1DM) and type 2 diabetes (T2DM) in adolescents in Western Europe (WE), we aimed to explore their epidemiology among 10-24 year-olds. Methods: Estimates were retrieved from the Global Burden of Diseases Study (GBD) 2019. We reported counts, rates per 100,000 population, and percentage changes from 1990 to 2019 for prevalence, incidence and years lived with disability (YLDs) of T1DM and T2DM, and the burden of T2DM in YLDs attributable to high body mass index (HBMI), for 24 WE countries. Results: In 2019, prevalence and disability estimates were higher for T1DM than T2DM among 10-24 years old adolescents in WE. However, T2DM showed a greater increase in prevalence and disability than T1DM in the 30 years observation period in all WE countries. Prevalence increased with age, while only minor differences were observed between sexes. Conclusion: Our findings highlight the substantial burden posed by DM in WE among adolescents. Health system responses are needed for transition services, data collection systems, education, and obesity prevention.

National and regional trends in the prevalence of type 2 diabetes and associated risk factors among Korean adults, 2009-2021

Disproportionate impact of COVID-19 on socioeconomic and behavioral variables may have impacted the prevalence of diabetes. We utilized nationwide long-term serial study from the 2009 to 2021 Korea Community Health Survey (KCHS). We explored national and regional prevalence and trends of diabetes according to the socioeconomic and behavioral factors before and during the pandemic. Also, we interpreted which groups became more vulnerable to the prevalence of diagnosed diabetes during the pandemic. A total of 2,971,349 adults aged (19 to 39, 40 to 59, and ≥ 60 years) were included in the analysis. The prevalence of diagnosed diabetes increased slowly during the pandemic (11.6% [95% CI 11.5-11.7] in 2020 and 12.4% [95% CI 12.3-12.6] in 2021), compared to the pre-pandemic era (7.9% [95% CI 7.8-7.9] in 2009-2011 and 11.3% [95% CI 11.3-11.4] in 2018-2019). Also, women, low-income group, low-educational group, and infrequent walking group showed less prevalence of diagnosed diabetes than the others. The diabetic population increased slowly than expected during the pandemic. The pandemic seems to contribute to an unanticipated increase in under-diagnosis of diabetes among the already minority. This study may suggest reinforcing access to healthcare services among the minority during the pandemic.

The T1D Index: Implications of Initial Results, Data Limitations, and Future Development

PURPOSE OF THE REVIEW

Current global information on incidence, prevalence, and mortality of type 1 diabetes (T1D) is limited, particularly in low- and middle-income countries. To address this gap in evidence, JDRF, Life for a Child, International Society for Pediatric and Adolescent Diabetes, and International Diabetes Federation have developed the T1D Index, which uses a Markov mathematical model, and machine learning and all available data to provide global estimates of the burden on T1D. This review assesses the methodology, limitations, current findings, and future directions of the Index.

RECENT FINDINGS

Global prevalence was estimated at 8.4 million in 2021, with 1.5 million <20 years (y). T1D prevalence varied from 1.5 to 534 per 100,000, with T1D accounting for <0.1-17.8% of all diabetes in different countries. A total of 35,000 young people <25 y are estimated to have died at clinical onset of T1D from non-diagnosis. An estimated 435,000 people <25 y were receiving "minimal care." Health-adjusted life years (HALYs) lost for individuals diagnosed with T1D at age 10 y in 2021 ranged from 14 to 55 y. These results show that interventions to reduce deaths from non-diagnosis, and improve access to at least an intermediate care level, are needed to reduce projected life years lost. The results have significant uncertainties due to incomplete data across the required inputs. Obtaining recent incidence, prevalence, and mortality data, as well as addressing data quality issues, misdiagnoses, and the lack of adult data, is essential for maintaining and improving accuracy. The index will be updated regularly as new data become available.