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Type 2 diabetes is a multifactorial disease with multiple underlying aetiologies. To address this heterogeneity, investigators of a previous study clustered people with diabetes according to five diabetes subtypes. The aim of the current study is to investigate the etiology of these clusters by comparing their molecular signatures. In three independent cohorts, in total 15,940 individuals were clustered based on five clinical characteristics. In a subset, genetic (N = 12,828), metabolomic (N = 2,945), lipidomic (N = 2,593), and proteomic (N = 1,170) data were obtained in plasma. For each data type, each cluster was compared with the other four clusters as the reference. The insulin-resistant cluster showed the most distinct molecular signature, with higher branched-chain amino acid, diacylglycerol, and triacylglycerol levels and aberrant protein levels in plasma were enriched for proteins in the intracellular PI3K/Akt pathway. The obese cluster showed higher levels of cytokines. The mild diabetes cluster with high HDL showed the most beneficial molecular profile with effects opposite of those seen in the insulin-resistant cluster. This study shows that clustering people with type 2 diabetes can identify underlying molecular mechanisms related to pancreatic islets, liver, and adipose tissue metabolism. This provides novel biological insights into the diverse aetiological processes that would not be evident when type 2 diabetes is viewed as a homogeneous disease. [ABSTRACT FROM AUTHOR]

Objective: The MHC region harbors the strongest loci for latent autoimmune diabetes in adults (LADA); however, the strength of association is likely attenuated compared with that for childhood-onset type 1 diabetes. In this study, we recapitulate independent effects in the MHC class I region in a population with type 1 diabetes and then determine whether such conditioning in LADA yields potential genetic discriminators between the two subtypes within this region.Research Design and Methods: Chromosome 6 was imputed using SNP2HLA, with conditional analysis performed in type 1 diabetes case subjects (n = 1,985) and control subjects (n = 2,219). The same approach was applied to a LADA cohort (n = 1,428) using population-based control subjects (n = 2,850) and in a separate replication cohort (656 type 1 diabetes case, 823 LADA case, and 3,218 control subjects).Results: The strongest associations in the MHC class II region (rs3957146, β [SE] = 1.44 [0.05]), as well as the independent effect of MHC class I genes, on type 1 diabetes risk, particularly HLA-B*39 (β [SE] = 1.36 [0.17]), were confirmed. The conditional analysis in LADA versus control subjects showed significant association in the MHC class II region (rs3957146, β [SE] = 1.14 [0.06]); however, we did not observe significant independent effects of MHC class I alleles in LADA.Conclusions: In LADA, the independent effects of MHC class I observed in type 1 diabetes were not observed after conditioning on the leading MHC class II associations, suggesting that the MHC class I association may be a genetic discriminator between LADA and childhood-onset type 1 diabetes. [ABSTRACT FROM AUTHOR]

Objective: Latent autoimmune diabetes in adults (LADA) shares clinical features with both type 1 and type 2 diabetes; however, there is ongoing debate regarding the precise definition of LADA. Understanding its genetic basis is one potential strategy to gain insight into appropriate classification of this diabetes subtype.Research Design and Methods: We performed the first genome-wide association study of LADA in case subjects of European ancestry versus population control subjects (n = 2,634 vs. 5,947) and compared against both case subjects with type 1 diabetes (n = 2,454 vs. 968) and type 2 diabetes (n = 2,779 vs. 10,396).Results: The leading genetic signals were principally shared with type 1 diabetes, although we observed positive genetic correlations genome-wide with both type 1 and type 2 diabetes. Additionally, we observed a novel independent signal at the known type 1 diabetes locus harboring PFKFB3, encoding a regulator of glycolysis and insulin signaling in type 2 diabetes and inflammation and autophagy in autoimmune disease, as well as an attenuation of key type 1-associated HLA haplotype frequencies in LADA, suggesting that these are factors that distinguish childhood-onset type 1 diabetes from adult autoimmune diabetes.Conclusions: Our results support the need for further investigations of the genetic factors that distinguish forms of autoimmune diabetes as well as more precise classification strategies. [ABSTRACT FROM AUTHOR]

Introduction: The formation of alliances with communities has become central to public health research, especially those involving more vulnerable and excluded groups. Recent thinking about science and society has labeled this different way of doing joint research as co-production of knowledge, a blurring of the boundaries between researchers and service users. Creating new knowledge together with people with lived experience both complicates and broadens the research process. In order to enable co-production, there is a need to create innovative environments that emphasize the value of both scientific and experience-based knowledge. Context and objectives: At Karolinska Institutet, a research project is underway that examines how participation and feelings of belonging are created or absent in different contexts and situations for adults living with acquired brain injury (ABI). The project is an example of participatory health research where a stated ambition is to, together with the allied community, capture their lived experiences and develop experience-based knowledge. In an ambition to create a supporting environment for the joint research process between researchers and people with ABI, the purpose of this study is to increase the knowledge about challenges and opportunities involved in this process. Method and data analysis: The research group consists of two academic researchers belonging to health care science and social science respectively, and three "co-researchers" with lived experience of ABI. The group has weekly digital meetings, where we work for an average of 1,5 hour, corresponding to the co-researchers' paid time in the project. We work with different parts of the research process: research design, preparing study information for different stakeholders, interview guides and text for the project webpage. A colleague was asked to conduct interviews with members in the research group about experiences from partaking in the research process considering the individual as well as the group process. These interviews, written reflections and notes from meetings were analyzed using inductive thematic content analysis to describe challenges and opportunities of co-production. Preliminary results: A constant challenge was to find the balance between the type of research activities we wanted to do as a group, in relation to what would be reasonable to demand from members of the research group with different assignments and allocated time. The fact that the co-researchers knew each other before they joined the group was considered a strength since it made them more comfortable with expressing their opinions in the group. It was easier to express opinions when one knew that sharing different types of knowledge claims was perceived as valuable contributions, which was especially emphasized by fellow researchers living with aphasia which sometimes affected their communication. Trust between group members was built over time, and among the co-researchers there was a willingness to help and perform at the same time as there was a concern that fatigue would occur on a meeting day. It was also discovered that certain spaces and places, such as digital and physical meetings were better suited to different types of activities. [ABSTRACT FROM AUTHOR]

Abstract: We aimed to investigate the genetic associations of neuropathic pain in a deeply phenotyped cohort. Participants with neuropathic pain were cases and compared with those exposed to injury or disease but without neuropathic pain as control subjects. Diabetic polyneuropathy was the most common aetiology of neuropathic pain. A standardised quantitative sensory testing protocol was used to categorize participants based on sensory profile. We performed genome-wide association study, and in a subset of participants, we undertook whole-exome sequencing targeting analyses of 45 known pain-related genes. In the genome-wide association study of diabetic neuropathy (N = 1541), a top significant association was found at the KCNT2 locus linked with pain intensity (rs114159097, P = 3.55 × 10-8). Gene-based analysis revealed significant associations between LHX8 and TCF7L2 and neuropathic pain. Polygenic risk score for depression was associated with neuropathic pain in all participants. Polygenic risk score for C-reactive protein showed a positive association, while that for fasting insulin showed a negative association with neuropathic pain, in individuals with diabetic polyneuropathy. Gene burden analysis of candidate pain genes supported significant associations between rare variants in SCN9A and OPRM1 and neuropathic pain. Comparison of individuals with the "irritable" nociceptor profile to those with a "nonirritable" nociceptor profile identified a significantly associated variant (rs72669682, P = 4.39 × 10-8) within the ANK2 gene. Our study on a deeply phenotyped cohort with neuropathic pain has confirmed genetic associations with the known pain-related genes KCNT2, OPRM1, and SCN9A and identified novel associations with LHX8 and ANK2, genes not previously linked to pain and sensory profiles, respectively., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association for the Study of Pain.)

Context: Peptidylglycine-α-amidating monooxygenase (PAM) is a critical enzyme in the endocrine system responsible for activation, by amidation, of bioactive peptides., Objective: To define the clinical phenotype of carriers of genetic mutations associated with impaired PAM-amidating activity (PAM-AMA)., Design: We used genetic and phenotypic data from cohort studies: the Malmö Diet and Cancer (MDC; 1991-1996; reexamination in 2002-2012), the Malmö Preventive Project (MPP; 2002-2006), and the UK Biobank (UKB; 2012)., Setting: Exome-wide association analysis was used to identify loss-of-function (LoF) variants associated with reduced PAM-AMA and subsequently used for association with the outcomes., Patients or Other Participants: This study included n∼4500 participants from a subcohort of the MDC (MDC-Cardiovascular cohort), n∼4500 from MPP, and n∼300,000 from UKB., Main Outcome Measures: Endocrine-metabolic traits suggested by prior literature, muscle mass, muscle function, and sarcopenia., Results: Two LoF variants in the PAM gene, Ser539Trp (minor allele frequency: 0.7%) and Asp563Gly (5%), independently contributed to a decrease of 2.33 [95% confidence interval (CI): 2.52/2.15; P = 2.5E-140] and 0.98 (1.04/0.92; P = 1.12E-225) SD units of PAM-AMA, respectively. The cumulative effect of the LoF was associated with diabetes, reduced insulin secretion, and higher levels of GH and IGF-1. Moreover, carriers had reduced muscle mass and function, followed by a higher risk of sarcopenia. Indeed, the Ser539Trp mutation increased the risk of sarcopenia by 30% (odds ratio 1.31; 95% CI: 1.16/1.47; P = 9.8E-06), independently of age and diabetes., Conclusion: PAM-AMA genetic deficiency results in a prediabetic sarcopenic phenotype. Early identification of PAM LoF carriers would allow targeted exercise interventions and calls for novel therapies that restore enzymatic activity., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Type 2 diabetes has been reproducibly clustered into five subtypes with different disease progression and risk of complications; however, etiological differences are unknown. We used genome-wide association and genetic risk score (GRS) analysis to compare the underlying genetic drivers. Individuals from the Swedish ANDIS (All New Diabetics In Scania) study were compared to individuals without diabetes; the Finnish DIREVA (Diabetes register in Vasa) and Botnia studies were used for replication. We show that subtypes differ with regard to family history of diabetes and association with GRS for diabetes-related traits. The severe insulin-resistant subtype was uniquely associated with GRS for fasting insulin but not with variants in the TCF7L2 locus or GRS reflecting insulin secretion. Further, an SNP (rs10824307) near LRMDA was uniquely associated with mild obesity-related diabetes. Therefore, we conclude that the subtypes have partially distinct genetic backgrounds indicating etiological differences., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)