Aims/hypothesis Type 1 diabetes is characterised by the destruction of pancreatic beta cells. Genetic factors account for approximately 50% of the total risk, with variants in the HLA region contributing to half of this genetic risk. Research has historically focused on populations of European ancestry. We developed HLA-focused type 1 diabetes genetic risk scores (T1D GRSHLA) using SNPs or HLA alleles from four ancestry groups (admixed African [AFR; T1D GRSHLA-AFR], admixed American [AMR; T1D GRSHLA-AMR], European [EUR; T1D GRSHLA-EUR] and Finnish [FIN; T1D GRSHLA-FIN]). We also developed an across-ancestry GRS (ALL; T1D GRSHLA-ALL). We assessed the performance of the GRS in each population to determine the transferability of constructed scores. Methods A total of 41,689 samples and 13,695 SNPs in the HLA region were genotyped, with HLA alleles imputed using the HLA-TAPAS multi-ethnic reference panel. Conditionally independent SNPs and HLA alleles associated with type 1 diabetes were identified in each population group to construct T1D GRSHLA models. Generated T1D GRSHLA models were used to predict HLA-focused type 1 diabetes genetic risk across four ancestry groups. The performance of each T1D GRSHLA model was assessed using receiver operating characteristic (ROC) AUCs, and compared statistically. Results Each T1D GRSHLA model included a different number of conditionally independent HLA-region SNPs (AFR, n=5; AMR, n=3; EUR, n=38; FIN, n=6; ALL, n=36) and HLA alleles (AFR, n=6; AMR, n=5; EUR, n=40; FIN, n=8; ALL, n=41). The ROC AUC values for the T1D GRSHLA from SNPs or HLA alleles were similar, and ranged from 0.73 (T1D GRSHLA-allele-AMR applied to FIN) to 0.88 (T1D GRSHLA-allele-EUR applied to EUR). The ROC AUC using the combined set of conditionally independent SNPs (T1D GRSHLA-SNP-ALL) or HLA alleles (T1D GRSHLA-allele-ALL) performed uniformly well across all ancestry groups, with values ranging from 0.82 to 0.88 for SNPs and 0.80 to 0.87 for HLA alleles. Conclusions/interpretation T1D GRSHLA models derived from SNPs performed equivalently to those derived from HLA alleles across ancestries. In addition, T1D GRSHLA-SNP-ALL and GRSHLA-allele-ALL models had consistently high ROC AUC values when applied across ancestry groups. Larger studies in more diverse populations are needed to better assess the transferability of T1D GRSHLA across ancestries. Graphical Abstract

Aims/hypothesis Type 1 diabetes manifests after irreversible beta cell damage, highlighting the crucial need for markers of the presymptomatic phase to enable early and effective interventions. Current efforts to identify molecular markers of disease-triggering events lack resolution and convenience. Analysing frequently self-collected dried blood spots (DBS) could enable the detection of early disease-predictive markers and facilitate tailored interventions. Here, we present a novel strategy for monitoring transient molecular changes induced by environmental triggers that enable timely disease interception. Methods Whole blood (10 μl) was sampled regularly (every 1–5 days) from adult NOD mice infected with Coxsackievirus B3 (CVB3) or treated with vehicle alone. Blood samples (5 μl) were dried on filter discs. DBS samples were analysed by proximity extension assay. Generalised additive models were used to assess linear and non-linear relationships between protein levels and the number of days post infection (p.i.). A multi-layer perceptron (MLP) classifier was developed to predict infection status. CVB3-infected SOCS-1-transgenic (tg) mice were treated with immune- or non-immune sera on days 2 and 3 p.i., followed by monitoring of diabetes development. Results Frequent blood sampling and longitudinal measurement of the blood proteome revealed transient molecular changes in virus-infected animals that would have been missed with less frequent sampling. The MLP classifier predicted infection status after day 2 p.i. with over 90% accuracy. Treatment with immune sera on day 2 p.i. prevented diabetes development in all (100%) of CVB3-infected SOCS-1-tg NOD mice while five out of eight (62.5%) of the CVB3-infected controls treated with non-immune sera developed diabetes. Conclusions/interpretation Our study demonstrates the utility of frequently collected DBS samples to monitor dynamic proteome changes induced by an environmental trigger during the presymptomatic phase of type 1 diabetes. This approach enables disease interception and can be translated into human initiatives, offering a new method for early detection and intervention in type 1 diabetes. Data and code availability Additional data available at https://doi.org/10.17044/scilifelab.27368322 . Additional visualisations are presented in the Shiny app interface https://mouse-dbs-profiling.serve.scilifelab.se/ . Graphical Abstract

Diabetologia -

Aims/hypothesis This study used serial block-face scanning electron microscopy (SBF-SEM), a nanoscale imaging technique in x-y-z planes, to investigate 3D ultrastructural changes in the retinal neurovascular unit (NVU) associated with diabetes. We hypothesised that this approach would reveal previously uncharacterised pathological alterations that contribute to the development of diabetic retinal disease (DRD). Methods Retinas from male diabetic and non-diabetic mice, as well as from human male donors with and without diabetes, were prepared for SBF-SEM imaging. Retinal tissue was microdissected, fixed and embedded for serial sectioning and 3D reconstruction. Ultrastructural analysis of the NVU was performed in capillary regions exclusively within the superficial vascular plexus of both mouse and human retinas. Image stacks were processed using Microscopy Image Browser for contrast normalisation and segmentation, with 3D visualisation performed in Amira software. Quantitative analyses were conducted on pericyte–endothelial cell peg-and-socket formations, cell–basement membrane (BM) interactions, endothelial tubule formation and vascular BM thickness. Results SBF-SEM revealed novel 3D ultrastructural changes in the retinal NVU of diabetic mice and humans, including: (1) partial detachment and reduced frequency of pericyte–endothelium peg-and-socket formations (p<0.05–0.001); (2) localised detachment of endothelial cells and pericytes from the vascular BM (p<0.05–0.01), along with macroglial cell retraction from the outer vascular BM; and (3) increased formation of endothelial tubules (p<0.01–0.001). These changes were observed in the absence of any obvious vascular BM thickening, as no significant differences in mean or maximum BM thickness were found between diabetic and non-diabetic retinal capillaries analysed in this study. Conclusions/interpretation This study provides new insights into the early ultrastructural changes in the retinal NVU in DRD, offering a basis for a better understanding of the pathological processes that contribute to the development of this disease. Data availability Links to all raw image stacks analysed in this article are available at https://doi.org/10.5281/zenodo.15210333 . The MATLAB vascular BM thickness measurement script is available at the GitHub link https://github.com/Curtis-WWIEM/BM_thickness . Graphical Abstract

Aims/hypothesis Glucose homeostasis, essential for metabolic health, requires coordinated insulin and glucagon activity to maintain blood glucose balance. Dysregulation of glucose homeostasis causes hyperglycaemia and glucose intolerance, hallmark features of type 2 diabetes. While SEC16 homologue B (SEC16B), an endoplasmic reticulum export factor, has been linked to obesity, type 2 diabetes and lipid metabolism, its role in glucose regulation remains poorly defined. This study aims to investigate SEC16B’s contribution to glucose homeostasis by systematically dissecting its conserved physiological mechanisms across species. Methods To interrogate SEC16B’s role, we combined Drosophila genetics (RNA interference-mediated dSec16 knockdown) with murine models (Sec16b deletion) under standard or high-fat diet conditions. Glucose and insulin tolerance tests assessed glucose homeostasis. Mechanistic insights into beta cell dysfunction were derived from immunostaining, glucose-stimulated insulin secretion assays and RNA-seq profiling of murine pancreatic islets. Results Both disruption of dSec16 in Drosophila and Sec16b deletion in mice triggered glucose intolerance under standard diet conditions, recapitulating conserved metabolic dysfunction. In addition, Sec16b loss impaired glycaemic control in mice fed a high-fat diet. Mechanistically, Sec16b deficiency impairs insulin secretion by downregulating cholinergic signalling and compromising intracellular Ca2+ influx in pancreatic beta cells. Conclusions/interpretation Our study reveals SEC16B, a genome-wide association study-identified obesity risk gene, as an evolutionarily conserved regulator of glucose homeostasis. By linking SEC16B to cholinergic-driven insulin secretion and calcium dynamics, we resolve a mechanistic gap in beta cell dysfunction and metabolic disease. This finding provides novel insights into the mechanisms underlying glucose homeostasis and may enhance our understanding of potential treatments for metabolic diseases. Graphical Abstract

Aims/hypothesis This study investigated insulin sensitivity using the hyperinsulinaemic–euglycaemic clamp technique in individuals with obesity and type 2 diabetes treated with tirzepatide at the low dose of 5 mg over a 12-week treatment period. Methods This prospective, single-arm, open-label, single-centre study was conducted in obese individuals with type 2 diabetes. Participants received tirzepatide 2.5 mg once weekly for 4 weeks; the dose was then increased to 5 mg for the remaining 8 weeks. The primary outcome was change in the glucose infusion rate. Secondary outcomes were changes in HbA1c, body weight, body composition, lipid profile, glucagon level, the HOMA2-IR and HOMA2-%β indices, and the association of these variables with the glucose infusion rate (GIR). Results Sixteen participants completed the study. The GIR increased from 3.21 to 5.16 mg min−1 kg−1 (p<0.001). HbA1c decreased from 63.4 to 43.6 mmol/mol (7.95% to 6.14%, p<0.001) and body weight decreased by 4.9 kg (5.0%, p<0.001). Muscle mass, fat mass and fat percentage significantly decreased by 1.8%, 9.1% and 4.5%, respectively. Glucagon decreased significantly from 28.8 pg/ml to 20.8 pg/ml. However, simple linear regression analysis revealed no significant relationship between changes in GIR and other clinical variables. Conclusions/interpretation Tirzepatide significantly improves insulin sensitivity within 12 weeks, indicating an early metabolic effect that is not solely attributable to weight loss. Trial registration UMIN registration number: UMIN000056862 Graphical Abstract

In economically developed countries most lean individuals presenting with insulin-dependent diabetes have autoimmune type 1 diabetes. However, in many rural areas of low- and middle-income countries (LMIC), 40–50% of individuals with a similar clinical presentation are negative for diabetes-associated autoantibodies at initial clinical presentation. The phenotype differs from the classical presentation of type 1 diabetes even in those with evidence of an autoimmune process: altered autoantibody profile; later peak age of onset; and, in those with post-pubertal clinical presentation, more marked male predominance. The incidence of insulin-dependent diabetes in LMIC is low, even when assessing those with and without autoantibodies together. A framework of possible pathophysiological mechanisms underlying the observed phenotypic differences is presented to explain how chronic undernutrition and micronutrient deficiencies might alter the presentation of insulin-dependent diabetes. Inhabitants of rural sub-Saharan Africa (SSA) depend almost entirely on staple foods grown locally in nutrient-deficient soil. The resulting chronic undernutrition, often intergenerational, affects linear growth and body morphology, and has direct immune and non-immune effects on beta cell development and function. Undernutrition directly affects thymic function, alters the autoimmune profile and is often associated with social deprivation and parasitic infection, both of which can delay and modify the (auto)immune response. Non-immune effects of undernutrition include beta cell stress, associated with apoptosis and formation of neoantigens. That environmental effects of undernutrition and social deprivation affect the altered insulin-dependent diabetes phenotype is shown by the movement back towards a classical type 1 diabetes phenotype in offspring of emigrants from SSA who are born in and develop insulin-dependent diabetes in an economically developed country. The degree of phenotype change depends on how long the parents have lived in their adopted country. It has recently been proposed that insulin-dependent diabetes in those who are mal/undernourished be called type 5 diabetes. There is need for clinician recognition of the altered phenotype(s) of insulin-dependent diabetes resulting from chronic undernutrition in rural LMIC. Additionally, changes in agricultural practice are needed to improve the nutrient content of food consumed by the rural population. Graphical Abstract

Aims/hypothesis Genetic association studies have demonstrated that partial loss of SLC30A8 Function protects against type 2 diabetes in humans. We investigated the impact of complete loss of SLC30A8 Function on type 2 diabetes risk and related phenotypes in humans. Methods The Pakistan Genome Resource (PGR), a biobank comprising whole-exome and whole-genome sequences of 145,037 participants, was analysed for phenotypic associations with SLC30A8 loss-of-function (LoF) variants. To follow up on the observations in the PGR, we conducted recall-by-genotype analyses of SLC30A8 LoF heterozygotes and homozygotes, as well as their participating family members, using OGTTs. Results We identified 18 SLC30A8 knockouts, including homozygotes for a variant enriched in South Asians (Gln174Ter), and 1024 heterozygotes for LoF variants. Type 2 diabetes risk was lower in SLC30A8 LoF heterozygotes and homozygotes relative to non-carriers, and the protective effect strengthens in a gene dose-dependent manner (ORadditive=0.62; 95% CI 0.53, 0.72; p=1.1×10–9; ORrecessive=0.34; 95% CI 0.12, 0.93; p=0.04). OGTTs in recall-by-genotype studies showed a gene dose-dependent reduction in glucose levels, coupled with elevated insulin. Conclusions/interpretation The corrected insulin response, disposition index and insulin sensitivity index in LoF heterozygotes and homozygotes indicated higher glucose-stimulated insulin secretion with preserved beta cell function that was independent of BMI. These data suggest that therapeutic inhibition of SLC30A8, up to and including complete knockout, may treat type 2 diabetes safely and effectively. Graphical Abstract

Aims/hypothesis This study aimed to assess the impact of adding dapagliflozin to insulin therapy on key hormonal determinants of glucose regulation and ketogenesis. We hypothesise that dapagliflozin increases glucagon-like peptide 1 (GLP-1), glucagon and ketone body concentrations, based on the results of a pilot study. Methods The study was designed as a randomised, placebo-controlled, open-label, crossover intervention study with two periods (dapagliflozin and placebo intake), including patients of the Department of Diabetes, Endocrinology, Clinical Nutrition & Metabolism, Inselspital, Bern University Hospital, University of Bern. Individuals with type 1 diabetes (C-peptide concentrations <0.1 nmol/l) with a duration >5 years and a BMI of 20–29 kg/m2 were included. They received 10 mg of dapagliflozin or placebo daily for 7 days throughout two independent treatment periods, separated by a 14 day washout period. Allocation was done by a computed randomisation tool (REDCap), without blinding of the participants or the investigators. On day 7 of each treatment period, hyperinsulinaemic–euglycaemic clamps (HECs) and OGTT clamps (OGTTCs) were performed to assess changes in the secretion of GLP-1, glucagon, somatostatin and total ketone bodies. The objective was to evaluate the effects of adding the sodium–glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin to insulin therapy on GLP-1 during OGTTC (primary endpoint), GLP-1 secretion during HEC, and glucagon, somatostatin and ketogenesis during OGTTC and HEC (secondary endpoints). The primary endpoint was concentrations of GLP-1 during OGTTC. Secondary endpoints included GLP-1 during HEC and glucagon, somatostatin and ketone body concentrations during OGTTC and HEC. Results A total of 13 individuals with type 1 diabetes were included and randomised. All of them received dapagliflozin and placebo, finished the sequences per protocol and were analysed per protocol. GLP-1 concentrations did not differ significantly between treatments in the OGTTC (median [IQR] dapagliflozin 192.8 [129.8–257.2] pmol/l vs placebo 176.3 [138.4–227.4] pmol/l; p=0.7) or HEC (median [IQR] dapagliflozin 208.6 [133.6–294.0] pmol/l vs placebo 203.1 [150.2–291.8] pmol/l; p=0.7). Glucagon concentrations did not significantly differ between treatments in the OGTTC (median [IQR] dapagliflozin 1.54 [0.84–3.68] ng/l vs placebo 1.54 [0.82–4.64] ng/l; p=0.8) or HEC (median [IQR] dapagliflozin 1.59 [0.87–3.54] ng/l vs placebo 1.63 [0.91–3.96] ng/l; p=0.3). Somatostatin concentrations remained comparable between treatments during the HEC (median [IQR] dapagliflozin 41.1 [26.8–73.8] pmol/l vs placebo 47.0 [23.0–77.6] pmol/l; p=0.2) and OGTTC (median [IQR] dapagliflozin 51.1 [31.1–77.0] pmol/l vs placebo 45.3 [30.0–70.5] pmol/l; p=0.2). Plasma ketone bodies were higher with dapagliflozin during the HEC (median [IQR] dapagliflozin 0.15 [0.04–0.47] mmol/l vs placebo 0.03 [0.01–0.12] mmol/l; p<0.001) and OGTTC (median [IQR] dapagliflozin 0.10 [0.03–0.22] mmol/l vs placebo 0.03 [0.01–0.12] mmol/l; p<0.001). Conclusions/interpretation Short-term dapagliflozin treatment in type 1 diabetes increases plasma ketone concentrations without affecting the secretion of GLP-1, glucagon or somatostatin. Higher ketone body concentrations highlight the elevated risk of diabetic ketoacidosis associated with the adjunct intake of dapagliflozin. Trial registration ClinicalTrials.gov NCT04035031. Funding Swiss National Science Foundation, project number 32003B_185019. Graphical Abstract

Aims/hypothesis The bromodomain and extra-terminal (BET) protein family acts as ‘epigenetic readers’ to identify the acetylation marks on histones that convert the acetylated lysine residues into observable phenotypes. BET proteins have gained attention due to their ability to modulate the transcription of pathology-related genes involved in cancer and autoimmune diseases, including type 1 diabetes mellitus. However, targeting BET proteins may have secondary effects on other host cells. We aimed to elucidate possible secondary effects of BET inhibition on pancreatic beta cell function. Methods We studied the effect of the small-molecule BET inhibitor I-BET151 on pancreatic beta cells in vitro, ex vivo and in vivo. GTTs, ITTs and glucose-stimulated insulin secretion assays were performed in healthy mice and a mouse model of diabetes following daily i.p. injections of I-BET151 for 2 weeks. Transcriptomic analysis was carried out on primary mouse islets, which were subjected to ex vivo I-BET151 treatment. Changes in expression were further validated in primary human islets. Results Administration of I-BET151 modestly but significantly increased glucose excursions and reduced insulin responses in both healthy mice and diabetic mice. We found that I-BET151 exposure significantly reduced the expression of Hnf4α (also known as Hnf4a; MODY1), Gck (MODY2), Hnf1α (also known as Hnf1a; MODY3), Glut2 and other genes essential for beta cell function in rat INS-1E insulinoma cells and in mouse primary islets and human islets. Global gene expression analysis in cells treated with I-BET151 showed a downregulation of the phosphoinositide-3-kinase (PI3K)–Akt pathway. Downregulation of forkhead box protein O1, a downstream transcriptional factor of the PI3K–Akt pathway, partially rescued I-BET151-driven downregulation of Gck and insulin secretion. Likewise, islets from I-BET151-treated mice showed a modest reduction in glucose-stimulated insulin secretion. Conclusions/interpretation The results presented here suggest that BET inhibition therapy should be used with caution due to possible bimodal effects at high concentrations at the detriment of pancreatic beta cell function. Graphical Abstract

Recent advances in genome-wide approaches, the availability of isolated human islets for research and the evaluation of novel incretin mimetics in large clinical trials have brought about remarkable progress in our understanding of the role of the pancreatic beta cell in type 2 diabetes. Here, we review key developments in type 2 diabetes initiation, progression and remission, focusing mostly on human studies published in the last 5 years. Progress in multi-omics technologies has enabled researchers to identify links between type 2 diabetes risk variants and gene regulatory networks in islet endocrine cells that control beta cell development, function and stress resilience. These studies support the notion that early abnormalities in insulin secretion, rather than a reduction in beta cell mass, play a fundamental and primary role in early type 2 diabetes pathogenesis. Contributing to these intrinsic beta cell defects are various pathogenic signals from other (endocrine and non-endocrine) islet cells, the exocrine pancreas, the gut and insulin-sensitive tissues. It has also become apparent that beta cells comprise a heterogeneous population that responds differently to stress situations and that sex-related differences in beta cell responses should not be underestimated. Finally, human clinical trials have clearly demonstrated that diabetes remission can be achieved using glucose-lowering therapies and particularly strategies focused on weight loss, including bariatric surgery and, more recently, the use of highly efficient new drugs targeting the incretin system. While progress in the last 5 years has been significant, much remains to be uncovered to bring these advances to the clinic and thereby alleviate the dramatic consequences of type 2 diabetes complications for the hundreds of millions of people who live with this disease. Graphical Abstract

Aims/hypothesis Pancreatic ductal adenocarcinoma-related diabetes mellitus (PDAC-DM) is a paraneoplastic syndrome with a poorly understood pathophysiology. PDAC-DM is often clinically confused with type 2 diabetes, resulting in delayed cancer detection and poorly individualised hyperglycaemia treatment. We investigated whether these forms of diabetes can be distinguished at the metabolic level. Methods Adults with either cancer treatment-naive PDAC-DM (n=28) or type 2 diabetes (n=97), and with diabetes onset within 3 years, underwent mixed-meal tolerance tests to investigate glucose metabolism. Outcomes included insulin sensitivity (Matsuda index), insulin secretion (insulinogenic index), beta cell function (oral disposition index), insulin clearance, and postprandial glucagon, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) responses. Results Compared with type 2 diabetes, individuals with PDAC-DM showed ~2.5-fold greater insulin sensitivity, ~81% lower insulin secretion and ~40% lower beta cell function. Insulin clearance was higher in the PDAC-DM group than the type 2 diabetes group, with and without adjustment for insulin sensitivity. Glucagon and GLP-1 levels increased after a meal in both groups, but levels were higher in the PDAC-DM group. GIP levels were similar between groups. The metabolic differences between groups persisted after adjustment for age, sex and BMI. Conclusions/interpretation PDAC-DM and type 2 diabetes are metabolically distinct, with different defects responsible for hyperglycaemia. PDAC-DM is characterised predominantly by insulin deficiency and displays higher insulin sensitivity than type 2 diabetes. There are also differences in alpha cell regulation and insulin clearance compared with type 2 diabetes. These findings identify biological characteristics that may have implications for individualised treatment of PDAC-DM and guide diagnostic biomarker discovery for early PDAC diagnosis. Graphical Abstract

To provide visual guidance in concise algorithms and tables to assist with clinical decision making in the management of adults with dyslipidemia to reduce risk of ASCVD and triglyceride-induced pancr...

Aims/hypothesis The aim of this work was to investigate tissue-specific insulin resistance in South Asian and Nordic women with previous gestational diabetes mellitus (pGDM) and to evaluate potential ethnic differences contributing to type 2 diabetes risk. Methods A cross-sectional study using a two-step hyperinsulinaemic–euglycaemic clamp with a glucose tracer was conducted to assess insulin sensitivity in muscle, liver and adipose tissue in 19 South Asian and 16 Nordic women with pGDM and prediabetes (impaired glucose tolerance and/or impaired fasting glucose), along with 16 ethnicity-specific control women. We assessed inflammation and mitochondrial genes by mRNA sequencing of adipose tissue. Results Both South Asian and Nordic women with pGDM showed reduced total glucose disposal (mainly due to muscle insulin resistance) and hyperinsulinaemia compared with the control group. Endogenous glucose production (mainly due to hepatic insulin resistance) was elevated in Nordics with pGDM, while South Asians with pGDM showed pronounced adipose tissue insulin resistance (reduced suppression of glycerol during clamp). mRNA sequencing of adipose tissue indicated increased tissue inflammation in South Asian women compared with Nordic women with pGDM. Furthermore, we observed a differential response to hyperinsulinaemia in South Asians vs Nordics related to mitochondrial mRNA, such as thymidine kinase 2 (TK2). Correlations between adiposity markers and insulin sensitivity also differed by ethnicity, suggesting that the pathways leading to type 2 diabetes may vary across populations. Conclusions/interpretation South Asian and Nordic women with pGDM exhibited differences in insulin resistance profiles, with South Asians showing greater adipose tissue insulin resistance and inflammation. Graphical Abstract

Aims/hypothesis The study aimed to explore the association between maternal glucose levels in pregnancy and offspring’s metabolism and adiposity at approximately 18 years of age. Methods Pregnant women from the Hong Kong Field Centre enrolled in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study underwent a 75 g OGTT at 24–32 gestational weeks. Offspring’s metabolic and adiposity traits were assessed at 18 years postpartum. Associations were evaluated using multiple linear regression and logistic regression. Results Among the 506 mother–child pairs followed up to 18 years, maternal fasting plasma glucose (FPG) in pregnancy was positively associated with offspring’s FPG (β = 0.06 [95% CI 0.02, 0.09]), while maternal 1 h plasma glucose (PG) showed a positive association with offspring’s FPG (β = 0.05), 30 min PG (β = 0.21) and 2 h PG (β = 0.14). All maternal glycaemic levels were associated with an increased risk of offspring being overweight/obese, particularly maternal 1 h PG (OR 1.50 [95% CI 1.17, 1.93]). Offspring of mothers with gestational diabetes mellitus showed a higher prevalence of abnormal glucose tolerance (11.86% vs 7.97%), impaired fasting glucose (1.89% vs 0.49%) and impaired glucose tolerance (10.34% vs 7.13%) than offspring of mothers with normal glucose tolerance, although these associations did not reach statistical significance in fully adjusted models, underscoring the benefit of considering maternal glucose as a continuous trait. Conclusions/interpretation Maternal glucose levels in pregnancy showed a long-term association with offspring’s metabolic health into young adulthood, with continuous associations across the full maternal glucose spectrum, suggesting a graded effect of maternal hyperglycaemia on offspring’s metabolic risk. Graphical Abstract