There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody–positive, 13% for single autoantibody–positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody–positive, 12% for single autoantibody–positive, and 0.5% for initially autoantibody-negative subjects.

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody–positive identical twins and multiple autoantibody–positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Previously generated genetic risk scores (GRSs) for type 1 diabetes (T1D) have not captured all known information at non-HLA loci or, particularly, at HLA risk loci. We aimed to more completely incorporate HLA alleles, their interactions, and recently discovered non-HLA loci into an improved T1D GRS (termed the "T1D GRS2") to better discriminate diabetes subtypes and to predict T1D in newborn screening studies.

In 6,481 case and 9,247 control subjects from the Type 1 Diabetes Genetics Consortium, we analyzed variants associated with T1D both in the HLA region and across the genome. We modeled interactions between variants marking strongly associated HLA haplotypes and generated odds ratios to create the improved GRS, the T1D GRS2. We validated our findings in UK Biobank. We assessed the impact of the T1D GRS2 in newborn screening and diabetes classification and sought to provide a framework for comparison with previous scores.

The T1D GRS2 used 67 single nucleotide polymorphisms (SNPs) and accounted for interactions between 18 HLA DR-DQ haplotype combinations. The T1D GRS2 was highly discriminative for all T1D (area under the curve [AUC] 0.92; P < 0.0001 vs. older scores) and even more discriminative for early-onset T1D (AUC 0.96). In simulated newborn screening, the T1D GRS2 was nearly twice as efficient as HLA genotyping alone and 50% better than current genetic scores in general population T1D prediction.

An improved T1D GRS, the T1D GRS2, is highly useful for classifying adult incident diabetes type and improving newborn screening. Given the cost-effectiveness of SNP genotyping, this approach has great clinical and research potential in T1D.

Progression to insulin therapy in clinically diagnosed type 2 diabetes is highly variable. GAD65 autoantibodies (GADA) are associated with faster progression, but their predictive value is limited. We aimed to determine if a type 1 diabetes genetic risk score (T1D GRS) could predict rapid progression to insulin treatment over and above GADA testing.

We examined the relationship between T1D GRS, GADA (negative or positive), and rapid insulin requirement (within 5 years) using Kaplan-Meier survival analysis and Cox regression in 8,608 participants with clinical type 2 diabetes (onset >35 years and treated without insulin for ≥6 months). T1D GRS was both analyzed continuously (as standardized scores) and categorized based on previously reported centiles of a population with type 1 diabetes (<5th [low], 5th–50th [medium], and >50th [high]).

In GADA-positive participants (3.3%), those with higher T1D GRS progressed to insulin more quickly: probability of insulin requirement at 5 years (95% CI): 47.9% (35.0%, 62.78%) (high T1D GRS) vs. 27.6% (20.5%, 36.5%) (medium T1D GRS) vs. 17.6% (11.2%, 27.2%) (low T1D GRS); P = 0.001. In contrast, T1D GRS did not predict rapid insulin requirement in GADA-negative participants (P = 0.4). In Cox regression analysis with adjustment for age of diagnosis, BMI, and cohort, T1D GRS was independently associated with time to insulin only in the presence of GADA: hazard ratio per SD increase was 1.48 (1.15, 1.90); P = 0.002.

A T1D GRS alters the clinical implications of a positive GADA test in patients with clinical type 2 diabetes and is independent of and additive to clinical features.

Central nervous system (CNS) features in children with permanent neonatal diabetes (PNDM) due to KCNJ11 mutations have a major impact on affected families. Sulfonylurea therapy achieves outstanding metabolic control but only partial improvement in CNS features. The effects of KCNJ11 mutations on the adult brain and their functional impact are not well understood. We aimed to characterize the CNS features in adults with KCNJ11 PNDM compared with adults with INS PNDM.

Adults with PNDM due to KCNJ11 mutations (n = 8) or INS mutations (n = 4) underwent a neurological examination and completed standardized neuropsychological tests/questionnaires about development/behavior. Four individuals in each group underwent a brain MRI scan. Test scores were converted to Z scores using normative data, and outcomes were compared between groups.

In individuals with KCNJ11 mutations, neurological examination was abnormal in seven of eight; predominant features were subtle deficits in coordination/motor sequencing. All had delayed developmental milestones and/or required learning support/special schooling. Half had features and/or a clinical diagnosis of autism spectrum disorder. KCNJ11 mutations were also associated with impaired attention, working memory, and perceptual reasoning and reduced intelligence quotient (IQ) (median IQ KCNJ11 vs. INS mutations 76 vs. 111, respectively; P = 0.02). However, no structural brain abnormalities were noted on MRI. The severity of these features was related to the specific mutation, and they were absent in individuals with INS mutations.

KCNJ11 PNDM is associated with specific CNS features that are not due to long-standing diabetes, persist into adulthood despite sulfonylurea therapy, and represent the major burden from KCNJ11 mutations.

Successful self-management of type 1 diabetes requires cognitive skills such as executive functioning (EF). In the transition to adolescence, youth take over responsibility for diabetes management. We set out to test: 1) the association between EF and glycemic control over time and 2) whether this association was moderated by: a) youth, shared, or parent responsibility for diabetes management and b) youth’s age.

Within the Diabetes IN DevelOpment study (DINO), parents of youth with type 1 diabetes (8–15 years at baseline; N = 174) completed a yearly assessment over 4 years. Glycemic control (HbA_1c) was derived from hospital charts. Youth’s EF was measured using the Behavior Rating Inventory of Executive Functioning (BRIEF)-parent report. The Diabetes Family Responsibility Questionnaire (DFRQ)-parent report was used to assess diabetes responsibility (youth, shared, and parent). Linear generalized estimating equations were used to analyze data including youth’s sex, age, and age of diabetes onset as covariates.

Relatively more EF problems are significantly associated with higher HbA_1c over time (β = 0.190; P = 0.002). More EF problems in combination with less youth responsibility (β = 0.501; P = 0.048) or more parental responsibility (β = –0.767; P = 0.006) are significantly associated with better glycemic control over time. Only age significantly moderates the relationship among EF problems, shared responsibility, and glycemic control (β = –0.024; P = 0.019).

Poorer EF is associated with worse glycemic control over time, and this association is moderated by responsibility for diabetes management tasks. This points to the importance of EF when youth take over responsibility for diabetes management in order to achieve glycemic control.

The effect of a healthy lifestyle on diabetes-related dementia remains unknown. We examined whether an active lifestyle and rich social network may counteract the increased risk of dementia in people with diabetes.

Dementia-free older adults from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) (n = 2,650) were followed up for 10 years. Diabetes was ascertained on the basis of medical history, medication use, medical records, or glycated hemoglobin (HbA_1c) ≥6.5% and prediabetes as HbA_1c between 5.7 and 6.5%. Dementia was diagnosed by specialists following standard criteria. An active lifestyle was defined as a moderate to high (vs. low) level of engagement in leisure activities or a rich social network (having moderate to rich [vs. poor] social connections and support). Hazard ratios (HRs) of dementia risk were derived from Cox regression models.

There were 246 incident dementia cases during follow-up. Those with diabetes (n = 243), but not those with prediabetes (n = 921), had greater risk of dementia (adjusted HR 2.0 [95% CI 1.4–2.9]) than diabetes-free participants. Participants with diabetes but low level of engagement in leisure activities (HR 4.2 [95% CI 2.2–8.2]) or a poor social network (HR 3.4 [95% CI 1.9–6.1]) had greater dementia risk than diabetes-free participants with moderate to high levels of leisure activity engagement or a moderate to rich social network. In participants with diabetes, an active lifestyle (high level of engagement in leisure activities or a rich social network) was associated with less of a raised risk (HR 1.9 [95% CI 1.1–3.4]).

An active and socially integrated lifestyle may significantly counteract the detrimental effect of diabetes on dementia risk.

To investigate the associations between different anthropometric measurements and development of distal sensorimotor polyneuropathy (DSPN) considering interaction effects with prediabetes/diabetes and to evaluate subclinical inflammation as a potential mediator.

This study was conducted among 513 participants from the Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort (aged 62–81 years). Anthropometry was measured at baseline. Incident DSPN was defined by neuropathic impairments using the Michigan Neuropathy Screening Instrument at baseline and follow-up. Associations between anthropometric measurements and DSPN were estimated by multivariable logistic regression. Potential differences by diabetes status were assessed using interaction terms. Mediation analysis was conducted to determine the mediation effect of subclinical inflammation in these associations.

After a mean follow-up of 6.5 years, 127 cases with incident DSPN were detected. Both general and abdominal obesity were associated with development of DSPN. The odds ratios (95% CI) of DSPN were 3.06 (1.57; 5.97) for overweight, 3.47 (1.72; 7.00) for obesity (reference: normal BMI), and 1.22 (1.07; 1.38) for 5-cm differences in waist circumference, respectively. Interaction analyses did not indicate any differences by diabetes status. Two chemokines (C-C motif chemokine ligand 7 [CCL7] and C-X-C motif chemokine ligand 10 [CXCL10]) and one neuron-specific marker (Delta/Notch-like epidermal growth factor–related receptor [DNER]) were identified as potential mediators, which explained a proportion of the total effect up to 11% per biomarker.

General and abdominal obesity were associated with incident DSPN among individuals with and without diabetes, and this association was partly mediated by inflammatory markers. However, further mechanisms and biomarkers should be investigated as additional mediators to explain the remainder of this association.

This study investigated the temporal dynamics of pancreas volume and microstructure in children and adolescents with recent-onset type 1 diabetes (T1D) and individuals without diabetes, including a subset expressing autoantibodies associated with the early stages of T1D.

MRI was performed in individuals with recent-onset stage 3 T1D (n = 51; median age 13 years) within 100 days after diagnosis (mean 67 days), 6 months, and 1 year postdiagnosis. Longitudinal MRI measurements were also made in similarly aged control participants (n = 57) and in autoantibody-positive individuals without diabetes (n = 20). The MRI protocol consisted of anatomical imaging to determine pancreas volume and quantitative MRI protocols interrogating tissue microstructure and composition.

Within 100 days of diabetes onset, individuals with T1D had a smaller pancreas (median volume 28.6 mL) than control participants (median volume 48.4 mL; P < 0.001), including when normalized by individual weight (P < 0.001). Longitudinal measurements of pancreas volume increased in control participants over the year, consistent with adolescent growth, but pancreas volume declined over the first year after T1D diagnosis (P < 0.001). In multiple autoantibody–positive individuals, the pancreas volume was significantly larger than that of the T1D cohort (P = 0.017) but smaller than that of the control cohort (P = 0.04). Diffusion-weighted MRI showed that individuals with recent-onset T1D had a higher apparent diffusion coefficient (P = 0.012), suggesting a loss of cellular structural integrity, with heterogeneous pancreatic distribution.

These results indicate that pancreas volume is decreased in stages 1, 2, and 3 of T1D and decreases during the first year after diabetes onset and that this loss of pancreatic volume is accompanied by microstructural changes.

Abnormally elevated proinsulin secretion has been reported in type 2 and early type 1 diabetes when significant C-peptide is present. We questioned whether individuals with long-standing type 1 diabetes and low or absent C-peptide secretory capacity retained the ability to make proinsulin.

C-peptide and proinsulin were measured in fasting and stimulated sera from 319 subjects with long-standing type 1 diabetes (≥3 years) and 12 control subjects without diabetes. We considered three categories of stimulated C-peptide: 1) C-peptide positive, with high stimulated values ≥0.2 nmol/L; 2) C-peptide positive, with low stimulated values ≥0.017 but <0.2 nmol/L; and 3) C-peptide <0.017 nmol/L. Longitudinal samples were analyzed from C-peptide–positive subjects with diabetes after 1, 2, and 4 years.

Of individuals with long-standing type 1 diabetes, 95.9% had detectable serum proinsulin (>3.1 pmol/L), while 89.9% of participants with stimulated C-peptide values below the limit of detection (<0.017 nmol/L; n = 99) had measurable proinsulin. Proinsulin levels remained stable over 4 years of follow-up, while C-peptide decreased slowly during longitudinal analysis. Correlations between proinsulin with C-peptide and mixed-meal stimulation of proinsulin were found only in subjects with high stimulated C-peptide values (≥0.2 nmol/L). Specifically, increases in proinsulin with mixed-meal stimulation were present only in the group with high stimulated C-peptide values, with no increases observed among subjects with low or undetectable (<0.017 nmol/L) residual C-peptide.

In individuals with long-duration type 1 diabetes, the ability to secrete proinsulin persists, even in those with undetectable serum C-peptide.

Adipose tissue insulin resistance is one of the pathophysiological components of type 2 diabetes. Herein we investigated: 1) adipose insulin resistance index (Adipose-IR) (calculated as fasting insulin x free fatty acids [FFAs]) in youth across the spectrum of adiposity from normal weight to obese and the spectrum from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) to type 2 diabetes, 2) the relationship of Adipose-IR with physical and metabolic characteristics, and 3) the predictive power of Adipose-IR for determining dysglycemia in youth.

A total of 205 youth had fasting glucose, insulin, FFA, Adipose-IR, body composition, visceral adipose tissue (VAT), leptin, and adiponectin evaluated.

Adipose-IR was 2.2-fold higher in obese NGT, 4.3-fold higher in IGT, and 4.6-fold higher in type 2 diabetes compared with that in normal-weight peers (all P < 0.05). Females with dysglycemia (IGT and type 2 diabetes) had higher Adipose-IR than their male counterparts (P < 0.001). Adipose-IR correlated positively with total body and visceral adiposity, fasting glucose, HOMA-IR, and leptin and negatively with adiponectin. Receiver operating characteristic curve analysis yielded an optimal cutoff for Adipose-IR of 9.3 μU/mL x mmol/L for determining dysglycemia with 80% predictive power.

Adipose-IR is a simple surrogate estimate that reflects pathophysiological alterations in adipose tissue insulin sensitivity in youth, with progressive deterioration from normal weight to obese and from NGT to IGT to type 2 diabetes. Adipose-IR can be applied in large-scale epidemiological/observational studies of the natural history of youth-onset type 2 diabetes and its progression or reversal with intervention strategies.

The importance of renin-angiotensin-aldosterone system (RAAS) activation in retinopathy for long-standing diabetes is not well understood. We determined retinopathy stage and evaluated associations with other vascular complications before and after physiological RAAS activation in adults with long-standing (≥50 years duration) type 1 diabetes.

Participants underwent retinal examination by digital funduscopic photography and optical coherence tomography and were classified as having nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or no diabetic retinopathy (NDR) with or without diabetic macular edema (DME). Neuropathy was measured by clinical neuropathy examination scores, electrophysiologically, and by corneal confocal microscopy. Renal function was measured by inulin and para-aminohippurate clearance methods. Arterial stiffness was measured by applanation tonometry. Renal function, blood pressure, and arterial stiffness were measured before and after RAAS activation with angiotensin II (ANGII). Associations were determined using linear regression.

Twelve (16%) of the 75 participants had NDR, 24 (32%) had NPDR, and 39 (52%) had PDR. A low overall prevalence of DME (4%) was observed. Those with PDR had worse nerve function and reduced corneal nerve density, were more likely to have macrovascular disease, and had increased arterial stiffness in response to ANGII compared with those with NPDR or NDR. Prevalence of kidney disease or renal hemodynamic function did not differ by retinopathy status.

PDR was associated with neuropathy severity and cardiovascular and peripheral vascular disease. In those with PDR, RAAS activation may be linked to vascular stiffening, an effect that persists in long-standing type 1 diabetes.

Pancreas size is reduced in patients at type 1 diabetes onset and in autoantibody (AAB)-positive donors without diabetes. We sought to determine whether pancreas volume (PV) imaging could improve understanding of the loss of pancreas size in first-degree relatives (FDRs) of patients with type 1 diabetes. We also examined relationships among PV, AAB status, and endocrine and exocrine functions.

We conducted a cross-sectional study that included five groups: AAB^– control subjects (no diabetes and no first- or second-degree relatives with type 1 diabetes) (N = 49), AAB^– FDRs (N = 61), AAB⁺ FDRs (N = 67 total: n = 31 with a single positive AAB [AAB⁺ single] and n = 36 with multiple positive AABs [AAB⁺ multiple]), and patients with recent-onset type 1 diabetes (<1 year) (N = 52). Fasting subjects underwent 1.5T pancreatic MRI, and PV and relative PV (RPV) (PV-to-BMI ratio) were analyzed between groups and for correlations with HbA_1c, C-peptide, glucose, and trypsinogen.

All FDR groups had significantly lower RPV adjusted for BMI (RPV_BMI) than control subjects (all P < 0.05). Patients with type 1 diabetes had lower RPV_BMI than AAB^– FDR (P < 0.0001) and AAB⁺ multiple (P ≤ 0.013) subjects. Transformed data indicated that trypsinogen levels were lowest in patients with type 1 diabetes.

This study demonstrates, for the first time, all FDRs having significantly smaller RPV_BMI compared with AAB^– control subjects. Furthermore, RPV_BMI was significantly lower in patients with recent-onset type 1 diabetes than in the AAB^– FDR and AAB⁺ multiple groups. As such, RPV_BMI may be a novel noninvasive biomarker for predicting progression through stages of type 1 diabetes risk. This study highlights the potential paracrine relationships between the exocrine and endocrine pancreas in progression to type 1 diabetes in subjects at risk.

To compare the incidence of intraocular lens (IOL) implantation for cataracts between people with and without type 2 diabetes and to determine associated risk factors in those with type 2 diabetes.

Participants with type 2 diabetes (n = 1,499) from the community-based observational Fremantle Diabetes Study Phase II (FDS2) were age, sex, and zip code matched 1:4 with residents without diabetes. IOL implantation status was ascertained between entry (2008–2011) and the end of 2016 using validated data linkage. Age-specific incidence rates and incidence rate ratios (IRRs) for cataract surgery were calculated. Predictors of IOL implantation in FDS2 participants were assessed using proportional hazards and competing risk regression modeling.

The crude IRR (95% CI) for cataract surgery in FDS2 participants (mean ± SD age 62.8 ± 10.8 years at entry) versus the matched group without diabetes was 1.50 (1.32–1.71), with the highest relative risk in those aged 45–54 years at the time of surgery (7.12 [2.05–27.66]). Competing risk analysis showed that age at entry, diabetes duration, serum HDL cholesterol, serum triglycerides, a severe hypoglycemic episode in the past year, and Asian and southern European ethnicity increased the risk of cataract surgery in participants with type 2 diabetes (P ≤ 0.025).

People with type 2 diabetes, especially those in younger age-groups, are at a significantly increased risk of cataract surgery than matched people without diabetes. Multifaceted prevention strategies should be incorporated as part of routine care. As well as limiting ultraviolet light exposure, these might include lipid-modifying treatment and strategies to avoid severe hypoglycemia.

Novel biomarkers are needed to better predict coronary artery calcification (CAC), a marker of subclinical atherosclerosis, and diabetic kidney disease (DKD) in type 1 diabetes. We evaluated the associations between serum uromodulin (SUMOD [a biomarker associated with anti-inflammatory and renal protective properties]), CAC progression, and DKD development over 12 years.

Participants (n = 527, 53% females) in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study were examined during 2002–2004, at a mean age of 39.6 ± 9.0 years and a median duration of diabetes of 24.8 years. Urine albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) determined by the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation were measured at baseline and after a mean follow-up period of 12.1 ± 1.5 years. Elevated albumin excretion was defined as ACR ≥30 mg/g, rapid GFR decline (>3 mL/min/1.73 m²/year), and impaired GFR as eGFR <60 mL/min/1.73 m². SUMOD was measured on stored baseline plasma samples (Meso Scale Discovery). CAC was measured using electron beam computed tomography. CAC progression was defined as a change in the square root–transformed CAC volume of ≥2.5.

Higher baseline SUMOD level conferred lower odds of CAC progression (odds ratio 0.68; 95% CI 0.48–0.97), incident elevated albumin excretion (0.37; 0.16–0.86), rapid GFR decline (0.56; 0.35–0.91), and impaired GFR (0.44; 0.24–0.83) per 1 SD increase in SUMOD (68.44 ng/mL) after adjustment for baseline age, sex, systolic blood pressure, LDL cholesterol, and albuminuria/GFR. The addition of SUMOD to models with traditional risk factors also significantly improved the prediction performance for CAC progression and incident DKD.

Higher baseline SUMOD level predicted lower odds of both CAC progression and incident DKD over 12 years in adults with type 1 diabetes.

Diabetes prevalence and incidence increase among individuals with hypothyroidism but also among those with hyperthyroxinemia, which seems contradictory. Both high free thyroxine (fT4) and high thyroid-stimulating hormone (TSH) are present in the resistance to thyroid hormone syndrome. A mild acquired resistance to thyroid hormone might occur in the general population and be associated with diabetes. We aimed to analyze the association of resistance to thyroid hormone indices (the Thyroid Feedback Quantile-based Index [TFQI], proposed in this work, and the previously used Thyrotroph T4 Resistance Index and TSH Index) with diabetes.

We calculated the aforementioned resistance to thyroid hormone indices based on a U.S. representative sample of 5,129 individuals ≥20 years of age participating in the 2007–2008 National Health and Nutrition Examination Survey (NHANES). Also, to approximate TFQI, a U.S.-referenced Parametric TFQI (PTFQI) can be calculated with the spreadsheet formula =NORM.DIST(fT4_cell_in_pmol_per_L,10.075,2.155,TRUE)+NORM.DIST(LN(TSH_cell_in_mIU_per_L),0.4654,0.7744,TRUE)–1. Outcomes of interest were glycohemoglobin ≥6.5%, diabetes medication, diabetes-related deaths (diabetes as contributing cause of death), and additionally, in a fasting subsample, diabetes and metabolic syndrome. Logistic and Poisson regressions were adjusted for sex, age, and race/ethnicity.

Odd ratios for the fourth versus the first quartile of TFQI were 1.73 (95% CI 1.32, 2.27) (P_trend = 0.002) for positive glycohemoglobin and 1.66 (95% CI 1.31, 2.10) (P_trend = 0.001) for medication. Diabetes-related death rate ratio for TFQI being above versus below the median was 4.81 (95% CI 1.01, 22.94) (P_trend = 0.015). Further adjustment for BMI and restriction to normothyroid individuals yielded similar results. Per 1 SD in TFQI, odds increased 1.13 (95% CI 1.02, 1.25) for diabetes and 1.16 (95% CI 1.02, 1.31) for metabolic syndrome. The other resistance to thyroid hormone indices showed similar associations for diabetes-related deaths and metabolic syndrome.

Higher values in resistance to thyroid hormone indices are associated with obesity, metabolic syndrome, diabetes, and diabetes-related mortality. Resistance to thyroid hormone may reflect energy balance problems driving type 2 diabetes. These indices may facilitate monitoring treatments focused on energy balance.

Hepatic insulin clearance is a significant regulator of glucose homestasis. We hypothesized that the improvement in insulin clearance rates (ICRs) under fasting conditions and in response to oral and intravenous (IV) glucose would improve similarly after Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB) as a function of weight loss; the difference in ICR after oral and IV glucose stimulation will be enhanced after RYGB compared with AGB, an effect mediated by glucagon-like peptide 1 (GLP-1).

In study 1, the ICR was calculated under fasting condition (F-ICR), after oral glucose (O-ICR), and after an isoglycemic IV glucose clamp (IV-ICR) in individuals from an established cohort with type 2 diabetes mellitus (T2DM) before, after 10% matched weight loss, and 1 year after either RYGB (n = 22) or AGB (n = 12). In study 2, O-ICR was studied in a separate cohort of individuals with T2DM (n = 22), before and 3 months after RYGB, with and without exendin(9-39) infusion.

In study 1, age, BMI, T2DM duration and control, and ICR did not differ between RYGB and AGB preintervention. Weight loss at 1 year was two times greater after RYGB than after AGB (31.6 ± 5.9% vs. 16.6 ± 9.8%; P < 0.05). RYGB and AGB both significantly increased F-ICR, O-ICR, and IV-ICR at 1 year. ICR was inversely associated with insulinemia. The difference between IV-ICR and O-ICR was significantly greater after RYGB versus AGB. GLP-1 antagonism with exendin(9-39) led to an increase in O-ICR in subjects post-RYGB.

Weight loss increased ICR, an effect more pronounced after RYGB compared with AGB. Our data support a potential role for endogenous GLP-1 in the control of postprandial ICR after RYGB.

The sodium–glucose cotransporter 2 inhibitors (SGLT2i) empagliflozin and canagliflozin reduce the incidence of major adverse cardiovascular events (MACE), all-cause mortality (ACM), and renal events in cardiovascular outcomes trials, with observational real-world evidence suggesting class effect benefits that include dapagliflozin. We examined the placebo arm of the Exenatide Study of Cardiovascular Event Lowering (EXSCEL) to determine whether the effects of drop-in open-label dapagliflozin on MACE, ACM, and estimated glomerular filtration rate (eGFR) were consistent with the SGLT2i class as a whole.

SGLT2i drop-in therapy occurred in 10.6% of EXSCEL participants, with 5.2% taking dapagliflozin. Propensity-matched cohorts of SGLT2i users and nonusers (n = 709 per group) were generated on the basis of their characteristics before open-label SGLT2i drop-in or at baseline for participants taking SGLT2i at enrollment and an equivalent study visit for non-SGLT2i users. Time to first adjudicated MACE and ACM was analyzed using Cox regression. eGFR slopes were compared between matched cohorts using a mixed-model repeated-measures analysis.

In adjusted analyses, SGLT2i users (compared with nonusers) had a numerically lower risk of MACE (adjusted hazard ratio 0.79 [95% CI 0.49–1.28]), as did dapagliflozin users (0.55 [0.26–1.15]). SGLT2i users had a significantly lower ACM risk (0.51 [0.27–0.95]; dapagliflozin: 0.66 [0.25–1.72]). Compared with nonusers, eGFR slope was significantly better for SGLT2i users overall (+1.78 [95% CI 0.87–2.69] mL/min/1.73 m² per year) and for dapagliflozin users (+2.28 [1.01–3.54] mL/min/1.73 m² per year).

This post hoc analysis of the placebo arm of EXSCEL supports a beneficial class effect for all SGLT2i, including dapagliflozin, for reduced ACM and less eGFR decline.

To assess the prevalence of cerebral small-vessel disease (SVD) in subjects with type 1 diabetes compared with healthy control subjects and to characterize the diabetes-related factors associated with SVD.

This substudy was cross-sectional in design and included 191 participants with type 1 diabetes and median age 40.0 years (interquartile range 33.0–45.1) and 30 healthy age- and sex-matched control subjects. All participants underwent clinical investigation and brain MRIs, assessed for cerebral SVD.

Cerebral SVD was more common in participants with type 1 diabetes than in healthy control subjects: any marker 35% vs. 10% (P = 0.005), cerebral microbleeds (CMBs) 24% vs. 3.3% (P = 0.008), white matter hyperintensities 17% vs. 6.7% (P = 0.182), and lacunes 2.1% vs. 0% (P = 1.000). Presence of CMBs was independently associated with systolic blood pressure (odds ratio 1.03 [95% CI 1.00–1.05], P = 0.035).

Cerebral SVD, CMBs in particular, is more common in young people with type 1 diabetes compared with healthy control subjects.

Metabolic surgery can cause amelioration, resolution, and possible cure of type 2 diabetes. Bariatric surgery is metabolic surgery. In the future, there will be metabolic surgery operations to treat type 2 diabetes that are not focused on weight loss. These procedures will rely on neurohormonal modulation related to the gut as well as outside the peritoneal cavity. Metabolic procedures are and will always be in flux as surgeons seek the safest and most effective operative modality; there is no enduring gold standard operation. Metabolic bariatric surgery for type 2 diabetes is more than part of the clinical armamentarium, it is an invitation to perform basic research and to achieve fundamental scientific knowledge.