AIMS:Exercise improves glycaemic control, yet some individuals show limited benefit, termed exercise resistance. We investigated tissue-specific adaptations to chronic exercise in a polygenic model of obesity-driven type 2 diabetes (T2D). MATERIALS AND METHODS:Male New Zealand Obese (NZO) mice were fed a high-fat diet and underwent 6 weeks of interval treadmill training. Physical capacity, body composition, glucose metabolism, skeletal muscle and liver glycogen and triglycerides, mitochondrial function, transcriptomics and systemic metabolites were assessed. RESULTS:The training regime had a positive impact on several physiological parameters, including increased physical capacity (18%, p < 0.01), skeletal muscle AMPK phosphorylation (25%, p < 0.05), complex I-linked respiration (67%, p < 0.05) and transcriptomic enrichment of muscle contraction pathways in trained versus sedentary NZO mice. However, body weight, fat mass, fasting glycaemia, insulin-stimulated glucose uptake, AKT phosphorylation and GLUT4 abundance remained unaltered. Plasma branched-chain amino acids (BCAAs) and ketone bodies (3.3-fold higher in trained, p < 0.05) increased, hepatic triglycerides rose (25%, p < 0.001) with hepatic glycogen depletion (37%, p < 0.05) and caloric intake was slightly higher. CONCLUSIONS:Interval training induced muscle-specific remodelling and enhanced physical capacity without improving systemic insulin sensitivity. Persistent adiposity, exacerbated hepatic steatosis and elevated circulating BCAAs may contribute to limited glycaemic improvement, with altered energy balance as a possible confounder. Consequently, the NZO model offers translational insight into tissue-uncoupled exercise resistance observed in human polygenic obesity and T2D heterogeneity.

Introduction and Objective: Genetic risk scores for type 1 diabetes (T1D), such as T1D-GRS2, are used for risk stratification, but it remains unclear if they also predict β-cell function (βCF) at disease onset. This study investigated using gold-standard measures, whether T1D-GRS2 is associated with reduced βCF, diabetes symptoms and ketonuria at diagnosis and longitudinally with a faster decline of βCF. Methods: We performed a cohort analysis within the German Diabetes Study (GDS) including 360 genotyped adults with recent-onset T1D (<1 year of diagnosis, age 36.9±12.0; 41% female; BMI 25.0±4 kg/m2). βCF was assessed from the C-peptide area under the curve (0-60 min) during intravenous glucose tolerance test and insulin sensitivity (M-value) from hyperinsulinemic-euglycemic clamp test. In a subset of N=149, repeated measurements were performed after a mean of 4.6 years. Analyses were conducted with linear and logistic regression models. Results: Male sex and higher BMI were associated with lower T1D-GRS2 at diagnosis independent of age (βmales=-0.21±0.10; p=0.04 and βBMI=-0.03±0.01; p=0.01). Higher T1D-GRS2 was associated with lower βCF at diagnosis, independent of sex, age, BMI and M-value. BMI showed a strong interaction with T1D-GRS (p<0.001). When stratifying BMI into tertiles (low-BMI: 16-22.6, mid-BMI: 22.6-25.9, high-BMI: 26-42.9 kg/m2), T1D-GRS2 was inversely associated with βCF only in the high-BMI group (β =−0.46, SE = 0.10, 95% CI −0.67 to −0.26, p = 1.93×10−5). Among ketonuria, fatigue and nausea, T1D-GRS was associated with higher probability of ketonuria, but not after adjustment for sex, age and BMI. In the longitudinal analysis, T1D-GRS was not associated with changes of βCF (5.6 × 10-6, p=0.54). Conclusion: Within the first year after diagnosis, an association of genetic T1D risk with lower βCF is present only in overweight or obese adults, independent of age and sex. However, genetic T1D risk does not seem to predict the subsequent decline of βCF. Disclosure I. Yurchenko: None. C. Binsch: None. K. Prystupa: None. L. Szczerbinski: Research Support; Current; Novo Nordisk. Consultant; Current; Eli Lilly and Company. A. Kretowski: None. K.B. Bódis: Other - travel support; Ended; Sanofi. Other - lecture honoraria; Ended; Pfizer Inc. D.M. Mendez Cardenas: None. S. Trenkamp: None. B. Knebel: None. H. Al-Hasani: None. M. Roden: Advisory Panel; Current; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly, Madrigal Pharmaceuticals, Inc., Novo Nordisk, Sanofi, Echosens. R. Wagner: Advisory Panel; Current; Sanofi. Speaker's Bureau; Ended; Daiichi Sankyo, Novo Nordisk.

BACKGROUND & AIMS:Type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD) frequently coexist and increase cardiovascular risk. Although habitual omega-3 (ω3) polyunsaturated fatty acids (PUFAs) may improve cardiovascular risk, their metabolic effects in type 2 diabetes and MASLD remain unclear. We hypothesized that ω3-PUFA intake reduces hepatocellular lipid content (HCL) in individuals carrying single-nucleotide polymorphisms (SNPs) of the fatty acid desaturase (FADS) 1 and FADS2 genes, which associate with higher desaturase activity. METHODS:We cross-sectionally analyzed 154 participants with recent-onset type 2 diabetes from the German Diabetes Study (GDS). HCL was measured using 1H-magnetic resonance spectroscopy and ω3-PUFA intake was assessed using semiquantitative food-frequency questionnaires. The cohort was divided into lower- and higher-ω3-PUFA groups according to median ω3-PUFA intake. Nine SNPs in FADS1 and FADS2 were genotyped using real-time PCR-based allelic discrimination. RESULTS:The higher-ω3-PUFA group featured lower HCL (6.9 ± 7.1% vs. 10.5 ± 9.1%, p= 0.01) and lower MASLD prevalence (49% vs. 65%, p= 0.05) than the lower-ω3-PUFA group. Adjusted multivariable regression analyses identified negative associations of ω3-PUFA intake with adipose-tissue insulin resistance, glycemia and cholesterol. The rs174546 SNP in FADS1 interacted with ω3-PUFA intake on HCL (p= 0.05). Among T allele carriers of rs174546, higher ω3-PUFA intake was associated with lower HCL (β = -2.60, p= 0.03). CONCLUSIONS:Adequate habitual ω3-PUFA intake may reduce HCL in recent-onset type 2 diabetes, but - contrasting our hypothesis - in those carrying the T allele of rs174546, which is linked to lower desaturase activity. This highlights the impact of gene-lifestyle interaction for managing MASLD in type 2 diabetes.

INTRODUCTION:Shunting of glycolytic intermediates into the pentose phosphate pathway via transketolase activation by benfotiamine has been suggested to protect from hyperglycemia-induced microvascular damage, but the long-term effects of benfotiamine on diabetic sensorimotor polyneuropathy (DSPN) remain unclear. RESEARCH DESIGN AND METHODS:This 1:1 randomized double-blind, placebo-controlled parallel group monocentric phase II trial compared the efficacy and safety of 1-year treatment with benfotiamine 300 mg two times per day versus placebo over 12 months in participants with type 2 diabetes and mild-to-moderate symptomatic DSPN. The primary endpoint was the change in corneal nerve fiber length (CNFL) assessed by corneal confocal microscopy (CCM) from baseline to 12 months. Secondary endpoints included three other CCM parameters, skin biopsy (four parameters), nerve conduction studies (13 measures), quantitative sensory testing (six parameters), cardiovascular autonomic function tests (17 indices), sudomotor function tests (five parameters), 15 clinical scores and scales for neuropathic symptoms and signs and 13 health-related quality of life and depression instruments. Pharmacokinetics included measurement of six thiamine analytes in blood. RESULTS:A total of 57 participants underwent randomization. The changes from baseline to 12 months in CNFL did not differ between the two groups. The corresponding changes in the secondary morphometric, functional and clinical neuropathic outcomes as well as quality of life were also similar in the two groups. Only the Neuropathy Symptom Score tended to improve after benfotiamine treatment (p=0.098 vs placebo). Benfotiamine treatment increased the concentrations of all six thiamine analytes studied (p≤0.003 vs placebo). Safety analysis showed no relevant differences between the groups in the rates of adverse events. CONCLUSIONS:In type 2 diabetes individuals with mild-to-moderate symptomatic DSPN, treatment with benfotiamine for 12 months was well tolerated, but had no significant effects on multiple morphometric, neurophysiological and clinical measures of neuropathy. TRIAL REGISTRATION NUMBER:European Clinical Trials Database (EudraCT) 2017-003054-16 registered on April 10 (https://eudract.ema.europa.eu/), 2018 and German Register for Clinical Trials DRKS00014832 registered on August 3, 2018 (https://drks.de/search/de).

Metabolic dysfunction-associated steatohepatitis (MASH) represents a progressive form of steatotic liver disease which increases the risk for fibrosis and advanced liver disease. The accumulation of discrete species of bioactive lipids has been postulated to activate signaling pathways that promote inflammation and fibrosis. However, the key pathogenic lipid species is a matter of debate. We explored candidates using various dietary, molecular, and genetic models. Mice fed a choline-deficient L-amino acid-defined high-fat diet (CDAHFD) developed steatohepatitis and manifested early markers of liver fibrosis associated with increased cholesterol content in liver lipid droplets within 5 d without any changes in total liver cholesterol content. Treating mice with antisense oligonucleotides against Coenzyme A synthase (Coasy) or treatment with bempedoic acid or atorvastatin decreased liver lipid droplet cholesterol content and prevented CDAHFD-induced MASH and the fibrotic response. All these salutary effects were abrogated with dietary cholesterol supplementation. Analysis of human liver samples demonstrated that cholesterol in liver lipid droplets was increased in humans with MASH and liver fibrosis and was higher in PNPLA3 I148M (variants rs738409) than in HSD17B13 variants (rs72613567). Together, these data identify cholesterol in liver lipid droplets as a critical mediator of MASH and demonstrate that Coenzyme A synthase knockdown and bempedoic acid are therapeutic approaches to reduce liver lipid droplet cholesterol content and thereby prevent the development of MASH and liver fibrosis.

BACKGROUND&AIMS:Lifestyle-induced weight reduction remains crucial for managing type 2 diabetes and steatotic liver disease, but its effectiveness varies. We postulated that the G allele in the rs738409 single nucleotide polymorphism within patatin-like phospholipase domain-containing protein 3 (PNPLA3), which associates with metabolic dysfunction-associated steatotic liver disease, also modulates diet-related metabolic effects. METHODS:Participants with type 2 diabetes were randomized to 8-week hypocaloric diets (energy intake: -1,256 kJ/d of, <30 kcal% fat): high in cereal fiber and coffee excluding red meat (HF-RM + C; n = 16), or low in cereal fiber, devoid of coffee, but high in red meat (LF + RM-C; n = 15). Whole-body insulin sensitivity (M value) was assessed using [2H]glucose and hyperinsulinemic-normoglycemic clamps, hepatic lipid content (HCL) and body fat volumes by magnetic resonance spectroscopy/imaging before and after intervention. RESULTS:Despite comparable weight loss, HCL decreased more in non-carriers (-65 %) than in G-allele carriers (-36 %) upon HF-RM + C diet (both p < 0.05 vs baseline and between groups), but only among non-carriers (-46 %, p < 0.05 vs baseline) upon LF + RM-C. Upon HF-RM + C diet, increase in insulin sensitivity was not different between carriers (+27 % p = 0.051 from baseline) and non-carriers (+21 %, p = 0.032 from baseline), p > 0.05 for between-group comparison. Upon LF + RM-C diet, both groups equally improved their whole-body insulin sensitivity (+42 % for non-carriers and +37 % for carriers, p < 0.05 vs baseline). Upon HF-RM + C diet, non-carriers decreased circulating interleukin-18 from baseline by -31 %, whereas, upon LF + RM-C diet, non-carriers decreased circulating anti-inflammatory interleukin-1 receptor antagonist levels by 14 % (both p < 0.05 vs baseline). CONCLUSIONS:Humans with the PNPLA3 G-allele show modified dietary-induced effects on steatotic liver disease in type 2 diabetes despite body weight reduction. Registration at Clinicaltrials.gov, Identifier number: NCT01409330.

OBJECTIVE:The severe insulin-resistant diabetes (SIRD) endotype is associated with metabolic dysfunction-associated steatotic liver disease and higher cardiovascular risk. We investigated whether skeletal muscle or adipose tissue lipids are elevated in SIRD. RESEARCH DESIGN AND METHODS:Participants (N = 420) of the German Diabetes Study (GDS) were assigned to diabetes clusters using a validated algorithm. 1H-magnetic resonance methods were used to quantify intramyocellular lipids (IMCLs), intrahepatic lipids (IHLs), and visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volumes. RESULTS:Aside from elevated IHLs (P < 0.01), SIRD showed higher VAT and SAT than other endotypes after adjustment for BMI (all P < 0.05) but not for multiple comparisons. All endotypes featured comparable IMCLs. VAT volume and IHLs correlated with cardiovascular risk scores (Framingham r = 0.661 and 0.548, respectively, P < 0.05). Polygenic risk scores for VAT were associated with higher cardiovascular risk. CONCLUSIONS:SIRD features higher IHLs and nominally higher VAT volume, which likely contribute to increased cardiovascular risk, highlighting implications for tailored prevention and treatment.

Aims: We examined the association of the G allele in the single-nucleotide polymorphism (SNP) rs738409 in the third exon of patatin-like phospholipase domain-containing 3 gene ( PNPLA3) gene, with chronic kidney disease in diabetes endotypes. Methods: Participants with recent-onset diabetes (n = 707) from the prospective German Diabetes Study (GDS) underwent cluster assignment, detailed phenotyping, genotyping and magnetic resonance spectroscopy to quantify hepatocellular lipid content (HCL). Results: Severe insulin-resistant diabetes (SIRD) had the lowest glomerular filtration rates (eGFR) and highest HCL compared to severe insulin-deficient, moderate obesity-related, moderate age-related and severe autoimmune diabetes endotypes (all p G 0.05). HCL was negatively associated with eGFR (r =-0.287, p G 0.01) across all groups. Stratification by G-allele carrier status did not reveal any association between HCL and eGFR among the endotypes. However, the proportion of G-allele carriers increased from 44 % for eGFR >60 ml/min to 52 % for eGFR G60 ml/min (p G 0.05). Conclusions: The PNPLA3 polymorphism may contribute to declining kidney function independently of liver lipids.

Fragestellung: Eine häufige (~25%) Spleißvariante im Hydroxysteroiddehydrogenase 17-beta 13 Gen (HSD17B13) verringert das Risiko einer Leberfibrose und -zirrhose, auch bei Metabolischer-Dysfunktion-assoziierten steatotischen Leberkrankheiten (MASLD). Der dafür verantwortliche Mechanismus ist noch weitgehend unklar.

Chronic stress episodes increase metabolic disease risk even after recovery. We propose that persistent stress detrimentally impacts hepatic metabolic reprogramming, particularly mitochondrial function. In male C57BL/6 mice chronic variable stress (Cvs) reduced energy expenditure (EE) and body mass despite increased energy intake versus controls. This coincided with decreased glucose metabolism and increased lipid β-oxidation, correlating with EE. After Cvs, mitochondrial function revealed increased thermodynamic efficiency (ƞ-opt) of complex CI, positively correlating with blood glucose and NEFA and inversely with EE. After Cvs recovery, the metabolic flexibility of hepatocytes was lost. Reduced CI-driving NAD+/NADH ratio, and diminished methylation-related one-carbon cycle components hinted at epigenetic regulation. Although initial DNA methylation differences were minimal after Cvs, they diverged during the recovery phase. Here, the altered enrichment of mitochondrial DNA methylation and linked transcriptional networks were observed. In conclusion, Cvs rapidly initiates the reprogramming of hepatic energy metabolism, supported by lasting epigenetic modifications.

Fragestellung: Eine fettreiche Ernährung beeinflusst die Zusammensetzung des Mikrobioms mit massiven Auswirkungen auf das Plasma-Metabolom. In Folge führt dies zur metabolischen Dysfunktion-assoziierten steatotischen Lebererkrankung (MASLD). Inwieweit die mitochondriale Dynamik sowie Funktion durch die HFD-induzierte Präsenz von metabolisch- oder signalaktiven Metaboliten reguliert wird, ist noch unklar.

Introduction & Objective: Weight loss is pivotal for, but variably effective in type 2 diabetes (T2D) and comorbidities. The G-allele in the rs738409 single nucleotide polymorphism within the patatin-like phospholipase domain-containing protein 3 (PNPLA3) associates with liver steatosis and differently with insulin resistance. We hypothesized that this G-allele may affect response to dietary interventions. Methods: T2D volunteers (age 18-69 years, BMI ≥30 kg/m2, HbA1c <9.0%) were randomly assigned to 8-w hypocaloric diets (1.256 kJ reduction in total daily energy intake), either high in cereal fiber and coffee, but red meat-free (healthy diet [HD]; n=16), or low in fiber, devoid of coffee, but rich in red meat (unhealthy diet [UD]; n=15). Genotyping was performed for the PNPLA3 gene. Insulin sensitivity (M-value) was measured by hyperinsulinemic-euglycemic clamps, hepatic lipid content (HCL) by 1H magnetic resonance spectroscopy before and after the intervention. Results: Baseline HCL was similar between groups (carriers: UD 18.5±8.5%, HD 14.6±8.4%; non-carriers: UD 13.5±4.2%, HD 17.8±7.3%). In the face of comparable body weight reduction (~4.7%), carriers and non-carriers decreased HCL from 0 to 8 weeks of UD (-57% and -46%, p<0.05), with no difference between groups. HD also led to reduction in HCL in non-carriers, but to lesser extent in carriers (-65% vs. -36%, p<0.05 vs baseline and between groups). Changes from baseline in liver fibrosis markers (fibrosis-4 index, AST/platelet ratio index, Forns score) and inflammation (interleukins) did not differ by carrier status. M-value improved in all groups (carriers +27% and non-carriers +21% on HD and carriers on UD +37%, all p<0.05 vs baseline) except for the non-carriers on UD. Conclusion: Low-energy diets improve insulin sensitivity and steatosis in T2D but the presence of the G allele of PNPLA3 reduces the beneficial effects of a healthy (cereal- and coffee-enriched, but red meat-free) diet on liver lipid content. Disclosure K. Pafili: None. O.P. Zaharia: None. K. Strassburger: None. B. Knebel: None. C. Herder: None. M. Huttasch: None. Y. Karusheva: None. S. Kabisch: Other Relationship; Sanofi, Boehringer-Ingelheim, Berlin-Chemie AG. Research Support; J. Rettenmaier & Söhne, Rosenberg, Germany, California Walnut Commission, Almond Board of California, Wilhelm-Doerenkamp-Foundation. Other Relationship; JuZo-Akademie, Lilly Diabetes. A. Strom: Consultant; Wörwag Pharma. J. Szendroedi: None. M. Roden: Advisory Panel; Eli Lilly and Company. Research Support; Boehringer-Ingelheim. Advisory Panel; Novo Nordisk. Research Support; Novo Nordisk. Advisory Panel; TARGET PharmaSolutions, Inc. Speaker's Bureau; AstraZeneca.

Introduction & Objective: A common (~25%) splice variant rs72613567:TA in hydroxysteroid dehydrogenase 17-beta 13 (HSD17B13) was shown to reduce the risk of hepatic fibrosis and cirrhosis. The mechanism underlying the protective function remains unclear. Methods: Carriers (n=647 of 1353) of the splice variant in the cohort of the German Diabetes Study (GDS) were identified by reverse transcription-polymerase chain reaction. Phenotyping comprised hepatic lipid content (HLC) and liver energy metabolism (inorganic phosphate (Pi), γATP by 1H/31P-magnetic resonance spectroscopy), insulin secretion, hepatic and whole-body insulin sensitivity (Botnia clamps with [6,6-²H2]glucose), physical fitness (spiroergometry with lactate assessment), resting energy expenditure during fasting and clamp (indirect calorimetry) including up to 2331 measurements and covering repeated visits over 15 years. Results: Compared to non-carriers, carriers of the hepatoprotective minor allele showed similar hepatic insulin sensitivity and γATP, but higher HLC and Pi, lower alanine aminotransferase (ALT) levels and an attenuated lactate increase after reaching the anaerobic threshold (VO2AT) (pinteraction=2E-11). This genetic modification associates with post-exercise lactate rise and was driven by elevated fasting plasma glucose levels (pinteraction=5E-4). Fasting endogenous glucose production, insulinemia, glycemia, energy expenditure, insulin sensitivity (M-value) and secretion were similar between groups. Only female carriers showed lower physical fitness (VO2 peak and VO2AT). Conclusion: Higher hepatic Pi suggests alterations of hepatic energy metabolism in carriers of the hepatoprotective variant. The blunted increase in lactate post VO2AT, depending on fasting glucose levels, highlights a potential link between the HSD17B13 variant and altered lactate kinetics during anaerobic exercise in diabetes. Disclosure D.M. Mendez Cardenas: None. K. Bódis: None. K. Prystupa: None. I. Yurchenko: None. M. Schön: None. C. Möser: None. O.P. Zaharia: None. D. Pesta: None. M. Heni: Research Support; Boehringer-Ingelheim. Advisory Panel; Amryt Pharma Plc. Speaker's Bureau; Amryt Pharma Plc. Advisory Panel; Boehringer-Ingelheim, Boehringer-Ingelheim. Speaker's Bureau; Lilly Diabetes, Novartis AG, Novo Nordisk, Sanofi. K. Pafili: None. Y. Kupriyanova: None. V. Schrauwen-Hinderling: None. M. Roden: Advisory Panel; Eli Lilly and Company. Research Support; Boehringer-Ingelheim. Advisory Panel; Novo Nordisk. Research Support; Novo Nordisk. Advisory Panel; TARGET PharmaSolutions, Inc. Speaker's Bureau; AstraZeneca. B. Knebel: None. R. Wagner: Speaker's Bureau; Sanofi. Advisory Panel; Lilly Diabetes. Speaker's Bureau; Boehringer-Ingelheim, Novo Nordisk. H. Al-Hasani: None. M. Bombrich: None.

AIMS:We recently reported that genetic variability in the TKT gene encoding transketolase, a key enzyme in the pentose phosphate pathway, is associated with measures of diabetic sensorimotor polyneuropathy (DSPN) in recent-onset diabetes. Here, we aimed to substantiate these findings in a population-based KORA F4 study. MATERIALS AND METHODS:In this cross-sectional study, we assessed seven single nucleotide polymorphisms (SNPs) in the transketolase gene in 952 participants from the KORA F4 study with normal glucose tolerance (NGT; n = 394), prediabetes (n = 411), and type 2 diabetes (n = 147). DSPN was defined by the examination part of the Michigan Neuropathy Screening Instrument (MNSI) using the original MNSI > 2 cut-off and two alternative versions extended by touch/pressure perception (TPP) (MNSI > 3) and by TPP plus cold perception (MNSI > 4). RESULTS:After adjustment for sex, age, BMI, and HbA1c, in type 2 diabetes participants, four out of seven transketolase SNPs were associated with DSPN for all three MNSI versions (all p ≤ 0.004). The odds ratios of these associations increased with extending the MNSI score, for example, OR (95% CI) for SNP rs62255988 with MNSI > 2: 1.99 (1.16-3.41), MNSI > 3: 2.27 (1.26-4.09), and MNSI > 4: 4.78 (2.22-10.26); SNP rs9284890 with MNSI > 2: 2.43 (1.42-4.16), MNSI > 3: 3.46 (1.82-6.59), and MNSI > 4: 4.75 (2.15-10.51). In contrast, no associations were found between transketolase SNPs and the three MNSI versions in the NGT and prediabetes groups. CONCLUSIONS:The link of genetic variation in transketolase enzyme to diabetic polyneuropathy corroborated at the population level strengthens the concept suggesting an important role of pathways metabolising glycolytic intermediates in the evolution of diabetic polyneuropathy.