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Advanced glycation end‐products (AGEs) are implicated in the pathogenesis of vascular disease. In previous studies we have found increased deposition of N(e)‐(carboxymethyl)lysine (CML) in intramyocardial vasculature in the heart in acute myocardial infarction and myocarditis. It is known that the process of inflammation plays a role in the formation of AGEs. In this study we have explored the presence of CML (a major AGE) in the heart of patients with epicarditis using a monoclonal anti‐CML antibody. Nine patients with epicarditis (n = 9) died and their hearts were used for this study, control were hearts from patients who died from conditions unrelated to heart disease and without signs of myocarditis or epicarditis CML deposition and complement were significantly increased in patients with epicarditis compared to control hearts. Thus epicarditis increases CML depositions in the intramyocardial vasculature. [ABSTRACT FROM AUTHOR]

Objective: Adipocyte insulin resistance (IR) is a key feature early in the pathogenesis of type 2 diabetes mellitus (T2DM), and although scarce, data in the literature suggest a direct role for iron and iron metabolism-related factors in adipose tissue function and metabolism. Serum ferritin and transferrin were shown to be associated with muscle insulin resistance (IR) and T2DM, but little is known about the role of iron metabolism on adipose tissue. We therefore investigated whether markers of iron metabolism were associated with adipocyte IR and plasma adiponectin.Research Design and Methods: Serum ferritin, transferrin, total iron, non-transferrin-bound iron (NTBI), transferrin saturation, and plasma adiponectin were determined in 492 individuals. Adipocyte IR was defined by the product of fasting insulin and nonesterified fatty acids (NEFAs). Using linear regression analyses, we investigated the difference in adipocyte IR or adiponectin (in %) according to differences in iron metabolism markers.Results: Serum ferritin (β = 1.00% increase in adipocyte IR per 10 μg/L [95% CI 0.66-1.34]), transferrin (4.18% per 0.1 g/L [2.88-5.50]), total iron (1.36% per μmol/L [0.61-2.12]), and NTBI (5.14% per μmol/L [1.88-8.52]) were associated with adipocyte IR after adjustment for several covariates, including inflammatory markers. All markers of iron metabolism were also associated with NEFAs (all P < 0.01). In addition, ferritin and transferrin were inversely associated with adiponectin (both P < 0.01).Conclusions: The observed associations of several markers of iron metabolism with adipocyte IR and adiponectin suggest that factors related to iron and iron metabolism may contribute to adipocyte IR early in the pathogenesis of T2DM. [ABSTRACT FROM AUTHOR]

Objective: In the general population, a low ankle-brachial index (ABI) (<0.9) is strongly associated with (cardiovascular) mortality. However, the association between the ABI and mortality may be weaker in individuals with diabetes, as ankle pressures may be elevated by medial arterial calcification and arterial stiffening, which occur more frequently in diabetes. Therefore, the aim of this study was to compare the association between ABI and mortality in individuals without and with diabetes.Research Design and Methods: We studied the associations between ABI and cardiovascular and all-cause mortality in 624 individuals from the Hoorn study, a population-based cohort of 50- to 75-year-old individuals (155 with diabetes and 469 without) followed for a median period of 17.2 years. Data were analyzed using Cox proportional hazards models.Results: During the follow-up period, 289 of 624 (46.3%) participants died (97 of 155 with and 192 of 469 without diabetes and 52 of 65 with and 237 of 559 without ABI <0.9): 85 (29.4%) of CVD (30 of 155 with and 55 of 469 without diabetes and 20 of 65 with and 65 of 559 without ABI <0.9). A low ABI was strongly associated with cardiovascular mortality (relative risk 2.57 [95% CI 1.50-4.40]) and all-cause mortality (2.02 [1.47-2.76]), after adjustment for Framingham risk factors. The associations of the ABI with mortality did not differ between individuals without and with diabetes for cardiovascular (P(interaction) = 0.45) or all-cause (P(interaction) = 0.63) mortality.Conclusions: In the Hoorn Study, associations between ABI and cardiovascular and all-cause mortality were similar in individuals without and with diabetes. Future studies should investigate, in both individuals without and with diabetes, whether measurement of ABI can be used to guide treatment decisions. [ABSTRACT FROM AUTHOR]

Objective: To investigate the associations of plasma levels of advanced glycation end products (AGEs) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunction, low-grade inflammation, and arterial stiffness.Research Design and Methods: We prospectively followed 169 individuals with diabetic nephropathy and 170 individuals with persistent normoalbuminuria who were free of CVD at study entry and in whom levels of N(ε)-(carboxymethyl)lysine, N(ε)-(carboxyethyl)lysine, pentosidine and other biomarkers were measured at baseline. The median follow-up duration was 12.3 (interquartile range 7.6-12.5) years.Results: During the course of follow-up, 82 individuals (24.2%) died; 85 (25.1%) suffered a fatal (n = 48) and/or nonfatal (n = 53) CVD event. The incidence of fatal and nonfatal CVD and of all-cause mortality increased with higher baseline levels of AGEs independently of traditional CVD risk factors: hazard ratio (HR) = 1.30 (95% CI = 1.03-1.66) and HR = 1.27 (1.00-1.62), respectively. These associations were not attenuated after further adjustments for markers of renal or endothelial dysfunction, low-grade inflammation, or arterial stiffness.Conclusions: Higher levels of AGEs are associated with incident fatal and nonfatal CVD as well as all-cause mortality in individuals with type 1 diabetes, independently of other risk factors and of several potential AGEs-related pathophysiological mechanisms. Thus, AGEs may explain, in part, the increased cardiovascular disease and mortality attributable to type 1 diabetes and constitute a specific target for treatment in these patients. [ABSTRACT FROM AUTHOR]

Objective: To investigate the associations of plasma levels of soluble receptor for advanced glycation end products (sRAGE) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunction, low-grade inflammation, arterial stiffness, and advanced glycation end products (AGEs).Research Design and Methods: We prospectively followed 169 individuals with diabetic nephropathy and 170 individuals with persistent normoalbuminuria who were free of CVD at study entry and in whom levels of sRAGE and other biomarkers were measured at baseline. The median follow-up duration was 12.3 years (7.6-12.5).Results: The incidence of fatal and nonfatal CVD and all-cause mortality increased with higher baseline levels of log-transformed sRAGE (Ln-sRAGE) independently of other CVD risk factors: hazard ratio (HR) 1.90 (95% CI 1.13-3.21) and 2.12 (1.26-3.57) per 1-unit increase in Ln-sRAGE, respectively. Adjustments for estimated glomerular filtration rate (eGFR(MDRD)), but not or to a smaller extent for markers of endothelial dysfunction, low-grade inflammation, arterial stiffness, and AGEs, attenuated these associations to HR 1.59 (95% CI 0.91-2.77) for fatal and nonfatal CVD events and to 1.90 (1.09-3.31) for all-cause mortality. In addition, in patients with nephropathy, the rate of decline of GFR was 1.38 ml/min/1.73 m(2) per year greater per 1-unit increase of Ln-sRAGE at baseline (P = 0.036).Conclusions: Higher levels of sRAGE are associated with incident fatal and nonfatal CVD and all-cause mortality in individuals with type 1 diabetes. sRAGE-associated renal dysfunction may partially explain this association. [ABSTRACT FROM AUTHOR]

Objective: Embryos exposed to a diabetic environment in utero have an increased risk to develop congenital heart malformations. The mechanism behind the teratogenicity of diabetes still remains enigmatic. Detrimental effects of glycation products in diabetic patients have been well documented. We therefore studied a possible link between glycation products and the development of congenital cardiovascular malformations. Furthermore, we investigated other possible mechanisms involved in this pathogenesis: alterations in the levels of vascular endothelial growth factor (VEGF) or phosphorylated Smad2 (the latter can be induced by both glycation products and VEGF).Research Design and Methods: We examined the temporal spatial patterning of the glycation products Nepsilon(carboxymethyl)lysine (CML) and methylglyoxal (MG) adducts, VEGF expression, and phosphorylated Smad2 during cardiovascular development in embryos from normal and diabetic rats.Results: Maternal diabetes increased the CML accumulation in the areas susceptible to diabetes-induced congenital heart disease, including the outflow tract of the heart and the aortic arch. No MG adducts could be detected, suggesting that CML is more likely to be indicative for increased oxidative stress than for glycation. An increase of CML in the outflow tract of the heart was accompanied by an increase in phosphorylated Smad2, unrelated to VEGF. VEGF showed a time-specific decrease in the outflow tract of embryos from diabetic dams.Conclusions: From our results, we can conclude that maternal diabetes results in transient and localized alterations in CML, VEGF expression, and Smad2 phosphorylation overlapping with those regions of the developing heart that are most sensitive to diabetes-induced congenital heart disease. [ABSTRACT FROM AUTHOR]

Background: Diastolic dysfunction is a frequent cause of heart failure, particularly in dialysis patients. Advanced glycation end-products (AGEs) are increased in dialysis patients and are suggested to play a role in the development of diastolic dysfunction. The aim of our study was to assess whether AGE accumulation in dialysis patients is related to the presence of diastolic dysfunction.Methods and Results: Data were analyzed from 43 dialysis patients, age 58 +/- 15 years, of whom 65% were male. Diastolic function was assessed using tissue velocity imaging (TVI) on echocardiography. Tissue AGE accumulation was measured using a validated skin-autofluorescence (skin-AF) reader. Plasma N(epsilon)-(carboxymethyl)lysine (CML) and N(epsilon)-(carboxyethyl)lysine (CEL) were measured by stable-isotope-dilution tandem mass spectrometry. Plasma pentosidine was measured by high-performance liquid chromatography. Skin-AF correlated with mean E' (r = -0.51, P < .001), E/A ratio (r = -0.39, P = .014), and E/E' (r = 0.38, P = .019). Plasma AGEs were not significantly associated with diastolic function. Multivariable linear regression analysis revealed that 54% of the variance of average E' was explained by age (P = .007), dialysis type (P = 0.016), and skin-AF (P = .013).Conclusions: Tissue AGEs measured as skin-AF, but not plasma AGE levels, were related to diastolic function in dialysis patients. Although this may support the concept that tissue AGEs explain part of the increased prevalence of diastolic dysfunction in these patients, the ambiguous relation between plasma and tissue AGEs needs further exploring. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We evaluated the association of biomarkers of endothelial dysfunction and inflammation with all-cause mortality and cardiovascular mortality and morbidity and decline in glomerular filtration rate (GFR) in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: We prospectively followed 199 type 1 diabetic patients with diabetic nephropathy and 192 patients with persistent normoalbuminuria. Biomarkers were measured at baseline. RESULTS: We constructed two Z scores: the mean inflammatory Z score combined C-reactive protein, interleukin-6, soluble intercellular adhesion molecule (sICAM-1), and secreted phospholipase A2 and the mean Z score for endothelial dysfunction combined soluble vascular cell adhesion molecule 1, plasminogen activator inhibitor-1, and sICAM-1. The mean Z score of inflammatory biomarkers was associated with mortality and the combined end point in patients with diabetic nephropathy after multivariate adjustment (hazard ratio 1.7 [95% CI 1.1-2.6]; P = 0.025 and 1.5 [1.1-2.2]; P = 0.017). The mean Z score for endothelial dysfunction biomarkers was associated with mortality in a model adjusting for age and sex in patients with diabetic nephropathy (1.6 [1.0-2.3]; P = 0.031). The mean Z score for endothelial dysfunction correlated with decline in GFR (r = -0.243; P = 0.001); the correlation persisted after multivariate adjustment (coefficient -1.38 [95% CI -2.27 to -0.50]; P = 0.002). CONCLUSIONS: Mean Z scores of inflammatory biomarkers are significantly associated with all-cause mortality and cardiovascular morbidity and mortality in patients with nephropathy after multivariate adjustment. These data suggest that the high risk of cardiovascular disease in type 1 diabetes may be explained in part by inflammatory activity. Mean Z score of endothelial dysfunction correlated after multivariate adjustment with the rate of decline in GFR. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The UK Prospective Diabetes Study (UKPDS) showed that treatment with metformin decreases macrovascular morbidity and mortality independent of glycaemic control. We hypothesized that metformin may achieve this by improving endothelial function and chronic, low-grade inflammation. Data on this issue are scarce and we therefore tested, in the setting of a randomized, placebo-controlled trial, whether metformin can affect endothelial function and low-grade inflammation. DESIGN: The Hyperinsulinaemia the Outcome of its Metabolic Effects (HOME) trial is a double-blind trial, in which all patients were randomized to receive either metformin or placebo in addition to insulin therapy. At the beginning and the end of a 16-week treatment period fasting blood samples were drawn and a physical examination was carried out. SETTING: The trial was conducted in the outpatient clinics of three nonacademic hospitals (Hoogeveen, Meppel and Coevorden; the Netherlands). SUBJECTS: Patients were included if they were between 30 and 80 years of age; had received a diagnosis of diabetes after the age of 25; had never had an episode of ketoacidosis; and their blood glucose-lowering treatment previously consisted of oral agents but now only consisted of either insulin (n = 345) or insulin and metformin (n = 45). We excluded pregnant women and women trying to become pregnant, patients with a Cockroft-Gault-estimated creatinine clearance <50 mL min(-1), or low plasma cholinesterase (reference value <3.5 units L(-1)), patients with congestive heart failure (New York Heart Association class III/IV), or patients with other serious medical or psychiatric disease. A total of 745 eligible patients were approached; 390 gave informed consent and were randomized (196 metformin, 194 placebo). About 353 patients completed 16 weeks of treatment (171 metformin, 182 placebo). MAIN OUTCOME MEASURES: The HOME trial was designed to study the metabolic and cardiovascular effects of metformin during a follow-up of 4 years. Presented here are the results of an interim analysis after 16 weeks of treatment. RESULTS: When compared with placebo, metformin treatment was associated with an increase in urinary albumin excretion of 21% (-1 to +48; P = 0.06); a decrease in plasma von Willebrand factor of 6% (-10 to -2; P = 0.0007); a decrease in soluble vascular cell adhesion molecule-1 of 4% (-7 to -2; P = 0.0002); a decrease in soluble E-selectin of 6% (-10 to -2; P = 0.008); a decrease in tissue-type plasminogen activator of 16% (-20 to -12; P < 0.0001); and a decrease in plasminogen activator inhibitor-1 of 20% (-27 to -10; P = 0.0001). These changes could not be explained by metformin-associated changes in glycaemic control, body weight or insulin dose. Markers of inflammation, i.e. C-reactive protein and soluble intercellular adhesion molecule-1, did not change with metformin treatment. CONCLUSIONS: In patients with type 2 diabetes treated with insulin, metformin treatment was associated with improvement of endothelial function, which was largely unrelated to changes in glycaemic control, but not with improvement of chronic, low-grade inflammation. [ABSTRACT FROM AUTHOR]

Diabetes is associated with cognitive impairment, but the underlying mechanism remains unclear. Methylglyoxal (MGO), a precursor to advanced glycation endproducts (AGEs), is elevated in diabetes and linked to microvascular dysfunction. In this study, overexpression of the MGO-detoxifying enzyme glyoxalase 1 (Glo1) was used in a mouse model of diabetes to explore whether MGO accumulation in diabetes causes cognitive impairment. Diabetes was induced with streptozotocin. Fasting blood glucose, cognitive function, cerebral blood flow, neurovascular coupling (NVC), Glo1 activity, MGO and AGEs were assessed. In diabetes, MGO-derived hydroimidazolone-1 increased in the cortex, and was decreased in Glo1-overexpressing mice compared to controls. Visuospatial memory was decreased in diabetes, but not in Glo1/diabetes. NVC response time was slightly increased in diabetes, and normalised in the Glo1-overexpressing group. No impact of diabetes or Glo1 overexpression on blood-brain barrier integrity or vascular density was observed. Diabetes induced a mild visuospatial memory impairment and slightly reduced NVC response speed and these effects were mitigated by Glo1. This study shows a link between MGO-related AGE accumulation and cerebrovascular/cognitive functions in diabetes. Modulation of the MGO-Glo1 pathway may be a novel intervention strategy in patients with diabetes who have cerebrovascular complications. KEY POINTS: Diabetes is associated with an increased risk of stroke, cognitive decline, depression and Alzheimer's disease, but the underlying mechanism remains unclear. Methylglyoxal (MGO), a highly reactive by-product of glycolysis, plays an important role in the development of diabetes-associated microvascular dysfunction in the periphery and is detoxified by the enzyme glyoxalase 1. Diabetes reduced visuospatial memory in mice and slowed the neurovascular coupling response speed, which was improved by overexpression of glyoxalase 1. MGO formation and MGO-derived advanced glycation endproduct (AGE) accumulation in the brain of diabetic mice are associated with a slight reduction in neurovascular coupling and mild cognitive impairment. The endogenous formation of MGO, and the accumulation of MGO-derived AGEs, might be a potential target in reducing the risk of vascular cognitive impairment in people with diabetes., (© 2024 The Author(s). The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

We aimed to examine the effects of isocaloric fructose restriction on adipose tissue distribution and serum adipokines. Individuals with BMI >28 kg/m 2 (n = 44) followed a 6-week fructose-restricted diet and were randomly allocated to (double-blind) oral supplementation with fructose (control) or glucose (intervention) powder three times daily. Visceral (VAT) and subcutaneous (SAT) adipose tissue was quantified with MRI. Serum interleukin 6 and 8, tumour necrosis factor alpha and adiponectin levels were measured with sandwich immunoassay. BMI decreased in both groups, but the change did not differ between groups (-0.1 kg/m 2 , 95%CI: -0.3; 0.5). SAT decreased statistically significantly in the control group (-23.2 cm 3 , 95%CI: -49.4; -4.1), but not in the intervention group. The change in SAT did not differ between groups (29.6 cm 3 , 95%CI: -1.2; 61.8). No significant differences in VAT were observed within or between study arms. The VAT/SAT ratio decreased statistically significantly in the intervention group (-0.02, 95%CI: -0.04; -0.003) and the change was significantly different between groups (-0.03, 95%CI: -0.54; -0.003). Serum adipokine levels were not affected by the intervention. This study shows that a fructose-restricted diet resulted in a favourable change in adipose tissue distribution, but did not affect serum adipokines. Further studies are warranted to clarify the underlying mechanisms how fructose affects adipose tissue distribution., (© 2024 The Author(s). Clinical Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

Diabetes and other age-related diseases are associated with an increased risk of cognitive impairment, but the underlying mechanisms remain poorly understood. Methylglyoxal (MGO), a by-product of glycolysis and a major precursor in the formation of advanced glycation end-products (AGEs), is increased in individuals with diabetes and other age-related diseases and is associated with microvascular dysfunction. We now investigated whether increased levels of circulating MGO can lead to cerebral microvascular dysfunction, blood-brain barrier (BBB) dysfunction, and cognitive impairment. Mice were supplemented or not with 50 mM MGO in drinking water for 13 weeks. Plasma and cortical MGO and MGO-derived AGEs were measured with UPLC-MS/MS. Peripheral and cerebral microvascular integrity and inflammation were investigated. Cerebral blood flow and neurovascular coupling were investigated with laser speckle contrast imaging, and cognitive tests were performed. We found a 2-fold increase in plasma MGO and an increase in MGO-derived AGEs in plasma and cortex. Increased plasma MGO did not lead to cerebral microvascular dysfunction, inflammation, or cognitive decline. This study shows that increased concentrations of plasma MGO are not associated with cerebral microvascular dysfunction and cognitive impairment in healthy mice. Future research should focus on the role of endogenously formed MGO in cognitive impairment., (© 2024. The Author(s).)

Context: Glucose excursions in persons with diabetes may drive chronic inflammation. Methylglyoxal (MGO) is formed from glucose, is elevated in persons with diabetes, and is a potent glycating agent linked with inflammation., Objective: We investigated whether glucose excursions are associated with low-grade inflammation and whether MGO mediates this association., Design: We used data from The Maastricht Study, an extensive phenotyping study into the etiology of type 2 diabetes and its complications., Participants: Data of 3017 participants, who underwent an oral glucose tolerance test and where data on MGO levels and inflammation were available, were used., Main Outcome Measures: Linear regression analyses, adjusted for potential confounders, evaluated associations between fasting plasma glucose (FPG), 2-hours plasma glucose (2h-PG) and HbA1c and low-grade inflammation (stdβ, [95% confidence interval]), calculated from plasma concentrations of C-reactive protein, serum amyloid A, interleukin-6, interleukin-8, tumor necrosis factor and soluble intercellular adhesion molecule-1. Mediation analyses investigated whether MGO mediated these associations., Results: 2h-PG (0.172 [0.110; 0.234]) and HbA1c (0.148 [0.101; 0.196]), but not FPG (0.049 [-0.002; 0.100]), were associated with low-grade inflammation. 2h-PG and HbA1c were also associated with 2h-MGO (0.471 [0.407; 0.534], and 0.244 [0.195; 0.294], respectively). Furthermore, 2h-MGO was independently and positively associated with low-grade inflammation (0.078 [0.037, 0.120]). 2h-MGO mediated 23% of the association between 2h-PG and inflammation, and 16% of the association between HbA1c and inflammation., Conclusions: MGO mediates the association between post-load glucose excursions and HbA1c with inflammation, providing evidence for a role of postprandial MGO formation to hyperglycemia-induced low-grade inflammation., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Objective: Stable isotope studies have shown that hepatic de novo lipogenesis (DNL) plays an important role in the pathogenesis of intrahepatic lipid (IHL) deposition. Furthermore, previous research has demonstrated that fructose 1-phosphate (F1P) not only serves as a substrate for DNL, but also acts as a signalling metabolite that stimulates DNL from glucose. The aim of this study was to elucidate the mediators of F1P-stimulated DNL, with special focus on two key regulators of intrahepatic glucose metabolism, i.e., glucokinase regulatory protein (GKRP) and carbohydrate response element binding protein (ChREBP)., Methods: Aldolase B deficient mice (Aldob -/- ), characterized by hepatocellular F1P accumulation, enhanced DNL, and hepatic steatosis, were either crossed with GKRP deficient mice (Gckr -/- ) or treated with short hairpin RNAs directed against hepatic ChREBP., Results: Aldob -/- mice showed higher rates of de novo palmitate synthesis from glucose when compared to wildtype mice (p < 0.001). Gckr knockout reduced de novo palmitate synthesis in Aldob -/- mice (p = 0.017), without affecting the hepatic mRNA expression of enzymes involved in DNL. In contrast, hepatic ChREBP knockdown normalized the hepatic mRNA expression levels of enzymes involved in DNL and reduced fractional DNL in Aldob -/- mice (p < 0.05). Of interest, despite downregulation of DNL in response to Gckr and ChREBP attenuation, no reduction in intrahepatic triglyceride levels was observed., Conclusions: Both GKRP and ChREBP mediate F1P-stimulated DNL in aldolase B deficient mice. Further studies are needed to unravel the role of GKRP and hepatic ChREBP in regulating IHL accumulation in aldolase B deficiency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Individuals with type 2 diabetes mellitus (T2DM) are at an increased risk for heart failure, yet preventive cardiac care is suboptimal in this population. Pyridoxamine (PM), a vitamin B 6 analog, has been shown to exert protective effects in metabolic and cardiovascular diseases. In this study, we aimed to investigate whether PM limits adverse cardiac remodeling and dysfunction in rats who develop T2DM. Male rats received a standard chow diet or Western diet (WD) for 18 weeks to induce prediabetes. One WD group received additional PM (1 g/L) via drinking water. Glucose tolerance was assessed with a 1 h oral glucose tolerance test. Cardiac function was evaluated using echocardiography and hemodynamic measurements. Histology on left ventricular (LV) tissue was performed. Treatment with PM prevented the increase in fasting plasma glucose levels compared to WD-fed rats ( p < 0.05). LV cardiac dilation tended to be prevented using PM supplementation. In LV tissue, PM limited an increase in interstitial collagen deposition ( p < 0.05) seen in WD-fed rats. PM tended to decrease 3-nitrotyrosine and significantly lowered 4-hydroxynonenal content compared to WD-fed rats. We conclude that PM alleviates interstitial fibrosis and oxidative stress in the hearts of WD-induced prediabetic rats.

Background: Cerebral microvascular dysfunction may contribute to depression via disruption of brain structures involved in mood regulation, but evidence is limited. We investigated the association of retinal microvascular function, a proxy for microvascular function in the brain, with incidence and trajectories of clinically relevant depressive symptoms., Methods: Longitudinal data are from The Maastricht Study of 5952 participants (59.9 ± 8.5 years/49.7% women) without clinically relevant depressive symptoms at baseline (2010-2017). Central retinal arteriolar equivalent and central retinal venular equivalent (CRAE and CRVE) and a composite score of flicker light-induced retinal arteriolar and venular dilation were assessed at baseline. We assessed incidence and trajectories of clinically relevant depressive symptoms (9-item Patient Health Questionnaire score ⩾10). Trajectories included continuously low prevalence (low, n = 5225 [87.8%]); early increasing, then chronic high prevalence (early-chronic, n = 157 [2.6%]); low, then increasing prevalence (late-increasing, n = 247 [4.2%]); and remitting prevalence (remitting, n = 323 [5.4%])., Results: After a median follow-up of 7.0 years (range 1.0-11.0), 806 (13.5%) individuals had incident clinically relevant depressive symptoms. After full adjustment, a larger CRAE and CRVE were each associated with a lower risk of clinically relevant depressive symptoms (hazard ratios [HRs] per standard deviation [s.d.]: 0.89 [95% confidence interval (CI) 0.83-0.96] and 0.93 [0.86-0.99], respectively), while a lower flicker light-induced retinal dilation was associated with a higher risk of clinically relevant depressive symptoms (HR per s.d.: 1.10 [1.01-1.20]). Compared to the low trajectory, a larger CRAE was associated with lower odds of belonging to the early-chronic trajectory (OR: 0.83 [0.69-0.99]) and a lower flicker light-induced retinal dilation was associated with higher odds of belonging to the remitting trajectory (OR: 1.23 [1.07-1.43])., Conclusions: These findings support the hypothesis that cerebral microvascular dysfunction contributes to the development of depressive symptoms.

Background: Preeclampsia is a multifaceted syndrome that includes maternal vascular dysfunction. We hypothesize that increased placental glycolysis and hypoxia in preeclampsia lead to increased levels of methylglyoxal (MGO), consequently causing vascular dysfunction., Methods: Plasma samples and placentas were collected from uncomplicated and preeclampsia pregnancies. Uncomplicated placentas and trophoblast cells (BeWo) were exposed to hypoxia. The reactive dicarbonyl MGO and advanced glycation end products (N ε -(carboxymethyl)lysine [CML], N ε -(carboxyethyl)lysine [CEL], and MGO-derived hydroimidazolone [MG-H]) were quantified using liquid chromatography-tandem mass spectrometry. The activity of GLO1 (glyoxalase-1), that is, the enzyme detoxifying MGO, was measured. The impact of MGO on vascular function was evaluated using wire/pressure myography. The therapeutic potential of the MGO-quencher quercetin and mitochondrial-specific antioxidant mitoquinone mesylate (MitoQ) was explored., Results: MGO, CML, CEL, and MG-H2 levels were elevated in preeclampsia-placentas (+36%, +36%, +25%, and +22%, respectively). Reduced GLO1 activity was observed in preeclampsia-placentas (-12%) and hypoxia-exposed placentas (-16%). Hypoxia-induced MGO accumulation in placentas was mitigated by the MGO-quencher quercetin. Trophoblast cells were identified as the primary source of MGO. Reduced GLO1 activity was also observed in hypoxia-exposed BeWo cells (-26%). Maternal plasma concentrations of CML and the MGO-derived MG-H1 increased as early as 12 weeks of gestation (+16% and +17%, respectively). MGO impaired endothelial barrier function, an effect mitigated by MitoQ, and heightened vascular responsiveness to thromboxane A2., Conclusions: This study reveals the accumulation of placental MGO in preeclampsia and upon exposure to hypoxia, demonstrates how MGO can contribute to vascular impairment, and highlights plasma CML and MG-H1 levels as promising early biomarkers for preeclampsia., Competing Interests: Disclosures None.

Dicarbonyl compounds are highly reactive precursors of advanced glycation end products (AGE), produced endogenously, present in certain foods and formed during food processing. AGE contribute to the development of adverse metabolic outcomes, but health effects of dietary dicarbonyls are largely unexplored. We investigated associations between three dietary dicarbonyl compounds, methylglyoxal (MGO), glyoxal (GO) and 3-deoxyglucosone (3-DG), and body weight changes in European adults. Dicarbonyl intakes were estimated using food composition database from 263 095 European Prospective Investigation into Cancer and Nutrition-Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home in Relation to Anthropometry participants with two body weight assessments (median follow-up time = 5·4 years). Associations between dicarbonyls and 5-year body-weight changes were estimated using mixed linear regression models. Stratified analyses by sex, age and baseline BMI were performed. Risk of becoming overweight/obese was assessed using multivariable-adjusted logistic regression. MGO intake was associated with 5-year body-weight gain of 0·089 kg (per 1-sd increase, 95 % CI 0·072, 0·107). 3-DG was inversely associated with body-weight change (-0·076 kg, -0·094, -0·058). No significant association was observed for GO (0·018 kg, -0·002, 0·037). In stratified analyses, GO was associated with body-weight gain among women and older participants (above median of 52·4 years). MGO was associated with higher body-weight gain among older participants. 3-DG was inversely associated with body-weight gain among younger and normal-weight participants. MGO was associated with a higher risk of becoming overweight/obese, while inverse associations were observed for 3-DG. No associations were observed for GO with overweight/obesity. Dietary dicarbonyls are inconsistently associated with body weight change among European adults. Further research is needed to clarify the role of these food components in overweight and obesity, their underlying mechanisms and potential public health implications.

Aims/hypothesis: Type 2 diabetes is a highly heterogeneous disease for which new subgroups ('clusters') have been proposed based on disease severity: moderate age-related diabetes (MARD), moderate obesity-related diabetes (MOD), severe insulin-deficient diabetes (SIDD) and severe insulin-resistant diabetes (SIRD). It is unknown how disease severity is reflected in terms of quality of life in these clusters. Therefore, we aimed to investigate the cluster characteristics and cluster-wise evolution of quality of life in the previously defined clusters of type 2 diabetes., Methods: We included individuals with type 2 diabetes from the Maastricht Study, who were allocated to clusters based on a nearest centroid approach. We used logistic regression to evaluate the cluster-wise association with diabetes-related complications. We plotted the evolution of HbA 1c levels over time and used Kaplan-Meier curves and Cox regression to evaluate the cluster-wise time to reach adequate glycaemic control. Quality of life based on the Short Form 36 (SF-36) was also plotted over time and adjusted for age and sex using generalised estimating equations. The follow-up time was 7 years. Analyses were performed separately for people with newly diagnosed and already diagnosed type 2 diabetes., Results: We included 127 newly diagnosed and 585 already diagnosed individuals. Already diagnosed people in the SIDD cluster were less likely to reach glycaemic control than people in the other clusters, with an HR compared with MARD of 0.31 (95% CI 0.22, 0.43). There were few differences in the mental component score of the SF-36 in both newly and already diagnosed individuals. In both groups, the MARD cluster had a higher physical component score of the SF-36 than the other clusters, and the MOD cluster scored similarly to the SIDD and SIRD clusters., Conclusions/interpretation: Disease severity suggested by the clusters of type 2 diabetes is not entirely reflected in quality of life. In particular, the MOD cluster does not appear to be moderate in terms of quality of life. Use of the suggested cluster names in practice should be carefully considered, as the non-neutral nomenclature may affect disease perception in individuals with type 2 diabetes and their healthcare providers., (© 2024. The Author(s).)

Background: Microvascular dysfunction is involved in the development of various cerebral disorders. It may contribute to these disorders by disrupting white matter tracts and altering brain connectivity, but evidence is scarce. We investigated the association between multiple biomarkers of microvascular function and whole-brain white matter connectivity., Methods and Results: Cross-sectional data from The Maastricht Study, a Dutch population-based cohort (n=4326; age, 59.4±8.6 years; 49.7% women). Measures of microvascular function included urinary albumin excretion, central retinal arteriolar and venular calibers, composite scores of flicker light-induced retinal arteriolar and venular dilation, and plasma biomarkers of endothelial dysfunction (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and von Willebrand factor). White matter connectivity was calculated from 3T diffusion magnetic resonance imaging to quantify the number (average node degree) and organization (characteristic path length, global efficiency, clustering coefficient, and local efficiency) of white matter connections. A higher plasma biomarkers of endothelial dysfunction composite score was associated with a longer characteristic path length (β per SD, 0.066 [95% CI, 0.017-0.114]) after adjustment for sociodemographic, lifestyle, and cardiovascular factors but not with any of the other white matter connectivity measures. After multiple comparison correction, this association was nonsignificant. None of the other microvascular function measures were associated with any of the connectivity measures., Conclusions: These findings suggest that microvascular dysfunction as measured by indirect markers is not associated with whole-brain white matter connectivity.

Endurance exercise training is a promising cardioprotective strategy in type 2 diabetes mellitus (T2DM), but the impact of its intensity is not clear. We aimed to investigate whether and how isocaloric moderate-intensity exercise training (MIT) and high-intensity interval exercise training (HIIT) could prevent the adverse cardiac remodeling and dysfunction that develop T2DM in rats. Male rats received a Western diet (WD) to induce T2DM and underwent a sedentary lifestyle ( n = 7), MIT ( n = 7) or HIIT ( n = 8). Insulin resistance was defined as the HOMA-IR value. Cardiac function was assessed with left ventricular (LV) echocardiography and invasive hemodynamics. A qPCR and histology of LV tissue unraveled underlying mechanisms. We found that MIT and HIIT halted T2DM development compared to in sedentary WD rats ( p < 0.05). Both interventions prevented increases in LV end-systolic pressure, wall thickness and interstitial collagen content ( p < 0.05). In LV tissue, HIIT tended to upregulate the gene expression of an ROS-generating enzyme (NOX4), while both modalities increased proinflammatory macrophage markers and cytokines (CD86, TNF-α, IL-1β; p < 0.05). HIIT promoted antioxidant and dicarbonyl defense systems (SOD2, glyoxalase 1; p < 0.05) whereas MIT elevated anti-inflammatory macrophage marker expression (CD206, CD163; p < 0.01). We conclude that both MIT and HIIT limit WD-induced T2DM with diastolic dysfunction and pathological LV hypertrophy, possibly using different adaptive mechanisms., Competing Interests: The authors declare no conflicts of interest.

Aims/hypothesis: To assess the associations between glucose metabolism status and a range of continuous measures of glycaemia with corneal nerve fibre measures, as assessed using corneal confocal microscopy., Methods: We used population-based observational cross-sectional data from the Maastricht Study of N=3471 participants (mean age 59.4 years, 48.4% men, 14.7% with prediabetes, 21.0% with type 2 diabetes) to study the associations, after adjustment for demographic, cardiovascular risk and lifestyle factors, between glucose metabolism status (prediabetes and type 2 diabetes vs normal glucose metabolism) plus measures of glycaemia (fasting plasma glucose, 2 h post-load glucose, HbA 1c , skin autofluorescence [SAF] and duration of diabetes) and composite Z-scores of corneal nerve fibre measures or individual corneal nerve fibre measures (corneal nerve bifurcation density, corneal nerve density, corneal nerve length and fractal dimension). We used linear regression analysis, and, for glucose metabolism status, performed a linear trend analysis., Results: After full adjustment, a more adverse glucose metabolism status was associated with a lower composite Z-score for corneal nerve fibre measures (β coefficients [95% CI], prediabetes vs normal glucose metabolism -0.08 [-0.17, 0.03], type 2 diabetes vs normal glucose metabolism -0.14 [-0.25, -0.04]; linear trend analysis showed a p value of 0.001), and higher levels of measures of glycaemia (fasting plasma glucose, 2 h post-load glucose, HbA 1c , SAF and duration of diabetes) were all significantly associated with a lower composite Z-score for corneal nerve fibre measures (per SD: -0.09 [-0.13, -0.05], -0.07 [-0.11, -0.03], -0.08 [-0.11, -0.04], -0.05 [-0.08, -0.01], -0.09 [-0.17, -0.001], respectively). In general, directionally similar associations were observed for individual corneal nerve fibre measures., Conclusions/interpretation: To our knowledge, this is the first population-based study to show that a more adverse glucose metabolism status and higher levels of glycaemic measures were all linearly associated with corneal neurodegeneration after adjustment for an extensive set of potential confounders. Our results indicate that glycaemia-associated corneal neurodegeneration is a continuous process that starts before the onset of type 2 diabetes. Further research is needed to investigate whether early reduction of hyperglycaemia can prevent corneal neurodegeneration., (© 2023. The Author(s).)