Comparative proximity biotinylation implicates the small GTPase RAB18 in sterol mobilization and biosynthesis.

Loss of functional RAB18 causes the autosomal recessive condition Warburg Micro syndrome. To better understand this disease, we used proximity biotinylation to generate an inventory of potential RAB18 effectors. A restricted set of 28 RAB18 interactions were dependent on the binary RAB3GAP1-RAB3GAP2 RAB18-guanine nucleotide exchange factor complex. Twelve of these 28 interactions are supported by prior reports, and we have directly validated novel interactions with SEC22A, TMCO4, and INPP5B. Consistent with a role for RAB18 in regulating membrane contact sites, interactors included groups of microtubule/membrane-remodeling proteins, membrane-tethering and docking proteins, and lipid-modifying/transporting proteins. Two of the putative interactors, EBP and OSBPL2/ORP2, have sterol substrates. EBP is a Δ8-Δ7 sterol isomerase, and ORP2 is a lipid transport protein. This prompted us to investigate a role for RAB18 in cholesterol biosynthesis. We found that the cholesterol precursor and EBP-product lathosterol accumulates in both RAB18-null HeLa cells and RAB3GAP1-null fibroblasts derived from an affected individual. Furthermore, de novo cholesterol biosynthesis is impaired in cells in which RAB18 is absent or dysregulated or in which ORP2 expression is disrupted. Our data demonstrate that guanine nucleotide exchange factor-dependent Rab interactions are highly amenable to interrogation by proximity biotinylation and may suggest that Micro syndrome is a cholesterol biosynthesis disorder.

Sustained low-grade inflammation in young participants with childhood onset type 1 diabetes: The Norwegian atherosclerosis and childhood diabetes (ACD) study.

BACKGROUND AND AIMS: Persons with type 1 diabetes (T1D) have increased mortality from cardiovascular disease. Early inflammation is important in the development of atherosclerosis. We aimed to evaluate the extent of inflammation and difference in mean over a five-year period in young persons with T1D compared to healthy controls. METHODS: The Norwegian Atherosclerosis and Childhood Diabetes (ACD) study is a prospective population-based cohort study on atherosclerosis development in childhood-onset T1D compared to healthy controls, with follow-ups every fifth year. The original study cohort consisted of 314 children with T1D on intensive insulin treatment and 120 healthy controls of similar age. Circulating levels of VCAM-1, TNA-α, P-selectin, E-selectin, CRP, IL-6, IL-18, MCP-1, MMP-9 and TIMP-1 were measured by ELISAs at baseline and at the five-year follow-up. RESULTS: The group with T1D had mean age 13.7 (SD = 2.8) years, disease duration 5.6 (SD = 3.4) years and HbA1c 68 (SD = 13.1) mmol/mol at baseline. Levels of almost all inflammatory markers were significantly increased in the group with T1D compared to controls, and significant mean-difference between the two groups over the five-year period was observed in four markers: IL-18, P-selectin, E-selectin and TIMP-1. CONCLUSIONS: The early low-grade inflammation present in young individuals with T1D five years after diagnosis is sustained at ten-year disease duration, with moderate changes for most markers of inflammation over time. The evolving inflammatory profile indicates an accelerated chain of events in the progression of early atheromatosis in T1D.

Germline homozygous missense DEPDC5 variants cause severe refractory early-onset epilepsy, macrocephaly and bilateral polymicrogyria.

DEPDC5 (DEP Domain-Containing Protein 5) encodes an inhibitory component of the mammalian target of rapamycin (mTOR) pathway and is commonly implicated in sporadic and familial focal epilepsies, both non-lesional and in association with focal cortical dysplasia. Germline pathogenic variants are typically heterozygous and inactivating. We describe a novel phenotype caused by germline biallelic missense variants in DEPDC5. Cases were identified clinically. Available records, including magnetic resonance imaging and electroencephalography, were reviewed. Genetic testing was performed by whole exome and whole-genome sequencing and cascade screening. In addition, immunohistochemistry was performed on skin biopsy. The phenotype was identified in nine children, eight of which are described in detail herein. Six of the children were of Irish Traveller, two of Tunisian and one of Lebanese origin. The Irish Traveller children shared the same DEPDC5 germline homozygous missense variant (p.Thr337Arg), whereas the Lebanese and Tunisian children shared a different germline homozygous variant (p.Arg806Cys). Consistent phenotypic features included extensive bilateral polymicrogyria, congenital macrocephaly and early-onset refractory epilepsy, in keeping with other mTOR-opathies. Eye and cardiac involvement and severe neutropenia were also observed in one or more patients. Five of the children died in infancy or childhood; the other four are currently aged between 5 months and 6 years. Skin biopsy immunohistochemistry was supportive of hyperactivation of the mTOR pathway. The clinical, histopathological and genetic evidence supports a causal role for the homozygous DEPDC5 variants, expanding our understanding of the biology of this gene.

Retinal venular oxygen saturation is associated with non-proliferative diabetic retinopathy in young patients with type 1 diabetes.

PURPOSE: To determine the contribution of retinal vessel density (VD), central retinal vessel diameter and retinal oxygen (O2 ) saturation independently of other known risk factors in the development of non-proliferative diabetic retinopathy (NPDR). METHODS: Macular optical coherence tomography angiography (OCTA), central retinal artery/vein equivalent diameter (CRAE/CRVE) measurements and retinal oximetry were performed in a cross-sectional study of 166 eyes from 166 individuals with type 1 diabetes (T1D) aged 14-30 years. Multiple logistic regression analysis was used to investigate whether O2 saturation, retinal vessel diameters and vessel density in the deep capillary plexus (VD-DCP) were associated with NPDR, when adjusting for known risk factors. The individuals were allocated to one group without and one group with NPDR. RESULTS: Multiple logistic regression analysis showed that age (OR = 1.25, 95% CI: 1.04-1.49) and AV-difference in O2 saturation (OR = 0.85, 95% CI 0.77-0.93) were significantly associated with NPDR. CONCLUSION: Our findings suggest that age and lower AV-O2 saturation difference contribute to explaining the grade of NPDR independently of other well-known risk factors. Reduced delivery of O2 to the retinal tissue is associated with the development of NPDR in young patients with T1D and should be given appropriate weight in the risk stratification at early stages of the disease.

Children with familial hypercholesterolemia display changes in LDL and HDL function: A cross-sectional study.

BACKGROUND: The functional status of lipoprotein particles contributes to atherogenesis. The tendency of plasma low-density lipoprotein (LDL) particles to aggregate and the ability of igh-density lipoprotein (HDL) particles to induce and mediate reverse cholesterol transport associate with high and low risk for cardiovascular disease in adult patients, respectively. However, it is unknown whether children with familial hypercholesterolemia (FH) display lipoprotein function alterations. HYPOTHESIS: We hypothesized that FH children had disrupted lipoprotein functions. METHODS: We analyzed LDL aggregation susceptibility and HDL-apoA-I exchange (HAE), and activity of four proteins that regulate lipoprotein metabolism (cholesteryl ester transfer protein, lecithin-cholesterol acyltransferase, phospholipid transfer protein, and paraoxonase-1) in plasma samples derived from children with FH (n = 47) and from normocholesterolemic children (n = 56). Variation in lipoprotein functions was further explored using an nuclear magnetic resonance-based metabolomics profiling approach. RESULTS: LDL aggregation was higher, and HAE was lower in FH children than in normocholesterolemic children. LDL aggregation associated positively with LDL cholesterol (LDL-C) and negatively with triglycerides, and HAE/apoA-I associated negatively with LDL-C. Generally, the metabolomic profile for LDL aggregation was opposite of that of HAE/apoA-I. CONCLUSIONS: FH children displayed increased atherogenicity of LDL and disrupted HDL function. These newly observed functional alterations in LDL and HDL add further understanding of the risk for atherosclerotic cardiovascular disease in FH children.

Associations between Macular OCT Angiography and Nonproliferative Diabetic Retinopathy in Young Patients with Type 1 Diabetes Mellitus.

METHODS: OCTA of both eyes was performed in a cross-sectional study of 14 to 30-year-old individuals with at least 10-year duration of T1D and controls recruited from the Norwegian Atherosclerosis and Childhood Diabetes (ACD) study. Vessel density (VD) and foveal avascular zone (FAZ) area in the superficial and deep capillary plexus (SCP and DCP), total retinal volume (TRV), and central macular thickness (CMT) were calculated using automated software. Univariate and multivariate ordered logistic regression (OLR) models were used accordingly. RESULTS: We included 168 control eyes and 315 T1D eyes. Lower VD in DCP (OR 0.65, 95% CI 0.51-0.83), longer diabetes duration (OR 1.51, 95% CI 1.22-1.87), and higher waist circumference (OR 1.08, 95% CI 1.02-1.14) were significantly associated with progression of NPDR. VD in SCP and DCP were significantly lower in T1D patients without diabetic retinopathy than in controls. CONCLUSIONS: Sparser VD in DCP is significantly associated with severity of NPDR, supporting that OCTA might detect the earliest signs of NPDR before it is visible by ophthalmoscopy.

Lipoprotein retention in the vascular wall - a potential therapeutic target? / Retensjon av lipoproteiner i årevegg ­ mulig mål for behandling?

Accumulation of lipoproteins in the vascular wall is one of the main causes of atherosclerosis. Inhibiting this type of binding could potentially limit the accumulation of lipoproteins in the vascular wall.

Venular oxygen saturation is increased in young patients with type 1 diabetes and mild nonproliferative diabetic retinopathy.

PURPOSE: To clarify how early in the development of diabetic retinopathy (DR) can oxygen (O2 ) saturation changes be detected. METHODS: Retinal oximetry was performed in a cross-sectional study, involving 14- to 30-year-old individuals: 185 with type 1 diabetes (T1D) and 94 controls. The subjects were divided into four groups according to the grade of DR. One-way ANOVA and post hoc tests were used to test for differences in the mean O2 saturations between the groups. RESULTS: Fifty-eight (31 %) of the T1D patients had nonproliferative DR. There was no significant difference in O2 saturations between controls and T1D patients with no DR. Arteriolar and venular O2 saturations in T1D patients were significantly higher in moderate/severe DR than in no DR (p = 0.009 and p > 0.001), while venular O2 saturation was significantly higher in mild DR than in no DR (p = 0.013). CONCLUSION: Increase in venular O2 saturation could not be detected before mild retinopathy had developed, and the retinal O2 saturation increase was measurable on the venular side first. Our results suggest that the increase in O2 saturation is likely a consequence of DR.

Annexin V+ Microvesicles in Children and Adolescents with Type 1 Diabetes: A Prospective Cohort Study.

BACKGROUND: Type 1 diabetes is a chronic disease including hyperglycemia and accelerated atherosclerosis, with high risk of micro- and macrovascular complications. Circulating microvesicles (cMVs) are procoagulant cell fragments shed during activation/apoptosis and discussed to be markers of vascular dysfunction and hypercoagulability. Limited knowledge exists on hypercoagulability in young diabetics. We aimed to investigate cMVs over a five-year period in children/adolescents with type 1 diabetes compared with controls and any associations with glycemic control and cardiovascular risk factors. We hypothesized increased shedding of cMVs in type 1 diabetes in response to vascular activation. METHODS: The cohort included type 1 diabetics (n = 40) and healthy controls (n = 40), mean age 14 years (range 11) at inclusion, randomly selected from the Norwegian Atherosclerosis and Childhood Diabetes (ACD) study. Citrated plasma was prepared and stored at -80°C until cMV analysis by flow cytometry. RESULTS: Comparable levels of Annexin V (AV+) cMVs were observed at inclusion. At five-year follow-up, total AV+ cMVs were significantly lower in subjects with type 1 diabetes compared with controls; however, no significant differences were observed after adjusting for covariates. In the type 1 diabetes group, the total AV+, tissue factor-expressing AV+/CD142+, neutrophil-derived AV+/CD15+ and AV+/CD45+/CD15+, and endothelial-derived AV+/CD309+ and CD309+/CD34+ cMVs were inversely correlated with HbA1c (r = -0.437, r = -0.515, r = -0.575, r = -0.529, r = -0.416, and r = -0.445, respectively; all p ≤ 0.01), however, only at inclusion. No significant correlations with cardiovascular risk factors were observed. CONCLUSIONS: Children/adolescents with type 1 diabetes show similar levels of AV+ cMVs as healthy controls and limited associations with glucose control. This indicates that our young diabetics on intensive insulin treatment have preserved vascular homeostasis and absence of procoagulant cMVs.

Procoagulant activity in children and adolescents on intensive insulin therapy.

BACKGROUND: Type 1 diabetes is associated with atherothrombosis, but limited data exist on procoagulant activity in the young. We investigated procoagulant activity in children/adolescents with type 1 diabetes using intensified insulin treatment compared with controls in a 5-year follow-up study, and further any associations with cardiovascular risk factors. METHODS: The study included 314 diabetes children/adolescents and 120 healthy controls. Prothrombin fragment 1+2 (F1+2), D-dimer, tissue-factor-procoagulant-activity (TF-PCA), and tissue-factor-pathway-inhibitor (TFPI) were analyzed with ELISAs. RESULTS: F1+2, D-dimer, and TF-PCA did not differ between the groups or correlate to HbA1c in the diabetes group at either time points. TFPI was significantly higher in the diabetes group compared with controls both at inclusion and follow-up (both P < .001). In the diabetes group, TFPI correlated significantly to HbA1c at both time points (r = 0.221 and 0.304, both P < .001). At follow-up, females using oral contraceptives had significantly elevated F1+2, D-dimer, and TF-PCA and lower TFPI compared to no-users (all P < .005), and females had lower TFPI (P = .017) and higher F1+2 compared with males (P = .052), also after adjusting for the use of oral contraceptives. CONCLUSIONS: The current results show similar procoagulant activity in children/adolescents with type 1 diabetes compared with controls over a 5-year period, indicating that these children using modern intensified insulin treatment are not at high thrombotic risk at younger age. The elevated levels of TFPI in the diabetes group, related to hyperglycaemia, are probably reflecting increased endothelial activation. These findings highlight the significance of optimal blood glucose control in children/adolescents with type 1 diabetes, to maintain a healthy endothelium.

High-density lipoprotein function is associated with atherosclerotic burden and cardiovascular outcomes in type 2 diabetes.

BACKGROUND AND AIMS: Measures of HDL function are emerging tools for assessing cardiovascular disease (CVD) event risk. HDL-apoA-I exchange (HAE) reflects HDL capacity for reverse cholesterol transport. METHODS: HAE was measured in 93 participants with type 2 diabetes (T2D) and at least one additional CVD risk factor in the Asker and Bærum Cardiovascular Diabetes study. At baseline and after seven years, the atherosclerotic burden was assessed by invasive coronary angiography. Major CVD events were registered throughout the study. RESULTS: Linear regression analysis demonstrated a significant inverse association between HAE and atherosclerotic burden. Cox proportional hazard regression analysis showed a significant association between HAE and a composite of major CVD events when controlling for waist-hip ratio, HR = 0.89, 95% CI = 0.80-1.00 and p=0.040. CONCLUSIONS: Despite the relatively small size of the study population and the limited number of CVD events, these findings suggest that HAE provides valuable information in determining CVD risk.

Preserved endothelial function in young adults with type 1 diabetes.

BACKGROUND AND AIM: Endothelial dysfunction is involved in the pathogenesis of atherosclerosis and is typically present in older adults with type 1 diabetes (T1D). In young adults, we aimed to assess the impact of T1D on endothelial function as detected by digital peripheral arterial tonometry (PAT) and its relationship with cardiovascular risk factors and long term glycemic control. MATERIALS AND METHODS: Reactive hyperemia index (RHI) as a measure of endothelial function was assessed by PAT in 46 T1D patients and 32 healthy controls. All were participants in the "Atherosclerosis and Childhood Diabetes" study, with baseline values registered five years previously. Annual measurements of HbA1c for assessment of glycemic burden were provided by the Norwegian Childhood Diabetes Registry. RESULTS: The diabetes patients had a mean age of 20.8 years, a median duration of diabetes of 10.0 years and a mean HbA1c of 8.7%. RHI was not significantly decreased in the diabetes group, mean 2.00 (SD = 0.59) vs. 2.21 (SD = 0.56), p = .116. There was no gender difference or any associations with traditional risk factors. Furthermore, there was no significant association between RHI and either HbA1c or long term glycemic burden. CONCLUSIONS: RHI as a measure of endothelial function was preserved in young adults with T1D compared with healthy controls.

Increased arterial stiffness in childhood onset diabetes: a cardiovascular magnetic resonance study.

Aims: Arterial stiffness is a strong predictor of cardiovascular events. We aimed to assess the impact of type 1 diabetes (T1D) on arterial stiffness and cardiac function in young adults. Methods and results: Aortic pulse wave velocity (PWV), distensibility, left ventricular (LV) function and LV mass were measured by cardiovascular magnetic resonance imaging (CMR) in 47 T1D patients and 33 healthy controls. All were participants in the Atherosclerosis and Childhood Diabetes study, with baseline values registered 5 years previously. The patients had a mean age of 20.8 years and a median duration of diabetes of 10.0 years. PWV was significantly higher in the diabetes group compared with controls, mean 4.10 (SD = 4.58) vs. 3.90 (SD = 4.04) m/s, P = 0.045. In the diabetes group, insulin pump users at baseline had lower PWV than multiple injection users, mean 3.94 (SD = 0.38) vs. 4.23 (SD = 0.48) m/s, P = 0.028. Also in the diabetes group, multiple regression analysis identified C-reactive protein (CRP), female gender and insulin pump use as independent baseline risk factors for PWV 5 years later. There was no difference in cardiac function or LV mass between the diabetes and control groups. Conclusion: In this prospective study, we found increased PWV assessed by CMR in young adults with T1D compared with controls. Also, CRP, female gender and insulin pump use emerged as independent baseline risk factors for PWV 5 years later.

Reduced HDL function in children and young adults with type 1 diabetes.

BACKGROUND: Patients with type 1 diabetes (T1D) are at increased risk of cardiovascular disease (CVD). Measures of high-density lipoprotein (HDL) function provide a better risk estimate for future CVD events than serum levels of HDL cholesterol. The objective of this study was to evaluate HDL function in T1D patients shortly after disease onset compared with healthy control subjects. METHODS: Participants in the atherosclerosis and childhood diabetes study were examined at baseline and after 5 years. At baseline, the cohort included 293 T1D patients with a mean age of 13.7 years and mean HbA1c of 8.4%, along with 111 healthy control subjects. Their HDL function, quantified by HDL-apoA-I exchange (HAE), was assessed at both time points. HAE is a measure of HDL's dynamic property, specifically its ability to release lipid-poor apolipoprotein A-I (apoA-I), an essential step in reverse cholesterol transport. RESULTS: The HAE-apoA-I ratio, reflecting the HDL function per concentration unit apoA-I, was significantly lower in the diabetes group both at baseline, 0.33 (SD = 0.06) versus 0.36 (SD = 0.06) %HAE/mg/dL, p < 0.001 and at follow-up, 0.34 (SD = 0.06) versus 0.36 (SD = 0.06)  %HAE/mg/dL, p = 0.003. HAE-apoA-I ratio was significantly and inversely correlated with HbA1c in the diabetes group. Over the 5 years of the study, the mean HAE-apoA-I ratio remained consistent in both groups. Individual changes were less than 15% for half of the study participants. CONCLUSIONS: This study shows reduced HDL function, quantified as HAE-apoA-I ratio, in children and young adults with T1D compared with healthy control subjects. The differences in HDL function appeared shortly after disease onset and persisted over time.

Advanced glycation end products in children with type 1 diabetes and early reduced diastolic heart function.

BACKGROUND: Reduced diastolic function is an early sign of diabetes cardiomyopathy in adults and is associated with elevated levels of HbA1c and advanced glycation end products (AGEs). OBJECTIVE: To assess the associations between early reduced diastolic function and elevated levels of HbA1c and AGEs in children and adolescents with type 1 diabetes (T1D). METHODS: One hundred fourty six T1D patients (age 8-18 years) without known diabetic complications were examined with tissue Doppler imaging and stratified into two groups according to diastolic function. A clinical examination and ultrasound of the common carotid arteries were performed. Methylglyoxal-derived hydroimidazolone-1 (MG-H1) was measured by immunoassay. RESULTS: At inclusion, 36 (25%) participants were stratified into a low diastolic function group (E'/A'-ratio < 2.0). Compared to the rest of the T1D children, these participants had higher body mass index (BMI), 22.8 (SD = 4.0) vs. 20.1 (SD = 3.4) kg/m2, p < 0.001, higher systolic blood pressure 104.2 (SD = 8.7) vs. 99.7 (SD = 9.3) mmHg, p = 0.010, and higher diastolic blood pressure, 63.6 (SD = 8.3) vs. 59.9 (SD = 7.9) mmHg, p = 0.016. The distensibility coefficient was lower, 0.035 (SD = 0.010) vs. 0.042 (SD = 0.02) kPa-1, p = 0.013, Young's modulus higher, 429 (SD = 106) vs. 365 (SD = 143), p = 0.009, and MG-H1 higher, 163.9 (SD = 39.2) vs. 150.3 (SD = 33.4) U/ml, p = 0.046. There was no difference in carotid intima-media thickness between the groups. There were no associations between reduced diastolic function and years from diagnosis, HBA1c, mean HBA1c, CRP or calculated glycemic burden. Logistic regression analysis showed that BMI was an independent risk factor for E'/A'-ratio as well as a non-significant, but relatively large effect size for MG-H1, indicating a possible role for AGEs. CONCLUSIONS: Early signs of reduced diastolic function in children and adolescents with T1D had higher BMI, but not higher HbA1c. They also had elevated serum levels of the advanced glycation end product MG-H1, higher blood pressure and increased stiffness of the common carotid artery, but these associations did not reach statistical significance when tested in a logistic regression model.

Soluble RAGE and atherosclerosis in youth with type 1 diabetes: a 5-year follow-up study.

BACKGROUND: Advanced glycation end products (AGEs) play a role in the development of late complications and atherosclerosis in diabetes by engaging the receptor for advanced glycation end products, RAGE. Receptor binding leads to activation of the vascular endothelium and increased inflammation in the vessel wall. The soluble variants of the receptor, endogenous secretory RAGE (esRAGE) and the cleaved cell-surface part of RAGE, which together comprise soluble RAGE (sRAGE), are suggested to have a protective effect acting as decoys for RAGE. We aimed to test whether high levels of soluble variants of RAGE could be protective against atherosclerosis development. METHODS: Participants in the prospective atherosclerosis and childhood diabetes study were examined at baseline (aged 8-18) and at follow-up after 5 years. Both sRAGE and esRAGE were measured by immunoassay in 299 patients with type 1 diabetes and 112 healthy controls at baseline and 241 patients and 128 controls at follow-up. The AGEs methylglyoxal-derived hydroimidazolone-1 (MG-H1) and carboxymethyllysine (CML) were measured by immunoassay. The surrogate markers of atherosclerosis assessed were carotid intima-media thickness (cIMT), C-reactive protein (CRP) and Young's modulus, measures of arterial wall thickness, inflammation and arterial stiffness, respectively. RESULTS: Levels of sRAGE and esRAGE correlated strongly both at baseline and at follow-up in both diabetes patients and controls. With increasing age, mean values of both variants declined, independent of gender, diabetes or pubertal stage. In the diabetes group, multiple regression analysis showed a positive association between both variants of soluble RAGE and cIMT. There was no significant relationship with Young's modulus, but a negative association between sRAGE at baseline and CRP at follow-up. The ratios between the AGEs and the variants of soluble RAGE were increased in diabetes patients compared to controls. CONCLUSIONS: The results show a possible protective effect of high levels of sRAGE at baseline against inflammation 5 years later, but not on arterial stiffness or wall thickness, in this cohort of adolescents and young adults with T1D.

The advanced glycation end product methylglyoxal-derived hydroimidazolone-1 and early signs of atherosclerosis in childhood diabetes.

BACKGROUND: Advanced protein glycation is an important mechanism for the development of late diabetic complications including atherosclerosis. Methylglyoxal-derived hydroimidazolone-1 is the most abundant advanced glycation end product in human plasma. AIM: To investigate the relationship between methylglyoxal-derived hydroimidazolone-1 and early signs of atherosclerosis in children and adolescents with type 1 diabetes and healthy controls. METHODS: A total of 314 diabetes patients aged 8-18 years were compared with 120 healthy controls. Serum methylglyoxal-derived hydroimidazolone-1 was measured by immunoassay. Atherosclerosis was evaluated by assessing carotid intima-media thickness by ultrasound, arterial stiffness by Young's modulus and inflammation by C-reactive protein. RESULTS: Methylglyoxal-derived hydroimidazolone-1 was significantly increased in the diabetes group compared with controls, 155.3 (standard deviation (SD) = 41.0) versus 143.0 (SD = 35.1) U/mL, p = 0.003, as was C-reactive protein, median 0.51 (0.27, 1.83) versus 0.31 (0.19, 0.67) mg/L, p < 0.001. There was no significant difference between the groups regarding carotid intima-media thickness or Young's modulus. Multiple regression analysis showed a significant positive association between methylglyoxal-derived hydroimidazolone-1 and C-reactive protein in the diabetes group. CONCLUSION: Serum levels of methylglyoxal-derived hydroimidazolone-1 in diabetes patients are increased and associated with low-grade inflammation, but not yet arterial stiffness or wall thickness. This indicates that methylglyoxal-derived hydroimidazolone-1 may be important in the early phase of the accelerated atherosclerotic process in diabetes.

Inflammation in childhood type 1 diabetes; influence of glycemic control.

OBJECTIVE: Patients with type 1 diabetes have increased mortality from cardiovascular disease, and inflammation is important in the development of atherosclerosis. Our aim was to evaluate the extent of inflammation and the influence of glycemic control in the early phases of atherosclerosis in childhood type 1 diabetes. MATERIALS AND METHODS: A population based cohort representative of all children with type 1 diabetes in Norway was studied. Diabetes patients (n = 314) were compared to healthy controls (n = 120), aged 8-18 years. Circulating levels of VCAM-1, ICAM-1, E-selectin, P-selectin, TNFα, IL-6, CRP, MCP-1, IL-18, MMP-9 and TIMP-1 were measured by immunoassays. RESULTS: The diabetes patients had a mean age of 13.7 (SD = 2.8) years, disease duration of 5.5 (SD = 3.4) years and HbA1c of 8.4 (SD = 1.2) % (68 mmol/mol, SD = 13.1). The levels of most of the measured markers were significantly increased in the diabetes group compared to controls. In the diabetes group, all except MCP-1 and MMP-9 were significantly correlated to HbA1c, albeit the relation to VCAM-1 was inverse. There were no significant correlations in the control group. The measured markers were only to a limited degree associated with traditional risk factors. CRP showed the most pronounced difference between diabetes patients and controls and the strongest correlation with HbA1c. The use of oral contraceptives profoundly increased CRP levels, independent of the presence of diabetes. CONCLUSIONS: Our results indicate that inflammation may play an important role in the accelerated atherosclerosis in early type 1 diabetes, and that this process seems primarily driven by hyperglycemia.