C. G. Schalkwijk

Markers of inflammation are cross-sectionally associated with microvascular complications and cardiovascular disease in type 1 diabetes--the EURODIAB Prospective Complications Study.

Aims/hypothesisThe pathogenesis of vascular complications in type 1 diabetes is poorly understood, but may involve chronic, low-grade inflammation. We investigated the association of markers of inflammation with vascular complications in type 1 diabetes.MethodsA cross-sectional nested case-control study of the follow-up data of the EURODIAB Prospective Complications Study. This study included 543 individuals (278 men) with type 1 diabetes diagnosed at <36 years of age. Cases (n=348) had complications of diabetes, controls (n=195) had no complications.ResultsC-reactive protein, interleukin-6 and tumour necrosis factor-α levels, which were combined in an inflammatory marker Z-score, were associated with albuminuria, retinopathy and cardiovascular disease. Calculated means (95% confidence intervals) of the marker Z-score were −0.15 (−0.22 to −0.07), 0.10 (−0.05 to 0.25), and 0.28 (0.15 to 0.41), p for trend <0.0001, in individuals with normo-, micro- and macroalbuminuria; −0.23 (−0.33 to −0.13), 0.14 (0.02 to 0.25) and 0.20 (0.07 to 0.32), p for trend <0.0001, in individuals with no, non-proliferative and proliferative retinopathy; and −0.28 (−0.39 to −0.18) and 0.06 (−0.08 to 0.20), p<0.001, in individuals without and with cardiovascular disease. Per 1xa0SD increase of the inflammatory marker Z-score, GFR decreased by −4.6 (−6.6 to −2.6) ml per min per 1.73xa0m2 (p<0.001).Conclusions/interpretationWe have shown that markers of inflammation are strongly and independently associated with microvascular complications and cardiovascular disease in type 1 diabetes. These data suggest that strategies to decrease inflammatory activity may help to prevent the development of vascular complications in type 1 diabetes.

Advanced Glycation End Products in Human Cancer Tissues: Detection of Nε‐(Carboxymethyl)lysine and Argpyrimidine

Abstract: Tumors are generally characterized by an increased glucose uptake and a high rate of glycolysis. Since one consequence of an elevated glycolysis is the nonenzymatic glycation of proteins, we studied the presence of advanced glycation end products (AGEs) in human cancer tissues. We detected the presence of the AGEs Nε‐(carboxymethyl)lysine (CML) and argpyrimidine in several human tumors using specific antibodies. Because AGEs have been associated with the etiology of a variety of different diseases, these results suggest that CML and argpyrimidine could be implicated in the biology of human cancer.

Aggressive antihypertensive therapy based on hydrochlorothiazide, candesartan or lisinopril as initial choice in hypertensive type II diabetic individuals: effects on albumin excretion, endothelial function and inflammation in a double-blind, randomized clinical trial.

We investigated the effects of aggressive antihypertensive therapy based on hydrochlorothiazide, candesartan or lisinopril on urinary albumin excretion, endothelial function and inflammatory activity in hypertensive type II diabetic individuals. A total of 70 hypertensive type II diabetic individuals were treated with three antihypertensive strategies in a randomized, double-blind, double-dummy design. Blood pressure was titrated to levels below 130/85u2009mmHg or a decrease in systolic pressure of 10% with a diastolic pressure below 85u2009mmHg. After titration, patients were treated for 12 months. Mean blood pressures changed from 157/93, 151/94 and 149/93 at baseline to 135/80, 135/82 and 131/80u2009mmHg after titration in the hydrochlorothiazide (n=24), candesartan (n=24) and lisinopril (n=22) groups. About 70% reached target blood pressures. However, only 45% had blood pressures <130/85u2009mmHg. Urinary albumin excretion and levels of soluble vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 decreased (GEE regression coefficients, −2.40u2009mg/24u2009h (P<0.001), −85u2009ng/ml (P=0.01) and −50u2009ng/ml (P=0.02)), but brachial artery endothelium-dependent and -independent vasodilation and levels of von Willebrand factor and C-reactive protein did not change (GEE regression coefficients, 0.21u2009mm (P=0.07), 0.04u2009mm (P=0.43), 0.04u2009IU/ml (P=0.33) and −1.15u2009mg/l (P=0.64)). No differences in outcome variables between treatment groups were observed. These data show that achievement of target blood pressures below 130/85u2009mmHg in hypertensive type II diabetes is difficult. Aggressive antihypertensive therapy can improve urinary albumin excretion, endothelial function and inflammatory activity in hypertensive type II diabetic individuals, regardless of the type of antihypertensive therapy used.

Plasma levels of AGE peptides in type 1 diabetic patients are associated with serum creatinine and not with albumin excretion rate: possible role of AGE peptide-associated endothelial dysfunction.

Abstract: Patients with renal impairment have an increased risk for cardiovascular disease, which may be the result of advanced glycation end products (AGEs). The aim of this study was to investigate the levels of AGE peptides in relation to kidney function and to study the relationship of AGE peptides with endothelial function and inflammation in type 1 diabetic patients. We measured plasma levels of AGE peptides with a simple fluorescent analytical procedure in patients with end‐stage renal disease with or without diabetes and in 60 type 1 diabetic patients categorized as having normo‐, micro‐, or macroalbuminuria. Using enzyme‐linked immunosorbent assays, we determined vascular cell adhesion molecule 1 (sVCAM‐1), sE‐selectin, plasminogen activator inhibitor 1 (PAI‐1), tissue type‐specific plasminogen activator (tPA), von Willebrand factor (vWF), and soluble thrombomodulin (sTM) to be markers of endothelial function and determined C‐reactive protein (CRP) to be a marker of inflammation. AGE peptides were increased approximately fivefold in patients with end‐stage renal disease, without difference between patients with or without diabetes. In type 1 diabetic patients, the increase of AGE peptides across the groups normo‐, micro‐, and macroalbuminuria (with medians [range] of 12.6% [7.8‐27.2%], 12.1% [7.8‐162%], and 46.5% [9.0‐248.9%]) was associated with serum creatinine level and not with albumin excretion rate (AER). The relationship with serum creatinine decreased but remained significant after adjusting for age, sex, diabetes duration, hemoglobin A1c (HbA1c), AER, systolic and diastolic blood pressure (BP), and CRP in multiple linear‐regression analysis. AGE peptide levels were significantly associated with sVCAM‐1 and sTM, independently of serum creatinine. However, these relationships were no longer significant after adjusting for age, sex, diabetes duration, HbA1c, AER, systolic and diastolic BP, and CRP. This study shows that plasma levels of AGE peptides rise with renal impairment, as determined by serum creatinine. AGE peptides are associated with some markers of endothelial activation, which may suggest an involvement of AGE peptides in the acceleration of cardiovascular complications in type 1 diabetic patients with renal impairment.

Associations of Advanced Glycation End-Products With Cognitive Functions in Individuals With and Without Type 2 Diabetes: The Maastricht Study

CONTEXTnAdvanced glycation end-products (AGEs) are thought to be involved in the pathogenesis of Alzheimers disease. AGEs are products resulting from nonenzymatic chemical reactions between reduced sugars and proteins, which accumulate during natural aging, and their accumulation is accelerated in hyperglycemic conditions such as type 2 diabetes mellitus.nnnOBJECTIVEnThe objective of the study was to examine associations between AGEs and cognitive functions.nnnDESIGN, SETTING, AND PARTICIPANTSnThis study was performed as part of the Maastricht Study, a population-based cohort study in which, by design, 215 participants (28.1%) had type 2 diabetes mellitus.nnnMAIN OUTCOME MEASURESnWe examined associations of skin autofluorescence (SAF) (n = 764), an overall estimate of skin AGEs, and specific plasma protein-bound AGEs (n = 781) with performance on tests for global cognitive functioning, information processing speed, verbal memory (immediate and delayed word recall), and response inhibition.nnnRESULTSnAfter adjustment for demographics, diabetes, smoking, alcohol, waist circumference, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, and lipid-lowering medication use, higher SAF was significantly associated with worse delayed word recall (regression coefficient, b = -0.44; P = .04), and response inhibition (b = 0.03; P = .04). After further adjustment for systolic blood pressure, cardiovascular disease, estimated glomerular filtration rate, and depression, associations were attenuated (delayed word recall, b = -0.38, P = .07; response inhibition, b = 0.02, P = .07). Higher pentosidine levels were associated with worse global cognitive functioning (b = -0.61; P = .04) after full adjustment, but other plasma AGEs were not. Associations did not differ between individuals with and without diabetes.nnnCONCLUSIONnWe found inverse associations of SAF (a noninvasive marker for tissue AGEs) with cognitive performance, which were attenuated after adjustment for vascular risk factors and depression.

BclI Glucocorticoid Receptor Polymorphism Is Associated With Greater Body Fatness: The Hoorn and CODAM Studies

CONTEXTnThe BclI polymorphism in the glucocorticoid receptor (GR) gene is associated with enhanced glucocorticoid (GC) sensitivity.nnnOBJECTIVEnOur objective was to investigate the association of the BclI polymorphism with body fatness and insulin resistance.nnnDESIGN AND SETTINGnWe conducted an observational cohort study, combining data from 2 cohort studies enriched with individuals with impaired glucose metabolism and/or diabetes mellitus type 2 (DM2).nnnPATIENTS AND METHODSnWe examined 1228 participants (mean age 64.7 years, 45% women) from the Cohort Study on Diabetes and Atherosclerosis Maastricht (CODAM, n = 543) and the Hoorn Study (n = 685). Body mass index (BMI), waist and hip circumferences, and waist-to-hip ratio (WHR) were obtained; insulin resistance was estimated using the homeostasis model assessment for insulin resistance (HOMA2-IR).nnnRESULTSnWe identified 519 noncarriers (CC), 540 heterozygous (CG) carriers, and 169 homozygous (GG) carriers of the G-allele of the BclI polymorphism. Homozygous carriers had a higher BMI (28.9 vs 27.9 kg/m(2)) and waist (99.6 vs 97.2 cm) and hip (105.5 vs 103.2 cm) circumference compared with noncarriers, also after adjustment for age, sex, cohort, glucose tolerance, and lifestyle risk factors: β = 0.94 kg/m(2) (95% confidence interval, 0.24-1.63), β = 2.84 cm (0.95;4.73) and β = 2.38 cm (0.88-3.87), respectively. Similar results were obtained when comparing homozygous carriers with heterozygous carriers: β = 1.03 kg/m(2) (0.34-1.72), β = 2.20 cm (0.31-4.08) and β = 1.99 cm (0.51-3.48), respectively. There were no differences in WHR. Ln-HOMA2-IR was higher in GG carriers compared with CG carriers; 0.29 vs 0.17 [β = 0.09 (0.01-0.17)], but this effect was attenuated after adjustment for BMI [β = 0.04 (-0.04 to 0.11)].nnnCONCLUSIONnHomozygous carriers of the BclI polymorphism of the GR gene have significantly greater total body fatness, contributing to higher HOMA2-IR, compared with heterozygous carriers and noncarriers.

Distinct associations of complement C3a and its precursor C3 with atherosclerosis and cardiovascular disease. The CODAM study.

Complement C3 is a novel risk factor for cardiovascular disease (CVD), but the underlying mechanism is currently unknown. We determined the associations of the anaphylatoxin C3a, the activation product of C3, and of C3 itself with estimates of atherosclerosis and CVD. We studied associations of C3a and C3 with carotid intima-media thickness (cIMT), ankle-arm blood pressure index (AAIx) and CVD in cross-sectional analyses among 545 participants of the Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) study (62% men, 59.4 ± 6.9 years) and examined effect modification by smoking. We conducted linear and logistic regression analyses with adjustments for age, sex, glucose metabolism status, lipids, adiposity, renal function, blood pressure, pack-years smoked, physical activity, use of medication and investigated mediation by inflammation. C3a was independently associated with cIMT (β=0.032 mm, [95% confidence interval: 0.004; 0.060]) and AAIx (β=-0.022, [-0.043; -0.001]), but C3 was not. Effect modification by smoking was only observed for CVD (P(smoking*C3a)=0.008, P(smoking*C3)=0.018), therefore these associations were stratified for smoking behaviour. Both C3a (odds ratio [OR] =2.96, [1.15; 7.62]) and C3 (OR =1.98, [1.21; 3.22]) were independently associated with CVD in heavy smokers. The association of C3 with CVD was independent of C3a. Low-grade inflammation did partially explain the association of C3a with AAIx, but not the other observed associations. This suggests that C3a and C3 have distinct roles in pathways leading to CVD. C3a may promote atherosclerosis and additionally advance CVD in heavy smokers. Conversely, C3 may be associated with CVD in heavy smokers via pathways other than atherosclerosis.

Up-Regulation of the Complement System in Subcutaneous Adipocytes from Nonobese, Hypertriglyceridemic Subjects Is Associated with Adipocyte Insulin Resistance

BACKGROUNDnDysfunctional adipose tissue plays an important role in the etiology of the metabolic syndrome, type 2 diabetes, and dyslipidemia. However, the molecular mechanisms underlying adipocyte dysfunction are incompletely understood.nnnAIMnThe aim of the study was to identify differentially regulated pathways in sc adipocytes of dyslipidemic subjects.nnnMETHODSnWhole-genome expression profiling was conducted on sc adipocytes from a discovery group of nine marginally overweight subjects with familial combined hyperlipidemia (FCHL) and nine controls of comparable body sizes as well as two independent confirmation groups. In this study, FCHL served as a model of familial insulin resistance and dyslipidemia, in the absence of frank obesity.nnnRESULTSnFunctional analyses and gene set enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes or a custom pathway database identified the complement system and complement regulators as one of the top up-regulated pathways in FCHL [false discovery rate (FDR) < 1E-30]. Higher adipocyte complement expression in FCHL was confirmed in the appropriate confirmation group. Higher complement gene expression was associated with lower adipocyte insulin receptor substrate-1 expression as marker of adipocyte insulin resistance, independent of age, sex, or disease status, and this association was corroborated in the two confirmation groups. Additionally, complement gene expression was associated with triglycerides in the discovery set and with triglycerides and/or waist circumference in the confirmation groups. Complement pathway up-regulation did not appear to be driven by hypertriglyceridemia because a 40% pharmacological reduction in triglycerides did not affect complement expression.nnnCONCLUSIONSnThese findings point to an up-regulation of a complement-related transcriptome in sc adipocytes under metabolically stressed conditions, even in the absence of overt obesity. Such up-regulation may subsequently influence downstream processes, including macrophage infiltration into adipose tissue and adipocyte insulin resistance.

The alternative complement pathway is longitudinally associated with adverse cardiovascular outcomes The CODAM study

The alternative pathway of complement activation is highly reactive and can be activated spontaneously in the vasculature. Activation may contribute to vascular damage and development of cardiovascular disease (CVD). We aimed to investigate functional components of the alternative pathway in cardiovascular risk. We studied 573 individuals who were followed-up for seven years. At baseline, we measured the enhancer properdin; the rate-limiting protease factor D (FD); and a marker of systemic activation, Bb. Using generalised estimating equations, we investigated their longitudinal associations with cardiovascular events (CVE, N=89), CVD (N=159), low-grade inflammation (LGI), endothelial dysfunction (ED) and carotid intima-media thickness (cIMT). Furthermore, we investigated associations with incident CVE (N=39) and CVD (N=73) in 342 participants free of CVD at baseline. CVE included myocardial infarction, stroke, cardiac angioplasty and/or cardiac bypass. CVD additionally included ischaemia on an electrocardiogram and/or ankle-brachial index < 0.9. In adjusted analyses, properdin was positively associated with CVE (per 1SD, longitudinal OR=1.36 [1.07; 1.74], OR for incident CVE=1.53 [1.06; 2.20]), but not with CVD. Properdin was also positively associated with ED (β=0.13 [95%CI 0.06; 0.20]), but not with LGI or cIMT. FD and Bb were positively associated with LGI (per 1SD, FD: β=0.21 [0.12; 0.29], Bb: β=0.14 [0.07; 0.21]), and ED (FD: β=0.20 [0.11; 0.29], Bb: β=0.10 [0.03; 0.18]), but not with cIMT, CVE or CVD. Taken together, this suggests that the alternative complement pathway contributes to processes of vascular damage, and that in particular a high potential to enhance alternative pathway activation may promote unfavourable cardiovascular outcomes in humans.

Higher Plasma Levels of von Willebrand Factor and C-Reactive Protein During a Peritoneal Dialysis Regimen with Less Glucose and Glucose Degradation Products

vintage, and ethnicity. However, the higher incidence of diabetes mellitus in the overhydrated patients is striking, and a causal link is possible. Diabetes may be associated with a greater incidence of ischemic heart disease and cardiac failure, and hyperglycemia can cause thirst. It is more difficult to explain why women predominated in the dehydration cohort. That observation raised concern that perhaps the BCM’s algorithm underestimates total body water in women, particularly given that the clinicians looking after these patients did not think that they were hypovolemic, requiring active treatment to increase hydration. However, it is particularly pertinent that these patients showed a decline of RRF that reached statistical significance in the case of creatinine clearance. Although the euvolemic and overhydrated groups were of similar size, the changes in RRF in these latter cohorts were not statistically significant. Perhaps the BCM accurately diagnosed dehydration that was not clinically evident, and that dehydration led to greater RRF decline. We reiterate that great care must be taken when drawing conclusions from the present study. The short follow-up period also negates our ability to report on cardiovascular outcomes other than blood pressure. However, one of the strengths of the study is that we intervened only in very overhydrated patients, meaning that, to achieve BCM-defined euvolemia, large changes in extracellular water were induced. Despite those large changes, we observed no evidence suggesting that the patients became dehydrated, and importantly, we were able to maintain euvolemia in most of them. We suggest that multi-frequency bioimpedance is safe and effective in the PD setting to improve fluid overload and optimize blood pressure control.