Association between carotid diameter and the advanced glycation endproduct Nε-Carboxymethyllysine (CML)

<p>Abstract</p> <p>Background</p> <p>N^ε-Carboxymethyllysine (CML) is the major non-cross linking advanced glycation end product (AGE). CML is elevated in diabetic patients and apparent in atherosclerotic lesions. AGEs are associated with hypertension and arterial stiffness potentially by qualitative changes of elastic fibers. We investigated whether CML affects carotid and aortic properties in normoglycemic subjects.</p> <p>Methods</p> <p>Hundred-two subjects (age 48.2 ± 11.3 years) of the FLEMENGHO study were stratified according to the median of the plasma CML level (200.8 ng/ml; 25^thpercentile: 181.6 ng/ml, 75^thpercentile: 226.1 ng/ml) into "high CML" versus "low CML" as determined by ELISA. Local carotid artery properties, carotid intima media thickness (IMT), aortic pulse wave velocity (PWV), blood pressure and fetuin-A were analyzed. In 26 patients after carotidectomy, CML was visualized using immunohistochemistry.</p> <p>Results</p> <p>According to the CML median, groups were similar for anthropometric and biochemical data. Carotid diameter was enlarged in the "high" CML group (485.7 ± 122.2 versus 421.2 ± 133.2 μm; P < 0.05), in particular in participants with elevated blood pressure and with "high" CML ("low" CML: 377.9 ± 122.2 μm and "high" CML: 514.5 ± 151.6 μm; P < 0.001). CML was associated fetuin-A as marker of vascular inflammation in the whole cohort (r = 0.28; P < 0.01) and with carotid diameter in hypertensive subjects (r = 0.42; P < 0.01). CML level had no effect on aortic stiffness. CML was detected in the subendothelial space of human carotid arteries.</p> <p>Conclusion</p> <p>In normoglycemic subjects CML was associated with carotid diameter without adaptive changes of elastic properties and with fetuin-A as vascular inflammation marker, in particular in subjects with elevated blood pressure. This may suggest qualitative changes of elastic fibers resulting in a defective mechanotransduction, in particular as CML is present in human carotid arteries.</p

Myeloid-related protein 8/14 complex describes microcirculatory alterations in patients with type 2 diabetes and nephropathy

<p>Abstract</p> <p>Background</p> <p>Inflammation contributes to cardiovascular complications in type 2 diabetes, which are often characterized by microvascular alterations. We investigated whether myeloid-related protein 8/14 complex (MRP8/14) secreted by transmigrating monocytes and granulocytes may represent a biomarker for microvascular alterations in patients with type 2 diabetes and nephropathy.</p> <p>Methods</p> <p>MRP8/14 was measured in 43 patients with type 2 diabetes and nephropathy. Additionally, the inflammatory markers Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were quantified. To detect microvascular alterations proteinuria and retinal vessel caliber were used as classical and novel marker, respectively. Proteinuria was quantified by protein-creatinine ratio (PCR); retinal vessel caliber was quantified after retina photography on digitalized retina pictures.</p> <p>Results</p> <p>MRP8/14 was positively associated with inflammation (<it>r </it>= 0.57), proteinuria (<it>r </it>= 0.40) and retinal arterial caliber (<it>r </it>= 0.48). Type 2 diabetic patients with MRP8/14 values above the median of 5.8 μg/ml demonstrated higher proteinuria and larger retinal artery caliber than patients with MRP8/14 values below the median (logPCR: -0.51 ± 0.52 versus -0.96 ± 0.46, <it>P </it>< 0.01; retinal artery lumen (μm): 178.3 ± 14.1 versus 162.7 ± 14.9 <it>P </it>< 0.01). Both groups did not differ with regard to metabolic factors and blood pressure. MRP8/14 was an independent predictor of retinal artery caliber in multivariate stepwise regression analysis (<it>β </it>= 0.607) and was positively associated with IL-6 (<it>r </it>= 0.57, <it>P </it>< 0.001) and TNF-α (<it>r </it>= 0.36, <it>P </it>< 0.05).</p> <p>Conclusion</p> <p>MRP8/14 – a marker for transendothelial migration – describes not only the state of inflammation in diabetic nephropathy, but additionally the degree of microvascular alterations in the glomerular and retinal bed. Therefore, MRP8/14 may be a potentially selective novel biomarker for microcirculatory defects in diabetic nephropathy.</p

Association of kidney donor risk index with the outcome after kidney transplantation in the eurotransplant senior program

Background: We evaluated the Kidney Donor Risk Index (KDRI) scoring system for kidney transplantation in the Eurotransplant Senior Program (ESP) that allocates kidneys from older donors to older recipients (≥65 years). Material and methods: We retrospectively analyzed data of 37 kidney transplant recipients and 36 kidney donors who participated in kidney transplantation program according to the ESP at our center from January 2004 until December 2013. Results: Mean recipient and donor age was 67.9±2.6 and 70.5±4.0 years respectively. The mean KDRI score was 1.7±0.27. Uncensored graft survival after 1 year and 5 years was 64.2% and 53.7% respectively. Subgroup analysis showed that in kidney transplantation with KDRI >1.83, graft survival was significantly reduced compared to lower KDRI subgroups. KDRI was significantly correlated with serum creatinine level at discharge (r=0.4). Conclusions: ESP kidneys represent a group of high-risk grafts with high KDRI scores. Higher KDRI scores in ESP kidneys was associated with reduced postoperative short-term and long-term graft outcomes. KDRI might be useful in decision-making for selecting donors for ESP kidney transplantation

Relationship between renal resistance index and renal function in liver transplant recipients after cessation of calcineurin inhibitor

End stage renal disease is a major complication after orthotopic liver transplantation (OLT). Vasoconstriction of renal arterial vessels because of calcineurin inhibitor (CNI) treatment plays a pivotal role in the development of renal insufficiency following OLT. Renal resistance can be measured non-invasively by determining the resistance index (RI) of segmental arteries by color-coded duplex ultrasonography, a measure with predictive value for future renal failure. Sixteen OLT patients on long-term CNI therapy were recruited prospectively and randomly assigned either to receive the m-TOR inhibitor sirolimus (SRL) or to continue on CNI treatment, and were followed for one yr. Serum creatinine (crea) declined after conversion to SRL, whereas it tended to increase in patients remaining on CNI (meanDelta crea SRL: -27, -18, -18, -15 micromol/L; meanDelta crea CNI: 4, 5, 8, 11 micromol/L at 1, 3, 6, 12 months, p = 0.02). RI improved after switching to SRL and was lower on SRL than on CNI (meanDeltaRI SRL: -0.04, -0.04, -0.03, -0.03; meanDeltaRI CNI: -0.006, 0.004, -0.007, -0.01 after 1, 3, 6, 12 months, p = 0.016). Individual changes of RI correlated significantly with individual changes of crea (r = 0.54, p < 0.001). Conversion from CNI to SRL can ameliorate renal function accompanied by a reduction of intrarenal RI after OLT

Arterial stiffness assessed by digital volume pulse correlates with comorbidity in patients with ESRD

BACKGROUND: Digital volume pulse (DVP), a noninvasive method for indirect assessment of arterial stiffness, was not tested previously in patients with end-stage renal disease (ESRD). Therefore, we compared the DVP-derived stiffness index (SI(DVP)) with aortic pulse wave velocity (PWV) determined by means of Doppler ultrasonography in 2 groups of patients with ESRD and analyzed the correlation between SI(DVP) and comorbidity. METHODS: Photoplethysmography was performed on the index finger of the dominant hand or the hand from the nonfistula arm in 49 renal transplant (TX) recipients and 48 hemodialysis (HD) patients. Pulse curves were analyzed with computer assistance. Comorbidity was assessed by using an established index. RESULTS: The intrasubject variability of SI(DVP) was 5.7%. SI(DVP) and aortic PWV values correlated significantly (r = 0.66; P = 0.001) in patients with ESRD. SI(DVP) could not be assessed reliably in 25% and 6% of HD patients and TX recipients, respectively. Multivariate regression analyses showed that SI(DVP) increased with age in both HD patients and TX recipients (r = 0.61; P < 0.001) and with systolic blood pressure (r = 0.53; P < 0.025), mean arterial pressure (r = 0.47; P < 0.05), and pulse pressure (r = 0.52; P = 0.02) in TX recipients. Severity of comorbid status was associated highly with individual residuals of age-adjusted SI(DVP) in HD patients and TX recipients (P < 0.001). CONCLUSION: DVP allows the measurement of arterial stiffness in most, but not all, patients with ESRD. SI(DVP) values correlate with comorbidity in HD patients and TX recipients

Arterial stiffness assessed by digital volume pulse correlates with comorbidity in patients with ESRD

BACKGROUND: Digital volume pulse (DVP), a noninvasive method for indirect assessment of arterial stiffness, was not tested previously in patients with end-stage renal disease (ESRD). Therefore, we compared the DVP-derived stiffness index (SI(DVP)) with aortic pulse wave velocity (PWV) determined by means of Doppler ultrasonography in 2 groups of patients with ESRD and analyzed the correlation between SI(DVP) and comorbidity. METHODS: Photoplethysmography was performed on the index finger of the dominant hand or the hand from the nonfistula arm in 49 renal transplant (TX) recipients and 48 hemodialysis (HD) patients. Pulse curves were analyzed with computer assistance. Comorbidity was assessed by using an established index. RESULTS: The intrasubject variability of SI(DVP) was 5.7%. SI(DVP) and aortic PWV values correlated significantly (r = 0.66; P = 0.001) in patients with ESRD. SI(DVP) could not be assessed reliably in 25% and 6% of HD patients and TX recipients, respectively. Multivariate regression analyses showed that SI(DVP) increased with age in both HD patients and TX recipients (r = 0.61; P < 0.001) and with systolic blood pressure (r = 0.53; P < 0.025), mean arterial pressure (r = 0.47; P < 0.05), and pulse pressure (r = 0.52; P = 0.02) in TX recipients. Severity of comorbid status was associated highly with individual residuals of age-adjusted SI(DVP) in HD patients and TX recipients (P < 0.001). CONCLUSION: DVP allows the measurement of arterial stiffness in most, but not all, patients with ESRD. SI(DVP) values correlate with comorbidity in HD patients and TX recipients

Sphingosine kinase modulates microvascular tone and myogenic responses through activation of Rhoa/Rho kinase

Background - RhoA and Rho kinase are important modulators of microvascular tone. Methods and Results - We tested whether sphingosine kinase (Sphk1) that generates the endogenous sphingolipid mediator sphingosine-1-phosphate (S1P) is part of a signaling cascade to activate the RhoA/Rho kinase pathway. Using a new transfection model, we report that resting tone and myogenic responses of isolated resistance arteries increased with forced expression of Sphk1 in smooth muscle cells of these arteries. Overexpression of a dominant negative Sphk1 mutant or coexpression of dominant negative mutants of RhoA or Rho kinase together with Sphk1 completely inhibited development of tone and myogenic responses. Conclusions - The tone-increasing effects of a Sphk1 overexpression suggest that Sphk1 may play an important role in the control of peripheral resistance