Benedita Sampaio-Maia

Fernandes Cerqueira, C

Pestana M

Quelhas Dos Santos, JQ

Simoes Silva, L

English

Open Repository of the University of Porto

RENAL AND CARDIAC RENALASE EXPRESSION DURING NORMAL AND HIGH-SALT DIETS IN CHRONIC KIDNEY DISEASE RAT MODEL

Dos Santos, JQ

Repositório Aberto da Universidade do Porto

defined as the first hospitalization with a diagnosis of chronic kidneydisease.Results: At baseline, 146 (19%) and 60 (7.6%) patients met metabolicsyndrome and microalbuminuria criteria, respectively. After a medianfollow-up of 11.6 years, renal end-point was reached in 15.8% of patientswith metabolic syndrome and in 8.9% of those without it (P! 0.0087). Therisk of renal events increased progressively starting from patients withneither metabolic syndrome nor microalbuminuria, to patients with onlyone of these abnormalities, and then to those with both. Significantinteraction was observed between metabolic syndrome and microalbumi-nuria. Patients with concomitant occurrence of metabolic syndrome andmicroalbuminuria at baseline showed a greater than 5-fold risk of renaloutcome as compared to patients with neither of these two risk factors. Thisrisk became even higher when data were adjusted for potential con-founders.Conclusions: Metabolic syndrome and microalbuminuria are independentand interactive predictors of renal outcome in non diabetic patients withprimary hypertension.2D.04 ARE 3 SAMPLES MANDATORY TO CONFIRM AMICROALBUMINURIA?J. Fauvel, S. Lepenven, M. Ducher. Université C Bernard, Hospices Civils deLyon, Lyon, FranceObjective: Urinary albumin excretion is subject to an intra individualvariability. Thus, for research purposes, it is recommended to assay micro-albuminuria on three urine samples collected over a short time interval. Theobjective of our analysis was to check the usefulness to triplicate samples tomake sure of the albuminuric status of a diabetic patient.Methods: Microalbuminuria is a urinary excretion of albumin to creatininratio (ACR) between 2.5 and 25mg/mmol creat in man and between 3.5 and35mg/mmol of creatinine in woman. Lower and upper thresholds are usuallycalled normoalbuminuria and macroalbuminuria respectively. We presentthe not planed retrospective analysis of 82 triplicates (3 consecutive days)morning urine samples obtained during the follow-up of 47 type 2 diabetics(85 % hypertensives) who participated in 3 international studies (ROAD-MAP, AVOID, ALTITUDE). All the measurements (immunoturbidimetry)were performed on fresh urines in the same laboratory. Concordance wasobtained if the second andor the third sample confirmed the albuminuricstatus obtained from the first sample.Results: 17 % of the patients were normoalbuminuric, 27 % microalbumi-nuric and 56 % macroalbuminuric. Mean ACR"SEM for the 3 successivesamples were 76" 10, 70" 9 and 72" 9mg/mmol creat. The concordancerate was 98.8 %. Only a man whose ACR was close to the microalbuminuricupper threshold had 2 clashing values in the successive samples. Thecoefficient of variation of the immunoturbidimetric method (4 %) widelyexplains this result.Conclusion: Our results clearly show that it is useless to repeat albuminuriameasurements to define the albuminuric status of hypertensive diabeticssubjects.2D.05 PROXIMAL SODIUM REABSORPTIONIS AN INDEPENDENT PREDICTOR OFHYPERTENSIONF. Galletti, L. D’Elia, D. De Palma, R. Ippolito, R. Iacone, G. Rossi,S. Avallone, P. Strazzullo. Department of Clinical & Experimental Medicine,Federico II University of Naples, Naples, ItalyObjective: Given the association between salt-sensitivity of blood pressure(BP) and risk of future hypertension (HPT), we investigated the predictiverole of alterations in segmental renal tubular sodium handling in thedevelopment of HPT during the 8 year follow-up of the Olivetti HeartStudy participants.Methods: A selected sample (n! 314) of OHS population wasexamined at baseline and after 8 years. The participants were includedif they were normotensive (SBP/DBP <140/90mm Hg without anti-hypertensive treatment) and had normal renal function (creatinine clear-ance - CrCl> 60ml/min) at baseline. Proximal and distal fractional tubularsodium reabsorption were calculated using the clearance of exogenouslithium.Results: The baseline sample characteristics were: age 49.3" 6.8 yrs, BMI26.4" 2.8kg/m2, SBP/DBP 119.8" 9.6/78.9" 6.4mm Hg, CrCl 90.9"18.2mL/min (M"SD). The HPT incidence in 8 years was 52%. Theparticipants who developed HPT (group A) compared with those who didnot (group B) had higher baseline SBP (122.4" 8.4mm Hg vs 117.0" 10.0,p< 0.0001), DBP (80.6" 5.6 VS 77.1" 6.7mm Hg, p< 0.0001), BMI(27.0" 2.9 vs 25.9" 2.6 kg/m2, p< 0.0001) and fractional proximal reabsorp-tion of sodium (75.8" 6.3 vs 73.8" 7.3 %, p! 0.01). At logistic regressionanalysis using standardised variables, a 1SD-higher proximal sodium reabsorp-tion at baseline predicted a 44%greater risk ofHPTin 8 years (95%C.I. 13–84,p! 0.003), independently of baseline SBP (OR: 1.88, 95% C.I. 1.43–2.47,p< 0.001), BMI (OR: 1.51, 95% C.I. 1.16–1.95, p! 0.002), age and creatinineclearance used as an index of glomerular filtration rate.Conclusions: In this sample of healthy adult male population, proximalsodium reabsorption indexed to glomerular filtration rate was an indepen-dent predictor of future HPT.2D.06 RENAL AND CARDIAC RENALASEEXPRESSION DURING NORMAL ANDHIGH-SALT DIETS IN CHRONIC KIDNEYDISEASE RAT MODELJ. Quelhas Dos Santos, B. Sampaio-Maia, L. Simões-Silva, C. Fernandes-Cerqueira, M. Pestana. 1Unit of Research and Development of Nephrology, Facultyof Medicine, University of Porto, Porto, Portugal, 2Faculty of Dental Medicine,University of Porto, Porto, PortugalRenalase, a new regulator of cardiac function and blood pressure (BP), is amonoamine oxidase secreted into blood mainly by the kidney but also by theheart and other tissues. A reduced renalase expression was described inpatients and in animal models of chronic kidney disease (CKD) andhypertension. In addition, the renalase knockout mouse is hypertensiveand exquisitely sensitive to cardiac ischemia. The aim of the present studywas to examine the influence of high sodium intake (HS) on renal and cardiacexpression of renalase in rats submitted to 3/4 nephrectomy (3/4nx) andSham surgery (Sham).Ten days after surgery, 3/4nx and Sham animals received a normal (NS) or aHS diet (40mmol/kg/day) during four days. BP and heart rate (HR) weremeasured daily using a photoelectric tail-cuff pulse detector. Fourteen daysafter surgery the animals were sacrificed and left ventricle (LV) and renalcortex (RC) were collected for protein quantification by Western-blottingusing the anti-renalase polyclonal primary antibody (1:200, Abcam, UK). Inaddition, cardiac morphometry and transversal cardiomyocyte diameter(TCD) were also evaluated in all groups.BP, HR and TCD were significantly increased in 3/4nx rats throughout thestudy. In addition, HS diet significantly increased BP, HR and TCD in both3/4nx and Sham rats. During NS diet the dimmer form of renalase wassignificantly reduced in both RC and LV from 3/4nx rats whereas during HSdiet bothmonomer and dimmer renalase forms were reduced in both RC andLV from 3/4nx rats. Moreover, HS diet significantly decreased both mono-mer and dimmer renalase isoforms in the LV from 3/4nx rats when comparedwith NS intake.Our results show that the reduced renalase expression in the LV from 3/4nxrats is further accentuated during HS intake. It is suggested that this maycontribute to the increased sodium-sensitivity of BP and enhanced cardio-vascular risk in CKD.e26 Journal of Hypertension Vol 28, e-Supplement A, June 2010

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RENAL AND CARDIAC RENALASE EXPRESSION DURING NORMAL AND HIGH-SALT DIETS IN CHRONIC KIDNEY DISEASE RAT MODEL

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