17th European Society on Hypertension Meeting

Milan, 2007

INGENIOUS HYPERCARE:

RENAL PHENOTYPE

Josep Redon. MD, PhD, FAHAHypertension Clinic. Internal MedicineHospital Clinico. University of Valencia

Spain

HO

ME B

PJRP B2: Genetics, genomics and proteomics on chronic kidney disease in hypertension

• Investigating the genetic, genomic and proteomic basis of susceptibility to renal damage (urinary albumin excretion and renal damage) in HTN patients

• Creating a large database of several thousand patients in different European countries

• Cross-sectional and follow-up investigations

HO

ME B

PJRP B2: Genetics, genomics and proteomics on chronic kidney disease in hypertension: Objectives

• To analyse genetic factors associated with renal phenotypes in hypertensive subjects: elevated urinary albumin excretion (microalbuminuria, proteinuria), reduced GFR, end-stage renal disease

• To detect novel early markers of renal damage in hypertension by using proteomics and to examine their association with genetic markers

HO

ME B

PJRP B2: Genetics, genomics and proteomics on chronic kidney disease in hypertension: Types of studies

• Family-based association study of renal phenotypes, conducted simultaneously in the A2, B2 and B3

• Case-control studies of renal phenotypes in previously recruited hypertensives

• Follow-up studies of renal phenotypes in preexisting cohorts and in the family study

HO

ME B

PPhenotypes for renal damage in hypertension:

yearsyears monthsmonths

UA

EU

AE

FG m

l/min

FG m

l/min

HO

ME B

PPrevalence of renal damage in hypertension. I-Demand project (927 subjects)

122(13.2%)

99(10.7%)

134(14.5%)

renal dysfunction: 38.5% of pts

microalbuminuria

N=233(25.3%)

eGFR 60 ml/min

N=221(24.0%)

HO

ME B

PSeven-year incidence of ESRD according baseline creatinine clearance and proteinuria in general population

Creatinine Clearance (ml/min)

Proteinuria (+) Proteinuria (-)

0 15 30 45 60 75 90 105 120 135

1000

100

10

1

0.1

0.01

Cu

mu

lati

ve I

ncid

en

ce o

f ES

RD

p

er

1.0

00 s

cre

en

ed

in

7 y

rs

From Iseki et al., 2004

HO

ME B

PPhenotypes for renal damage in hypertension: GFR

Cockroft-Gault Formula (140- age) x body weight

(serum creatinine * 72)

* x 0.85 (if female)

MDRD Formula 186 * serum creatinine -1.154 * age -0.203

* 0.742 (if female) * 1.210 (if AA)

eGFReGFR

HO

ME B

PStages of chronic renal disease

Stage Description GF ml/min/ 1.73 m2

Prevalence

- On risk -

1 Renal lesion with GF normal or increased

>90 3.3 %

2 Renal lesion with GF slightly reduced

60-89 3.0 %

3 GF moderately reduced 30-59 4.3 %

4 GF severely reduced 15-29 0.2 %

5 Renal failure <15 o dialysis 0.1 %

HO

ME B

PPrevalence of chronic renal failure in hypertension

Serum Cr eCrCl> 1.4-1.5 mg/dl < 60 ml/min

HOT 18790 2.5% 12.3%

INSIGHT 6321 3.1 % 29.1%

HOPE 9173 10.5 % 36.4% **

H Clinico 1539 5.3 % 17.5 % *

(n)

HO

ME B

PCreatinine and cardiovascular morbidity and mortality. HOPE study

Mann et al. Ann Intern Med 2001

0

10

20

30

40

50

60

Primary

outcome

CV

mortality

Creatinine <1,4 mg/dl Creatinine >1,4mg/dl

Myocardial

infarction

Total

mortality

HO

ME B

PCardiovascular risk and creatinine values >1.5 mg/dl. HOT study

Adapted from Ruilope et al, JASN 2001

CV eventsMI

StrokeCV mortality

Total mortality0

1

2

3

4RR

HO

ME B

PCardiovascular disease and probability of GFR decline. The ARIC study

Elsaved et al. Arch Intern Med 2007

HO

ME B

PRelationship between serum levels of creatinine and creatinine clearance

Miravalles, Rodicio (data on file)

HO

ME B

PFormulans to estimate the GFR

Cockroft-Gault Formula (140- age) x body weight

(serum creatinine * 72)

* x 0.85 (if female)

MDRD Formula 186 * serum creatinine -1.154 * age -0.203

* 0.742 (if female) * 1.210 (if AA)

eGFReGFR

HO

ME B

PRelationship between MDRD and Cockcroft-Gault formulas to estimate renal function

Miravalles, Rodicio (data on file)

eG

FR

(m

l/m

in/1

.73

m2

)

Creatinine clearance (ml/min)

HO

ME B

PRelationship between two methods to estimate GFR: MDRD formula and I-talamate

MDRD

Iodo-talamate

Rule et al. Ann Intern Med 2004

HO

ME B

PGFR and standarized rates of hospitalization and cardiovascular events

Kaiser Permanent Renal RegistryKaiser Permanent Renal Registry

Go, A. S. et al. N Engl J Med 2004

HO

ME B

PAssociation of eGFR, and cystatin C with risk for death in elderly without chronic kidney disease

Shlipak et al. Ann Intern Med 2006

HO

ME B

PRelationship between serum cystatin C and creatinine clearance

Miravalles, Rodicio (data on file)

ROC curves to detect patients with GFR 60 – 90 mL/min

Cystatin C 0.671 (0.576 – 0.756)

Creatinine0.578 (0.481 – 0.675)

HO

ME B

PMeasuring GFR in the JRP A2, B2 and B3 (I)

• MDRD formula in each of the centres

• Creatinine will be measured in the coordinating centre with a standarized method and GFR will be recalculated

• Cystatin C will be measured in the coordinating centre

HO

ME B

PPhenotypes for renal damage in hypertension: Urinary albumin excretion

UAEUAE

HO

ME B

PPrevalence of microalbuminuria according BP categories. NAHNES III

80

70

60

50

40

30

20

10

0

Pre

vale

nce o

f alb

um

inu

ria,

%

optimal normal high normal stage 1 stage 2 stage 3

men women

5 8 712 12

1416

21

3135

56 55

from Jones, et al. 2003

HO

ME B

PNatural history of microalbuminuria

Redon et al. Curr Hypertens Rep 2007

0

10

20

30

40

50

60

Time x BP

Insulin-resistant

Non-insulin resistant

Nephrosclerosis

Mic

roalb

um

inu

ria

perc

en

tag

e (

%)

60

HO

ME B

PChanges in UAE categories according the UAE level and the presence of treatment at the begining

Group of patients Number subjects

(%) Rate100

patientes/year

Microalbuminurics

Regresion untreated 61 59 27.8

Regresion treated 191 40 18.0

Progresion 11 7.3

Proteinurics

Regresion untreated 12 33 17.4

Regresion treated 46 54 20.7

from Pascual, et al. J Hypertens 2006

HO

ME B

PUAE and risk of cardiovascular and non-cardiovascular mortality

Hillege et al Circulation 2000

60

HO

ME B

PUrinary albumin excretion and cardiovascular mortality. NAHNES II

Muntner et al. JASN 2002

<30 mg/dL, n=852830-299 mg/dL, n=196300 mg/dL, n=62

1.00

0.75

0.50

0.25

0.0050 55 60 65 70 75 80 85

Age (yr)

Cu

mu

lati

ve C

V d

isease

mort

ality

HO

ME B

PMicroalbuminuria and GFR changes overtime. The PREVEND study

Microalbuminuria

Delt

a c

reati

nin

e c

leara

nce

(m

l/m

in p

er

4 y

ear)

Urinary albumin excretion (mg/24hr)

1 10 100 1000-15

-10

-5

0

5

10

Verhave et al. JASN 2003

HO

ME B

PPassage, metabolization and excretion of albumin in the urine

Total albumin (IMRA and non-IMRA), fragments

Tubular cells

Reabsorption

Degradation

Back-leak

Back-leak

Filtration

HO

ME B

PMethods to measure albumin in urine

• Antibody recognisable albumin Immunoassays (RIA, nephelometry)

• Albumin not detected by immunoassays HPLC, precipitation

• Peptide fragments Spectrophotometry

HO

ME B

PCircadian variability of UAE in essential hypertensionCircadian variability of UAE in essential hypertension

1

10

100

1000N

igh

t U

AE (

µg

/min

)

1 10 100 1000

Day UAE (µg/min)

Redón et al, Med Clin, 1995

HO

ME B

PIntraindividual variability of UAE measurementsIntraindividual variability of UAE measurements

1

10

100

1000Fir

st

day

24-h

ou

rs (

µg

/min

)

1 10 100 1000

Second day 24 hours (µg/min)

DM tipo 1

HTA

Redón et al, Med Clin 1995

HO

ME B

PUAE: samples and units of measurementUAE: samples and units of measurement

Spot Night 24 hour

mg/24 h

mg/min

mg/mmol Cr

mg/g Cr

Urine sample

Un

its

HO

ME B

PUAE: samples and units of measurementUAE: samples and units of measurement

Spot Night 24 hour

mg/24 h 30-299

mg/min 20-199

mg/mmol Cr 3-29

mg/g Cr 30-299

Urine sample

Un

its

HO

ME B

PUrinary albumin stability over timein ideal conditions: 4ºC and protected from light

DayPercentageof negatives

who still negative

Percentageof positives

who still positiveAgreement

Correlationcoefficient

HO

ME B

PUrinary albumin measurement by using RIA and HPLC

HO

ME B

PBland-Altman plot of two methods for measuring urinary albumin: RIA and HPLC

HO

ME B

PMeasuring UAE in the JRP A2, B2 and B3 (I)

• First voiding urine in the morning

• 3 different days

• Measurements with nephelometrie and simultaneous examination of sediment (or disptick) in each of the centres

• 5 aliquots to store frozen at -20º at least (maintain at 4º out of light until frozen , recomendable no more than 4 hours)

• Samples frozen should be sent to the coordinating center (each 3 or 6 months)

HO

ME B

PMeasuring UAE in the JRP A2, B2 and B3 (and the others) (II)

• Measurements of albumin (nephrelometrie, HPLC) and creatinine

• UAE will be analyzed as qualitative and quantitative traits

• Measurement of other markers (oxidative stress)

• Proteomics in a small sample (with special requirements for urine collection and storage)

HO

ME B

PRisk for ESRD according BP categories in the Kaiser Permanent Register (21-year follow-up)

men women

120-129/80-84130-139/85-89

140-159/90-99

160-179/100-109

180-209/110-119≥210/120

70

60

50

40

30

20

10

0

Ag

e-a

dju

ste

d E

SR

D r

ate

s

per

100000 p

ers

on

-yrs

Blood pressure categoryfrom Hsu, et al. 2005

aRR 1.62aRR 1.98

aRR 2.59

aRR 3.86aRR 3.88

aRR 4.25

<120/80