VITAMINA D: QUANTO DI NUOVO E DI

IGNOTO?

Mario Cozzolino, MD, PhD

Dipartimento di Scienze della Salute

Università degli Studi di Milano

UO Nefrologia e Dialisi, AO San Paolo, Milano

2

OUTLINE

Basics and background on vitamin D metabolism in CKD Vitamin D deficiency and cardiovascular diseases and its risk factors Natural vitamin D treatment in CKD Perspectives & Conclusions

3

OUTLINE

Basics and background on vitamin D metabolism in CKD Vitamin D deficiency and cardiovascular diseases and its risk factors Natural vitamin D treatment in CKD Perspectives & Conclusions

PTH

Calcio

Fosforo Vitamina

D

FGF23

CKD-MBD

PTH

Calcio

Fosforo Vitamina

D

FGF23

CKD-MBD

TOP 10 Medical Breakthroughs 2007

Adapted from Time Magazine, US Edition 2007 (Dec 24);26:170

Benefits of Vitamin D

• Bone strength

• Diabetes

• Gum disease

• Multiple sclerosis

• Cancer (in particular colon cancer)

7

Vitamin D

Vitamin D metabolism

Vitamin D sources

Nutrition UV-B induced vitamin D

production in the skin

80-90% 10-20%

8

Vitamin D metabolism

Pilz S, et al. Nature Reviews Cardiology 2009, 6: 621-630

Pathophysiology

ng/ml

HL~1 month

pg/ml

HL<1 day

Serum 1,25(OH)2D: Derived from the kidney

Tissue 1,25(OH)2D: Produced from serum 25(OH)D

9

"The Survival advantage conferred by light skin as our ancestors

migrated to higher latitudes is generally believed to have resulted from

the importance of maintaining adequate vitamin D levels under

conditions of reduced exposure to UV-B"

Giovannucci E, Therapy 2008; 5:655-658

Vitamin D and skin

10

Vitamin D (25[OH]D) status in CKD

>30 ng/mL 10-30 ng/mL <10 ng/mL

Decrease in intestinal

calcium absorption and

an increase in PTH in

patients with 25(OH)D

levels < 30ng/mL

(<75nmol/L)

11

Reduced 25D/1,25D Occurs Early in CKD

Levin A, et al. Kidney Int 2007;71:31–8

†p<0.001

iPTH (pg/mL) 1,25D (pg/mL) 25D (ng/mL)

*as measured by 1,25D

n=61 n=117 n=230 n=396 n=355 n=358 n=204 n=93

†

79–70 69–60 59–50 49–40 39–30 29–20 <20

eGFR Interval (mL/min/1.73 m2)

0

≥80

5

10

15

20

25

30

35

40

45

50

1,2

5D

(p

g/m

L)

25

D (

ng

/mL

)

†

0

50

100

150

iPT

H l

eve

l (p

g/m

L)

(n=1814)

12

OUTLINE

Basics and background on vitamin D metabolism in CKD Vitamin D deficiency and cardiovascular diseases and its risk factors Natural vitamin D treatment in CKD Perspectives & Conclusions

Hypothesis: Mechanisms of VDR Activation Impact on CV Outcomes

↓ Atherosclerosis

and vascular

calcification

Li YC, et al. J Clin Invest 2002;110:229–38; Mathieu C, et al. Trends Mol Med 2002;8:174–9

VDR activation

↓ Inflammation

↓ Heart failure

↓ Morbidity and mortality

↓ RAAS

↓ LVH

↑ Cardiomyocyte

remodeling

System Tissue

Gastrointestinal Esophagus, stomach, small intestine, large intestine,

Hepatic Liver parenchyma cells

Endocrine Parathyroid, pancreatic β-cells, thyroid C-cells

Exocrine Parotid gland, sebaceous gland

Reproductive Testis, spermatocytes, ovary, placenta, uterus, endometrium, yolk sac

Immune Thymus, bone marrow, B cells, T cells

Respiratory Lung alveolar cells

Skeletal Osteoblasts, osteocytes, chondrocytes

Muscle Striated muscle

Epidermis/appendage Skin, breast, hair follicles

Central nervous system Brain neurons

Connective tissue Fibroblasts, stroma

VDR Distribution in the Body

Cardiovascular Vascular smooth muscle cells, endothelial cells, cardiomyocytes

Renal Proximal and distal tubules, collecting duct, podocytes

Endothelial cells have VDR

and express 1-alpha hydroxylase Merke, et al. JCI 1989

VSMC cells have VDR

Kawashima H. BBRC. 1987

and express 1-alpha hydroxylase Somjen D, Circulation 2005

Vitamin D and the vasculature

Lack of VDR induces senescence in VSMCs

Absence of VDR in mouse VSMC induces an arrest in G1 phase and a decrease in proliferation levels, probably due to a development of a premature cellular senescence

Valcheva P, et al. Nephrol Dial Transplant 2008;1(Suppl 2):132. #SP313

Growth curve of VSMC in

10% FBS DMEM

100000

200000

300000

400000

500000

0 0 10 20 30 40 50 60

KO y=108924e0.0154x

R2=0.9486

WT y=87445e0.0322x

R2=0.9362

Cell

num

be

r

Time (hours)

WT KO

17

Vitamin D and the cardiovascular system

Vitamin D receptor (VDR) expression:

Heart: Cardiomyocytes and cardiac fibroblasts

Cells of the vessel wall: Endothelial cells,

vascular smoorth muscle cells, macrophages

1-alpha hydroxylase expression:

Heart: Cardiomyocytes and cardiac fibroblasts

Cells of the vessel wall: Endothelial cells,

vascular smooth muscle cells, macrophages

18

Vitamin D receptor (VDR) knock-out mice

Myocardial hypertrophy

Arterial hypertension

Overexpression of renin (renin angiotensin aldosterone system; RAAS)

Xiang W, et al. Am J Physiol Endocrinol Metab 2005;288:125-132

VDR Knock-out models

19

Vitamin D receptor KO

Bouillon R et al. Endocrine Reviews 2008; 29:726-776

Selective VDR knock out in the heart

causes myocardial dysfunction

Gardner DG, et al. 14th Workshop of vitamin D, Brugge, Belgium, Oct 2009

21

Vitamin D effects on the cardiovascular system

VITAMIN D EFFECTS ON THE CARDIOVASCULAR

SYSTEM

EFFECTS ON THE MYOCARDIUM

Antihypertrophic effects

Modulation of calcium flux and contractility

Renin suppression

Modulation of extracellular matrix turnover

EFFECTS ON THE VESSELS

Anti-atherosclerotic effects

Inhibition of vascular calcification

Improvement of endothelial function

EFFECTS ON CARDIOVASCULAR

RISK FACTORS

Reno-protective effects

Anti-hypertensive effects

Anti-diabetic effects

PTH suppression

Anti-inflammatory effects

Anti-oxidative effects

All-cause and CV Mortality in 25D Quartiles

Su

rviv

al

Time (years)

0.6

0.7

0.8

0.9

1

0 2 4 6 8

Q4

(high)

Q3

Q2

Q1

(low)

0.6

0.7

0.8

0.9

1

0 2 4 6 8

Q4

(high)

Q3

Q2

Q1

(low)

All-cause mortality (HR 2.08 [95% CI, 1.60–2.70]

high vs low)

Cardiovascular mortality (HR 2.22 [95% CI, 1.57–3.13]

high vs low)

p<0.001 across all quartiles

Dobnig H, et al. Arch Intern Med 2008;168:1340–9

0

0.5

1

1.5

2

2.5

3

Low Serum 25D Levels (Quartiles) are Associated with Higher Prevalence of Peripheral Arterial Disease

Melamed M et al. Arterioscler Thromb Vasc Biol 2008;28:1179–85

1

(lowest,

<17.8)

2

(17.8 to 23.4)

3

(23.5 to 29.1)

4

(highest,

≥29.2)

Serum 25D, ng/mL

(range)

Pre

vale

nce r

atio

*p<0.001 compared with the reference group of 25D 29.2 ng/mL

REF

*

Multivariable adjusted† prevalence ratios of peripheral arterial disease (PAD)

(ankle/brachial index <0.9) by quartiles of serum 25D

†see notes page for all confounders

• A nested case-control study in 18,225 men (40 to 75 years; no CVD) in the Health Professionals Follow-up Study

Low 25D Levels Associated with Increased Risk of Myocardial Infarction in Men

15.1–22.5 22.6–29.9

0.0

0.5

1.0

1.5

2.0

≤15.0

Rela

tive r

isk o

f M

I o

ver

10 y

ears

≥30.0 REF

Baseline plasma 25D, ng/mL†

2.5

Giovannucci E, et al. Arch Intern Med 2008;168:1174–80

63/87*

*Cases/controls, no; †SI conversion factor: To convert 25D to nanomoles per liter, multiply by 2.496

156/307* 165/299*

70/207*

p-value (trend) <0.01

25

OUTLINE

Basics and background on vitamin D metabolism in CKD Vitamin D deficiency and cardiovascular diseases and its risk factors Natural vitamin D treatment in CKD Perspectives & Conclusions

26

Vitamin D in CKD

Pilz S, et al. Nature Reviews Cardiology 2009, 6: 621-630

Low serum levels of

1,25(OH)2D

Low serum levels of

25(OH)D

Natural (nutritional)

vitamin D treatment

Pathophysiology

Active vitamin D treatment:

1,25(OH)2D (=calcitriol)

or

Selective VDR agonists (ie

paricalcitol, doxercalciferol,

maxacalcitol, falecalcitriol )

27

PTH effects on the cardiovascular system

PTH receptors are widely expressed

throughout the cardiovascular system

including the myocardium

PTH infusions increase blood pressure in

healthy volunteers and PTH modifies

contractile functions of the myocardium

PTH levels were highlighted as a

cardiovascular risk factor in

epidemiological studies

Schlüter KD et al. Cardiovasc Res 1998,37:34-41

Fitzpatrick LA et al. Curr Osteoporos Rep 2008,6:77-83

Hagström E et al. Circulation 2009,119:2765-2771

28

Natural vitamin D effects on PTH

Cozzolino M, et al. Eur J Heart Failure 2010

Impact of VDR activators on CV endpoints and patient outcome

Kidney fibrosis VDR effect

• Interstitial volume • Glomerulosclerosis • TGF-β1

ANF, atrial natriuretic factor; ANP, atrial natriuretic protein; BMP-2, bone morphogenetic protein-2; BNP, brain natriuretic protein; IL-1β,

interleukin-1β; LV, left ventricular; MGP, matrix Gla protein; PAI-1, plasminogen activator inhibitor-1; TGF-β, tumour growth factor-β; TNF-α, tumour necrosis factor-α; VEGF, vascular endothelial growth factor

VDR activators Cardiovascular Modulation Outcome

Inactive vitamin D

• Ergocalciferol

• Cholecalciferol

1α-hydroxyvitamin D

• Alfacalcidol

• Doxercalciferol

1,25-dihydroxyvitamin D

• Calcitriol

Selective 1,25D

• Paricalcitol

• Maxacalcitol

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Decreased • Hypertension • Heart weight • LV hypertrophy • Posterior wall thickness • Left ventricular end-

diastolic pressure • BNP, ANF, ANP • Renin and angiotensin • VEGF • PAI-1 • Tissue factor

Increased • Fractional shortening • Vascular relaxation • Thrombomodulin

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Calcification VDR effect

Inducers • BMP-2 • Type 1 collagen • IL-1β and TNF-α

Inhibitors • MGP • Osteopontin • Type IV collagen

Other effects

Cozzolino M, et al. Eur J Heart Failure 2010

Impact of VDR activators on CV endpoints and patient outcome

Kidney fibrosis VDR effect

• Interstitial volume • Glomerulosclerosis • TGF-β1

ANF, atrial natriuretic factor; ANP, atrial natriuretic protein; BMP-2, bone morphogenetic protein-2; BNP, brain natriuretic protein; IL-1β,

interleukin-1β; LV, left ventricular; MGP, matrix Gla protein; PAI-1, plasminogen activator inhibitor-1; TGF-β, tumour growth factor-β; TNF-α, tumour necrosis factor-α; VEGF, vascular endothelial growth factor

VDR activators Cardiovascular Modulation Outcome

Inactive vitamin D

• Ergocalciferol

• Cholecalciferol

1α-hydroxyvitamin D

• Alfacalcidol

• Doxercalciferol

1,25-dihydroxyvitamin D

• Calcitriol

Selective 1,25D

• Paricalcitol

• Maxacalcitol

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Decreased • Hypertension • Heart weight • LV hypertrophy • Posterior wall thickness • Left ventricular end-

diastolic pressure • BNP, ANF, ANP • Renin and angiotensin • VEGF • PAI-1 • Tissue factor

Increased • Fractional shortening • Vascular relaxation • Thrombomodulin

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Calcification VDR effect

Inducers • BMP-2 • Type 1 collagen • IL-1β and TNF-α

Inhibitors • MGP • Osteopontin • Type IV collagen

Other effects

VDR activators

Inactive vitamin D

•Ergocalciferol

•Cholecalciferol

1α-hydroxyvitamin D

•Alfacalcidol

•Doxercalciferol

1,25-dihydroxyvitamin D

•Calcitriol

Selective 1,25D

•Paricalcitol

•Maxacalcitol

Cozzolino M, et al. Eur J Heart Failure 2010

Impact of VDR activators on CV endpoints and patient outcome

Kidney fibrosis VDR effect

• Interstitial volume • Glomerulosclerosis • TGF-β1

ANF, atrial natriuretic factor; ANP, atrial natriuretic protein; BMP-2, bone morphogenetic protein-2; BNP, brain natriuretic protein; IL-1β,

interleukin-1β; LV, left ventricular; MGP, matrix Gla protein; PAI-1, plasminogen activator inhibitor-1; TGF-β, tumour growth factor-β; TNF-α, tumour necrosis factor-α; VEGF, vascular endothelial growth factor

VDR activators Cardiovascular Modulation Outcome

Inactive vitamin D

• Ergocalciferol

• Cholecalciferol

1α-hydroxyvitamin D

• Alfacalcidol

• Doxercalciferol

1,25-dihydroxyvitamin D

• Calcitriol

Selective 1,25D

• Paricalcitol

• Maxacalcitol

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Decreased • Hypertension • Heart weight • LV hypertrophy • Posterior wall thickness • Left ventricular end-

diastolic pressure • BNP, ANF, ANP • Renin and angiotensin • VEGF • PAI-1 • Tissue factor

Increased • Fractional shortening • Vascular relaxation • Thrombomodulin

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Calcification VDR effect

Inducers • BMP-2 • Type 1 collagen • IL-1β and TNF-α

Inhibitors • MGP • Osteopontin • Type IV collagen

Other effects

Cardiovascular

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Cozzolino M, et al. Eur J Heart Failure 2010

Impact of VDR activators on CV endpoints and patient outcome

Kidney fibrosis VDR effect

• Interstitial volume • Glomerulosclerosis • TGF-β1

ANF, atrial natriuretic factor; ANP, atrial natriuretic protein; BMP-2, bone morphogenetic protein-2; BNP, brain natriuretic protein; IL-1β,

interleukin-1β; LV, left ventricular; MGP, matrix Gla protein; PAI-1, plasminogen activator inhibitor-1; TGF-β, tumour growth factor-β; TNF-α, tumour necrosis factor-α; VEGF, vascular endothelial growth factor

VDR activators Cardiovascular Modulation Outcome

Inactive vitamin D

• Ergocalciferol

• Cholecalciferol

1α-hydroxyvitamin D

• Alfacalcidol

• Doxercalciferol

1,25-dihydroxyvitamin D

• Calcitriol

Selective 1,25D

• Paricalcitol

• Maxacalcitol

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Decreased • Hypertension • Heart weight • LV hypertrophy • Posterior wall thickness • Left ventricular end-

diastolic pressure • BNP, ANF, ANP • Renin and angiotensin • VEGF • PAI-1 • Tissue factor

Increased • Fractional shortening • Vascular relaxation • Thrombomodulin

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Calcification VDR effect

Inducers • BMP-2 • Type 1 collagen • IL-1β and TNF-α

Inhibitors • MGP • Osteopontin • Type IV collagen

Other effects

Modulation

Decreased •Hypertension •Heart weight •LV hypertrophy •Posterior wall thickness •Left ventricular end-diastolic pressure •BNP, ANF, ANP •Renin and angiotensin •VEGF •PAI-1 •Tissue factor

Increased •Fractional shortening •Vascular relaxation •Thrombomodulin

Cozzolino M, et al. Eur J Heart Failure 2010

Impact of VDR activators on CV endpoints and patient outcome

Kidney fibrosis VDR effect

• Interstitial volume • Glomerulosclerosis • TGF-β1

ANF, atrial natriuretic factor; ANP, atrial natriuretic protein; BMP-2, bone morphogenetic protein-2; BNP, brain natriuretic protein; IL-1β,

interleukin-1β; LV, left ventricular; MGP, matrix Gla protein; PAI-1, plasminogen activator inhibitor-1; TGF-β, tumour growth factor-β; TNF-α, tumour necrosis factor-α; VEGF, vascular endothelial growth factor

VDR activators Cardiovascular Modulation

Inactive vitamin D

• Ergocalciferol

• Cholecalciferol

1α-hydroxyvitamin D

• Alfacalcidol

• Doxercalciferol

1,25-dihydroxyvitamin D

• Calcitriol

Selective 1,25D

• Paricalcitol

• Maxacalcitol

Hormone

Heart

Vasculature

Kidney

VDR

VDR

VDR

VDR

Immune cells VDR

Decreased • Hypertension • Heart weight • LV hypertrophy • Posterior wall thickness • Left ventricular end-

diastolic pressure • BNP, ANF, ANP • Renin and angiotensin • VEGF • PAI-1 • Tissue factor

Increased • Fractional shortening • Vascular relaxation • Thrombomodulin

Outcome

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Calcification VDR effect

Inducers • BMP-2 • Type 1 collagen • IL-1β and TNF-α

Inhibitors • MGP • Osteopontin • Type IV collagen

Other effects

Outcome

Acute Repair

Integrity restored

Chronic Repair

Damage limitation

Morbidity/

Mortality

Improved

Vitamin D and Outcome: Classical U-Curve Relationship

Adverse events

Vitamin D status

Immune system

Cancer defense

Bone health

sHPT

RAS

Myoc. fibrosis

Mortality

Survival benefit in ESRD (Teng / Thadani etc.)

Accelerated arteriosclerosis

low high ultra- high

Mortality

Ca x P

intermediate

Cozzolino M & Branderburg V, Clinical Nephrology 2009,

0

1

2

3

4

5

6

7

5 10 15 20 25 30 35 40

-2

0

2

4

6

8

10

5 10 15 20 25 30 35

-2

0

2

4

6

8

10

0.40 0.60 0.80 1.00 1.20 1.40 1.60

0

1

2

3

4

5

6

7

0.40 0.60 0.80 1.00 1.20 1.40 1.60

4

6

8

10

12

14

16

18

20

0.40 0.60 0.80 1.00 1.20 1.40 1.60

1,25D and 25D Levels are Correlated with Arterial Parameters in HD Patients

London G, et al. J Am Soc Nephrol 2007;18:613–20

Log10 25D (μg/L)

1,25D (ng/L)

r= -0.535

p<0.0001

n=52

r=0.616

p<0.0001

n=42

r=0.584

p<0.001

n=37

FM

D (

% o

f b

ase

line

dia

me

ter)

Ao

rtic

PW

V (

m/s

)

Bra

ch

ial a

rtery

dis

ten

sib

ility

(kP

a1

0-1

.10

-3)

FM

D (

% o

f b

ase

line

dia

me

ter)

4

6

8

10

12

14

16

18

20

5 10 15 20 25 30 35 40

Ao

rtic

PW

V (

m/s

)

r= -0.616

p<0.0001

n=40

r=0.632

p<0.001

n=30

r=0.741

p<0.0001

n=27

Bra

ch

ial a

rtery

dis

ten

sib

ility

(kP

a1

0-1

.10

-3)

Flow-mediated dilation (FMD) Brachial artery distensibility Aortic PWV

37

Vitamin D status and sudden cardiac death

in hemodialysis patients

38

Kaplan Meier curve for sudden cardiac death according to 25-hydroxyvitamin D groups

Vitamin D status and

CVD mortality

Pilz S, et al. Nephrology, Dialysis and Transplantation, 2011 Mar 4. [Epub ahead of print]

Patients with eGFR <60 mL/min/1.73m² (n=444)

During a median follow up of 9.4 years 159 CVD deaths occurred

25(OH)D levels

>30 ng/ml

20-29.99 ng/ml

10-19.99 ng/ml

<10 ng/ml

Adjusted HR: Severe deficient vs.

sufficient 5.61 (1.89-16.6)

128 CKD 2-5 Patients

41

OUTLINE

Basics and background on vitamin D metabolism in CKD Vitamin D deficiency and cardiovascular diseases and its risk factors Natural vitamin D treatment in CKD Perspectives & Conclusions

March 23, 2011

43

Vitamin D supplementation

and mortality

Autier P, et al. Arch Intern Med 2007; 167: 1730-1737

44

Take home messages

The cardiovascular system is a target tissue for vitamin D

and a poor vitamin D status, which is present in the majority

of CKD patients, is a risk factor for cardiovascular mortality

It is suggested to test for and treat reduced 25(OH)D

concentrations with natural vitamin D: this therapy is safe,

cheap and simple, reduces PTH levels and might also reduce

cardiovascular events and mortality