Heart Failure, Sudden Cardiac Death and Vitamin D

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Heart Failure, Sudden Cardiac Death and Vitamin D

Stefan Pilz, M.D.

Department of Internal Medicine

Division of Endocrinology and Nuclear Medicine

Medical University of Graz

Auenbruggerplatz 15, 8036 Graz, Austria

++43 650 9103667 / ++43 316 673216 (FAX)

stefan.pilz@...

http://www.vitasearch.com/CP/experts/SPilzAT09-16-08.pdf

" Association of Vitamin D Deficiency with Heart Failure and Sudden

Cardiac Death

In a Large Cross-Sectional Study of Patients Referred for Coronary

Angiography, "

J Clin Endocrinol Metab, 2008 August 5; [Epub ahead of print]. 46572

(9/2008)

Kirk Hamilton: Can you please share with us your educational background

and current position?

Stefan Pilz: I obtained my M.D. degree from the Medical University of

Graz, Austria in 2003 and I finished

my training as a general practitioner in 2007. After working for the

Department of Public Health, Social and

Preventive Medicine at the University of Heidelberg, Mannheim, Germany,

I started my residency at the

Department of Internal Medicine, Division of Endocrinology and Nuclear

Medicine, at the Medical University

of Graz in 2008.

KH: What got you interested in studying the role of vitamin D and heart

diseases such as heart failure and

sudden cardiac death?

SP: Case reports of children with rickets suffering from severe heart

failure that could be successfully treated

with calcium plus vitamin D, and, observations of myocardial dysfunction

in vitamin D receptor knock-out

mice.

KH: What would be the theoretic mechanism of how vitamin D might reduce

the incidence of these

conditions?

SP: Cardiomyocytes express the vitamin D receptor and it was shown that

vitamin D regulates the

expression of several genes that are important for myocardial function

and structure. It was demonstrated that

treatment with active forms of vitamin D could prevent myocardial

hypertrophy and dysfunction via modulation

of cardiac gene expressions supporting the notion that vitamin D exerts

direct effects on cardiomyocytes that

may protect against myocardial diseases. Apart from this, vitamin D

might also reduce the incidence of heart

diseases by beneficial effects on cardiovascular risk factors like e.g.

diabetes mellitus and arterial hypertension.

There is also evidence that vitamin D might protect against

atherosclerosis by direct effects on the vessel walls.

KH: How do you best assess vitamin D status? Should the test be done

fasting? First thing in the morning?

SP: Serum 25-hydroxyvitamin D levels are considered to be the best

indicator of vitamin D status. Blood

samplings for determination of 25-hydroxyvitamin D are usually done in

the morning after an overnight fast but

the influence of the time of day of blood collection and meals is not

significant. It is, however, important for the

interpretation of 25-hydroxyvitamin D levels to consider the season of a

year in which blood was drawn

because there exists a significant seasonal variation in

25-hydroxyvitamin D levels with highest levels in

summer and lowest levels in winter, which can be attributed to

variations in ultraviolet-B exposure of the skin.

In this context, it is important to mention that dermal vitamin D

production is the most important source for

circulating 25-hydroxyvitamin D levels.

KH: What are the levels for deficiency, sufficiency and optimal levels?

SP: Vitamin D deficiency is commonly defined as 25-hydroxyvitamin D

levels below 20 ng/ml. Vitamin D

insufficiency is defined as 25-hydroxyvitamin D levels between 20 and

below 30 ng/ml and persons with 25-

hydroxyvitamin D levels of 30 ng/ml or above are considered to have a

sufficient vitamin D status.

KH: Can you tell us about your study and the basic results?

SP: In the Ludwigshafen Risk and Cardiovascular Health (LURIC) study we

included over 3000 patients

that were routinely referred to coronary angiography. Patients with

prevalent heart failure had significantly

reduced levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D.

Furthermore, patients that died due to

heart failure (n=116) and sudden cardiac death (n=188) during a median

follow-up period of 7.7 years had

significantly reduced 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D

levels at baseline.

KH: Do you think the benefit of vitamin D might be greater for sudden

cardiac death than for heart failure?

SP: I am not sure whether the benefit of vitamin D is greater for sudden

cardiac death than for heart failure,

but our results suggest that the effects of vitamin D might be more

important for the physiology of the

cardiomyocytes and less for the coronary vessels because we observed

significant associations between vitamin

D deficiency and myocardial diseases whereas 25-hydroxyvitamin D levels

were not significantly associated

with angiographic coronary artery disease.

KH: Should cardiovascular patients be screened for vitamin D status?

SP: Yes.

KH: Should all patients be screened for vitamin D status?

SP: Yes. There exits compelling evidence that a sufficient vitamin D

status is important for multiple health

outcomes including apart from cardiovascular diseases also cancer,

musculoskeletal, autoimmune and infectious

diseases.

KH: What do you think are reasonable preventive doses of vitamin D if

someone is not able to get a vitamin

D level done?

SP: Two thousand IU of vitamin D per day.

KH: How toxic is vitamin D? Has the risk to vitamin D toxicity been

exaggerated?

SP: The potential toxicity of vitamin D lies almost exclusively in

causing hypercalcemia and there exists a

wide consensus among experts in this field that the risk of vitamin D

toxicity has been exaggerated in the past.

Vitamin D intoxication occurs only at very high 25-hydroxyvitamin D

levels (e.g. above 150 ng/ml) and recent

studies have shown that no side effects were observed with daily vitamin

D doses of up to 10,000 IU over long

time periods.

KH: Do you have any further comments on this very interesting subject?

SP: Yes, it is important for me to underline that in view of the

multiple beneficial effects of vitamin D, its

supplementation has, in my opinion, immense potential for the

improvement of public health when considering

the high prevalence of vitamin D deficiency (almost 50% among the world

population has insufficient vitamin

D status) and the easy, inexpensive, and relatively safe way in which

vitamin D can be supplemented.

--

ne Holden, MS, RD

" Ask the Parkinson Dietitian " http://www.parkinson.org/

" Eat well, stay well with Parkinson's disease "

" Parkinson's disease: Guidelines for Medical Nutrition Therapy "

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