Nutrition Support Blog: Thiamine – Don’t you want to be one (B1)?

Posted by SF8N at Mar 05, 2012 09:20 AM |

March 5, 2012

Nutrition Support Blog: Thiamine – Don’t you want to be one (B1)?

by Joe Krenitsky, MS, RD

It is more than 100 years since Kanehiro Takaki discovered the role of diet in preventing Beriberi and Casimir Funk isolated the vital amine in rice bran that is responsible.  What is truly amazing is that 100 years later we are still evolving in our understanding of the full importance and appropriate doses of thiamine for various medical conditions.

We have been sensitized to the importance of vitamins over the past several years, especially when providing parenteral nutrition, due the chronic and recurring shortages of parenteral vitamins. It is unbelievably tragic that in this day and age we would have patients harmed by the lack of a vitamin we have known about for so long!1,2

Physicians are generally well-educated about the essential need to provide thiamine to patients with alcohol abuse.  However, some experts feel that the typical U.S. doses of 100 mg/day may substantially underdose those patients with the greatest need for thiamine.  See the article link below for more details on thiamine dosing recommendations for patients with Wernicke’s encephalopathy:

http://www.medicine.virginia.edu/clinical/departments/medicine/divisions/digestive-health/nutrition-support-team/nutrition-articles/ThomsonArticle.pdf

One patient population where we are quite likely to routinely underestimate the frequency of thiamine deficiency is our cardiology patients (and any others receiving long-term diuretic therapy).  Loop diuretics like Furosemide (Lasix) increase urinary thiamine losses.3  Although potassium-sparing diuretics like Spironolactone (Aldactone) do not seem to waste as much thiamine as loop diuretics, there is some data that Spironolactone may still be a risk factor for thiamine deficiency.4,5  Population studies have revealed that 1/3 to ½ of CHF admissions have biochemical evidence of thiamine deficiency.5  In one study, 98% of patients receiving high-dose furosemide (80 mg/day or more) had evidence of thiamine deficiency.6

Despite the available data about the frequency of thiamine deficiency, based on my conversations with RD’s from a number of hospitals, it is often not standard practice to check thiamine adequacy in patients admitted with heart failure.  One reason why thiamine is not routinely checked is that there is very limited data (outside of case reports) about the clinical ramifications of thiamine deficiency or response to treatment.  However, a recent randomized study with a modest number of patients (n= 9) reported that thiamine supplementation significantly improved the ejection fraction compared to placebo in patients with chronic heart failure.7

There certainly is a need for additional research into the ramifications of thiamine deficiency and outcomes of treatment in all of our patients exposed to high-dose or extended diuresis, including those with hepatic failure and ventilator weaning.  However, until there is additional data, we probably should be investigating thiamine status more often in patients that are at nutrition risk and/or receiving high dose or extended-duration diuresis.  In patients with severe malnutrition, especially those receiving diuretics it is frequently prudent to check thiamine but then begin empiric supplementation due to the prolonged “turn-around time” for send out lab results.  After all, you don’t need to have a name like Casimir Funk to be thinking about thiamine.

References

1.   Ferrie S.  Case report of acute thiamine deficiency occurring as a complication of vitamin-free parenteral nutrition.  Nutr Clin Pract. 2012;27(1):65-68.

2.   Klein M, Weksler N, Gurman GM.  Fatal metabolic acidosis caused by thiamine deficiency.  J Emerg Med. 2004;26(3):301-3.

3. Rieck J, Halkin H, Almog S, et al.  Urinary loss of thiamine is increased by low doses of furosemide in healthy volunteers.  J Lab Clin Med. 1999;134(3):238-243.

4.   Rocha RM, Silva GV, de Albuquerque DC, et al.  Influence of spironolactone therapy on thiamine blood levels in patients with heart failure.  Arq Bras Cardiol. 2008;90(5):324-328.

5.   Hanninen SA, Darling PB, Sole MJ, et al.  The prevalence of thiamin deficiency in hospitalized patients with congestive heart failure.  J Am Coll Cardiol. 2006;47(2):354-361.

6.   Zenuk C, Healey J, Donnelly J, et al.  Thiamine deficiency in congestive heart failure patients receiving long term furosemide therapy. Can J Clin Pharmacol. 2003;10(4):184-188.

7.   Schoenenberger AW, Schoenenberger-Berzins R, der Maur CA, Suter PM, Vergopoulos A, Erne P.  Thiamine supplementation in symptomatic chronic heart failure: a randomized, double-blind, placebo-controlled, cross-over pilot study.  Clin Res Cardiol. 2012;101(3):159-64.


“If everybody's thinking alike, somebody isn't thinking.”

          -- George S. Patton 

 

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Posted by SF8N at Mar 04, 2012 04:02 PM
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