ajg2004141a

American Journal of Gastroenterology ISSN0002-9270 C 2004by Am.Coll.of Gastroenterology

Published by Blackwell Publishing

LETTER TO THE EDITOR

Does the Addition of Methane Determinations Increase the Yield

of Hydrogen Breath Tests for

Sugar Malabsorption?

TO THE EDITOR:In their recent paper on the hydrogen

breath test Di Stefano et al.(1)comment on the need for ad-

ditional information regarding the role of methane in sugar

malabsorption.They also made reference to a1994article by

Corazza et al.(2)which documented that out of13healthy

subjects with a false negative hydrogen breath response to

lactose,11had a greater than100%CH4increase over the

fasting baseline,their criterion for malabsorption.While a

prospective evaluation will be needed,this prompted us to re-

view our data base on breath testing(3).Ten percent solution

challenges of lactose(25g),fructose(25g),and sorbitol(5g)

were administered in321patients with functional dyspepsia

and subsequent methane and hydrogen evaluations were per-

formed.Malabsorption of lactose was based on a>20ppm

rise or a>10ppm(either H2or CH4)rise for fructose or sor-

bitol,respectively.Retrospective evaluation showed that147

patients(46.1%)had baseline CH4values on all3tests to be >10ppm.We de?ned this group as“methane formers.”In this group,if hydrogen breath tests were administered without

methane evaluations then it would have missed11lactose,39

fructose,and30sorbitol malabsorbing patients.In the other

group,174patients did not have CH4levels of>10ppm on all

3tests,and the additional CH4measurements only identi?ed

2individuals with sorbitol malabsorption.

It would appear that the availability of CH4determina-

tions in addition to H2will increase the accuracy of breath

testing for sugar malabsorption,especially in certain sub-

jects.Clearly,these investigations will be most cost effective

in patients identi?ed to be“methane formers”based on one

or more screening determinations.Bjorneklett and Jenssen

claim that a single midday sample1–2h after lunch would

be suf?cient as long as the subject had not smoked for>10

min and room air CH4was subtracted(4).In their Norwegian

population,a similar percentage of patients(44%)evaluated

by their criteria would be considered to be methane produc-

ers.In view of the fact that methanogenic bacteria remove four moles of hydrogen per mole of CO2reduced(5),theo-retically it may be clinically relevant to compare the degree of discomfort after equivalent H2and CH4responses(ppm) in order to recommend appropriate dietary adjustments.

Daniel S.Mishkin,M.D.C.M.,F.R.C.P(C)

Seymour Mishkin,M.D.C.M.,F.R.C.P(C)

David Blank,M.D.C.M.,F.R.C.P.(C)

Morty Yalovsky,Ph.D.

Gastroenterology Fellow PGY-6

Monte?ore Medical Center

Albert Einstein College of Medicine

Bronx,New York

Division of Gastroenterology

Division of Clinical Biochemistry

McGill University Health Center

and Department of Management

McGill University,Montreal

Quebec,Canada

REFERENCES

1.Di Stefano M,Miceli E,Malservisi S,et al.Mixing of the

intestinal content and variations of fermentation capacity do not affect the results of hydrogen breath test.Am J Gastroen-terol2003;98:1584–7.

2.Corazza GR,Benati G,Strocchi A,et al.The possible role

of breath methane measurement in detecting carbohydrate malabsorption.J Lab Clin Med1994;124:695–700.

3.Mishkin D,Sablauskas L,Y alovsky M,et al.Fructose and

sorbitol malabsorption in ambulatory patients with func-tional dyspepsia:Comparison with lactose maldigestion/ malabsorption.Dig Dis Sci1997;42:2591–8.

4.Bjorneklett A,Jenssen E.Relationships between hydro-

gen(H2)and methane(CH4)production in man.Scand J Gas-troenterol1982;17:985–92.

5.Gibson GR,Cummings JH,Macfarlane GT,et al.Alterna-

tive pathways for hydrogen disposal during fermentation in the human colon.Gut1990;31:679–83.

Reprint requests and correspondence:Daniel S.Mishkin, M.D.C.M.,Gastroenterology Fellow PGY-6,Monte?ore Medical Center,Albert Einstein College of Medicine,Bronx,New Y ork. Received September14,2003;accepted October28,2003