BACKGROUND: The National Health and Nutrition Examination Survey (NHANES) has monitored total homocysteine (tHcy) concentrations in a nationally-representative sample of the US population since 1991. Until recently, however, data could not be compared across survey periods because of changes in analytical methods and specimen matrices. Such an analysis of these data could supplement current knowledge regarding whether the US folic acid fortification program has modified national plasma tHcy concentrations. METHODS: We examined tHcy data in the prefortification NHANES III survey (phase II, 1991-1994) and in 3 postfortification survey periods (1999-2000, 2001-2002, and 2003-2004). We applied method adjustment equations to the survey data based on method comparison studies of separate samples. Persons with chronic kidney disease were excluded from the analyses. RESULTS: Mean plasma tHcy concentrations decreased by 8%, 9%, and 10% for adolescent, adult, and older men and by 6%, 3%, and 13% for women, respectively, from before to after fortification. Concentrations remained unchanged between the first and third postfortification survey periods. Prevalence estimates of increased plasma tHcy concentrations (>13 micromol/L) for older men and women decreased from prefortification (32% and 20%, respectively) to postfortification (14% and 5%, respectively) but remained unchanged thereafter (16% and 14%, respectively [males] and 5% and 9%, respectively [females]). CONCLUSIONS: After adjusting for method changes, we quantified a prefortification to postfortification decrease in circulating tHcy concentrations of about 10% in a national sample of the US population. This change is similar to effects seen in intervention trials with folic acid and in smaller observational studies.
BACKGROUND: The National Health and Nutrition Examination Survey (NHANES) has monitored total homocysteine (tHcy) concentrations in a nationally-representative sample of the US population since 1991. Until recently, however, data could not be compared across survey periods because of changes in analytical methods and specimen matrices. Such an analysis of these data could supplement current knowledge regarding whether the US folic acid fortification program has modified national plasma tHcy concentrations. METHODS: We examined tHcy data in the prefortification NHANES III survey (phase II, 1991-1994) and in 3 postfortification survey periods (1999-2000, 2001-2002, and 2003-2004). We applied method adjustment equations to the survey data based on method comparison studies of separate samples. Persons with chronic kidney disease were excluded from the analyses. RESULTS: Mean plasma tHcy concentrations decreased by 8%, 9%, and 10% for adolescent, adult, and older men and by 6%, 3%, and 13% for women, respectively, from before to after fortification. Concentrations remained unchanged between the first and third postfortification survey periods. Prevalence estimates of increased plasma tHcy concentrations (>13 micromol/L) for older men and women decreased from prefortification (32% and 20%, respectively) to postfortification (14% and 5%, respectively) but remained unchanged thereafter (16% and 14%, respectively [males] and 5% and 9%, respectively [females]). CONCLUSIONS: After adjusting for method changes, we quantified a prefortification to postfortification decrease in circulating tHcy concentrations of about 10% in a national sample of the US population. This change is similar to effects seen in intervention trials with folic acid and in smaller observational studies.
Authors: Daniel A Enquobahrie; Henry A Feldman; Deanna H Hoelscher; Lyn M Steffen; Larry S Webber; Michelle M Zive; Eric B Rimm; Meir J Stampfer; Stavroula K Osganian Journal: Public Health Nutr Date: 2012-10 Impact factor: 4.022
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Authors: Michele L Mietus-Snyder; Mark K Shigenaga; Jung H Suh; Swapna V Shenvi; Ashutosh Lal; Tara McHugh; Don Olson; Joshua Lilienstein; Ronald M Krauss; Ginny Gildengoren; Joyce C McCann; Bruce N Ames Journal: FASEB J Date: 2012-05-01 Impact factor: 5.191
Authors: A David Smith; Stephen M Smith; Celeste A de Jager; Philippa Whitbread; Carole Johnston; Grzegorz Agacinski; Abderrahim Oulhaj; Kevin M Bradley; Robin Jacoby; Helga Refsum Journal: PLoS One Date: 2010-09-08 Impact factor: 3.240
Authors: Regan L Bailey; Anne C Looker; Zhaohui Lu; Ruzong Fan; Heather A Eicher-Miller; Tala H Fakhouri; Jaime J Gahche; Connie M Weaver; James L Mills Journal: Am J Clin Nutr Date: 2015-07-29 Impact factor: 7.045
Authors: Gwenaëlle Douaud; Helga Refsum; Celeste A de Jager; Robin Jacoby; Thomas E Nichols; Stephen M Smith; A David Smith Journal: Proc Natl Acad Sci U S A Date: 2013-05-20 Impact factor: 11.205