title: Long-term fatty acid stability in human serum cholesteryl ester, triglyceride, and phospholipid fractions.
abstract: Fatty acid profiles of biological specimens from epidemiological/clinical studies can serve as biomarkers to assess potential relationships between diet and chronic disease risk. However, data are limited regarding fatty acid stability in archived specimens following long-term storage, a variable that could affect result validity. Our objective was to determine the effect of prolonged storage at -80 degrees C on the fatty acid profiles of serum cholesteryl ester (CE), triglyceride (TG), and phospholipid (PL) fractions. This was accomplished by determining the fatty acid profile of frozen, archived, previously unthawed serum samples from 22 subjects who participated in a controlled feeding trial. Initial analysis was performed after trial completion and the repeat analysis after 8-10 years of storage using GC. No significant differences were observed among the majority of fatty acids regardless of lipid fraction. Reliability coefficients were high for the fatty acid classes (saturated fatty acid : 0.70, MUFA : 0.90, PUFA : 0.80). When differences were identified, they were limited to low abundance fatty acids (<or=1.5 mol%). These differences were quantitatively small and likely attributable to technical improvements in GC methodology rather than sample degradation. Thus, our data demonstrate that storage at -80 degrees C up to 10 years does not significantly influence serum CE, TG, or PL fatty acid profiles.
authors.affiliation: Cardiovascular Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. nirupa.matthan@tufts.edu
authors.forename: Nirupa R
authors.initials: NR
authors.lastname: Matthan
authors.forename: Blanche
authors.initials: B
authors.lastname: Ip
authors.forename: Nancy
authors.initials: N
authors.lastname: Resteghini
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Ausman
authors.forename: Alice H
authors.initials: AH
authors.lastname: Lichtenstein
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002788:Cholesterol Esters / Q000097:blood*; D002849:Chromatography, Gas / Q000379:methods; D015925:Cryopreservation; D004041:Dietary Fats / Q000009:adverse effects; D004194:Disease; D005227:Fatty Acids / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood*
chemical_list: D015415:Biomarkers; D002788:Cholesterol Esters; D004041:Dietary Fats; D005227:Fatty Acids; D010743:Phospholipids; D014280:Triglycerides
references.citation: Lancet. 1986 Feb 8;1(8476):307-10
references.pmid: 2868172
references.citation: J Lipid Res. 2006 Dec;47(12):2814-9
references.pmid: 16983146
references.citation: Am J Epidemiol. 1997 Jun 15;145(12):1114-22
references.pmid: 9199541
references.citation: Prog Lipid Res. 2008 Sep;47(5):348-80
references.pmid: 18435934
references.citation: Clin Chim Acta. 2002 Jul;321(1-2):63-7
references.pmid: 12031594
references.citation: Int J Vitam Nutr Res. 1986;56(3):231-9
references.pmid: 3781746
references.citation: Atherosclerosis. 2003 Nov;171(1):97-107
references.pmid: 14642411
references.citation: Clin Chim Acta. 1981 Jul 18;114(1):111-6
references.pmid: 7249369
references.citation: Ann Nutr Metab. 2006;50(2):95-102
references.pmid: 16373991
references.citation: Br J Nutr. 1995 Apr;73(4):605-12
references.pmid: 7794875
references.citation: Curr Opin Lipidol. 2006 Feb;17(1):22-7
references.pmid: 16407712
references.citation: Eur J Clin Nutr. 2000 May;54(5):367-72
references.pmid: 10822282
references.citation: J Nutr. 2001 Mar;131(3):828-33
references.pmid: 11238766
references.citation: N Engl J Med. 1999 Jun 24;340(25):1933-40
references.pmid: 10379016
references.citation: J Lipid Res. 1964 Oct;5:600-8
references.pmid: 14221106
references.citation: J Nutr. 2003 Mar;133 Suppl 3(3):925S-932S
references.pmid: 12612178
references.citation: Am J Clin Nutr. 1998 Jan;67(1):25-30
references.pmid: 9440371
references.citation: J Lipid Res. 1992 Dec;33(12):1871-6
references.pmid: 1479296
references.citation: J Nutr. 2006 Mar;136(3):565-9
references.pmid: 16484525
references.citation: Public Health Nutr. 2002 Dec;5(6A):977-84
references.pmid: 12633522
references.citation: Am J Clin Nutr. 1995 Jul;62(1):68-73
references.pmid: 7598068
references.citation: J Biol Chem. 1957 May;226(1):497-509
references.pmid: 13428781
references.citation: Lipids Health Dis. 2005 Dec 05;4:30
references.pmid: 16329761
references.citation: Prostaglandins Leukot Essent Fatty Acids. 1992 Nov;47(3):203-7
references.pmid: 1475276
references.citation: Am J Clin Nutr. 1995 Sep;62(3):572-8
references.pmid: 7661119
references.citation: Public Health Nutr. 2002 Dec;5(6A):865-71
references.pmid: 12638594