Assessment of essential fatty acid and omega3-fatty acid status by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3.
BACKGROUND
Early suspicion of essential fatty acid deficiency (EFAD) or omega3-deficiency may rather focus on polyunsaturated fatty acid (PUFA) or long-chain PUFA (LCP) analyses than clinical symptoms. We determined cut-off values for biochemical EFAD, omega3-and omega3/22:6omega3 [docosahexaenoic acid (DHA)]-deficiency by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3, respectively.


METHODS
Cut-off values, based on 97.5 percentiles, derived from an apparently healthy omnivorous group (six Dominica breast-fed newborns, 32 breast-fed and 27 formula+LCP-fed Dutch low-birth-weight infants, 31 Jerusalem infants, 33 Dutch 3.5-year-old infants, 69 omnivorous Dutch adults and seven Dominica mothers) and an apparently healthy group with low dietary LCP intake (81 formula-fed Dutch low-birth-weight infants, 12 Dutch vegans). Cut-off values were evaluated by their application in an EFAD suspected group of 108, mostly malnourished, Pakistani children, three pediatric patients with chronic fat-malabsorption (abetal-ipoproteinemia, congenital jejunal and biliary atresia) and one patient with a peroxisomal beta-oxidation disorder.


RESULTS
Erythrocyte 20:3omega9, 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3 proved age-dependent up to 0.2 years. Cut-off values for ages above 0.2 years were: 0.46mol% 20:3omega9 for EFAD, 0.068mol/mol 22:5omega6/20:4omega6 for omega3-deficiency, 0.22mol/mol 22:5omega6/22:6omega3 for omega3/DHA-marginality and 0.48mol/mol 22:5omega6/22:6omega3 for omega3/DHA-deficiency. Use of RBC 20:3omega9 and 22:5omega6/20:4omega6 cut-off values identified 20.4% of the Pakistani subjects as EFAD+omega3-deficient, 12.9% as EFAD+omega3-sufficient, 38.9% as EFA-sufficient+omega3-deficient and 27.8% as EFA-sufficient+omega3-sufficient. The patient with the peroxisomal disorder was classified as EFA-sufficient, omega3-sufficient (based on RBC 22:5omega6/20:4omega6) and omega3/DHA-deficient (based on RBC 22:5omega6/22:6omega3). The three other pediatric patients were classified as EFAD, omega3-deficient and omega3/DHA-deficient.


CONCLUSIONS
Use of the combination of the present cut-off values for EFA, omega3 and omega3/DHA status assessment, as based on 97.5 percentiles, may serve for PUFA supplement intervention until better concepts have emerged.
Fokkema
M R
MR
Department of Pathology and Laboratory Medicine, Groningen University Hospital, The Netherlands. m.r.fokkema@path.azg.nl
Smit
E N
EN
Martini
I A
IA
Woltil
H A
HA
Boersma
E R
ER
Muskiet
F A J
FA
D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000097:blood; D001903:Bottle Feeding; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D014676:Diet, Vegetarian; D019424:Dominica; D004912:Erythrocytes / Q000737:chemistry*; D005228:Fatty Acids, Essential / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight / Q000097:blood; D007231:Infant, Newborn; D007557:Israel; D009426:Netherlands; D010154:Pakistan; D012016:Reference Values; D015203:Reproducibility of Results
D005228:Fatty Acids, Essential; D015525:Fatty Acids, Omega-3; D015126:8,11,14-Eicosatrienoic Acid; C010944:mead acid