Erythrocyte membrane docosapentaenoic acid levels are associated with islet autoimmunity: the Diabetes Autoimmunity Study in the Young.
OBJECTIVE
We previously reported that lower n-3 fatty acid intake and levels in erythrocyte membranes were associated with increased risk of islet autoimmunity (IA) but not progression to type 1 diabetes in children at increased risk for diabetes. We hypothesise that specific n-3 fatty acids and genetic markers contribute synergistically to this increased risk of IA in the Diabetes Autoimmunity Study in the Young (DAISY).


METHODS
DAISY is following 2,547 children at increased risk for type 1 diabetes for the development of IA, defined as being positive for glutamic acid decarboxylase (GAD)65, IA-2 or insulin autoantibodies on two consecutive visits. Using a case-cohort design, erythrocyte membrane fatty acids and dietary intake were measured prospectively in 58 IA-positive children and 299 IA-negative children.


RESULTS
Lower membrane levels of the n-3 fatty acid, docosapentaenoic acid (DPA), were predictive of IA (HR 0.23; 95% CI 0.09, 0.55), while α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were not, adjusting for HLA and diabetes family history. We examined whether the effect of dietary intake of the n-3 fatty acid ALA on IA risk was modified by fatty acid elongation and desaturation genes. Adjusting for HLA, diabetes family history, ethnicity, energy intake and questionnaire type, ALA intake was significantly more protective for IA in the presence of an increasing number of minor alleles at FADS1 rs174556 (pinteraction = 0.017), at FADS2 rs174570 (pinteraction = 0.016) and at FADS2 rs174583 (pinteraction = 0.045).


CONCLUSIONS
The putative protective effect of n-3 fatty acids on IA may result from a complex interaction between intake and genetically controlled fatty acid desaturation.
Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, 13001 E. 17th Place, Campus Box B119, Aurora, CO, 80045, USA, Jill.Norris@ucdenver.edu.
Jill M
JM
Norris
Miranda
M
Kroehl
Tasha E
TE
Fingerlin
Brittni N
BN
Frederiksen
Jennifer
J
Seifert
Randall
R
Wong
Michael
M
Clare-Salzler
Marian
M
Rewers
D001323:Autoantibodies / Q000097:blood* / Q000235:genetics; D015551:Autoimmunity / Q000235:genetics / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D000090943:Delta-5 Fatty Acid Desaturase; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control; D004032:Diet; D018450:Disease Progression; D004281:Docosahexaenoic Acids / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000378:metabolism; D002149:Energy Intake; D004910:Erythrocyte Membrane / Q000378:metabolism*; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D008297:Male; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors
D001323:Autoantibodies; D000090943:Delta-5 Fatty Acid Desaturase; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D044943:Fatty Acid Desaturases; C000716847:FADS1 protein, human; C533241:FADS2 protein, human; C026219:docosapentaenoic acid