Plasma phospholipid and dietary fatty acids as predictors of type 2 diabetes: interpreting the role of linoleic acid.
BACKGROUND
Dietary fatty acids may be associated with diabetes but are difficult to measure accurately.


OBJECTIVE
We aimed to investigate the associations of fatty acids in plasma and diet with diabetes incidence.


METHODS
This was a prospective case-cohort study of 3737 adults aged 36-72 y. Fatty acid intake (/kJ) and plasma phospholipid fatty acids (%) were measured at baseline, and diabetes incidence was assessed by self-report 4 y later. Logistic regression excluding (model 1) and including (model 2) body mass index and waist-hip ratio was used to calculate odds ratios (ORs) for plasma phospholipid and dietary fatty acids.


RESULTS
In plasma phospholipid, positive associations with diabetes were seen for stearic acid [OR model 1, highest versus lowest quintile: 4.14 (95% CI: 2.65, 6.49), P for trend < 0.0001] and total saturated fatty acids [OR model 1: 3.76 (2.43, 5.81), P for trend < 0.0001], whereas an inverse association was seen for linoleic acid [OR model 1: 0.22 (0.14, 0.36), P for trend < 0.0001]. Dietary linoleic [OR model 1: 1.77 (1.19, 2.64), P for trend = 0.002], palmitic [OR model 1: 1.65 (1.12, 2.43), P for trend = 0.012], and stearic [OR model 1: 1.46 (1.00, 2.14), P for trend = 0.030] acids were positively associated with diabetes incidence before adjustment for body size. Within each quintile of linoleic acid intake, cases had lower baseline plasma phospholipid linoleic acid proportions than did controls.


CONCLUSIONS
Dietary saturated fat intake is inversely associated with diabetes risk. More research is required to determine whether linoleic acid is an appropriate dietary substitute.
Hodge
Allison M
AM
Cancer Epidemiology Centre, The Cancer Council Victoria, Melbourne, Australia. allison.hodge@cancervic.org.au
English
Dallas R
DR
O'Dea
Kerin
K
Sinclair
Andrew J
AJ
Makrides
Maria
M
Gibson
Robert A
RA
Giles
Graham G
GG
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D019787:Linoleic Acid / Q000097:blood*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014739:Victoria / Q000453:epidemiology
D001786:Blood Glucose; D004041:Dietary Fats; D007328:Insulin; D010743:Phospholipids; D019787:Linoleic Acid