<b><i>Objective</i></b><b> </b>Prospective associations
between omega-3 fatty acid biomarkers and type 2 diabetes (T2D) risk are not
consistent in individual studies. We aimed to summarize prospective associations
between biomarkers of alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic
acid (DPA), and docosahexaenoic acid (DHA), and T2D risk through an individual
participant-level pooled analysis.
<p><b><i>Research
Design and Methods </i></b>Our analysis incorporated data from a
global consortium of 20 prospective studies from 14 countries. We included 65,147 participants
who had blood measurements of ALA, EPA, DPA, or DHA and were free of diabetes
at baseline.</p>
<p><i>De novo</i>
harmonized analyses were performed in each cohort following a pre-specified
protocol and cohort-specific associations were pooled using inverse
variance-weighted meta-analysis.</p>
<p><b><i>Results</i></b><b> </b>A total of 16,693 incident T2D
cases were identified during
follow-up (median follow-up ranging from 2.5 to 21.2 years). In pooled
multivariable analysis, per inter-quintile range (difference between the 90<sup>th</sup>
and 10<sup>th</sup> percentiles for each fatty acid), EPA, DPA, DHA, and their
sum were associated with lower T2D incidence, with hazard ratios (HRs) and 95%
confidence intervals (CIs) of 0.92 (0.87, 0.96), 0.79 (0.73, 0.85), 0.82 (0.76,
0.89) and 0.81 (0.75, 0.88), respectively (all <i>P</i><0.001). ALA was not associated with T2D, 0.97 (0.92, 1.02) per
inter-quintile range. Associations were robust across pre-specified subgroups as
well as in sensitivity analyses. </p>
<p><b><i>Conclusions </i></b><a></a><a>Higher
circulating biomarkers of seafood-derived omega-3 fatty acids, including EPA,
DPA, DHA, and their sum were associated with lower risk of T2D in a global
consortium of prospective studies. </a>The
biomarker of plant-derived ALA was not significantly associated with T2D risk. </p>
Omega-3 fatty acid biomarkers and subsequent depressive symptoms