Omega-3 Fatty Acid/Fish Intake and Brachial Artery Flow-Mediated Dilation
Jennifer S. Anderson, MD, PhD, MEdCardiology Fellow/Research Fellow
in the Multi-Ethnic Study of Atherosclerosis
Background
• Multiple studies have shown an inverse relationship between fish/omega-3 fatty acid consumption and cardiovascular events/death
• One potential mechanism includes omega-3 fatty acids’ impact on endothelial function
• Flow-mediated dilation (FMD) is a noninvasive surrogate for endothelial function
• Few studies have examined the relationship between dietary fish and FMD
Study Hypotheses
1. Consumption of non-fried fish foods rich in long-chain omega-3 fatty acids (eicosapentanoic acid (EPA), docosahexanoic acid (DHA)) will be positively associated with larger FMD across ethnic groups.
Omega-3 rich (EPA, DHA) diet Flow-mediated dilation (FMD)
2. Concentrations of EPA and DHA in plasma phospholipids will demonstrate positive associations with FMD.
• Cross-sectional analysis of MESA participants– n=6,814 men and women aged 45-85 years, free of CVD– Multi-center participation, 6 U.S. sites
• Baseline data collection including:– 120-item food frequency questionnaire– FMD measures (n = 3,137)– plasma phospholipid/fatty acid measures (n = 1,642)
Study Design
Exposure Measures: Dietary FishNon-fried fish tuna, salmon, sardines, sashimi or
sushi; other broiled, steamed, baked, or raw fish including trout, sole, halibut, poke, grouper
Shellfish (non-fried) shrimp, lobster, crab, oysters, mussels
Fish in mixed dishes(non-fried)
fish in enchiladas, burritos, quesadilla, pasta, stew, gumbo, paella, or salad
Fried fish fried fish or fish sandwich, fried shrimp, calamari
Exposure Measures: Plasma EPA and DHA
Outcome: Brachial Artery Measures
Baseline brachial artery diameterMaximum brachial artery diameter
• Multivariate linear regression• Stepwise approach• Final model included:
• Stratified by gender, race/ethnicity
Statistics
AgeGenderRace/ethnicitySmokingEducation
Income levelPhysical activitySystolic & diastolic BPLipid levelsBMI
Non-fried Fish & Brachial Measures: Overall Results, Baseline Artery Diameter
(n = 642) (n = 943) (n = 838) (n = 714)
Never/rare 1-3x/mo 1-2x/wk >2x/wk4.1
4.2
4.3
4.4
4.5
Unadjusted
Non-fried Fish Frequency
Base
line
diam
eter
, mm
*p < 0.001
Non-fried Fish & Brachial Measures: Baseline Diameter, Stratification by Gender*
Men Women
Never/rare 1-3x/mo 1-2x/wk >2x/wk3.8
3.9
4.0
4.1
4.2
Non-fried Fish Frequency
Never/rare 1-3x/mo 1-2x/wk >2x/wk4.6
4.7
4.8
4.9
5.0
Non-fried Fish Frequency
Base
line
diam
eter
, mm
*p = 0.02
(n = 338) (n = 455) (n = 411) (n = 344) (n = 304) (n = 488) (n = 427) (n = 370)
p = 0.10
*adjusted for age, race, BMI, smoking, diabetes, SBP, DBP, total:HDL, exercise, income, education, and HRT (women)
Non-fried Fish & Brachial Measures: FMD, Stratification by Gender*
Men Women
Test for gender-fish interaction significant (p = 0.008 and 0.05 for baseline diameter & FMD, respectively)
Never/rare 1-3x/mo 1-2x/wk >2x/wk3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
Non-fried Fish Frequency(n = 304) (n = 488) (n = 427) (n = 370)(n = 338) (n = 455) (n = 411) (n = 344)
*p = 0.007
Never/rare 1-3x/mo 1-2x/wk >2x/wk3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
Non-fried Fish Frequency
FMD,
% c
hang
e
p = 0.23
*adjusted for age, race, BMI, smoking, diabetes, SBP, DBP, total:HDL, exercise, income, education, and HRT (women)
Non-fried Fish & Brachial Measures: FMD, Stratification by Gender* & Race/Ethnicity
*results for women shown, fully adjusted model
white black chinese hispanic2
2.5
3
3.5
4
4.5
5
5.5
Never/rare 1-3x/mo 1x/wk ≥2x/wkNon-fried fish Frequency
FMD,
% ch
ange
*p = 0.02
Plasma EPA+DHA & Brachial Measures: FMD, Stratification by Gender*
1 2 3 43.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
Men
Quartile, plasma EPA+DHA%
FMD,
% ch
ange
p = 0.33
(n = 221) (n = 173) (n = 203) (n = 178)
*adjusted for age, race, BMI, smoking, diabetes, SBP, DBP, total:HDL, exercise, income, education, and HRT (women)
Plasma EPA+DHA & Brachial Measures: FMD, Stratification by Gender*
p = 0.33
(n = 221) (n = 173) (n = 203) (n = 178)
*adjusted for age, race, BMI, smoking, diabetes, SBP, DBP, total:HDL, exercise, income, education, and HRT (women)
Summary 1. Gender differences were observed in the
relationship between non-fried fish and both baseline artery diameter and FMD within the MESA cohort
2. Results examining plasma EPA+DHA levels corroborated results observed in dietary non-fried fish intake
3. Some race/ethnic differences were suggested
Next Steps
1. Are gender differences in brachial measures explained by variation in plasma %EPA vs %DHA?
2. Gender differences in the relationship between fish consumption & clinical events within MESA?
3. Gender differences in fish consumption & other markers of subclinical CVD (i.e. IMT, LV structure/function)?
4. Results replicable in other large cohorts with mixed race/ethnic groups?
Acknowledgements
Mentors & MESA coauthors:David Herrington, MD, MHS
Jennifer Nettleton, PhDDavid Siscovick, MD, MPH
Craig Johnson, MPHMichael Tsai, PhD
And special thanks to:Georgia Saylor