Predictors of Omega-3 Index in Patients With Acute Myocardial Infarction Full Text
Mayo Clinic Proceedings, 07/01/2011
Exclusive author commentary
Salisbury AC et al. – Potentially modifiable factors, such as patient–reported fast food intake, fish intake, and smoking, are independently associated with the omega–3 index in patients with acute myocardial infarction (AMI). These characteristics may be useful to identify patients who would benefit most from omega–3 supplementation and lifestyle modification.Methods
- Dietary habits of 1487 patients in the 24–center Translational Research Investigating Underlying disparities in acute Myocardial infarction Patients' Health status (TRIUMPH) registry between April 11, 2005, and September 28, 2007, were assessed by asking about the frequency of fast food and nonfried fish consumption.
- All patients had erythrocyte omega–3 index measured at the time of hospital admission for AMI.
- The authors used multivariable linear regression to identify independent correlates of the omega–3 index and modified Poisson regression to predict risk of a low omega–3 index (<4%).
- The proportion of patients with a low omega–3 index increased with more frequent fast food intake (18.9% for <1 time monthly, 28.6% for 1–3 times monthly, 28.8% for 1–2 times weekly, and 37.6% for ≥3 times weekly; P<.001).
- In contrast, a low omega–3 index was less common among patients with more frequent fish intake (35.1% for <1 time monthly, 24.9% for 1–3 times monthly, 16.1% for 1–2 times weekly, and 21.1% for ≥3 times weekly; P<.001).
- Fish intake, older age, race other than white, and omega–3 supplementation were independently associated with a higher omega–3 index, whereas frequent fast food intake, smoking, and diabetes mellitus were associated with a lower omega–3 index.
Adam C. Salisbury, MD, MSc (07/01/2011) comments:
Omega-3 fatty acid intake is associated with lower mortality in patients with coronary artery disease, and patients with high red blood cell omega-3 fatty acid levels have lower mortality than those with low omega-3 indices. In this large, multicenter cohort of patients hospitalized with acute myocardial infarction, we found that patient's characteristics and dietary practices were strong predictors of favorable omega-3 indices. These findings have two important clinical implications. First, guideline recommended fish and omega-3 supplement intake was strongly associated with higher omega-3 indices. However, unhealthy lifestyle practices (including fast food consumption and smoking) were associated with lower omega-3 indices. This suggests that simply offering omega-3 supplements may be less likely to augment omega-3 fatty acid levels, and potentially less likely to improve outcomes, than more comprehensive lifestyle counseling that addresses multiple dietary and lifestyle behaviors. Second, we found that patients with low omega-3 indices, who may be most likely to benefit from supplementation and diet counseling, could be accurately identified using routinely available patient characteristics (age, race, diabetes, smoking and dietary habits). Using patient characteristics to target omega-3 supplements to high risk patients avoids the cost of omega-3 index testing, and informing patients of their risk for low omega-3 levels may reinforce their adherence to treatment. Further studies are needed to understand whether targeting omega-3 supplements to higher risk patients improves patients' adherence or outcomes. Moreover, research is needed to determine whether providing counseling on comprehensive dietary modification, in addition to omega-3 fatty acid supplementation, improves results in better outcomes than providing omega-3 fatty acid supplements alone.