Written by Chrystal Moulton, Staff Writer. Serum DGLA was a significant predictor of total death in elderly patients who recently experienced myocardial infarction (p= 0.012).
Linoleic acid [LA] is an essential fatty acid found in vegetable oils 1. Linoleic acid [LA] is converted to dihomo-gamma-linolenic acid [DGLA], which, in previous studies, is associated with a reduction in all-cause mortality 2. In the current trial, researchers investigated the association between serum LA:DGLA [n-6 polyunsaturated fatty acids or PUFAs] and mortality in elderly patients 1.
Participants in this study were selected from the OMEMI trial—a multicenter, double-blind, placebo-controlled clinical trial 3. The OMEMI trial (or Omega-3 Fatty Acids in Elderly with Myocardial Infarction trial) evaluated the effect of 1.8g n-3 PUFA (polyunsaturated fatty acids) supplementation versus placebo (corn oil) on major adverse clinical events (MACE) after heart attack in elderly patients. In the OMEMI trial, serum n-3 fatty acid levels did not lower the risk of adverse cardiovascular events 3. Researchers in this trial used the data from the OMEMI trial to determine whether n-6 PUFAs, specifically LA & DGLA serum levels, could serve as a predictor of major adverse clinical events (or MACE). Major adverse clinical events (MACE) included all-cause mortality, stroke, hospitalization for heart failure, unscheduled coronary revascularization, and heart attack. Participants were seen at baseline, 3 months, 12 months, and 24 months. Fatty acid profile of serum phospholipid was measured at baseline and end of trial. Participants between the ages 70 and 82 who experienced a heart attack two to eight weeks prior were included in this study. Participants who regularly supplemented with cod liver oil were allowed to maintain their regular supplementation through the study period.
In total, 1,027 eligible patients were enrolled in the trial. Blood samples were collected from 1,002 patients. Fifty-five patients died during this trial. Median DGLA across the study population was 2.89% weight (of total fatty acids). Assessment was done based on quartiles of LA:DGLA with quartile 1 being the lowest ratio and quartile 4 being the highest. Researchers assessed the interaction between n-6 PUFA levels as a whole and clinical outcomes and found no statistical association (p=0.40). Researchers observed a significant increase in MACE from quartile 1 of LA:DGLA to quartile 4 (p= 0.049). The most significant MACE observed from LA:DGLA quartile 1 to 4 was stroke (p= 0.05), which contributed to the increase in MACE by the end of the trial (2 years). At baseline, individuals with a high ratio of LA:DGLA, had higher serum HDL and lower serum triglycerides (p<0.001). When assessing MACE across quartiles of DGLA, researchers found no significant differences between the lowest and highest quartiles of DGLA. Also, the ratio LA:DGLA was not significantly associated with MACE after adjusting for potential confounders [p= 0.052]. However, total death was significantly associated with serum DGLA when comparing quartiles 2-4 with quartile 1 (lowest) [HR= 0.51, p= 0.016]. Even after adjusting for potential confounders, DGLA remained a significant predictor of total death [HR=0.47, p= 0.012]. Serum DGLA was not a significant predictor of MACE (p= 0.067).
In this trial, researchers found serum DGLA was a significant predictor of total mortality in elderly patients with a recent heart attack. Concentrations of other essential n-6 PUFAs were not associated with major adverse clinical events.
Source: Nilsen, Dennis Winston T., Peder Langeland Myhre, Are Kalstad, Erik Berg Schmidt, Harald Arnesen, and Ingebjørg Seljeflot. “Serum Levels of Dihomo-Gamma (γ)-Linolenic Acid (DGLA) Are Inversely Associated with Linoleic Acid and Total Death in Elderly Patients with a Recent Myocardial Infarction.” Nutrients 13, no. 10 (2021): 3475.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/.
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Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
- Nilsen DWT, Myhre PL, Kalstad A, Schmidt EB, Arnesen H, Seljeflot I. Serum Levels of Dihomo-Gamma (γ)-Linolenic Acid (DGLA) Are Inversely Associated with Linoleic Acid and Total Death in Elderly Patients with a Recent Myocardial Infarction. Nutrients. Sep 30 2021;13(10)doi:10.3390/nu13103475
- Nilsen DWT, Aarsetoey H, Pönitz V, et al. The prognostic utility of dihomo-gamma-linolenic acid (DGLA) in patients with acute coronary heart disease. International journal of cardiology. Dec 15 2017;249:12-17. doi:10.1016/j.ijcard.2017.09.202
- Kalstad AA, Myhre PL, Laake K, et al. Effects of n-3 Fatty Acid Supplements in Elderly Patients After Myocardial Infarction: A Randomized, Controlled Trial. Circulation. Feb 9 2021;143(6):528-539. doi:10.1161/circulationaha.120.052209
