PRAGUE, CZECH REPUBLIC — Adherence to a Mediterranean-style diet showed a dose-dependent protective association with the presence, number, and thickness of atherosclerotic plaques independent of other risk factors, in a new study.
The association was strongest for femoral arteries and among smokers, suggesting the dietary pattern may protect against cardiovascular disease by preventing oxidation of atherogenic lipoproteins, lead author Dr Rocio Mateo-Gallego (Hospital Universitario Miguel Servet, Zaragoza, Spain) said here at the European Atherosclerosis Society 2017 Annual Congress.
She noted that the presence of plaques has been mostly studied in carotid arteries using ultrasonography, although recently iliofemoral plaques identified by ultrasonography have been shown to be more frequent, better correlated with CVD risk and highly associated with coronary calcium.
What hasn't been examined before is the association of iliofemoral plaques and Mediterranean diet adherence in the real world, the researchers note. Those were not well studied in the PREDIMED study, a rare randomized, controlled trial of a kind of Mediterranean diet that showed regression of carotid plaques over several years, among other insights.
To address this, the investigators used ultrasonography to assess the extent of atherosclerotic plaques in carotid, femoral, and aorta territories in 2523 middle-aged auto workers (mean age 51 years; 95% men) without a history of CV disease in the Aragon Workers Health Study. Of these, plaque was present in any territory in 1983 participants.
A 134-item food frequency questionnaire was used to compute the Alternative Mediterranean index (aMED), which considers the consumption of fruits, vegetables, nuts, legumes, whole grains, fish, red meats, alcohol, and the monounsaturated-fat/saturated-fat ratio. The total score could range from 0 to 9, with higher scores reflecting higher Mediterranean diet adherence.
The overall aMED score was 4.19, representing a moderate adherence to the Mediterranean diet, without any difference among sexes.
Compared with participants in the lowest aMED quartile (0–2 points), those in the highest quartile (6–9 points) were older (51.7 years vs 50.9 years) and less likely to be current smokers (25.3% vs 44%).
When participants in the highest vs lowest aMED quartiles were compared, there was a significant reduction in the presence of plaques in femoral arteries (odds ratio 0.74, 95% CI 0.54–1.02; P=0.045) independent of all risk factors and mediators.
In the highest aMED quartile, the presence of plaque was significantly reduced in the aorta after adjustment for age and sex (OR 0.72, 95% CI 0.55–0.94; P=0.006), but this difference did not retain statistical significance after full adjustment (P=0.303). No significant differences in carotid plaques were observed between the two aMED quartiles in any of the models.
Among smokers in the highest aMED quartile, however, the presence of plaques was reduced 61% in the femoral arteries (OR 0.39, 95% CI 0.22–0.69; P=0.001) and 67% in any territory (OR 0.33, 95% CI 0.14–0.79; P=0.008).
The aMED score was also inversely associated with the number of plaques in all territories except for carotids, Mateo-Gallego said.
Session moderator Dr Chris Packard (University of Glasgow, Scotland) told heartwire from Medscape that the carotid findings are consistent with prior studies and that the strength of the association observed in the other beds was substantial. The aMED score also provides a practical way of assessing the Mediterranean diet food frequency questionnaire.
"Of all the diets that we've studied, everybody comes back and says the Mediterranean diet is the one we should follow, so if the aMED score is a tool that people could use that is related to outcomes or surrogates, you could begin to use it as something to encourage your patients," he said.
Mateo-Galego reports EAS support in the form of a young investigator fellowship. Packard reports receiving research support Roche and MSD and honoraria from MSD, Sanofi/Regeneron, Amgen, and Pfizer.
Heartwire from Medscape © 2017
Cite this: Fewer Plaques With Real-World Adherence to Mediterranean Diet - Medscape - Apr 26, 2017.