Marine n-3 fatty acid treatment for carotid plaques in patients with type 2 diabetes.

Fish oil supplementation did not significantly reduce carotid plaque prevalence in patients with type 2 diabetes over 14 months.

• 415 patients with type 2 diabetes were randomly assigned to high-dose (3.0 g/day), low-dose (1.5 g/day), or placebo (refined olive oil) in a double-blind RCT.
• P trend = 0.111 for carotid plaque prevalence across dose groups.
• Odds ratios (95% CIs) of carotid plaque risk were 1.11 (0.56–2.22) for low-dose and 0.54 (0.26–1.13) for high-dose compared to placebo.
• 383 participants (92.3%) completed the 14-month intervention, and 359 patients (86.5%) completed carotid ultrasound exams.

Fish oil supplementation showed no significant effect on the incidence of new carotid plaques or regression of existing plaques.

• P for trend = 0.304 for incidence of new carotid plaques.
• P for trend = 0.390 for regression of existing carotid plaques.
• These secondary outcomes were assessed across placebo, low-dose, and high-dose groups.

High-dose fish oil supplementation significantly reduced remnant cholesterol and several triglyceride-containing lipoprotein subclasses.

• High-dose (3.0 g/day) intervention significantly reduced remnant cholesterol.
• Significant reductions were also observed in LDL-1-triglycerides (TG), HDL-4-TG, and HDL-3-TG.
• These changes were measured using NMR-derived lipoprotein subclass analysis.
• Low-dose intervention did not produce the same significant lipoprotein improvements.

High-dose fish oil significantly reduced carotid plaque risk specifically in patients with low genetic risk for remnant cholesterol, with no significant benefit in those with medium or high genetic risk.

• P for interaction = 0.008; FDR = 0.056 for the genetic risk subgroup analysis.
• No significant benefit was observed in patients with medium or high genetic risk for remnant cholesterol.
• Genetic interactions with supplementation were explored as part of the study design.
• This finding suggests a potential gene-diet interaction relevant to personalized nutritional strategies.

The trial was a 14-month double-blind randomized controlled trial enrolling 415 patients with type 2 diabetes.

• Participants were randomly assigned to three arms: high-dose (3.0 g/day marine n-3 fatty acids), low-dose (1.5 g/day), or placebo (refined olive oil).
• The primary outcome was prevalence of carotid plaques assessed by carotid ultrasound.
• Secondary outcomes included changes in NMR-derived lipoprotein subclasses and genetic interaction analyses.
• The trial was registered at ClinicalTrials.gov as NCT03708887.