Studies have shown that the reduction in serum TAG concentrations with long-chain n-3 fatty acid supplementation is highly variable among individuals. The objectives of the present study were to compare the proportions of individuals whose TAG concentrations lowered after high-dose DHA and EPA, and to identify the predictors of response to both modalities. In a double-blind, controlled, crossover study, 154 men and women were randomised to three supplemented phases of 10 weeks each: (1) 2·7 g/d of DHA, (2) 2·7 g/d of EPA and (3) 3 g/d of maize oil, separated by 9-week washouts. As secondary analyses, the mean intra-individual variation in TAG was calculated using the standard deviation from the mean of four off-treatment samples. The response remained within the intra-individual variation (±0·25 mmol/l) in 47 and 57 % of participants after DHA and EPA, respectively. Although there was a greater proportion of participants with a reduction >0·25 mmol/l after DHA than after EPA (45 υ. 32 %; P 0·25 mmol/l after both DHA and EPA had higher non-HDL-cholesterol, TAG and insulin concentrations compared with other responders at baseline (all P < 0·05). In conclusion, supplementation with 2·7 g/d DHA or EPA had no meaningful effect on TAG concentrations in a large proportion of individuals with normal mean TAG concentrations at baseline. Although DHA lowered TAG in a greater proportion of individuals compared with EPA, the magnitude of TAG lowering among them was similar.
Keywords: Apo B total apo B100; CRP C-reactive protein; FADS1 fatty acid desaturase 1 or delta-5 fatty acid desaturase; FADS2 fatty acid desaturase 2 or delta-6 fatty acid desaturase; GAPDH glyceraldehyde 3-phosphate dehydrogenase; HDL-C HDL-cholesterol; HMG-CoA reductase 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase; LCn3-PUFA long-chain n-3 PUFA; LDL-C LDL-cholesterol; LDL-R LDL receptor; PCSK9 proprotein convertase subtilisin/kexin type 9; REDUCE-IT Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial; SREBP sterol regulatory element-binding protein; DHA; EPA; Intra-individual variations; TAG; Variability.