Abstract P059: Effects Of Saturated Fatty Acid On Lipoprotein(a): A Systematic Review And Meta-analysis

Abstract

Background: Elevated lipoprotein(a) [Lp(a)] is a significant contributor to residual CVD risk. Replacement of saturated fatty acids (SFA) with mono- and polyunsaturated fatty acids (MUFA and PUFA), carbohydrates (CHO) has established effects on traditional lipid parameters related to CVD; however, the evidence for Lp(a) is inconsistent. Moreover, some evidence suggests replacing SFA with other macronutrients increases Lp(a). Objective: The aim was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of replacing SFA with MUFA, PUFA, trans fatty acids (TFA) and CHO on Lp(a). Methods: PubMed, Cochrane Central, ClinicalTrials.gov, and Web of Science were searched for RCTs with a duration of ≥13 days that included healthy adults ages 20-65 y and examined the effect of diets differing in SFA, MUFA, PUFA, or CHO on Lp(a). Exclusion criteria included changes in protein/alcohol and >10% weight loss in last 6 months. Diet comparisons were extracted from trials to assess the effect of substitution of SFA for other macronutrients. Data are presented as weighted means. Data were analyzed using a mixed model approach (SAS 9.4). Results: Twenty-seven articles met criteria for inclusion and data were available for analysis for 15 articles. There were 39 comparisons between SFA and other macronutrients. Lp(a) was measured by macra, polyclonal, or sandwich enzyme linked immunosorbent assay (ELISA), particle enhanced turbidimetric immunoassay, or radioimmunoassay. SFA was substituted for TFA ( k =6), MUFA ( k =9), and PUFA ( k =3). Five trials compared a high SFA diet with a high CHO diet. A total of 539 adults (44.7 + 31.6 y) were included in the pooled sample. Overall, the mean displacement of SFA for other macronutrients was 6.7% of kcals. Mean Lp(a) across the included studies was 100.5 + 100.3 mg/dl. Replacement of SFA with MUFA, PUFA or CHO did not significantly affect Lp(a). Lp(a) was 6.1 mg/dl (p=0.021; 95% CI: -11.3, -0.9) lower when SFA replaced TFA. Conclusions: Overall, substitution of SFA for other macronutrients did not impact Lp(a) concentrations. Lower levels of Lp(a) were observed when 5% of kcals from TFA were replaced with SFA, although the clinical relevance of this finding is unclear. Further research examining the effect of SFA replacement on Lp(a) is needed due to the methodological quality of the available data and heterogeneity in Lp(a) measurement methods utilized.