A low-fat, high-complex carbohydrate diet supplemented with long-chain (n-3) fatty acids alters the postprandial lipoprotein profile in patients with metabolic syndrome.

Dietary fat intake plays a critical role in the development of metabolic syndrome (MetS). This study addressed the hypothesis that dietary fat quantity and quality may differentially modulate postprandial lipoprotein metabolism in MetS patients. A multi-center, parallel, randomized, controlled trial conducted within the LIPGENE study randomly assigned MetS patients to 1 of 4 diets: high-SFA [HSFA; 38% energy (E) from fat, 16% E as SFA], high-monounsaturated fatty acid [HMUFA; 38% E from fat, 20% E as MUFA], and 2 low-fat, high-complex carbohydrate [LFHCC; 28% E from fat] diets supplemented with 1.24 g/d of long-chain (LC) (n-3) PUFA (ratio 1.4 eicosapentaenoic acid:1 docosahexaenoic acid) or placebo (1.24 g/d of high-oleic sunflower-seed oil) for 12 wk each. A fat challenge with the same fat composition as the diets was conducted pre- and postintervention. Postprandial total cholesterol, triglycerides (TG), apolipoprotein (apo) B, apo B-48, apo A-I, LDL-cholesterol, HDL-cholesterol and cholesterol, TG, retinyl palmitate, and apo B in TG-rich lipoproteins (TRL; large and small) were determined pre- and postintervention. Postintervention, postprandial TG (P < 0.001) and large TRL-TG (P = 0.009) clearance began earlier and was faster in the HMUFA group compared with the HSFA and LFHCC groups. The LFHCC (n-3) group had a lower postprandial TG concentration (P < 0.001) than the other diet groups. Consuming the LFHCC diet increased the TG (P = 0.04), large TRL-TG (P = 0.01), TRL-cholesterol (P < 0.001), TRL-retinyl palmitate (P = 0.001), and TRL-apo B (P = 0.002) area under the curve compared with preintervention values. In contrast, long-term ingestion of the LFHCC (n-3) diet did not augment postprandial TG and TRL metabolism. In conclusion, postprandial abnormalities associated with MetS can be attenuated with LFHCC (n-3) and HMUFA diets. The adverse postprandial TG-raising effects of long-term LFHCC diets may be avoided by concomitant LC (n-3) PUFA supplementation to weight-stable MetS patients.

Effects of rs7903146 variation in the Tcf7l2 gene in the lipid metabolism of three different populations.

BACKGROUND: TCF7L2 rs7903146 is an important genetic factor predicting type 2 diabetes (T2DM) which has also been linked to higher cardiovascular risk. To date, there is little information about the additional impact of this single nucleotide polymorphism (SNP) beyond glucose metabolism. METHODOLOGY/PRINCIPAL FINDINGS: We studied whether rs7903146 influenced postprandial lipid metabolism in three different populations (healthy young men, metabolic syndrome (MetS) patients and elderly persons). Eighty-eight healthy males were submitted to a single saturated fatty acid-rich test meal. Additionally, 110 middle-aged MetS patients and 20 healthy elderly persons (≥ 65 years) were submitted to three different dietary models followed by test meals. Minor allele homozygotes for rs7903146 showed a worse postprandial lipemia profile in young males, as seen by a lower HDL-cholesterol and Apo A1 concentration during the postprandial lipemia and a trend towards higher triglycerides (TG), than the other genotypes. In healthy elderly persons, carriers of the minor allele showed higher total cholesterol, LDL-cholesterol, Apo B and TG in the fasting state, and a higher postprandial area under the curve for total cholesterol, Apo B, small-triglyceride rich lipoprotein (TRL) cholesterol and small-(TRL) triglycerides. These results were accompanied by differential changes in adipokines. We did not observe any influence of rs7903146 on the postprandium of MetS patients. CONCLUSIONS/SIGNIFICANCE: Healthy young males and elderly persons who are carriers of the mutant allele for rs7903146 have an impaired postprandial lipid metabolism that may be mediated by an alteration in adipokine regulation, and may be related to the higher cardiovascular risk observed in these persons. TRIAL REGISTRATION: ClinicalTrials.gov NCT00429195.

Interleukin 1B variant -1473G/C (rs1143623) influences triglyceride and interleukin 6 metabolism.

CONTEXT: IL1b (IL1B or IL1ß), a key modulator of the immune response, exerts its functions mainly via IL6 regulation. Fatty meals cause transient hypertriglyceridemia and are considered to be proinflammatory, but the extent of these responses shows high interindividual susceptibility. OBJECTIVE: We evaluated the influence of a genetic variant located in the promoter region of IL1B (-1473G/C) on fasting and postprandial lipids and IL6. DESIGN, SETTING, AND PARTICIPANTS: A total of 477 people over age 65 yr were genotyped for IL1B -1473G/C, and we evaluated fasting lipids depending on genotype. Then, 88 healthy young men were also genotyped and were fed a saturated fatty acid-rich meal. Serial blood samples were drawn for 11 h after the meal, and lipid fractions and IL6 were assayed. MAIN OUTCOME AND INTERVENTIONS: Fasting lipids were studied in the aged persons. Fasting and postprandial measurements of lipids and IL6 were performed in the healthy young men. RESULTS: In the aged persons, CC subjects (minor allele homozygotes) showed higher triglyceride (P = 0.002) and cholesterol (P = 0.011) levels. Healthy young male carriers of the minor C allele showed higher postprandial triglycerides (P = 0.037), and those carried into large triglyceride-rich lipoproteins (P = 0.004). In addition, they showed higher postprandial IL6 concentrations (P = 0.008). CONCLUSIONS: Our work shows that inflammatory genes may regulate fasting and postprandial lipids because the carriers of the minor allele of an IL gene variant have altered lipid metabolism. To reinforce these gene-phenotype findings, IL6 (the natural effector of IL1B) was increased in these persons.

Dietary fat differentially influences regulatory endothelial function during the postprandial state in patients with metabolic syndrome: from the LIPGENE study.

OBJECTIVE: To investigate whether endothelium-dependent vasomotor function and plasma levels of cellular adhesion molecules are affected by diets with different fat quantity and quality during the postprandial state in subjects with the metabolic syndrome (MetS). METHODS: Patients were randomly assigned to one of four isoenergetic diets distinct in fat quantity and quality: high-SFA (HSFA); high-MUFA (HMUFA) and two low-fat, high-complex carbohydrate (LFHCC) diets, supplemented with 1.24g/day of long chain n-3 PUFA (LC n-3 PUFA) or placebo for 12 weeks each. Flow-associated vasodilatation of the brachial artery and postprandial plasma levels of total nitrites, nitric oxide (NO) synthase, soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and P-selectin were assessed post-intervention. RESULTS: Post-intervention postprandial flow-associated vasodilatation was significantly higher after the HMUFA diet (P<0.05) compared to subjects adhering to the other three diets. Consistently, the postprandial NO synthase response significantly increased during the HMUFA compared with the HSFA and LFHCC (placebo) diets. Postprandial sICAM-1 levels were lower during the HMUFA than during the HSFA and LFHCC n-3 diets. CONCLUSIONS: Our data support the notion that the HMUFA diet improves postprandial endothelial cell function and decreases postprandial plasma sICAM-1 concentrations in patients with the MetS. These findings suggest that the postprandial state is important for understanding possible cardio-protective effects associated with the Mediterranean diet particularly in subject with the MetS.