JLR Patient-Oriented and Epidemiological Research
Four nights of sleep restriction suppress the postprandial lipemic response and decrease satietyChronic sleep restriction, or inadequate sleep, is associated with increased risk of cardiometabolic disease. Laboratory studies demonstrate that sleep restriction causes impaired whole-body insulin sensitivity and glucose disposal. Evidence suggests that inadequate sleep also impairs adipose tissue insulin sensitivity and the NEFA rebound during intravenous glucose tolerance tests, yet no studies have examined the effects of sleep restriction on high-fat meal lipemia. We assessed the effect of 5 h time in bed (TIB) per night for four consecutive nights on postprandial lipemia following a standardized high-fat dinner (HFD).
DGAT2 partially compensates for lipid-induced ER stress in human DGAT1-deficient intestinal stem cellsDietary lipids are taken up as FAs by the intestinal epithelium and converted by diacylglycerol acyltransferase (DGAT) enzymes into triglycerides, which are packaged in chylomicrons or stored in cytoplasmic lipid droplets (LDs). DGAT1-deficient patients suffer from vomiting, diarrhea, and protein losing enteropathy, illustrating the importance of this process to intestinal homeostasis. Previously, we have shown that DGAT1 deficiency causes decreased LD formation and resistance to unsaturated FA lipotoxicity in patient-derived intestinal organoids.
n-3 PUFAs improve erythrocyte fatty acid profile in patients with small AAA: a randomized controlled trialAbdominal aortic aneurysm (AAA) is an important cause of death in older adults, which has no current drug therapy. Inflammation and abnormal redox status are believed to be key pathogenic mechanisms for AAA. In light of evidence correlating inflammation with aberrant fatty acid profiles, this study compared erythrocyte fatty acid content in 43 AAA patients (diameter 3.0–4.5 cm) and 52 healthy controls. In addition, the effect of omega-3 PUFA (n-3 PUFA) supplementation on erythrocyte fatty acid content was examined in a cohort of 30 AAA patients as part of a 12 week randomized placebo-controlled clinical trial.
Macronutrient-specific effect of the MTNR1B genotype on lipid levels in response to 2 year weight-loss dietsCompelling evidence indicates that lipid metabolism is in partial control of the circadian system. In this context, it has been reported that the melatonin receptor 1B (MTNR1B) genetic variant influences the dynamics of melatonin secretion, which is involved in the circadian system as a chronobiotic. The objective was to analyze whether the MTNR1B rs10830963 genetic variant was related to changes in lipid levels in response to dietary interventions with different macronutrient distribution in 722 overweight/obese subjects from the POUNDS Lost trial.
Individual serum saturated fatty acids and markers of chronic subclinical inflammation: the Insulin Resistance Atherosclerosis StudyRecent evidence has documented distinct effects of individual saturated FAs (SFAs) on cardiometabolic outcomes, with potential protective effects from odd- and very long-chain SFAs (VLSFAs). Cross-sectional and prospective associations of individual serum SFAs (12:0, 14:0, 15:0, 16:0, 18:0, 20:0, 22:0, and total SFA) with proinflammatory biomarkers and adiponectin were investigated in 555 adults from the IRAS. Principal component analysis (PCA) of proinflammatory markers yielded three clusters: principal component (PC) 1: fibrinogen, white cell count, C-reactive protein; PC 2: plasminogen activator inhibitor-1 (PAI-1), TNF-α, IL-18; PC 3: IL-6 and IL-8.
Weekday variation in triglyceride concentrations in 1.8 million blood samplesTriglyceride (TG) concentration is used as a marker of cardiometabolic risk. However, diurnal and possibly weekday variation exists in TG concentrations. The objective of this work was to investigate weekday variation in TG concentrations among 1.8 million blood samples drawn between 2008 and 2015 from patients in the Capital region of Denmark. Plasma TG was extracted from a central clinical laboratory information system. Weekday variation was investigated by means of linear mixed models. In addition to the profound diurnal variation, the TG concentration was 4.5% lower on Fridays compared with Mondays (P < 0.0001).
Identification and characterization of a novel DGAT1 missense mutation associated with congenital diarrheaAcyl-CoA:diacylglycerol acyltransferase (DGAT)1 and DGAT2 catalyze triglyceride (TG) biosynthesis in humans. Biallelic loss-of-function mutations in human DGAT1 result in severe congenital diarrhea and protein-losing enteropathy. Additionally, pharmacologic inhibition of DGAT1 led to dose-related diarrhea in human clinical trials. Here we identify a previously unknown DGAT1 mutation in identical twins of South Asian descent. These male patients developed watery diarrhea shortly after birth, with protein-losing enteropathy and failure to thrive.
Epigenome-wide association study of triglyceride postprandial responses to a high-fat dietary challengePostprandial lipemia (PPL), the increased plasma TG concentration after consuming a high-fat meal, is an independent risk factor for CVD. Individual responses to a meal high in fat vary greatly, depending on genetic and lifestyle factors. However, only a few loci have been associated with TG-PPL response. Heritable epigenomic changes may be significant contributors to the unexplained inter-individual PPL variability. We conducted an epigenome-wide association study on 979 subjects with DNA methylation measured from CD4+ T cells, who were challenged with a high-fat meal as a part of the Genetics of Lipid Lowering Drugs and Diet Network study.
Plasma fatty acids, oxylipins, and risk of myocardial infarction: the Singapore Chinese Health StudyWe aimed to examine the prospective association between plasma FAs, oxylipins, and risk of acute myocardial infarction (AMI) in a Singapore Chinese population. A nested case-control study with 744 incident AMI cases and 744 matched controls aged 47–83 years was conducted within the Singapore Chinese Health Study. Nineteen plasma FAs and 12 oxylipins were quantified using MS. These were grouped into 12 FA clusters and 5 oxylipin clusters using hierarchical clustering, and their associations with AMI risk were assessed.
Effect of fish oil on monoepoxides derived from fatty acids during cardiac surgeryOur objective was to assess the dynamics of monoepoxides derived from polyunsaturated fatty acids (MEFAs), and their response to n-3 PUFA supplementation, in the setting of acute tissue injury and inflammation (cardiac surgery) in humans. Patients (479) undergoing cardiac surgery in three countries were randomized to perioperative fish oil (EPA + DHA; 8–10 g over 2–5 days preoperatively, then 2 g/day postoperatively) or placebo (olive oil). Plasma MEFAs derived from n-3 and n-6 PUFAs were measured 2 days postoperatively.
Associations of human retinal very long-chain polyunsaturated fatty acids with dietary lipid biomarkersThe human retina is well-known to have unique lipid profiles enriched in long-chain polyunsaturated fatty acids (LC-PUFAs) and very long-chain polyunsaturated fatty acids (VLC-PUFAs) that appear to promote normal retinal structure and function, but the influence of diet on retinal lipid profiles in health and disease remains controversial. In this study, we examined two independent cohorts of donor eyes and related their retinal lipid profiles with systemic biomarkers of lipid intake. We found that serum and red blood cell lipids, and to a lesser extent orbital fat, are indeed excellent biomarkers of retinal lipid content and n-3/n-6 ratios in both the LC-PUFA and VLC-PUFA series.
Increased palmitate intake: higher acylcarnitine concentrations without impaired progression of β-oxidationPalmitic acid (PA) is associated with higher blood concentrations of medium-chain acylcarnitines (MCACs), and we hypothesized that PA may inhibit progression of FA β-oxidation. Using a cross-over design, 17 adults were fed high PA (HPA) and low PA/high oleic acid (HOA) diets, each for 3 weeks. The [1-13C]PA and [13-13C]PA tracers were administered with food in random order with each diet, and we assessed PA oxidation (PA OX) and serum AC concentration to determine whether a higher PA intake promoted incomplete PA OX.
Lipidomic changes of LDL in overweight and moderately hypercholesterolemic subjects taking phytosterol- and omega-3-supplemented milkThe benefits of dietary phytosterols (PhySs) and long-chain n-3 PUFA (ω3) have been linked to their effects as cholesterol- and triglyceride (TGL)-lowering agents. However, it remains unknown whether these compounds have further metabolic effects on LDL lipid composition. Here, we studied the effects of PhyS- or ω3-supplemented low-fat milk (milk) on the LDL-lipidome. Overweight and moderately hypercholesterolemic subjects (n = 32) were enrolled in a two-arm longitudinal crossover study. Milk (250 ml/day), enriched with either 1.57 g PhyS or 375 mg ω3 (EPA + DHA), was given to the participants during two sequential 28 day intervention periods.