👤 Shin'ichiro Yasunaga

Dietary unsaturated fat, protein, and carbohydrate have well-established effects on HDL (high-density lipoprotein) cholesterol levels, but whether these effects are connected causally to coronary heart disease (CHD) has been called into question. Protein-based minor HDL subspecies are emerging as novel and likely causal biomarkers, direct or inverse, for risk of CHD, diabetes, and other conditions. HDL-raising drugs such as CETP (cholesteryl ester transfer protein) inhibitors raise certain HDL subspecies that have adverse effects on CHD risk. We hypothesize that dietary unsaturated fat, protein, and carbohydrate differentially affect 15 minor protein-based HDL subspecies with diverse functionality in lipid metabolism, antioxidation, immunity, hemostasis, and protease inhibition. We analyzed the apo (apolipoprotein) A1 concentrations of 15 minor HDL subspecies after 4 weeks on each diet in 141 participants in the OmniHeart trial (Optimal Macronutrient Intake Trial to Prevent Heart Disease), a randomized 3-period crossover, controlled feeding study. The diet rich in carbohydrate contained 58% carbohydrate, 27% fat, and 15% protein, and the diets rich in unsaturated fat and protein replaced 10% of carbohydrate with unsaturated fat or protein, respectively. Unsaturated fat replacing dietary carbohydrate increased concentrations of apoA1 in lipid metabolism subspecies including HDL that contains apoA2, apoE, or apoC1 that has been associated with reduced risk of CHD. Protein replacing carbohydrate increased apoE HDL, consistent with lower CHD risk, and decreased concentrations of several other HDL subspecies that were associated with higher risk of CHD including HDL that contains PLMG (plasminogen), A2M (alpha-2-macroglobulin), or apoL1. Network analysis showed connections between functional groups of HDL subspecies that are quantitatively affected by dietary macronutrients. Replacing dietary carbohydrate with unsaturated fat or protein raised levels of protein-based HDL subspecies associated with lower risk of CHD or lowered the levels of those associated with higher risk of CHD. Minor HDL subspecies with diverse functions may mediate the association of dietary patterns with risk of CHD. URL: https://www.clinicaltrials.gov; Unique identifier: NCT00051350. Show less

The aetiology of metabolic syndrome is complex, being determined by the interplay of both genetic and environmental factors. The aim of this study was to identify genetic polymorphisms that confer susceptibility to metabolic syndrome, to allow prediction of genetic risk for this condition. The study population comprised 2417 unrelated Japanese subjects (1522 with metabolic syndrome and 895 controls). The genotypes for 44 polymorphisms of 31 candidate genes related to lipid metabolism were determined using a combination of PCR and sequence-specific oligonucleotide probes with suspension array technology. The chi(2) test and subsequent multivariate logistic regression analysis with adjustment for age, sex and smoking status found that the-3A-->G and 553G-->T (Gly185Cys) polymorphisms of APOA5, the 2052T-->C (Val653Val) and 1866C-->T (Asn591Asn) polymorphisms of LDLR, the 13989A-->G (Ile118Val) polymorphism of CYP3A4 and the 1014T-->A polymorphism of C1QTNF5 were significantly (false discovery rate <0.05) associated with the prevalence of metabolic syndrome, with the variant alleles of APOA5 and C1QTNF5 representing risk factors for and those of LDLR and CYP3A4 being protective against this condition. Serum levels of triglycerides and high-density lipoprotein (HDL) cholesterol differed significantly (p<0.05) among APOA5 genotypes; the serum level of HDL cholesterol differed among LDLR genotypes; and the fasting plasma glucose level and body mass index differed between CYP3A4 and C1QTNF5 genotypes, respectively. APOA5, LDLR, CYP3A4 and C1QTNF5 are susceptibility loci for metabolic syndrome in Japanese people. Genotypes for these polymorphisms may prove informative for prediction of genetic risk for metabolic syndrome. Show less

The purpose of the present study was to identify genetic variants that confer susceptibility to dyslipidemia. A total of 5213 individuals from two independent populations were examined: Subject panel A comprised 3794 individuals who visited participating hospitals; subject panel B comprised 1419 community-dwelling elderly individuals. The genotypes for 100 polymorphisms of 65 candidate genes were determined. The chi(2) test and multivariable logistic regression analysis revealed that seven polymorphisms of APOA5, APOC3, APOA1, ACAT2, and LPL were significantly associated with hypertriglyceridemia, six polymorphisms of APOA5, LIPC, and CYP3A4 with low HDL-cholesterol, and three polymorphisms of APOE and CCR2 with high LDL-cholesterol in subject panel A. For validation of these associations, the same polymorphisms were examined in subject panel B. Six polymorphisms of APOA5, APOC3, APOA1, and LPL were again significantly associated with hypertriglyceridemia, three polymorphisms of APOA5 with low HDL-cholesterol, and two polymorphisms of APOE with high LDL-cholesterol. Serum triglyceride, HDL-cholesterol, and LDL-cholesterol concentrations differed significantly among genotypes of these corresponding polymorphisms in both subject panels. These results indicate that polymorphisms of APOA5, APOC3, APOA1, and LPL are determinants of hypertriglyceridemia and that those of APOA5 and APOE are determinants of low HDL-cholesterol and high LDL-cholesterol, respectively, in Japanese individuals. Show less