Presentation on theme: "Director, Nutrition and Genomics Laboratory"— Presentation transcript:
1Director, Nutrition and Genomics Laboratory Gender, Nutrigenomics and CVDJose M Ordovas, PHDDirector, Nutrition and Genomics LaboratoryJean Mayer USDA Human Nutrition Research Center on Aging at Tufts University
2Do we Really Need to Take this Uncertain Walk Into the Future?
3Yes, Considering that this has been the Path of Nutrition Recommendations
7Plasma Lipoprotein Metabolism Intestinal epithelial cellBiliary cholesterolDietary cholesterolArterial lumenAtherosclerotic plaque/foam cellsOvaryIntestineMuscleSkinAdrenalBile aciduptakeLuminal cholesterolMicellar cholesterolMTPCEACATexcretion(esterification)ABC G5 ABC G8Cholesterol TransporterHDLCMFree cholesterolHDLSynthesis – Peripheral TissuesAbsorption – IntestineSR-B1Increased liver LDL receptor activity decreases circulating LDL-CDecreased liver LDL receptor activity increases circulating LDL-CLDLLiverLDLLDL/apo B–EReceptorTwo sources of cholesterolConceptually, it might be argued that circulating cholesterol originates from predominantly two sources: synthesis (from liver and peripheral tissues) and absorption (from the intestine). Irrespective of the origins of cholesterol, it is the liver that normally serves as the main regulatory organ that determines LDL-C blood levels. (Cholesterol from endothelial macrophages associated with arterial cholesterol plaques are clinically important, but only a very minor contributor to total circulating cholesterol.)Animal data suggest that most cholesterol synthesis in the body is from peripheral tissues such as intestine, muscle, and skin. The greatest amount of cholesterol produced per gram of tissue is from endocrine organs such as the ovary, adrenal glands, and gastrointestinal tract. This is because cholesterol is the "backbone" precursor for many hormones.The relative contribution of cholesterol from any of these sources is dependent upon genetic predisposition, diet, drug therapies, interplay of enzymatic up- and down-regulations, and other potential factors. Decreased cholesterol contribution to the liver may increase hepatic LDL receptor activity and thus reduce circulating LDL-C blood levels, which in turn is associated with reduced risk for CHD. Thus, different lipid-altering drugs whose mechanism of action reduces different sources of cholesterol may have complementary actions in lowering LDL-C.Additional abbreviation on slide: SR-B1 = scavenger receptor class B, type 1.References:Bays H, Dujovne C. Colesevelam HCl: a non-systemic lipid-altering drug. Expert Opin Pharmacother 2003;4:Dietschy JM, Turley SD, Spady DK. Role of liver in the maintenance of cholesterol and low density lipoprotein homeostasis in different animal species, including humans. J Lipid Res 1993;34:Spady DK, Dietschy JM. Sterol synthesis in vivo in 18 tissues of the squirrel monkey, guinea pig, rabbit, hamster, and rat. J Lipid Res 1983;24:Synthesis - LiverHealthier artery with decreased plaqueAtherosclerotic plaqueArtery with increased plaqueBays H et al. Expert Opin Pharmacother 2003;4:
9Since our beginning in 1948, the Framingham Heart Study, under the direction of the National Heart, Lung and Blood Institute; NHLBI (formerly known as the National Heart Institute) has been committed to identifying the common factors or characteristics that contribute to cardiovascular disease (CVD). We follow CVD development over a long period of time in a large group of participants who had not yet developed overt symptoms of CVD or suffered a heart attack or stroke.Our Study began by recruiting an Original Cohort of 5,209 men and women between the ages of 30 and 62 from the town of Framingham, Massachusetts and since has added an Offspring Cohort (1971) and a Third Generation Cohort, which began in 2002.Over the years, careful monitoring of the Framingham Study population has led to the identification of several major CVD risk factors, as well as a collection of valuable information on the effects of these factors such as blood pressure, blood triglyceride and HDL cholesterol levels, age, gender, and psychosocial issues. Risk factors for other physiological conditions such as dementia have been and continue to be investigated. In addition, the relationships between physical traits and genetic patterns are being studied.
10CVD rates, plasma Cholesterol and APOE alleles The Framingham Study bcdThis slide represents CVD rates in Framingham according to apoE alleles. In women things are according to what it will be expected:E4>E3>E2; however, in men the risk is E4~E3>E2. This is paradoxical because E2 have lower cholesterol levels than E3 and E4.The explanation of this paradox comes from the fact that male carriers of the APOE2 allele have higher levels of another atherogenic particle (remnants) that are not measured in the clinical practice nowadays. These data will be published in the next 2-3 months in Atherosclerosis.HOWEVER, it is IMPORTANT, as I will explain more detail in one of the coming slides, that each of these genes contribute only 1-5% to the variability in lipids and/or CVD and that in addition, there is a strong interaction with the environment that may increase or decrease this contribution.Lahoz C et al. Atherosclerosis ;154:
12Variability in LDL-C response following Diet Therapy MenWomen
13LDL-C Response to a Therapeutic Diet by APOE allele Lopez-Miranda et al. J Lipid Res. 1994;35:
14Pharmacogenetics of Statins: Response is Gender Specific
15PL PL Ch Ch Ch Ch LCAT HL CE CETP FA Ch CE TG Ch HDL3 HDL3 HDL2b HDL2a Pre-beta2HDLChPre-beta1 HDLPre-beta3HDLLCATHDL3ApoA-IHDL3HDL-RHLHDL2bHDL2aCECETPFAChLiverCETGChTo apoB containinglipoproteinsTo periphery
16High Density Lipoprotein The APOA1-APOC3-APOA4-APOA5 locusCHD Risk According to HDL-CLevels: The Framingham StudyHigh Density LipoproteinapoA-IapoA-IIPhospholipids andFree CholesterolTriglyceride andCholesteryl EstersHigh density lipoproteins (HDL) have received the familial name of carriers of the “good cholesterol”. This is based on the evidence that increasing concentrations in blood are protective for coronary heart disease (CHD). The major protein in HDL is apoA-I and this is coded by the APOA1 gene. This gene is part of the APOA1-C3-A4 gene complex on chromosome 11 here showing some of the common polymorphism. We have demonstrated that: The apoC-III/SstI polymorphism may be quite relevant for non insulin dependent diabetes mellitus (NIDDM) and interaction with dietary habits and ethnicity.The ApoA-IV 360 polymorphism is a marker of dietary response. In the following slides we show the importance of taking into consideration interactions between genes and dietary factors to understand the genetics of cardiovascular disease (CVD). We will use as an example the APOA1 gene polymorphism located –75 bases to the APOA1 gene (this polymorphism is known as the –75(G/A) MspI).Jose M. OrdovasSstI360347MspI
17Ordovas et al. Am. J. Clin. Nutr. (2002) Mean Plasma HDL-C and Apolipoprotein AI by APOA1(-75G/A) Genotypes in the Framingham StudyOrdovas et al. Am. J. Clin. Nutr. (2002)
18Ordovas et al. Am. J. Clin. Nutr. (2002) Polyunsaturated fatty acids modulate the effects of theAPOA1-75(g/a) polymorphism on HDL-C levels in a genderSpecific manner: The Framingham StudyP<0.001Unexpected!More PUFA= More HDLCExpected!More PUFA= LESS HDLCIf we go back to the Framingham Study population and we take into consideration the factor “diet” then the picture that emerges is very different to that seen in the previously shown association study.If we concentrate on those subjects with a low consumption of Polyunsaturated fatty acids (PUFA, commonly found in vegetable oils, nuts and fish) (PUFA <4%, blue bars), we see how the A allele is associated in an allele dose dependent manner with lower HDL-C levels. Therefore, for these subjects the presence of the A allele will be detrimental. If we now concentrate of those subjects with an average intake of PUFA (4-8%, green bars), then we observe that the effect of the polymorphism is neutral, and that is in fact what most population studies have shown because the average consumption of PUFa is within that range. However, if we now go to those with a HIGH PUFA intake, then the effect is reverse. The A allele is associated with increased HDL-C levels and in this case, the A allele is potentially protective for CHD. Therefore, this example shows how, depending on the allele we can suggest the most optimal diet for the individual. If one is an AA or GA then probably they should consume a high PUFA diet. Conversely, if one is a GG. Probably the recommended diet should not exceed 8% of PUFA.Ordovas et al. Am. J. Clin. Nutr. In pressJose M. OrdovasOrdovas et al. Am. J. Clin. Nutr. (2002)
29PLIN, Diet and Metabolic Syndrome Corella D et al. Perilipin gene variation determines higher susceptibility to insulin resistance in Asian women when consuming a high-saturated fat, low-carbohydrate diet. Diabetes Care 2006 Jun;29(6):
31Summary Genotype/Phenotype associations may be gender dependent. Gene-environment interactions are also gender dependent.For this type of studies, gender-specific statistical analyses should be part of the “Standard Operating Procedures” and therefore included as part of the experimental design.There is potential for future personalized dietary recommendations to decrease risk of chronic disorders, but gender must be part of the equation.