Helen Bilianou

Assessment and Clinical Relevance of Non-Fasting and Postprandial Triglycerides: An Expert Panel Statement

An Expert Panel group of scientists and clinicians met to consider several aspects related to non-fasting and postprandial triglycerides (TGs) and their role as risk factors for cardiovascular disease (CVD). In this context, we review recent epidemiological studies relevant to elevated non-fasting TGs as a risk factor for CVD and provide a suggested classification of non-fasting TG concentration. Secondly, we sought to describe methodologies to evaluate postprandial TG using a fat tolerance test (FTT) in the clinic. Thirdly, we discuss the role of non-fasting lipids in the treatment of postprandial hyperlipemia. Finally, we provide a series of clinical recommendations relating to non-fasting TGs based on the consensus of the Expert Panel: 1). Elevated non-fasting TGs are a risk factor for CVD. 2). The desirable non-fasting TG concentration is <2 mmol/l (<180 mg/dl). 3). For standardized postprandial testing, a single FTT meal should be given after an 8 h fast and should consist of 75 g of fat, 25 g of carbohydrates and 10 g of protein. 4). A single TG measurement 4 h after a FTT meal provides a good evaluation of the postprandial TG response. 5). Preferably, subjects with non-fasting TG levels of 1-2 mmol/l (89-180 mg/dl) should be tested with a FTT. 6). TG concentration ≤ 2.5 mmol/l (220 mg/dl) at any time after a FTT meal should be considered as a desirable postprandial TG response. 7). A higher and undesirable postprandial TG response could be treated by aggressive lifestyle modification (including nutritional supplementation) and/or TG lowering drugs like statins, fibrates and nicotinic acid.

The use of statins alone, or in combination with pioglitazone and other drugs, for the treatment of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and related cardiovascular risk. An Expert Panel Statement

Non-alcoholic fatty liver disease (NAFLD), the most common liver disease, is characterized by accumulation of fat (>5% of the liver tissue), in the absence of alcohol abuse or other chronic liver diseases. It is closely related to the epidemic of obesity, metabolic syndrome or type 2 diabetes mellitus (T2DM). NAFLD can cause liver inflammation and progress to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis or hepatocellular cancer (HCC). Nevertheless, cardiovascular disease (CVD) is the most common cause of death in NAFLD/NASH patients. Current guidelines suggest the use of pioglitazone both in patients with T2DM and in those without. The use of statins, though considered safe by the guidelines, have very limited use; only 10% in high CVD risk patients are on statins by tertiary centers in the US. There are data from several animal studies, 5 post hoc analyses of prospective long-term survival studies, and 5 rather small biopsy proven NASH studies, one at baseline and on at the end of the study. All these studies provide data for biochemical and histological improvement of NAFLD/NASH with statins and in the clinical studies large reductions in CVD events in comparison with those also on statins and normal liver. Ezetimibe was also reported to improve NAFLD. Drugs currently in clinical trials seem to have potential for slowing down the evolution of NAFLD and for reducing liver- and CVD-related morbidity and mortality, but it will take time before they are ready to be used in everyday clinical practice. The suggestion of this Expert Panel is that, pending forthcoming randomized clinical trials, physicians should consider using a PPARgamma agonist, such as pioglitazone, or, statin use in those with NAFLD/NASH at high CVD or HCC risk, alone and/or preferably in combination with each other or with ezetimibe, for the primary or secondary prevention of CVD, and the avoidance of cirrhosis, liver transplantation or HCC, bearing in mind that CVD is the main cause of death in NAFLD/NASH patients.

Definition of Postprandial Lipaemia

At the present time, there is no widely agreed definition of postprandial lipaemia (PPL). This lack of a shared definition limits the identification and treatment of patients with exaggerated PPL as well as the evaluation of potential therapeutic agents. PPL is a complex syndrome characterized by non-fasting hypertriglyceridaemia that is associated with an increased risk of vascular events. This review considers the definition of PPL and the methodology for assessing this process.

Gender differences in the lipid profile of dyslipidemic subjects

OBJECTIVE We evaluated the gender-associated differences in lipid profile of subjects intended to receive lipid-lowering therapy with emphasis on the associations between triglycerides (TG) and other plasma lipid variables. DESIGN Lipid profiles of 1385 patients [aged 55+/-11 years, 549 women (40%)] were evaluated. Eligible subjects fulfilled one or more of the following criteria: total cholesterol (TC)>or=6.2 mmol/l, TG>or=1.7 mmol/l, and high-density lipoprotein cholesterol (HDL-C)<1.0 mmol/l. Patients were divided into subgroups according to TG and HDL-C levels. RESULTS Women aged on average 3.5 years older, had higher TC and HDL-C, lower TG and a correspondingly lower TC/HDL-C ratio than men. High TG and low HDL-C in tandem appeared twice more frequently in men. Inverse correlations between HDL-C and TG levels were found to exist in the entire cohort (r=-0.354, p<0.001) and in all various subgroups. In the subgroup with TG<1.7 mmol/l, women had higher TC and HDL-C, lower TG levels and lower TC/HDL-C ratio compared with men. In the subgroup with TG>or=1.7 mmol/l, women had higher TC and HDL-C levels and lower TC/HDL ratio compared with men. In the subgroup with HDL-C>or=1.0 mmol/l women had higher HDL-C, lower TG levels and lower TC/HDL-C ratio compared with men. CONCLUSIONS Elevated TG levels and low HDL-C in tandem are common lipid abnormalities in the clinical setting of primary and secondary preventions. Gender-associated differences in the lipid profile are evident in subjects presenting with dyslipidemia and might be of potential relevance for diagnostics and therapy for the prevention of atherosclerosis.

The role of common variants of the cholesteryl ester transfer protein gene in left main coronary artery disease

BackgroundThe cholesteryl ester transfer protein (CETP) has a central role in the lipid metabolism and therefore may alter the susceptibility to atherosclerosis.MethodsThe DNA of 471 subjects [133 subjects with angiographically documented left main coronary artery disease (LMCAD), 241 subjects with more peripheral coronary artery disease (MPCAD) and 97 subjects self reported healthy (Controls)] was analyzed for the frequency of TaqIB and I405V polymorphisms in the gene coding CETP.ResultsThere is no significant difference in CETP allele frequency or genotype distribution among LMCAD and MPCAD patients although there is statistical difference between LMCAD and Controls (p = 0.001). Specifically, patients with LMCAD and B1B1 genotype of TaqIB polymorphism were more frequent present compared to Controls (33.8% vs 22.9%, respectively). The frequency of B2B2 genotype was 3 times lower in the LMCAD group compared to Controls (10.5% vs 30.2%, respectively). In the LMCAD group the frequency of B1 allele compared to Controls was higher (62% vs 46%, respectively, p = 0.001). The relationship between TaqIB gene polymorphism and the LMCAD was independent of lipid profile, with the exception of apolipoprotein A.ConclusionsThese findings indicate that the TaqIB polymorphism may have potential importance in screening individuals at high risk for developing CAD. However, this polymorphism cannot distinguish between LMCAD and MPCAD. Further prospective investigations in larger populations are required to confirm these findings.

Primary and Secondary Hypertriglyceridaemia

Familial hypertriglyceridaemia is inherited in an autosomal dominant manner. The responsible genetic abnormality is unknown but recently, a novel gene encoding apolipoprotein AV has been linked to familial hypertriglyceridaemia. All patients develop the same phenotype with elevated levels of very low density lipoproteins (VLDL) in plasma. The main disorder of this dyslipidaemia is decreased intestinal absorption of biliary acids, leading to a compensatory increase of VLDL production. In familial hypertriglyceridaemia, a marked increase in plasma triglyceride (TG) levels can cause acute pancreatitis. Moreover, patients with other genetic factors, like familial chylomicronaemia, familial combined hyperlipidaemia, familial dysbetalipoproteinaemia and other rare disorders (e.g. Tangier disease and fish eye disease) may present increase of TG levels or cholesterol levels or both. Secondary hypertriglyceridaemias include hypothyroidism, kidney abnormalities (e.g. nephrotic syndrome or chronic kidney failure), diabetes mellitus, heavy alcohol consumption and obesity. In men and postmenopausal women, it seems that estrogen deficiency is responsible for higher TG levels compared with premenopausal women postprandially. In every state -fasting or postprandial-, women demonstrate lower plasma TG levels compared with men. This fact is due not only to increased muscular TG uptake and storage but also to higher TG clearance. Many studies demonstrated an age impact on plasma TG increase and larger variation of fasting TG levels caused by age. Also, hypertriglyceridaemia (TG >150 mg/dl; 1.7 mmol/l) is one of the diagnostic criteria of metabolic syndrome. Finally, several drugs may increase TG levels (e.g. chlorthalidone or beta-blockers).

Ageing, longevity, exceptional longevity and related genetic and non genetics markers: panel statement.

In May 2012, a group of scientists and clinicians met in Athens (Greece) to consider the relevance of ageing, longevity, exceptional longevity and related genetic and non genetic markers. During this meeting, we firstly reviewed recent epidemiological and clinical studies on ageing, longevity and exceptional longevity, briefly analyzed the ageing theories and discussed successful and unsuccessful ageing also taking into account the evolutionary perspective. Secondly, we considered the three phenotypes based on the definition of ageing, longevity and exceptional longevity and the associated biomarkers. Third, we discussed proposed treatments suitable to counteract or slow down ageing. Finally, this panel produced a consensus statement to highlight the importance of ageing, longevity and exceptional longevity, since this is a rapidly increasing phenotype worldwide. We acknowledge that not all experts in this field may completely agree with this statement.

The Frequency of 4 Common Gene Polymorphisms in Nonagenarians, Centenarians, and Average Life Span Individuals

Single nucleotide polymorphisms of angiotensin-converting enzyme (ACE) such as rs1799752, nuclear factor kappa B (NFkB) such as rs28362491 and cholesteryl ester transport protein (CETP) such as rs708272 (TaqB1) and rs5882 (I405V) were evaluated in nonagenarians, centenarians, and average life span individuals (controls). The study population (n = 307; 190 nonagenarians, 12 centenarians and 105 middle-aged controls) was genotyped for ACE, NFkB, and CETP genetic variants. The age of nonagenarian and centenarian group ranged between 90 and 111 years; centenarians and controls age ranged from 99 to 111, and from 18 to 80 years, respectively. The I carriers of ACE I/D gene were fewer in nonagenarians compared to centenarians (37.6% vs 62.5%, P = .016). The I carriers of ACE gene were more frequent in centenarians compared to controls (62% vs 41%, P = .045). No differences in frequency of common NFkB and CETP genotypes between patients with exceptional longevity and middle-aged patients were observed.

Aging Men and Lipids

Many theories aim at explaining the mechanisms of aging and death in humans. Decreased levels of androgens, growth hormone, and insulin-like growth factor accompany natural aging in men. Androgens influence the growth and maturation of men in various stages of their life. The action of androgens is performed by binding or not binding to androgen receptors. However, various actions of androgens were clarified after the discovery and genotyping of the androgen receptor. The influence of androgens on the lipid profile was reported by several researchers. This negative influence of androgens in men and the positive influence of estrogens in women are responsible for the higher impact of atherogenesis in men compared with women. In aging men, this negative influence of androgens on the lipid profile is more pronounced. This review considers the influence of age on lipid metabolism in men.

Effects of estrogens on atherogenesis.

Cardiovascular disease, in spite of the significant interventions that have been made for primary and secondary preventions, is still the main cause of death in men and women in the western world. The prevalence of myocardial infarction in women with normal level of estrogens is very rare and 3-5 times lower than in men. However, this favorable relationship disappears in older women. Thus, the results from several clinical trials regarding the hormone status of women and the occurrence of cardiovascular events have led to the conclusions that estrogens exert a protective effect on atherogenesis, on formation of the atherosclerotic plaque, and, subsequently, on clinical manifestations of atherogenesis. In the last years, after the development of models for studying atherogenesis significant progress has been made, concerning the understanding of evolutionary biological and cellular events, leading to atherogenesis. In this review, atherogenesis (the formation of atherosclerotic plaque and its stages), the factors which advance atherogenesis (environmental and genetic), the effect of estrogens on the stages of atherogenesis, and the effect of estrogens on the factors which promote atherosclerosis will be discussed. Finally, hormone replacement therapy will be briefly described.