Lipoprotein-associated phospholipase A2 activity is increased in patients with definite familial hypercholesterolemia compared with other forms of hypercholesterolemia.

BACKGROUND AND AIM: Lipoprotein-associated phospholipase A2 (Lp-PLA2) plays a key role in atherosclerosis development. It is considered a marker of increased risk of cardiovascular disease (CVD) and plaque vulnerability. Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol and a higher prevalence of early CVD. Our aim was to evaluate the differences in Lp-PLA2 activity in a population of hypercholesterolemic patients with and without definite FH. METHODS AND RESULTS: Hypercholesterolemic patients were consecutively recruited. Definite FH was defined according to Dutch Lipid Clinic Network criteria ≥8. All patients underwent routine clinical examination and biological assessments and Lp-PLA2 activity was measured in blood samples. Among 469 patients, 118 had a definite diagnosis of FH. Lp-PLA2 activity was significantly higher in definite FH patients compared to non-definite FH patients (206.5 ± 54.5 vs. 180.8 ± 48.4 nmol/min/mL, p < 0.0001). Lp-PLA2 positively correlated with total cholesterol, LDL-C and apolipoprotein B and negatively with HDL-C and apolipoprotein A-1. In multivariate analysis, definite FH diagnosis, LDL-C, HDL-C and statin treatment remained correlates of Lp-PLA2 independently of systolic blood pressure. CONCLUSIONS: Lp-PLA2 activity was higher in definite FH than in non-definite FH patients independently of LDL-C levels and statin treatment. These results highlight the particular phenotype of FH subjects among hypercholesterolemic patients. As increased Lp-PLA2 activity suggests, FH patients exhibit higher arterial inflammation that may contribute to their high cardiovascular risk. Our results reinforce the potential beneficial role of statins pleiotropic effects and the need for proper identification and treatment of FH patients.

Baseline metabolic disturbances and the twenty-five years risk of incident cancer in a Mediterranean population.

BACKGROUND AND AIMS: Obesity is predictive of metabolic syndrome (metS), type 2 diabetes, cardiovascular (CV) disease and cancer. The aim of the study is to assess the risk of incident cancer connected to obesity and metS in a Mediterranean population characterized by a high prevalence of obesity. METHODS AND RESULTS: As many as 1133 subjects were enrolled in two phases and followed for 25 years (859 subjects) or 11 years (274 subjects) and incident cancer was registered in the follow-up period. Anthropometric measures and biochemical parameters were filed at baseline and evaluated as predictors of incident cancer by measuring hazards ratios (HR) using multivariate Cox parametric hazards models. Best predictive threshold for metabolic parameters and metS criteria were recalculated by ROC analysis. Fasting Blood Glucose >5.19 mmol/L [HR = 1.58 (1.0-2.4)] and the TG/HDL ratio (log10) (Males > 0.225, Females > 0.272) [HR = 2.44 (1.3-4.4)] resulted independent predictors of survival free of cancer with a clear additive effect together with age classes [45-65 years, HR = 2.47 (1.3-4.4), 65-75 years HR = 3.80 (2.0-7.1)] and male gender [HR = 2.07 (2.3-3.1)]. CONCLUSIONS: Metabolic disturbances are predictive of cancer in a 25 years follow-up of a Mediterranean population following a traditional Mediterranean diet. The high prevalence of obesity and metS and the observed underlying condition of insulin resistance expose this population to an increased risk of cardiovascular disease and cancer despite the healthy nutritional habits.

SGK-1 protects kidney cells against apoptosis induced by ceramide and TNF-α.

Ceramide regulates several different cellular responses including mechanisms leading to apoptosis. Serum- and glucocorticoid-inducible protein kinase (SGK)-1 is a serine threonine kinase, which activates survival pathways in response to stress stimuli. Recently, we demonstrated an anti-apoptotic role of SGK-1 in human umbilical endothelial cells treated with high glucose. In the present study, since ceramide induces apoptosis by multiple mechanisms in diabetes and its complication such as nephropathy, we aimed to investigate whether SGK-1 may protect even against apoptosis induced by ceramide in kidney cells. Human embryonic kidney (HEK)-293 cells stable transfected with SGK-1 wild type (SGK-1wt) and its dominant negative gene (SGK-1dn) have been used in this study. Apoptotic stimuli were induced by C2-ceramide and TNF-α to increase endogenous synthesis of ceramide. Upon activation with these stimuli, SGK-1wt transfected cells have a statistically significant reduction of apoptosis compared with SGK-1dn cells (P<0.001). This protection was dependent on activation of caspase-3 and Poly-ADP-ribose-polymerase-1 (PARP-1) cleavage. SGK-1 and AKT-1 two highly homologous kinases differently reacted to ceramide treatment, since SGK-1 increases in response to apoptotic stimulus while AKT-1 decreases. This enhancement of SGK-1 was dependent on p38-mitogen-activated-protein kinases (p38MAPK), cyclic-adenosine-monophosphate/protein kinase A (cAMP/PKA) and phosphoinositide-3-kinase (PI3K) pathways. Especially, by using selective LY294002 inhibitor, we demonstrated that the most involved pathway in the SGK-1 mediated process of protection was PI3K. Treatment with inhibitor of SGK-1 (GSK650394) significantly enhanced TNF-α-dependent apoptosis in HEK-293 cells overexpressing SGK-1wt. Caspase-3, -8 and -9 selective inhibitors confirmed that SGK-1 reduced the activation of caspase-dependent apoptosis, probably by both intrinsic and extrinsic pathways. In conclusion, we demonstrated that in kidney cells, overexpression of SGK-1 is protective against ceramide-induced apoptosis and the role of SGK-1 can be potentially explored as a therapeutic target in conditions like diabetes, where ceramide levels are increased.

A novel component of the metabolic syndrome: the oxidative stress.

The metabolic syndrome (MS) represents a cluster of cardiovascular (CV) risk factors associated to CV disease and type 2 diabetes. It is still under debate whether MS is a mere aggregation of risk factors or it represents a clinical entity with visceral obesity as underlying pathophysiological trigger. The publication of several diagnostic criteria of MS by scientific associations or experts panels reflects this uncertainty in understanding the real nature of MS. Besides the metabolic disturbances of MS, as visceral obesity, hypertriglyceridemia, low HDL cholesterol, hypertension and hyperglycemia, novel mechanisms of arterial damage have been identified. This paper reviews the evidence showing that MS and MS factors are characterized by increased oxidative stress, a relevant factor contributing to the development of metabolic and cardiovascular complications. In the next future, the measure of plasma oxidative stress may contribute to identify a subset of MS patients at increased CV risk, candidates to more intensive therapies.

Obesity and the metabolic syndrome in a student cohort from Southern Italy.

BACKGROUND AND AIM: Cardiovascular (CV) risk factors present in childhood predict future CV events. Few data regarding the metabolic syndrome (MS) prevalence are available in adolescents from Mediterranean areas where obesity is becoming a social emergency. This study presents data of MS prevalence in a student cohort from southern Italy. METHODS AND RESULTS: 1629 students between 7 and 14 years of age underwent anthropometric measurements and a blood sample was obtained to assess biochemical parameters. MS risk factors were calculated based on age and gender adjusted percentiles of parameter distributions. MS prevalence rate was 0.022 using paediatric, age-adjusted criteria; the rate increased to 0.029 using a 90th percentile criteria for fasting blood glucose instead of >100mg/dL. Using the criteria issued by the International Diabetes Federation the MS prevalence rate dropped to 0.005. The exploratory factor analysis identified four factors: age/fat related, lipids, blood pressure and blood glucose. Family history of type 2 diabetes mellitus was associated with triglyceride [OR=1.55 (1.0-2.3)] and BMI [OR=1.71 (1.2-2.4)] but not to blood glucose by logistic regression analysis. CONCLUSIONS: In a student cohort from Southern Italy, obesity is associated with the features of MS.

A case of adult onset type II citrullinemia with portal-systemic shunt.

A 48-year-old woman who had conscious disturbance and abnormal behaviors had been misdiagnosed as having hepatic encephalopathy due to hyperammonemia and portal-systemic shunt, and retrograde transvenous obliteration of the shunt did not improve her symptoms. Thereafter, analyses of plasma amino acids and citrin gene revealed a diagnosis of adult onset type II citrullinemia (CTLN2). She underwent auxiliary partial orthotopic liver transplantation (APOLT) using a left lobe graft from her brother, and her symptoms as well as hyperammonemia improved. Our case demonstrates the importance of CTLN2 as a differential diagnosis in patients with hyperammonemia and consciousness disturbance, even if they present with a portal-systemic shunt.

Down regulation of CD11b and CD18 expression in children with hypercholesterolemia: a preliminary report.

BACKGROUND AND AIM: Cell adhesion molecules play an important role in the development of atherosclerosis mediating the attachment of monocytes to the endothelium. The aim of our study was to assess the cell surface expression of CD11b/CD18 integrin on the phagocytes of children affected by hypercholesterolemia. METHODS AND RESULTS: Twenty-six children with hypercholesterolemia (15 males, mean age 8.3, range 2-18) with a family history of early cardiovascular disease, as well as 26 children with normocholesterolemia matched for gender and age (15 males, mean age 8.3) were studied. Cell surface expression of CD11b/CD18 on peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry. The geometric mean percentages of CD11b and CD18 expression were significantly lower in the hypercholesterolemic group [52 (95% confidence intervals, 40-68) and 88 (84-93)] than in the control group [87 (83-91), P<0.0001 and 93 (89-96), P<0.05], respectively. After correction for age, gender, and pubertal status, CD11b cell surface expression on PBMC was inversely and independently correlated with total cholesterol concentrations (r=-0.395; P<0.01) and LDL (r=-0.307; P<0.05), as well as with triglycerides (r=-0.406; P<0.01). CONCLUSIONS: In children with hypercholesterolemia, cell surface expression of CD11b and CD18 on PBMC was significantly decreased. Follow-up studies are necessary to determine the clinical implications of these findings in the context of the natural course and progression of atherosclerosis in high risk children.

Hypertension and diabetes mellitus are associated with cardiovascular events in the elderly without cardiovascular disease. Results of a 15-year follow-up in a Mediterranean population.

BACKGROUND AND AIMS: Epidemiological prospective data on cardiovascular (CV) events in elderly subjects from Mediterranean populations are lacking. We aimed to investigate 15-year incidence of CV events and to evaluate the association with CV risk factors in an elderly Mediterranean population. METHODS AND RESULTS: The population of a small Sicilian village were enrolled, visited and a blood sample was drawn at baseline. CV events were recorded in the 15 years of follow-up. From 1351 subjects (75% of the resident population); 315 were in the age range 65-85 years; 266 subjects free from CV disease were analysed. Seventy-seven CV events were recorded in 73 out of 266 subjects, with a 19.7% rate (in 10 years). Hypertension (HTN) (hazards ratio=2.1) and diabetes mellitus (DM) (hazards ratio=1.8) were independently associated with CV events. Subjects with both DM and HTN showed a lower survival free of CV events compared to those with DM or HTN. CONCLUSIONS: In a 15-year follow-up of an elderly Mediterranean population free from CV disease, diabetes mellitus and hypertension were related to CV events. The control of risk factors in the elderly needs to be reinforced to achieve better results in terms of CV prevention.

Effect of the -420C/G variant of the resistin gene promoter on metabolic syndrome, obesity, myocardial infarction and kidney dysfunction.

OBJECTIVE: Resistin is an adipokine that has been suggested to be correlated with markers of inflammation and to be predictive of coronary atherosclerosis and type II diabetes in humans. A common single nucleotide polymorphism (SNP) (-420C/G) in the promoter of resistin is associated with increased resistin plasma levels and susceptibility to type II diabetes. The aim of this study was to investigate the association of the -420C/G polymorphism with metabolic syndrome, obesity, myocardial infarction and kidney disease. DESIGN AND RESULTS: First we studied 1542 subjects from the PLIC study (a population based cohort). GG carriers showed an higher prevalence of obesity and metabolic syndrome as well as increased plasma triglycerides levels, BMI, systolic and diastolic blood pressure and cardiovascular risk according to Framingham algorithm (P < 0.05 for all). Next we investigated the presence of the -420C/G resistin polymorphism in a case-control study that included 300 subject with myocardial infarction and 300 age and sex matched controls and then we studied the role of the -420C/G SNP in 88 patients with mild to moderate renal dysfunction. No statistically significant differences in allele frequencies between the PLIC study, the myocardial infarction (MI) cases and the subjects with renal dysfunction were observed. Pro-inflammatory gene expression profiling of peripheral blood mononuclear cells failed to detect any difference between wild type subjects and carriers of the rare allele. CONCLUSION: Our data suggest that the presence of the -420C/G SNP of the resistin gene is associated with increased obesity and metabolic syndrome, although it is not different in subjects at high cardiovascular risk such as patients with myocardial infarction or patients with renal dysfunction compared with controls.

A novel mutation of the extracellular matrix protein 1 gene (ECM1) in a patient with lipoid proteinosis (Urbach-Wiethe disease) from Sicily.

BACKGROUND: Lipoid proteinosis (LP), also known as Urbach-Wiethe disease, is a rare autosomal recessive disorder characterized by a hoarse voice, warty skin infiltration and scarring. Mutations within the extracellular matrix protein 1 (ECM1) gene cause LP. OBJECTIVES: We report the molecular analysis of the ECM1 gene in a Sicilian patient with LP in order to extend the mutation spectrum of this genodermatosis. METHODS: We studied a 32-year-old female born from consanguineous parents who was diagnosed at the age of 11 years as having LP. She has a clinical phenotype corresponding to Urbach-Wiethe disease characterized by papules/nodules, indurated plaques and sometimes ulcerated lesions primarily involving the skin and mucous membranes, and extracutaneous features such as epilepsy, hoarseness of the voice and neuropsychiatric abnormalities. Samples of clinically affected skin obtained by biopsies were analysed after staining with haematoxylin and eosin, periodic acid-Schiff (PAS), and PAS-diastase. The whole ECM1 gene was analysed by direct sequencing. RESULTS: We identified a homozygous nonsense mutation in exon 6 of the ECM1 gene, C589T (Q197Ter). CONCLUSIONS: Over 60% of mutations occur in exons 6 and 7. Exon 7 is alternatively spliced and frameshift mutations in exon 7 lead to ablation of the ECM1a transcript, but not the shorter ECM1b transcript that normally lacks this exon. Homozygous nonsense or frameshift mutations in exon 6 are predicted to affect both full-length ECM1a and ECM1b transcripts, whereas ECM1b should be unaffected for similar types of mutation in exon 7. It has been suggested that individuals with mutations in exon 7 have a slightly milder phenotype than those with exon 6 mutations. This is the first report with respect to a novel mutation of the ECM1 gene responsible for recessive LP in Sicily.

The C(-260)>T gene polymorphism in the promoter of the CD14 monocyte receptor gene is not associated with acute myocardial infarction.

CD surface molecules mediates cell activation and signaling. In particular, CD14 on blood monocytes mediate monocyte/macrophage activation by lipopolysaccharide. Lipopolysaccharide and its receptor, CD14, have been implicated in atherogenesis. It has been recently shown that a C(-260)T polymorphism in the promoter of the CD14 receptor may be a risk factor for coronary artery disease. Recently this association has been questioned because no increased risk was found with the T allele, even in the homozygous state. In the present study we investigated a possible association between the C(-260)T polymorphism in the CD14 promoter and acute myocardial infarction. Two hundred and thrteen patients with and acute myocardial infarction 213 healthy controls were included in the study. Genotype frequencies of the C(-260)T polymorphism in the CD14 promoter were determined by polimerase chain reaction and the amplified product was cleaved with HaeIII. The frequency of the T allele was not significantly different in patients compared with controls. In this study we were not able to detect differences of frequency of the allele T (-260) in the promoter of the CD14 receptor gene in survivors of myocardial infarction and controls.

Two Italian kindreds carrying the Arg136-->Ser mutation of the Apo E gene: development of premature and severe atherosclerosis in the presence of epsilon 2 as second allele.

BACKGROUND AND AIMS: Type III hyperlipoproteinemia, or dysbetalipoproteinemia, is commonly associated with apolipoprotein E2 homozygosity (Cys112, Cys158). Apo E2-Christchurch (Arg136-->Ser), a rare mutation of the Apo E gene, located in the receptor-binding domain of the protein, has been found to be associated in the vast majority of cases of dysbetalipoproteinemia. METHODS AND RESULTS: This is the first report of two Italian kindreds carrying the Arg136-->Ser mutation. One family is a four-generation kindred from Genoa (Liguria, Italy) with a high rate of mortality due to coronary artery disease: the proband was a 51-year-old woman with previous myocardial infarction and residual angina, severe carotid atherosclerosis, peripheral arterial vascular disease and arterial hypertension. The other family was identified in Palermo (Sicily, Italy): the proband was an overweight 62-year-old man with a mixed form of hyperlipidemia. The mutation, which was identified by means of Apo E genotyping followed by direct sequencing, co-segregated with the same haplotype in the two families. CONCLUSIONS: The family histories and clinical examinations of these subjects clearly show that the Apo E Arg136-->Ser variant fully expresses a type III phenotype in association with a second allele coding for Apo E2, and only partially in association with a second allele coding for Apo E4.

Low-density-lipoprotein peak particle size in a Mediterranean population.

BACKGROUND: The predominance of small, dense low-density lipoprotein (LDL) particles ('LDL phenotype B') has been associated with a three-fold increased risk of myocardial infarction, but the feasibility of the identification of small, dense LDL as independent predictors of coronary artery disease risk in population studies remains questioned. Design We evaluated the LDL peak particle size and its relation with other established risk factors for coronary heart disease in a group of 156 randomized subjects living on the Mediterranean island of Ustica (71 males and 85 women, range of age 20-69 years), representing approximately 30% of the total population. RESULTS: The prevalence of LDL phenotype B subjects was low (approximately 15% in both men and women) and there was a clear trend for both genders in reducing the LDL peak particle size with age. Moreover, LDL phenotype B subjects had higher BMI values, prevalence of diabetes and plasma triglyceride (TG) levels and lower plasma HDL-C concentrations in comparison with LDL phenotype A individuals; in a multivariate analysis, plasma TG levels were the only variable independently associated with LDL peak particle size. CONCLUSIONS: In this population, which appears to be somewhat protected by premature coronary artery disease, a low prevalence of the LDL pattern B was found in both men and women, and plasma TG could have a key role in regulating the LDL peak particle size. The follow up, still ongoing, will provide useful information on the predictive role of LDL peak particle size on cardiovascular risk, at least in a low-risk population.

Autosomal recessive hypercholesterolemia in a Sicilian kindred harboring the 432insA mutation of the ARH gene.

We describe a Sicilian family presenting a recessive form of hypercholesterolemia harboring a mutation of the autosomal recessive hypercholesterolemia (ARH) gene. In two of the three sibs, a 26-year-old male and a 22-year-old female, a severe hypercholesterolemia was diagnosed with very high levels of plasma cholesterol (15.9 and 12.2 mmol/l, respectively); tendon xanthomatas and xanthelasms were present and in the male proband was documented a diffuse coronary atherosclerotic disease with a rapid and fatal progression. Both the parents had normal or slightly increased levels of plasma cholesterol. All causes of secondary hypercholesterolemia were ruled out as well as an involvement of the LDL receptor or apoB genes. Beta-Sitosterol plasma levels were in the normal range. Cultured fibroblasts from skin biopsy from parents and the two probands displayed a normal ability to bind and degrade 125I-LDL. Direct sequencing of ARH gene demonstrated the presence of a 432insA mutation in homozygosis in the two probands; parents were heterozygotes for the same mutation. This mutation is the first report of a mutation of the ARH gene responsible for recessive forms of hypercholesterolemia in Sicily.

Factor VII activity is an independent predictor of cardiovascular mortality in elderly women of a Sicilian population: results of an 11-year follow-up.

The aim of the Epidemiological project "Ventimiglia di Sicilia" is to identify the cardiovascular risk factors in a Sicilian population with a low risk profile and healthy nutritional habits. The risk of cardiovascular mortality in older subjects (over 60 years of age) is presented for an 11 year follow-up. Females showed higher prevalence of diabetes mellitus, hypertension, obesity and higher levels of total, LDL and HDL cholesterol, factor VII activity and fibrinogen compared to males. Cardiovascular mortality was related to hypertension and obesity in males, to high factor VII activity, obesity and diabetes mellitus in females. In a Logistic Regression model the same variables were independently correlated to cardiovascular mortality with the exception of obesity. In conclusion, these findings suggest that in a population with a low risk profile, other factors, such as factor VII activity, may emerge as predictors of cardiovascular mortality.

Distribution of risk factors, plasma lipids, lipoproteins and dyslipidemias in a small Mediterranean island: the Ustica Project.

BACKGROUND AND AIM: The populations of the Mediterranean area have a low incidence of cardiovascular disease (CHD). The aims of this paper are: 1) to present demographic data of the population of Ustica, a small island in the southern part of the Tyrrhenian sea that has reduced communications with the mainland and a diet presumably rich in fish; and 2) to evaluate the distribution of risk factors, plasma lipids, lipoproteins and dyslipidemias in this population. METHODS AND RESULTS: We invited all of the free-living resident population aged more than 14 years (about 800 individuals) to participate in the study; 576 responded, for a participation rate of about 73%. The distribution of cardiovascular risk factors, plasma lipids, lipoproteins and dyslipidemias were evaluated in all of the subjects. More than 60% of the population was out of the normal weight range. Total and low-density lipoprotein cholesterol levels were respectively 207.4 +/- 46.7 and 141.7 +/- 42.4 mg/dL, and similar in males and females. Lipoprotein (a) (Lp[a]) levels presented the classical "skewed" distribution and, among the apolipoprotein(a) isoforms, there was a clear predominance of intermediate-sized kringle IV repeats. Overall, 43% of the subjects had a lipid disorder: the prevalence of hypercholesterolemia was 22.8% (3.2% with severe hypercholesterolemia terolemia > or = 300 mg/dL); low high-density lipoprotein cholesterol levels were found in 22.5%; the so-called lipid triad in 2.1%; and high Lp(a) levels in 6.2%. Large familial clusters were found for some lipid disorders. CONCLUSIONS: A large prevalence of body weight disturbances and high frequency of dyslipidemias are the main characteristics of this population. Ongoing data and future longitudinal studies will better clarify the relative influence of each parameter on CHD risk and total mortality.

Carotid atherosclerosis in hypercholesterolemic patients: relationship with cardiovascular events.

BACKGROUND AND AIM: Extracranial cerebrovascular atherosclerosis is a common feature of hypercholesterolemia and carotid lesions are good predictors of cardiovascular events in the general population. Factors associated with the carotid damage of hypercholesterolemic patients and their relationships with the occurrence of clinical events are investigated in this study. METHODS AND RESULTS: One hundred and seventeen cardiovascular event-free hypercholesterolemic subjects underwent a complete clinical examination to look for additional risk factors. A blood sample was collected for lipoprotein determination and an ultrasound high resolution B-mode imaging examination of the common carotid arteries was performed. Patients were treated according to the current guidelines during a 4-yr follow-up and all major cardiovascular events were recorded. The prevalence of subjects with increased intima-media thickness and plaque was 21.4% and 29.9% respectively, higher than in normolipidemic controls. Carotid lesions were significantly related to age, hypertension and LDL-cholesterol and HDL-cholesterol levels. The relative risk of developing a major clinical event was 3.92 (95% CI 1.54-9.95, p < 0.004) among categories of carotid status. At multivariate analysis, cardiovascular events were independently related to the diagnosis of familial hypercolesterolemia (FH), baseline carotid score and mean levels of LDL-cholesterol and HDL-cholesterol during the follow-up. CONCLUSIONS: Common risk factors cooperate with plasma lipoprotein levels in increasing the frequency of carotid lesions of hypercholesterolemic patients. Since such lesions are useful predictors of clinical events, B-mode ultrasound evaluation of the carotids should be routinely included in the management of these patients.