Reported muscle symptoms during statin treatment amongst Italian dyslipidaemic patients in the real-life setting: the PROSISA Study

AIM

Statin-associated muscle symptoms (SAMS) are a major determinant of poor treatment adherence and/or discontinuation, but a definitive diagnosis of SAMS is challenging. The PROSISA study was an observational retrospective study aimed to assess the prevalence of reported SAMS in a cohort of dyslipidaemic patients.

METHODS

Demographic/anamnestic data, biochemical values and occurrence of SAMS were collected by 23 Italian Lipid Clinics. Adjusted logistic regression was performed to estimate odds ratio (OR) and 95% confidence intervals for association between probability of reporting SAMS and several factors.

RESULTS

Analyses were carried out on 16 717 statin-treated patients (mean ± SD, age 60.5 ± 12.0 years; 52.1% men). During statin therapy, 9.6% (N = 1599) of patients reported SAMS. Women and physically active subjects were more likely to report SAMS (OR 1.23 [1.10-1.37] and OR 1.35 [1.14-1.60], respectively), whist age ≥ 65 (OR 0.79 [0.70-0.89]), presence of type 2 diabetes mellitus (OR 0.62 [0.51-0.74]), use of concomitant nonstatin lipid-lowering drugs (OR 0.87 [0.76-0.99]), use of high-intensity statins (OR 0.79 [0.69-0.90]) and use of potential interacting drugs (OR 0.63 [0.48-0.84]) were associated with lower probability of reporting SAMS. Amongst patients reporting SAMS, 82.2% underwent dechallenge (treatment interruption) and/or rechallenge (change or restart of statin therapy), with reappearance of muscular symptoms in 38.4% (3.01% of the whole cohort).

CONCLUSIONS

The reported prevalence of SAMS was 9.6% of the whole PROSISA cohort, but only a third of patients still reported SAMS after dechallenge/rechallenge. These results emphasize the need for a better management of SAMS to implement a more accurate diagnosis and treatment re-evaluation.

Hypertriglyceridemia and omega-3 fatty acids: Their often overlooked role in cardiovascular disease prevention

AIMS

This review aims to describe the pathogenic role of triglycerides in cardiometabolic risk, and the potential role of omega-3 fatty acids in the management of hypertriglyceridemia and cardiovascular disease.

DATA SYNTHESIS

In epidemiological studies, hypertriglyceridemia correlates with an increased risk of cardiovascular disease, even after adjustment for low density lipoprotein cholesterol (LDL-C) levels. This has been further supported by Mendelian randomization studies where triglyceride-raising common single nucleotide polymorphisms confer an increased risk of developing cardiovascular disease. Although guidelines vary in their definition of hypertriglyceridemia, they consistently define a normal triglyceride level as <150 mg/dL (or <1.7 mmol/L). For patients with moderately elevated triglyceride levels, LDL-C remains the primary target for treatment in both European and US guidelines. However, since any triglyceride level in excess of normal increases the risk of cardiovascular disease, even in patients with optimally managed LDL-C levels, triglycerides are an important secondary target in both assessment and treatment. Dietary changes are a key element of first-line lifestyle intervention, but pharmacological treatment including omega-3 fatty acids may be indicated in people with persistently high triglyceride levels. Moreover, in patients with pre-existing cardiovascular disease, omega-3 supplements significantly reduce the risk of sudden death, cardiac death and myocardial infarction and are generally well tolerated.

CONCLUSIONS

Targeting resistant hypertriglyceridemia should be considered as a part of clinical management of cardiovascular risk. Omega-3 fatty acids may represent a valuable resource to this aim.

The vitamin D receptor (VDR) gene rs11568820 variant is associated with type 2 diabetes and impaired insulin secretion in Italian adult subjects, and associates with increased cardio-metabolic risk in children

BACKGROUND AND AIMS

1α,25-dihydroxyvitamin-D3, the biologically active vitamin D, plays a central role in several metabolic pathways through the binding to the vitamin D receptor (VDR). VDR has been shown to be involved in cardiovascular diseases, cancer, autoimmunity and type 2 diabetes mellitus (T2DM). Several polymorphisms in the VDR gene have been described. Among these, the rs11568820 G-to-A nucleotide substitution was found to be functional, modulating the transcription of the VDR gene. Objective of this study was to perform an association study between rs11568820 polymorphism and T2DM in a cohort of Italian adults with T2DM and in non-diabetic controls. To add further insight into the role of VDR gene we explored whether this association begins early in life in overweight/obese children, or becomes manifest only in adulthood.

METHODS AND RESULTS

As many as 1788 adults and 878 children were genotyped for the rs11568820 polymorphism. All participants underwent oral glucose tolerance tests (OGTT), with measurement of glucose and insulin levels. Indices of insulin-resistance and secretion were also calculated. The AA genotype was significantly more frequent in adults with T2DM compared to controls (7.5% vs. 4.6%, P = 0.037), and conferred a higher risk of T2DM (ORHom = 1.69C.I. = [1.13-2.53], P = 0.011). In the adult cohort, rs11568820 was also associated with reduced indices of β-cell insulin secretion. In children, the AA genotype was associated with 2 h high-normal glucose, a marker of cardio-metabolic risk.

CONCLUSIONS

Our study demonstrates for the first time that VDR gene AA carriers have higher risk of T2DM and impaired insulin secretion. In children, the association between AA homozygous and high-normal 2h glucose suggests that mild alterations associated with this genotype may appear early in life.

Hydroxypyridinones with enhanced iron chelating properties. Synthesis, characterization and in vivo tests of 5-hydroxy-2-(hydroxymethyl)pyridine-4(1H)-one

an tautomeric changes positively influence coordinating ability?

Non-alcoholic fatty liver disease, metabolic syndrome and patatin-like phospholipase domain-containing protein3 gene variants

BACKGROUND & AIMS

Non-alcoholic fatty liver disease was traditionally interpreted as a condition which may progress to liver-related complications. However, the increased mortality is primarily a result of cardiovascular diseases. It has been suggested that fatty liver can be considered as the hepatic consequence of the metabolic syndrome. The aim was to describe the different clinical presentations of non-alcoholic fatty liver disease on the basis of the patatin-like phospholipase domain-containing protein3 (PNPLA3) rs738409 gene variant.

METHODS

Fatty liver was defined by ultrasonographic Hamaguchi's criteria in 211 consecutive subjects with non-alcoholic fatty liver disease. The rs738409 polymorphism was determined by TaqMan assays. Metabolic syndrome was defined according to ATPIII modified criteria.

RESULTS

Prevalence of PNPLA3-148II, PNPLA3-148IM, and PNPLA3-148MM genotypes was 45.0%, 40.7%, and 14.3% respectively. Prevalence of metabolic syndrome progressively increased with the severity of liver steatosis (from 52.5% to 65.2%, and 82.3% respectively, p<0.01). The PNPLA3-148MM group had significantly lower mean serum triglycerides (p<0.001), Framingham cardiovascular risk score (p<0.01) and lower prevalence of metabolic syndrome (p<0.05) and its components. Age and HOMA-IR were positive independent predictors of metabolic syndrome, while a negative independent association was found between metabolic syndrome and the homozygotes PNPLA3 I148M variant.

CONCLUSIONS

We suggest a lower prevalence of MetS and reduced cardiovascular risk in NAFLD patients with PNPLA3MM genotype.

Stereospecific generation of homochiral helices in coordination polymers built from enantiopure binaphthyl-based ligands

The novel enantiopure spacer 2,2′-dimethoxy-1,1′-binaphthyl-3,3′-bis(4-pyridyl-amido) has been designed to prepare helical coordination polymers here investigated by means of experimental and theoretical data.

Arterial function and structure after a 1-year lifestyle intervention in children with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Lifestyle modification has been the mainstay of controlling childhood obesity and has proved to be effective in reducing cardiovascular risk factors. However, it is currently unknown whether the subclinical atherosclerotic changes associated with nonalcoholic fatty liver disease (NAFLD) in such population are reversible.

METHODS AND RESULTS

We analyzed changes of brachial flow-mediated dilation (FMD), carotid intima-media thickness (cIMT), clinical, laboratory, and imaging data in 120 obese children with NAFLD, at the end of a 1-year intervention program with diet and physical exercise. The lifestyle intervention led to a significant mean decrease of body mass index (BMI)-standard deviation score (SDS), waist circumference (WC) and fat mass, along with diastolic blood pressure, triglycerides, liver enzymes, insulin, insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR), and high-sensitivity C-reactive protein. At the end of the study, FMD improved (P < 0.0001), while cIMT did not change significantly (P = 0.20). A significant decrease in hepatic fat content as measured by magnetic resonance imaging was also observed. Changes in FMD were inversely associated with changes in BMI-SDS, WC, total cholesterol, non-HDL cholesterol, liver enzymes, HOMA-IR, physical activity, and hepatic fat content. After including in the model all the significant variables as well as age, gender, pubertal status, and baseline FMD values, changes in FMD were significantly and independently associated with changes in WC and total cholesterol.

CONCLUSION

Also in obese children with NAFLD arterial function may be restored by improving metabolic risk factors and reducing visceral adiposity following a 1-year lifestyle intervention.

Heritability, genetic correlation and linkage to the 9p21.3 region of mixed platelet-leukocyte conjugates in families with and without early myocardial infarction

BACKGROUND AND AIMS

Variations in mixed platelet-leukocyte conjugate formation in human whole blood could be genetically determined. We quantified platelet and leukocyte activation and interaction in families with or without early myocardial infarction and evaluated their heritability, genetic correlation and linkage to the 9p21.3 region.

METHODS AND RESULTS

The study population included 739 subjects (≥ 15 years old) from 54 large pedigrees, 23 with and 31 without familial myocardial infarction. Mixed platelet-leukocyte conjugates and markers of platelet or leukocyte activation (P-selectin, CD11b and L-selectin surface expression) were measured both before and after in vitro blood stimulation with collagen-ADP. All traits had significant genetic components (17.5-65.3% of the phenotypic variability), while shared household effects (0-39.6%) and environmental covariates (0-10.2%) tended to be smaller. Stimulated platelet-polymorphonuclear leukocyte (PMN) and platelet-monocyte conjugates showed the highest linkage to the 9p21.3 region (LOD = 0.94 and 1.33, respectively; empirical p value = 0.017 and 0.009). PMN markers resulted strongly genetically correlated between them in bivariate analysis among pairs of quantitative traits.

CONCLUSION

This study supports a genetic regulation of human mixed platelet-leukocyte conjugates.

[Two uncommon extrapulmonary forms of Mycoplasma pneumoniae infection]

Mycoplasma pneumonia is the second most frequent bacterium in pneumonia and the leading intracellular type. M. pneumoniae pulmonary infection is characterized by a slower onset profile and a lower biological inflammatory picture than pneumococcal infection. Both upper and lower respiratory tracts are often affected and sometimes a Kawasaki-like syndrome can be associated, with conjunctivitis or cheilitis. Extrapulmonary forms of the disease can occur, whether or not it is associated with pulmonary infection. We report two cases: in the first case, a renal form of M. pneumoniae disease developed in a 6-year-old girl, with membranous proliferative glomerulonephritis expressed as a picture of impure nephritic syndrome with decreased serum complement concentration, following an upper respiratory infection. Diagnosis was obtained by means of a kidney biopsy. The second case occurred in an 8-year-old girl who expressed, after a respiratory tract infection, neurological symptoms such as ocular flutter, perception disorder, and ataxia. This onset is typical of post-infectious rhombencephalitis. Biological investigations and imaging were normal. In both cases, M. pneumoniae infection was diagnosed on the basis of immunoglobulin M-positive serology. Direct exploration of the bacterium was negative, due to its fragility and delayed diagnostic hypothesis. Several forms of M. pneumoniae infection are either the direct effect of the bacterium or are secondary to a cross-immunological reaction. As its frequency is increasing, M. pneumoniae infection should be raised as a cause of atypical, less well-known extrapulmonary forms of the disease.

Arterial function and structure after a 1-year lifestyle intervention in children with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Lifestyle modification has been the mainstay of controlling childhood obesity and has proved to be effective in reducing cardiovascular risk factors. However, it is currently unknown whether the subclinical atherosclerotic changes associated with nonalcoholic fatty liver disease (NAFLD) in such population are reversible.

METHODS AND RESULTS

We analyzed changes of brachial flow-mediated dilation (FMD), carotid intima-media thickness (cIMT), clinical, laboratory, and imaging data in 120 obese children with NAFLD, at the end of a 1-year intervention program with diet and physical exercise. The lifestyle intervention led to a significant mean decrease of body mass index (BMI)-standard deviation score (SDS), waist circumference (WC) and fat mass, along with diastolic blood pressure, triglycerides, liver enzymes, insulin, insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR), and high-sensitivity C-reactive protein. At the end of the study, FMD improved (P < 0.0001), while cIMT did not change significantly (P = 0.20). A significant decrease in hepatic fat content as measured by magnetic resonance imaging was also observed. Changes in FMD were inversely associated with changes in BMI-SDS, WC, total cholesterol, non-HDL cholesterol, liver enzymes, HOMA-IR, physical activity, and hepatic fat content. After including in the model all the significant variables as well as age, gender, pubertal status, and baseline FMD values, changes in FMD were significantly and independently associated with changes in WC and total cholesterol.

CONCLUSION

Also in obese children with NAFLD arterial function may be restored by improving metabolic risk factors and reducing visceral adiposity following a 1-year lifestyle intervention.

Management of statin-intolerant patient

Large scale clinical trials have undoubtedly demonstrated that statins are effective in reducing cardiovascular events and all-cause mortality in almost all patient populations. Also the short and long-term safety of statin therapy has been well established in the majority of treated patients. Nevertheless, intolerance to statins must be frequently faced in the clinical practice. The most commonly observed adverse effects of statins are muscle symptoms and elevation of hepatic aminotransferase and creatinine kinase (CK) levels. Overall, myalgia (muscle pain with or without plasma CK elevations) and a single abnormally elevated liver function test constitute approximately two-thirds of reported adverse events during statin therapy. These side effects raise concerns in the patients and are likely to reduce patient's adherence and, consequently, the cardiovascular benefit. Therefore, it is mandatory that clinicians improve knowledge on the clinical aspects of side effects of statins and the ability to manage patients with intolerance to statins. Numerous different approaches to statin-intolerant patients have been suggested, but an evidence-based consensus is difficult to be reached due to the lack of controlled trials. Therefore, it might be useful to review protocols and procedures to control statin intolerance. The first step in managing intolerant patients is to determine whether the adverse events are indeed related to statin therapy. Then, the switching to another statin or lower dosage, the alternate dosing options and the use of non-statin compounds may be practical strategies. However, the cardiovascular benefit of these approaches has not been established, so that their use has to be employed after a careful clinical assessment of each patient.

Management of metabolic syndrome in children and adolescents

Concomitantly with the increasing prevalence of childhood obesity, the prevalence of metabolic syndrome (MS) is rising among children and adolescents, leading to fears for future epidemics of type 2 diabetes mellitus and cardiovascular disease in the young. This makes the accurate identification and the appropriate treatment of children and adolescents with MS an important priority for health care systems. This review will focus on the management of each component of MS, including the nonalcoholic fatty liver disease (NAFLD), which is currently considered as the hepatic component of the syndrome. The most relevant target of treatment of MS in children and adolescents is the abdominal obesity. To this end, we will discuss the efficacy of dietary approaches, possibly coupled with regular physical activity, on eliciting visceral fat reduction. We will also highlight several aspects of the treatment of the high triglyceride/low high-density lipoprotein cholesterol phenotype, including the use of non-pharmacological measures, and indications for instituting drug therapies. Part of this review will address treatment of glucose abnormalities, including the benefits of lifestyle modification alone, and the potential adjunctive role of hypoglycemic drugs. The treatment of hypertension in children with MS also requires a multifaceted approach and the available data of this topic will be examined. The remainder of this review will address treatment to reverse NAFLD and prevent progression to end-stage disease.

[Lifestyle and global cardiovascular risk: a prospective study on a borderline hypertensive population]

BACKGROUND AND AIMS

Arterial hypertension is a well known risk factor for cardiovascular diseases. Today, it is possible to calculate the cardiovascular risk at 10 years with the risk card. The reduction of cardiovascular risk is based on a multi-factorial approach including the lifestyle modification. In Italy, OEC study has calculated that a certain proportion of borderline hypertensives, not eligible for a pharmacological treatment, remain at risk. Borderline arterial hypertension (140-150/90-95 mmHg) in Italian population is documented in 19% of males and 14% of females.: Aim of the study is to examine the efficacy of the lifestyle changes in reducing the global cardiovascular risk in bordeline hypertensives.

MATERIALS AND METHODS

102 patients affected by borderline hypertensive (46 M and 56 F, mean age: 55.6 yrs ) were enclosed in a 12 months prospective study. Three checks were programmed during the follow-up, i.e., at beginning, 6 months and 12 months later. At the start of the study every patient received a list of lifestyle changes to be respected. Pressure arterial systolic and diastolic were obtained at beginning and at the end of successive. At the last check each patient received a questionnaire to be filled up. According to the calculated score, each patient was classified as: non-responder (score: 0-3), partially responder (score: 4-6), responder (score: 7-9).

RESULTS

A significant reduction of the globalcardiovascular risk has been observed at the end of the study in both the responders and partially responders. Such a reduction was seen to be due to positive changes in blood pressure and total, HDL, LDL cholesterol.

CONCLUSIONS

This study confirmed that a non-pharmacological therapy based on lifestyle changes has to be preventively administered in the presence of a borderline hypertension because of its beneficial effects in reducing the global risk of cardiovascular disease. Therefore, we firmly think that a prompt utilization of a correct lifestyle can sort the triple effect of improving the expectancy of life, ameliorating the quality of life, reducing the social costs of arterial hypertension.

Serum adiponectin is decreased in patients with familial combined hyperlipidemia and normolipaemic relatives and is influenced by lipid-lowering treatment

BACKGROUND AND AIMS

Hypoadiponectinemia has been reported in patients with familial combined hyperlipidemia (FCHL) presenting increased waist circumference and insulin resistance. However, no studies have evaluated this association in non-obese FCHL patients. Moreover, it is unclear whether correction of lipoprotein abnormalities may influence adiponectin levels in FCHL.

METHODS AND RESULTS

We have compared serum levels of adiponectin in 199 non-obese FCHL patients (BMI 25.96+/-3.7), 116 normolipaemic (NL) non-affected relatives (BMI 24.4+/-4.0) and 192 controls (BMI 28.0+/-7.4). In a subgroup of FCHL patients, changes in adiponectin levels after treatment with atorvastatin (n=22) or fenofibrate (n=26) were also evaluated. FCHL patients as well as their NL relatives showed lower serum adiponectin levels compared to controls (9.7+/-5.4 microg/mL, 10.7+/-5.3 microg/mL and 17.3+/-13.7microg/mL, respectively; p<0.0001 for all comparisons). After controlling for confounders, the strongest association with hypoadiponectinemia was observed with family history of FCHL, followed by HDL-C (negatively) and age (positively). These variables jointly explained 15% of the total variance of serum adiponectin levels. After 24-week of treatment, adiponectin was increased by 12.5% (p<0.05) by atorvastatin and was reduced by 10% by fenofibrate, resulting in a treatment difference of 22.5% in favor of atorvastatin (p<0.017).

CONCLUSIONS

FCHL patients showed lower serum adiponectin levels compared to controls. Also normolipaemic relatives of FCHL patients presented decreased levels of adiponectin, suggesting a possible common background in the determination of this abnormality. Overall, these observations indicate that hypoadiponectinemia may be an inherent characteristic of the FCHL phenotype. In FCHL patients hypoadiponectinemia may be partially corrected by atorvastatin but not by fenofibrate treatment.

Tumor necrosis factor alpha (TNFalpha) and its soluble receptor p75 (sTNF-R p75) in familial combined hyperlipidemia (FCHL)

BACKGROUND AND AIM

Familial combined hyperlipidemia (FCHL) is a genetic disorder of lipid metabolism associated with insulin resistance and abnormalities in fatty acid metabolism whose underlying mechanisms are largely unknown. Perturbations in the TNFalpha/TNF-R pathway may play a role in these abnormalities.

METHODS AND RESULTS

We determined plasma levels of TNFalpha and sTNF-R p75 in 85 FCHL patients (TC 245+/-45 mg/dl; TG 260+/-148 mg/dl; apoB 148+/-37 mg/dl) and in 29 age- and sex-matched normolipemic relatives (NL) (TC 187+/-22.8 mg/dl; TG 115+/-37 mg/dl; apoB 106+/-16 mg/dl). Thirty-four normolipemic subjects (TC 180+/-34 mg/dl; TG 107+/-42 mg/dl; apoB 95+/-22 mg/dl) were also included as unrelated controls (NC). Plasma free fatty acids (NEFA) were also measured and insulin sensitivity was evaluated by HOMA. Levels of sTNF-R p75 were significantly reduced in FCHL compared to NL (2.30+/-0.55 ng/ml vs. 2.64+/-0.88 ng/ml, p<0.05) but not compared to NC (2.35+/-0.68 ng/ml). HOMA values were comparable in all groups and did not show any relation with plasma levels of sTNF-R p75. Logistic analysis demonstrated that a low concentration of sTNF-R p75 was an independent predictor of the affected status within FCHL families, but this role was no longer evident when FCHL patients were compared to NC. In FCHL, age (p<0.001) was positively, and TG (p=0.029) and HDL-C (p=0.025) were negatively correlated with plasma concentrations of sTNF-R p75. In the other groups, age (in NL) and non-HDL-C (in NC) were significantly correlated with sTNF-R p75.

CONCLUSIONS

Although our data do not support a causative role of TNFalpha/TNF-R alterations in FCHL, they confirm that variation in TNF-R shedding may influence lipid phenotypic expression in FCHL families.

Cholesteryl ester transfer protein TaqIB variant, high-density lipoprotein cholesterol levels, cardiovascular risk, and efficacy of pravastatin treatment: individual patient meta-analysis of 13,677 subjects

BACKGROUND

Several studies have reported that the cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism is associated with HDL cholesterol (HDL-C) levels and the risk of coronary artery disease (CAD), but the results are inconsistent. In addition, an interaction has been implicated between this genetic variant and pravastatin treatment, but this has not been confirmed.

METHODS AND RESULTS

A meta-analysis was performed on individual patient data from 7 large, population-based studies (each >500 individuals) and 3 randomized, placebo-controlled, pravastatin trials. Linear and logistic regression models were used to assess the relation between TaqIB genotype and HDL-C levels and CAD risk. After adjustment for study, age, sex, smoking, body mass index (BMI), diabetes, LDL-C, use of alcohol, and prevalence of CAD, TaqIB genotype exhibited a highly significant association with HDL-C levels, such that B2B2 individuals had 0.11 mmol/L (0.10 to 0.12, P<0.0001) higher HDL-C levels than did B1B1 individuals. Second, after adjustment for study, sex, age, smoking, BMI, diabetes, systolic blood pressure, LDL-C, and use of alcohol, TaqIB genotype was significantly associated with the risk of CAD (odds ratio=0.78 [0.66 to 0.93]) in B2B2 individuals compared with B1B1 individuals (P for linearity=0.008). Additional adjustment for HDL-C levels rendered a loss of statistical significance (P=0.4). Last, no pharmacogenetic interaction between TaqIB genotype and pravastatin treatment could be demonstrated.

CONCLUSIONS

The CETP TaqIB variant is firmly associated with HDL-C plasma levels and as a result, with the risk of CAD. Importantly, this CETP variant does not influence the response to pravastatin therapy.

Detection of coronary artery stenoses using breath-hold magnetic resonance coronary angiography. Comparison with conventional x-ray angiography

PURPOSE

To detect coronary artery stenoses, we compare breath-hold magnetic resonance coronary angiography (MRCA) to conventional coronary angiography (CA).

MATERIALS AND METHODS

Sixty-five patients with suspected coronary artery disease underwent MRCA and CA within one week. MRCA examination was performed by using the two-dimensional (2D) breath-hold technique with a fast spoil gradient-echo sequence/spiral. Each imaging sequence was obtained within one breath-hold in expiration (14 seconds of apnoea). The assessment of coronary artery stenoses on magnetic resonance (MR) angiograms was independently performed by two blinded readers and compared to conventional CA images.

RESULTS

Three hundred and ninety segments were evaluated by the two imaging techniques. MRCA correctly detected 76 of 88 (86%) stenoses, and recognized 242 of 302 (80%) not affected segments. The Pearson correlation coefficient between MRCA and CA in assessing coronary narrowings was very high: r = 0.85. Despite this the mean difference was 4.5 with a standard error of estimate of 0.21, indicating that MRCA slightly overestimates the degree of stenoses.

CONCLUSIONS

Our study showed that 2D breath-hold MRCA is an accurate technique in displaying and quantifying the most significant stenoses in the proximal and middle segments of the coronary arteries.

Clinical and biochemical characterisation of patients with autosomal recessive hypercholesterolemia (ARH)

BACKGROUND AND AIM

Inherited hypercholesterolemias are common disorders characterised by elevated LDL-C levels and premature coronary heart disease. We have recently described a recessive form of hypercholesterolemia (autosomal recessive hypercholesterolemia, ARH) in which LDL catabolism is reduced because of a mutation in the gene coding for an adaptor protein that impairs LDL-receptor (LDL-R) activity in the liver. The aim of this study was to characterise in detail the phenotypes of subjects with homozygous and heterozygous ARH.

METHODS AND RESULTS

We have so far identified six Italian families with ARH and studied the clinical and biochemical characteristics of 11 homozygotes (age 13-47 years) and 12 obligate heterozygotes (age 42-83 years). The study protocol included an evaluation of the lipoprotein profile, LDL-R activity in fibroblasts, LDL binding activity, and apo E genotype; a structured questionnaire (CHD risk factors, medical history, current medications); a physical examination, resting and stress ECG, ultrasound examinations (heart, carotid arteries, Achilles tendons) and coronary angiography. The pedigrees were characterised by the absence of vertical transmission; consanguinity was documented in two families. Only the two previously described Sardinian mutations, ARH1 (c.432insA) and ARH2 (c.65G > A), were identified in the probands. All of the ARH homozygotes had large tendinous xanthomas, two had exertional angina, and four a positive stress ECG. None had experienced myocardial infarction or stroke. More than half had instrumental signs of atherosclerosis such as a positive stress ECG or positive carotid echo-doppler examination. The ARH heterozygotes were consistently normal and had a normal lipid profile.

CONCLUSIONS

The ARH phenotype resembles that of familial hypercholesterolemia (FH) homozygotes, but ARH may be a less serious illness. The absence of vertical transmission, and the presence of mild coronary heart disease and consanguinity, can suggest a possible diagnosis of ARH. ARH might be considered a phenocopy of FH but heterozygous subjects seem to have a consistently normal phenotype.

PON1 L55M polymorphism is not a predictor of coronary atherosclerosis either alone or in combination with Q192R polymorphism in an Italian population

BACKGROUND

The present study evaluated the role of the PON1 L55M polymorphism independently and in conjunction with the Q192R polymorphism on the risk of coronary atherosclerosis in an Italian population.

MATERIALS AND METHODS

Three hundred and ninety-one subjects with significant coronary stenosis (> 50%) (coronary artery disease-positive; CAD+), 196 subjects with normal coronary arteries (< 10% stenosis) (CAD-) and 178 healthy controls were screened using a combination of polymerase chain reaction and restriction enzyme digestion.

RESULTS

In the pooled population, the frequencies of L and M alleles were 0.63 and 0.37, respectively; the most common haplotypes were QQ/LM (24.2%) and QR/LL (21.8%) and a strong linkage disequilibrium between L/55 and R/192 alleles was observed (D' = -0.91; P < 0.0001). CAD+ subjects did not show any significant differences in the distribution of PON1-55 genotypes as compared to CAD- subjects and population controls (chi2 = 1.5, P = 0.8). After controlling for other risk factors, the low-concentration M allele was not associated with a significant change of CAD risk (OR 1.02; 95% CI 0.80-1.29; P = 0.87). Moreover, the L55M polymorphism did not show any interaction with other risk factors such as smoking, diabetes, hypertension, low levels of high-density lipoprotein (HDL) or high ratios of low-density to high-density lipoproteins. The combination of L55M with the Q192R polymorphism did not show any effect on CAD risk. However, a marginal decrease in myocardial infarction risk was detected when QQ/MM carriers (OR 0.51; 95% CI 0.26-0.99; P = 0.048), but not LL/RR carriers, were compared with subjects not homozygous for an L or R allele.

CONCLUSIONS

These findings did not indicate a major effect of the PON1 L55M polymorphism, either alone or in combination with the Q192R polymorphism, on CAD risk. Additional studies are needed for a better evaluation of the role of the 55/192 PON1 genotypes in combination on myocardial infarction risk.