Canibais e Reis

 

BMC Public Health. 2006 Oct 23;6:262.

Relative risk for cardiovascular atherosclerotic events after smoking cessation: 6-9 years excess risk in individuals with familial hypercholesterolemia. (pdf)

Kramer A, Jansen AC, van Aalst-Cohen ES, Tanck MW, Kastelein JJ, Zwinderman AH.
Department of Medical Informatics, Academic Medical Center, University of Amsterdam, The Netherlands. <>

BACKGROUND: Smoking history is often di- or trichotomized into for example "never, ever or current smoking". However, smoking must be treated as a time-dependent covariate when lifetime data is available. In particular, individuals do not smoke at birth, there is usually a wide variation with respect to smoking history, and smoking cessation must also be considered. METHODS: Therefore we analyzed smoking as a time-dependent risk factor for cardiovascular atherosclerotic events in a cohort of 2400 individuals with familial hypercholesterolemia who were followed from birth until 2004. Excess risk after smoking-cessation was modelled in a Cox regression model with linear and exponential decaying trends. The model with the highest likelihood value was used to estimate the decay of the excess risk of smoking. RESULTS: Atherosclerotic events were observed in 779 patients with familial hypercholesterolemia and 1569 individuals had a smoking history. In the model with the highest likelihood value the risk reduction of smoking after cessation follows a linear pattern with time and it appears to take 6 to 9 years before the excess risk is reduced to zero. The risk of atherosclerotic events due to smoking was estimated as 2.1 (95% confidence interval 1.5; 2.9). CONCLUSION: It was concluded that excess risk due to smoking declined linearly after cessation in at least six to nine years.

 

Eur Heart J. 2006 Sep;27(18):2240-6. Epub 2006 Jul 6.

Diagnosing familial hypercholesterolaemia: the relevance of genetic testing. (pdf)

van Aalst-Cohen ES, Jansen AC, Tanck MW, Defesche JC, Trip MD, Lansberg PJ, Stalenhoef AF, Kastelein JJ.
Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.

Comment in: Eur Heart J. 2006 Sep;27(18):2150-1.

AIMS: We assembled a cohort of patients with familial hypercholesterolaemia (FH) for both basic and clinical research. We used a set of established diagnostic criteria to define FH. Some put forward that a definite diagnosis of FH is made when a mutation in the LDL-receptor (LDLR) gene is identified. We therefore set out to determine in these patients whether patients with a DNA diagnosis would differ significantly from those diagnosed clinically. METHODS AND RESULTS: We randomly selected 4000 hypercholesterolaemic patients from the Dutch Lipid Clinic network database. Phenotypical data were acquired by reviewing medical records. After review of medical records, 2400 patients could be defined as having FH. An LDLR mutation was identified in 52.3% of these patients. Patients with and without an LDLR mutation demonstrated different clinical and laboratory characteristics. Low-density lipoprotein cholesterol was higher in patients with an LDLR mutation, whereas triglycerides were higher in patients without an LDLR mutation. The phenotypic differences between the groups remained even after stratification for the presence or absence of tendon xanthomas. CONCLUSION: Despite the use of stringent clinical criteria to define FH patients, two cohorts could be identified within our study population, namely those patients with and those without an LDLR mutation. Our findings suggest that among those without an LDLR mutation, patients with other causes of dyslipidaemia may be present. These observations underline the relevance of genetic testing in FH for clinical practice, for screening purposes, and for research involving these patients.

 

CMAJ. 2006 Apr 11;174(8):1124-9.

Heterozygous familial hypercholesterolemia: an underrecognized cause of early cardiovascular disease. (pdf)

Yuan G, Wang J, Hegele RA.
Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ont.

Heterozygous familial hypercholesterolemia (HeFH) is a monogenic disorder that affects about 1 in 500 people, with a higher prevalence in certain subpopulations such as people of Quebecois, Christian Lebanese and Dutch South Afrikaner extraction. HeFH is characterized by cholesterol deposits affecting the corneas, eyelids and extensor tendons; elevated plasma concentrations of low-density lipoprotein (LDL) cholesterol; and accelerated vascular disease, especially coronary artery disease (CAD). Although HeFH is genetically heterogeneous, it is most often caused by heterozygous mutations in the LDLR gene encoding the LDL receptor. We describe a man who was diagnosed with HeFH after he had a myocardial infarction at 33 years of age. By DNA sequence analysis, he was found to have a heterozygous splicing mutation in his LDLR gene. This discovery expanded the growing mutational spectrum in patients with HeFH in Ontario. Given that HeFH is a treatable cause of early vascular disease, it is important that this condition be recognized, diagnosed and treated in affected patients; but as yet, there is no consensus on the best approach. Diagnostic criteria based on family history and clinical presentation have been proposed for patients with suspected HeFH. Biochemical or molecular screening might be considered to detect new cases of HeFH in populations with a relatively high HeFH prevalence and a relatively small number of possible causative mutations. So far, however, the most cost-effective and efficient systematic strategy to detect previously undiagnosed cases of HeFH is still cascade testing: clinical and biochemical screening of close relatives of the proband patient diagnosed with HeFH. Pharmacologic treatment of HeFH is cost-effective.

 

Diabetes Care. 2006 May;29(5):1125-7.

Metabolic syndrome and risk of coronary, cerebral, and peripheral vascular disease in a large Dutch population with familial hypercholesterolemia. (pdf)

Rana JS, Jansen AC, Zwinderman AH, Nieuwdorp M, van Aalst-Cohen ES, Jukema JW, Trip MD, Kastelein JJ.
Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, Room F4-159.2, 1105 AZ Amsterdam, Netherlands.

 

J Intern Med. 2006 Aug;260(2):183-5.

Lipoprotein (a) and risk of cardiovascular disease in patients with metabolic syndrome in a population of familial hypercholesterolaemia. (pdf)

Rana JS, Jansen AC, Zwinderman AH, van Aalst-Cohen ES, Jukema JW, Trip MD, Kastelein JJ.

 

Arterioscler Thromb Vasc Biol. 2005 Jul;25(7):1475-81. Epub 2005 May 5.

Genetic determinants of cardiovascular disease risk in familial hypercholesterolemia. (pdf)

Jansen AC, van Aalst-Cohen ES, Tanck MW, Cheng S, Fontecha MR, Li J, Defesche JC, Kastelein JJ.
Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands.

OBJECTIVE: To investigate the contribution of polymorphisms in multiple candidate genes to cardiovascular disease (CVD) risk in a large cohort of patients with heterozygous familial hypercholesterolemia (FH). METHODS AND RESULTS: We genotyped 1940 FH patients for 65 polymorphisms in 36 candidate genes. During 91.451 person-years, 643 (33.1%) patients had at least 1 cardiovascular event. Multifactorial Cox survival analysis revealed that the G20210A polymorphism in the prothrombin gene was strongly associated with a significantly increased CVD risk (GA versus GG; P<0.001). CONCLUSIONS: In a large cohort of FH patients, we found that the G20210A polymorphism in the prothrombin gene is strongly associated with CVD risk. Our results constitute a step forward in the unraveling of the hereditary propensity toward CVD in FH and might lead to better risk stratification and hence to more tailored therapy for CVD prevention.

 

Eur J Hum Genet. 2005 Oct;13(10):1137-42.

Genetic determinants of plasma HDL-cholesterol levels in familial hypercholesterolemia. (pdf)

van Aalst-Cohen ES, Jansen AC, Boekholdt SM, Tanck MW, Fontecha MR, Cheng S, Li J, Defesche JC, Kuivenhoven JA, Kastelein JJ.
Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands.

The objective of this study was to determine the extent to which common genetic variants can explain the variation of high-density lipoprotein cholesterol (HDL-C) plasma levels in familial hypercholesterolemia (FH). FH is characterized by elevated low-density lipoprotein cholesterol levels and premature cardiovascular disease (CVD). Although low HDL-C levels have been shown to affect the severity of the clinical phenotype, little is known about the factors that determine HDL-C levels in these patients. A cohort of 1002 heterozygous FH patients was genotyped for polymorphisms in the genes encoding for ATP-binding cassette transporter A1, apolipoprotein (apo) AIV, apoCIII, apoE, cholesteryl transfer ester protein, hepatic lipase, lipoprotein lipase, and two paraoxonases. Multiple linear regression showed that, together, these polymorphisms explain only 3.9% of the variation of HDL-C plasma levels. When significant two-way interactions between the polymorphisms were also taken into account, the explained variation rose to 12.5%. In a regression model that also incorporated sex, smoking, alcohol use, body mass index, and concomitant beta-blocker use as covariates, the explained variation of HDL-C plasma levels even increased to 32.5%. This study provides direct evidence that multiple, modestly penetrant, but highly prevalent, polymorphisms can explain a substantial part of the variation of HDL-C plasma levels in a representative large cohort of heterozygous FH patients.

 

Heart. 2004 Dec;90(12):1431-7.

Established and emerging coronary risk factors in patients with heterozygous familial hypercholesterolaemia. (pdf)

Neil HA, Seagroatt V, Betteridge DJ, Cooper MP, Durrington PN, Miller JP, Seed M, Naoumova RP, Thompson GR, Huxley R, Humphries SE.
Division of Public Health & Primary Health Care, Institute of Health Sciences, University of Oxford, Old Road, Headington, Oxford OX3 7LF, UK.

OBJECTIVES: To assess the clinical and biochemical factors associated with inter-individual variation in susceptibility to coronary artery disease (CAD) in treated heterozygous familial hypercholesterolaemia. DESIGN: A cross sectional study was conducted of 410 patients recruited from six lipid clinics in the UK. RESULTS: CAD was documented in 104 of the 211 men and in 55 of the 199 women with mean ages of onset of 43.1 and 46.5 years, respectively. CAD was significantly more common in men (49% v 28%, p < 0.001) and in patients who had smoked cigarettes versus patients who had never smoked (51% v 28%, p < 0.001). After adjusting for age, sex, and current smoking status, there were no significant differences between patients with or without CAD in lipoprotein(a), homocysteine, fibrinogen, plasminogen activator inhibitor-1, white blood cell count, body mass index, glucose, triglyceride or total cholesterol. However, high density lipoprotein (HDL) cholesterol concentrations were significantly lower in those with CAD (6%, 95% confidence interval (CI) 1% to 11%, p = 0.03) and this difference was greater in women than men (12% v 2%, p = 0.041). CONCLUSIONS: These results indicate that emerging coronary risk factors appear not to be associated with CAD in adults with treated familial hypercholesterolaemia, but the strong association with smoking suggests that patients should be identified early in childhood and discouraged from ever starting to smoke.

 

J Intern Med. 2004 Dec;256(6):482-90.

The contribution of classical risk factors to cardiovascular disease in familial hypercholesterolaemia: data in 2400 patients. (pdf)

Jansen AC, van Aalst-Cohen ES, Tanck MW, Trip MD, Lansberg PJ, Liem AH, van Lennep HW, Sijbrands EJ, Kastelein JJ.
Department of Vascular Medicine, Academic Medical Centre, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.

OBJECTIVE: To determine the contribution of classical risk factors to the development of cardiovascular disease (CVD) in patients with heterozygous familial hypercholesterolaemia (FH). DESIGN: A retrospective, multi-centre, cohort study. Extensive data were collected by scrutinizing medical records and the use of questionnaires. Multivariate Cox regression was used to study the relationship between potential risk factors and the occurrence of CVD. SETTING AND SUBJECTS: We included 2400 FH patients from 27 Dutch lipid clinics. The diagnosis of FH was based upon the presence of a low-density lipoprotein receptor mutation or upon strict clinical criteria. MAIN OUTCOME MEASURES: Cardiovascular mortality and CVD. RESULTS: During 112.943 person-years, 782 (32.6%) patients had had at least one cardiovascular event. Male gender (RR 2.82, 95% CI 2.37-3.36), smoking (RR 1.67, 95% CI 1.40-1.99), hypertension (RR 1.36, 95% CI 1.06-1.75), diabetes mellitus (RR 2.19, 95% CI 1.36-3.54), low HDL-C (RR 1.37, 95% CI 1.15-1.63) and elevated lipoprotein(a) levels (RR 1.50, 95% CI 1.20-1.79) proved to be independent CVD risk factors. These six risk factors explained 18.7% of the variation in the occurrence of CVD. CONCLUSIONS: Male gender, smoking, hypertension, diabetes mellitus, HDL cholesterol and lipoprotein(a) levels proved to be important risk factors for CVD in FH patients. In addition to the routine institution of statin therapy, controlling these factors needs special attention in the management of this disorder.

 

Am J Cardiol. 2001 Mar 1;87(5):547-53.

Evaluation of coronary risk factors in patients with heterozygous familial hypercholesterolemia.

Hopkins PN, Stephenson S, Wu LL, Riley WA, Xin Y, Hunt SC.
Department of Pathology, University of Utah School of Medicine, Salt Lake City, USA.

Age at onset of clinically manifested coronary artery disease (CAD) varies widely among patients with familial hypercholesterolemia (FH). A number of factors in addition to high low-density lipoprotein cholesterol (LDL) have been suggested as predictors of risk among patients with FH, but a comprehensive examination of their utility is lacking. We therefore measured plasma lipids, carotid intima-medial thickness, and a variety of coronary risk factors in 262 patients with FH > or = 30 years old (68 of whom had premature CAD). Age (p < 0.0001) and gender were the most important determinants of premature CAD risk, with men having 5.64 times the risk of women (p < 0.0001). In addition, cigarette smoking (odds ratio [OR] 2.71, p = 0.026), smaller LDL as determined by the LDL cholesterol/LDL apolipoprotein B ratio (OR 2.60, p = 0.014), and white blood cell count (p = 0.014) were also statistically significant risk factors. Lipoprotein(a) and the presence of xanthoma were associated with risk only in very early coronary cases. After correction for age, carotid intima-media thickness was not associated with CAD risk. Insulin, fibrinogen, homocysteine, plasma C-reactive protein, and the angiotensin-converting enzyme insertion/deletion polymorphism were unrelated to risk in this cohort. These results provide little justification for extensive investigation of risk factors among patients with FH, at least for the risk factors examined here. Rather, the inherent high LDL cholesterol of these patients should be the focus of preventive efforts. The novel finding of increased risk with smaller LDL may prove useful but needs further confirmation.

 

Arterioscler Thromb. 1991 Mar-Apr;11(2):290-7.

Genetic and environmental factors affecting the incidence of coronary artery disease in heterozygous familial hypercholesterolemia. (pdf)

Hill JS, Hayden MR, Frohlich J, Pritchard PH.
Department of Pathology, University of British Columbia, Vancouver, Canada.

This study explores the influence of selected genetic and environmental factors on the clinical expression of heterozygous familial hypercholesterolemia (FH). A detailed examination of the physical and biochemical features of FH was performed in a large cohort of 208 females and 156 males. Females with FH had higher levels of total, low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol when compared with males, although the concentration of HDL cholesterol was significantly lower for both sexes when compared with normals. The reported incidence of coronary artery disease (CAD) was 31% for men and 13% for women, which was lower when compared with figures from previous studies. The average age of onset of coronary symptoms was delayed in females, with a mean age of 55 years compared with 48 years for males (p less than 0.05). A greater risk of developing CAD in men was associated with lower levels of HDL cholesterol and a history of smoking. In women, however, CAD was associated with elevated triglycerides and the presence of hypertension. The frequencies of the epsilon 2, epsilon 3, and epsilon 4 alleles of apolipoprotein E in 125 unrelated FH subjects did not differ significantly from the normal population. In addition, there was no apparent relation between apo E4 and the concentration of any of the parameters in the plasma lipid profile; however, the presence of the E2 isoform was associated with significantly elevated triglycerides in both sexes. This study has allowed us to identify those factors, which, in addition to total cholesterol levels, are associated with the development of premature coronary atherosclerosis in heterozygous FH.

 

Atherosclerosis. 1982 Aug;44(2):201-10.

Coronary artery disease in heterozygous familial hypercholesterolemia.

Hirobe K, Matsuzawa Y, Ishikawa K, Tarui S, Yamamoto A, Nambu S, Fujimoto K.

Serum lipids, lipoproteins and Achilles tendon thickness in 52 patients with heterozygous familial hypercholesterolemia (FH) were investigated in order to clarify what are the important factors for the development of coronary artery disease (CAD) in heterozygous FH patients. There were no significant differences in the average concentration of total cholesterol and triglyceride between the patients with and those without CAD. The HDL cholesterol (HDL-C) level was significantly lower in patients with CAD than in those without, and the HDL-C value was within the normal range in most of the patients with heterozygous FH, if not associated with CAD. Although most of the males aged over 50 years had CAD and a decreased level of HDL-C, many of the aged females were without signs of CAD. The HDL-C value of heterozygous FH patients with CAD was significantly lower compared with the age-matched group without CAD. The Achilles tendon was thicker in patients with CAD than in those without CAD, both for males and females, although it was less closely correlated with the incidence of CAD than HDL-C or the atherogenic index. A forecast concerning the development of CAD in heterozygous FH may be possible if we consider multiple parameters, such as HDL-C, atherogenic index, Achilles tendon thickness, etc.