Association of atherogenic low-density lipoprotein subfractions with carotid atherosclerosis

Abstract

Patients with carotid atherosclerosis are at increased risk of both stroke and ischaemic heart disease. Low-density lipoprotein (LDL) is a heterogeneous group of particles, with small, dense particles being more atherogenic. We studied 79 patients (51 men, mean +/- SD age 62.4 +/- 11.7 years) referred for Doppler ultrasound assessment of the carotid arteries. Evidence of carotid atherosclerosis, defined as the presence of atherosclerotic plaque, stenosis or occlusion in one or more of the six carotid artery segments examined, was found in 44 patients (56%). LDL subfractions were analysed by disc polyacrylamide gel electrophoresis with prior ultracentrifugation of serum to remove chylomicrons. This method produces a LDL score; the higher the score, the greater the proportion of the more atherogenic LDL subfractions. Mean LDL score was significantly higher in diseased patients (mean +/- SD, 1.56 +/- 0.61) than the normal group (1.26 +/- 0.65) (t = 2.12, p = 0.037). There was no significant association between LDL score and severity of carotid artery stenosis. Age (adjusted odds ratio 1.09, 95% CI 1.03-1.15) and smoking history (2.09, 95% CI 1.10-3.98) predicted carotid atherosclerosis in logistic regression analysis, with LDL score achieving borderline significance (2.20, 95% CI 0.91-5.29). Small, dense LDL subfractions are associated with carotid atherosclerosis and may be a modifiable risk factor for stroke as well as ischaemic heart disease.

Análise de parâmetros bioquímicos séricos e urinários em atletas de meia maratona

“…Diversos estudos demonstraram o aumento na concentração sérica de ácido úrico após a realização de exercício físico extenuante (4,(28)(29)(30), embora Robertson e cols. tenham observado uma redução nos níveis séricos de ácido úrico depois de uma sessão de exercício físico intenso.…”

“…O ácido úrico plasmático pode neutralizar radicais peroxil na fase aquosa e contribuir com a defesa antioxidante plasmática. A conversão de hipoxantina em xantina/ácido úrico é catalizada pela xantina oxidase e está associada à formação de íon superóxido, oriundo da semiubequinona da cadeia de transporte de elétrons (12,28,30). A análise estatística dos resultados mostra uma redução significativa na concentração de ácido úrico sérico após a meia maratona (p < 0,05).…”

Prevalence of Dyslipidemia in Patients with Malignant Hypertension

“…Indeed, a preponderance of small LDL particles has been shown to be associated with both coronary and carotid artery disease. [10,11] Interest in the 'atherogenic lipid profile' has been raised by the presence of prospective observational studies showing increased risk of vascular events in individuals with raised triglycerides, low HDLcholesterol. [12,13] Additionally, there is some evidence that fibrates, which improve this dyslipidaemia through their action on lipoprotein lipase activity, may reduce the brisk of vascular events in patients exhibiting this phenotype.…”

Distinct effects of fixed combinations of valsartan with either amlodipine or hydrochlorothiazide on lipoprotein subfraction profile in patients with hypertension

“…Several studies have shown that small-dense LDL (sdLDL) particles are more atherogenic than large and buoyant LDL (lbLDL), 9 and are associated with increased risk of coronary artery disease or stroke. 10,11 High-density lipoprotein (HDL) also consists of a heterogeneous group of particles differing not only in size and density, but also in chemical composition and physiological function. The exact role that HDL particles of different size play in the pathogenesis of atherosclerosis is currently under investigation.…”