RESUMEN
BACKGROUND AND AIMS: epidemiological studies suggest polyunsaturated fatty acids protect against the development of atherosclerosis. The aim of this study was to perform a randomized controlled trial of gamma-linolenic and eicosapentaenoic acids in patients with lower limb atherosclerosis. Main outcome measures were: cholesterol and lipoprotein concentrations; haemostatic and rheological variables; the ankle brachial pressure index; walking distance; and cardiovascular events and death. METHODS: 120 men and women with stable intermittent claudication were randomized to 2 years treatment with either a combination of gamma-linolenic and eicosapentaenoic acids, or placebo. RESULTS: 39 (65.0 cent) of those taking fatty acids and 36 (60.0 cent) of those taking placebo completed the trial. Lipid concentrations did not differ significantly during the trial. In those taking fatty acids, haematocrit was significantly higher than in the placebo group after 6 months (46.1 cent compared with 44.6 cent, P = 0.01), and systolic blood pressure was significantly lower after 2 years (150|mmHg compared with 161.8|mmHg, = 0.05). There was no difference in walking distance, but there was a small reduction in non-fatal coronary events in the fatty acid group (10 cent compared with 15 cent, P > 0.05). CONCLUSIONS: a combination of polyunsaturated fatty acids produced a statistically significant reduction in systolic blood pressure, but no other significant benefits on risk factors. The trend towards fewer coronary events in those taking fatty acids warrants further investigation.
Asunto(s)
Suplementos Dietéticos , Ácido Eicosapentaenoico/administración & dosificación , Claudicación Intermitente/dietoterapia , Ácido gammalinolénico/administración & dosificación , Anciano , Arteriosclerosis/sangre , Arteriosclerosis/dietoterapia , Arteriosclerosis/mortalidad , Presión Sanguínea , Femenino , Humanos , Claudicación Intermitente/sangre , Claudicación Intermitente/mortalidad , Masculino , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
The concentrations of the major lipoprotein classes and of high density lipoprotein (HDL) subfractions in 63 male patients with arteriosclerosis of the lower limbs (claudication) were determined and compared with values from 63 healthy controls. The patients with peripheral arterial disease (PAD) had reduced levels of total HDL-cholesterol and HDL2b of large particle size, increased levels of small HDL3c particles and a high ratio of total plasma-cholesterol to HDL-cholesterol (coronary risk factor). The PAD patients, however, had lower levels of low density lipoprotein (LDL)-cholesterol but higher concentrations of very low density lipoprotein (VLDL)-cholesterol and plasma triglyceride than healthy subjects. This study therefore suggests that in PAD, the protective effect of HDL may be more important than the atherogenic effect of LDL. It further suggests that while HDL-cholesterol HDL2b and the ratio of total plasma-cholesterol to HDL-cholesterol may provide valid indices for identifying individuals at risk of PAD, other factors, such as LDL and total cholesterol, may not provide such an appropriate risk indicator.
Asunto(s)
Arteriosclerosis Obliterante/sangre , Pierna/irrigación sanguínea , Lípidos/sangre , Arteriosclerosis Obliterante/etiología , HDL-Colesterol/sangre , VLDL-Colesterol/sangre , Electroforesis en Gel de Campo Pulsado , Humanos , Lipoproteínas/sangre , Lipoproteínas HDL/sangre , Lipoproteínas HDL2 , Masculino , Persona de Mediana Edad , Factores de Riesgo , Fumar/efectos adversos , UltracentrifugaciónRESUMEN
Epidemiological evidence suggests that antioxidants protect against the development of atherosclerosis. To determine the effectiveness of antioxidant therapy in patients with lower limb atherosclerosis, a randomized placebo-controlled trial was performed in 120 men and women with intermittent claudication and an ankle/brachial pressure index (ABPI) < or = 0.9. The study was analysed on an intention-to-treat basis. After 2 years, there were no significant differences between antioxidant and placebo groups in plasma cholesterol, lipoproteins, haemostatic or rheological factors. However, after 6 months, low density lipoprotein cholesterol was significantly lower in those taking antioxidant (108.0 mg/dl compared with 120.1 mg/dl, p < 0.05). There were no differences in the ABPI or walking distance, although both groups improved slightly with time. The incidence of cardiovascular events and death was nonsignificantly lower in the antioxidant compared with the placebo group: event rates per year were 5.5% (95% CI 2.4-8.6) in the first year and 9.6% (95% CI 6.8-12.4) in the second year for those on antioxidants; and 7.7% (95% CI 5.1-10.3) and 13.3% (95% CI 8.9-17.7) respectively for those on placebo. Significantly fewer serious adverse events occurred in the antioxidant than the placebo group: 21.8% (95% CI 16.2-27.4) compared with 40.0% (95% CI 33.9-46.1). This study therefore suggests that although antioxidants may prevent cardiovascular events in patients with peripheral atherosclerosis, they do not improve lower limb function.