No abstract

A multicenter case-control study was conducted to evaluate the relations between antioxidant status assessed by biomarkers and acute myocardial infarction. Incidence cases and frequency matched controls were recruited from 10 European countries to maximize the variance in exposure within the study. Adipose tissue needle aspiration biopsies were taken shortly after the infarction and analyzed for levels of carotenoids and tocopherols. An examination of colinearity including all covariates and the three carotenoids, alpha-carotene, beta-carotene, and lycopene, showed that the variables were sufficiently independent to model simultaneously. When examined singularly, each of the carotenoids appeared to be protective. Upon simultaneous analyses of the carotenoids, however, using conditional logistic regression models that controlled for age, body mass index, socioeconomic status, smoking, hypertension, and maternal and paternal history of disease, lycopene remained independently protective, with an odds ratio of 0.52 for the contrast of the 10th and 90th percentiles (95% confidence interval 0.33-0.82, p = 0.005). The associations for alpha- and beta-carotene were largely eliminated. We conclude that lycopene, or some substance highly correlated which is in a common food source, may contribute to the protective effect of vegetable consumption on myocardial infarction risk.

Immigrants from the Indian subcontinent (South Asians) in England and Wales have higher morbidity and mortality from coronary heart disease than the general population; this seems to apply to both Hindus and Muslims. Studies in north west London and Trinidad found that the increased risk of coronary heart disease in Indians was not explained by dietary fat intakes, smoking, blood pressure, or plasma lipids. In the present study the distribution of coronary risk factors was measured in an East London borough where the mortality and attack rate from coronary heart disease are higher in the Asian population, predominantly Muslims from Bangladesh, than in the rest of the population. In a sample of 253 men and women aged 35-69 from general practice, mean plasma cholesterol concentrations were lower in Bangladeshi than in European men and women. Mean systolic blood pressures were 10 mm Hg lower in Bangladeshis. Plasma fibrinogen concentrations were similar in Bangladeshis and Europeans and factor VII coagulant activity was lower in Bangladeshi than in European men. In contrast with the findings in Hindus in north west London, smoking rates were high in Bangladeshi men and the ratio of polyunsaturated fatty acids to saturated fatty acids in plasma lipids was lower in Bangladeshis than in Europeans. Diabetes was three times more common in Bangladeshis than in Europeans and serum insulin concentrations measured after a glucose load were twice as high in Bangladeshis. High insulin concentrations in Bangladeshis were associated with high plasma triglyceride and low high-density lipoprotein cholesterol concentrations. Insulin resistance, leading to diabetes, hyperinsulinaemia, and secondary lipoprotein disturbances, is a possible mechanism for the high rates of coronary heart disease in South Asians in Britain and overseas.

Abstract-Omega-3 fatty acids have potential antiatherogenic, antithrombotic, and antiarrhythmic properties, but their role in coronary heart disease remains controversial. To evaluate the association of omega-3 fatty acids in adipose tissue with the risk of myocardial infarction in men, a case-control study was conducted in eight European countries and Israel. Cases (nϭ639) included patients with a first myocardial infarction admitted to coronary care units within 24 hours from the onset of symptoms. Controls (nϭ700) were selected to represent the populations originating the cases. Adipose tissue levels of fatty acids were determined by capillary gas chromatography. The mean (ϮSD) proportion of ␣-linolenic acid was 0.77% (Ϯ0.19) of fatty acids in cases and 0.80% (Ϯ0.19) of fatty acids in controls (Pϭ0.01). The relative risk for the highest quintile of ␣-linolenic acid compared with the lowest was 0.42 (95% confidence interval [CI] 0.22 to 0.81, P-trendϭ0.02). After adjusting for classical risk factors, the relative risk for the highest quintile was 0.68 (95% CI 0.31 to 1.49, P-trendϭ0.38). The mean proportion of docosahexaenoic acid was 0.24% (Ϯ0.13) of fatty acids in cases and 0.25% (Ϯ0.13) of fatty acids in controls (Pϭ0.14), with no evidence of association with risk of myocardial infarction. In this large case-control study we could not detect a protective effect of docosahexaenoic acid on the risk of myocardial infarction. The protective effect of ␣-linolenic acid was attenuated after adjusting for classical risk factors (mainly smoking), but it deserves further research.

No abstract

The gradients in proportions of polyunsaturated fatty acids probably reflect differences in dietary intake of linoleic acid.

No abstract

We studied variables known to change with thyroid hormone status in 18 patients with subclinical hypothyroidism before and during treatment with thyroxine in a dose sufficient to restore the plasma TSH response to TRH to normal. There was an associated increase in both plasma total T4 and free T4 within the normal range but plasma total T3 and free T3 were unchanged. As a result of thyroxine treatment there was a small but significant increase (P less than 0.05) in left ventricular ejection fraction (LVEF) with maximal exercise but no significant changes in LVEF at rest and moderate exercise, continuously monitored mean sleeping heart rate, day/night ratios of urinary sodium excretion, peripheral nerve conduction velocities, fasting serum triglycerides, total cholesterol (TC), high density lipoproteins (HDL) or TC/HDL ratios. On this evidence we do not consider that thyroxine replacement therapy is indicated in patients with subclinical hypothyroidism.