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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is accumulating evidence that free radicals may contribute to various diseases such as cancer or cardiovascular disease. Possible health hazards can to some extent be prevented by the body's multilevel defense system against free radicals, which comprises, besides others, antioxidant vitamins. The 12-year mortality follow-up of 2,974 participants of the Basal Study allowed to test the hypothesis that low antioxidant vitamin plasma concentrations (vitamin A, C, E and carotene) were associated with increased death from cancer of various sites and death from atherosclerosis such as ischemic heart disease and stroke, respectively. For the analysis 204 cancer cases, 132 fatalities from ischemic heart disease (IHD) and 31 deaths from cerebral vascular disease were available. Cancer mortality. Overall mortality from cancer was associated with low mean plasma levels of carotene adjusted for cholesterol (p less than 0.01) and of vitamin C (p less than 0.01). Bronchus and stomach cancers were associated with a low mean plasma carotene level (p less than 0.01). Subjects with subsequent stomach cancer had also lower mean vitamin C and lipid-adjusted vitamin A levels than survivors (p less than 0.05). Calculating the relative risk with exclusion of mortality during the first two years of follow-up, low plasma carotene was associated with an increased risk for bronchus cancer (RR 1.8, p less than 0.05), and the small number of stomach cancer cases (RR 2.95, p less than 0.05) low plasma levels of carotene and vitamin A with all cancer types (RR 2.47, p less than 0.01), and low plasma retinol in older subjects (greater than 60 years) with lung cancer (RR 2.17, p less than 0.05). Studies in other cohorts with a poor vitamin E status revealed an increased risk of subsequent cancer at low vitamin E levels as well. It is concluded that low plasma levels of all major essential antioxidants are associated with an increased risk of subsequent cancer mortality. Cardio-vascular mortality. Plasma carotene concentration below quartile 1 was associated with an increased risk for IHD (RR 1.53, p = 0.02). The same was true for low levels of both carotene and vitamin C (RR = 1.96, p = 0.022). The risk of cerebrovascular death was elevated in subjects with low carotene in the presence of low vitamin C plasma concentration (RR 4.17, p less than 0.01). These data confirm and extend recent findings on an inverse correlation of beta-carotene and vitamin C respectively to CVD.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Inverse correlation between essential antioxidants in plasma and subsequent risk to develop cancer, ischemic heart disease and stroke respectively: 12-year follow-up of the Prospective Basel Study. 145 Jun

The behavior of native retinyl palmitate labeled intestinally derived lipoproteins and their remnants was studied in 8 NZW and 8 WHHL (5 homo- and 3 heterozygote) normal-fed rabbits and in 3 cholesterol-fed NZW, after 1 month of cholesterol feeding, and 3 and 5 months after resuming normal feeding. Palmitate labeled lipoproteins were produced by the intestine after administration of 50,000 IU of Vitamin A, together with olive oil via gastric intubation. Blood was drawn before and 3,6,9,12,24, and in some instances, 48 h later. Retinol (R) and retinyl palmitate (RP) were measured in whole serum and in the chylomicron, d less than 1006, d greater than 1006 less than 1019, d greater than 1019 less than 1063, d greater than 1063 less than 1210 g/ml lipoprotein fractions and in the infranatant. The R content of the serum was almost all concentrated in the infranatant, it did not change during the vitamin A test and was similar in WHHL, and normal- or cholesterol-fed NZW rabbits. In the normal-fed NZW the RP content of the serum increased within 6 h after giving the vitamin A fat meal (peak value less than 200 microgram/100 ml) and then decreased. In the WHHL homozygotes, the RP increased to a much greater degree (peak value 600-1820 micrograms) and for a much longer time, as it was still increased in the 5 cases studied after 24 h, and in 3 cases studied after 48 h. Similar RP curves were obtained in NZW rabbits, after 1 month of cholesterol feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
Atherosclerosis 1990 Dec
PMID:Retinyl palmitate labeled intestinally derived lipoproteins accumulate in the circulation of WHHL rabbits. 210 74

The metabolic remnants of triglyceride-rich lipoproteins are atherogenic in man and experimental animals. Particles resembling lipoprotein remnants have been found in plasma from patients with chronic renal failure (CRF). In this study we took advantage of the observation that retinyl esters are transported only by lipoproteins that originate in the intestine, that is, by chylomicrons (CM) and their remnants. To investigate further remnant metabolism in CRF, plasma RE were measured by reverse-phase high performance liquid chromatography in 20 non-diabetic hemodialyzed patients with CRF and 20 hospitalized non-diabetic control subjects 12-15 h after the administration of retinyl ester, 25000 IU orally. Total plasma RE were increased 3-fold in the CRF patients (P less than 0.001). Quantitative analysis of retinoids and lipids in fractions separated by unit-gravity flotation and flocculation in 3% polyvinylpyrrolidone indicated that the plasma RE were not contained among intact CM. Mean plasma retinol in CRF was also elevated consistent with previous observations and the known role of the kidney in retinol-binding protein metabolism. Although postabsorptive RE concentration was correlated positively and significantly with plasma triglyceride concentration in both groups, RE were higher in CRF patients at comparable plasma triglyceride concentrations. These data support the proposal that atherogenic lipoprotein remnants accumulate in the plasma of patients with CRF.
Atherosclerosis 1985 Nov
PMID:Retinyl ester retention in chronic renal failure. Further evidence for a defect in chylomicron remnant metabolism. 408 53

Primary and secondary vitamin deficiencies cause many metabolic diseases which possible are life-threatening. Nevertheless none of the hypovitaminosis is known to give rise to hyperlipoproteinemias and/or atherosclerosis. On the other hand, the hypolipemic effect of several vitamins, like retinol, ascorbate, tocopherol and nicotinate, has clearly been demonstrated. This effect takes place either on clinically non-demonstrable hypovitaminosis, or by a true pharmacological activity of those factors. In the last case several different mechanisms are probably involved, which are described in the present paper. The use of vitamins in metabolic disorders is justified both for the primary prevention, in order to correct the causes of hyperlipoproteinemias, and in the secondary one, to diminish the blood fat levels, which increase the risk of atherogenesis.
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PMID:[Vitamins in the prevention of hyperlipoproteinemia and atherosclerosis (author's transl)]. 702 63

A recent report based on data from the first National Health and Nutrition Examination Survey suggested that low intake of vitamin A may be associated with a greater risk of airway obstruction. We attempted to replicate these findings in a population-based sample of middle-aged adults (n = 15,743) who participated in the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study. Vitamin A intake was estimated from a 66-item food frequency questionnaire, and the presence of airway obstruction was determined by spirometry. Although airway obstruction was associated in ARIC with well-established risk factors such as age, sex, and smoking, there was little evidence for a role of vitamin A. With only one exception, vitamin A intake was unrelated to airway obstruction in all smoking categories using either categorical or continuous measures of lung function (FEV1, FVC, FEV1/FVC). Only among current smokers in the upper tertile of lifetime cigarette smoking (> 41 pack-years) was the odds ratio of having airway obstruction for the lowest quartile of vitamin A intake compared with the highest quartile elevated (1.7 [95% confidence interval 1.1 to 2.7]). Despite some biological plausibility that vitamin A intake may prevent obstructive lung disease, the inability to demonstrate association in a larger population study, with better estimation of usual dietary intake, casts doubt on the existence of causal relationship.
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PMID:Does dietary vitamin A protect against airway obstruction? The Atherosclerosis Risk in Communities (ARIC) Study Investigators. 792 73

The mechanisms by which exposure to cigarette smoke dramatically increase the incidence and severity of atherosclerosis and the incidence of lung cancer, chronic obstructive airways disease, and emphysema are incompletely understood. Epidemiologic evidence has suggested a modifying role for antioxidant micronutrients, including tocopherols and carotenoids, in these disease processes. It has been suggested that oxidants in cigarette smoke could be involved. We exposed freshly obtained human plasma to the gas phase of cigarette smoke to assess its effects on tocopherols, carotenoids, and retinol. Exposure to cigarette smoke led to the depletion of most of the lipophilic antioxidants in 20 mL human plasma. The order of disappearance was lycopene > alpha-tocopherol > trans-beta-carotene++ > (lutein + zeaxanthin) = cryptoxanthin > gamma-tocopherol = retinol. However, despite a substantial loss of alpha-tocopherol, there was very little peroxidative damage to lipids, and no detectable change in the content of polyunsaturated fatty acid-rich cholesterol esters. We conclude that a wide spectrum of lipophilic micronutrients undergo degradation when exposed to gas-phase cigarette smoke. The relevance of these in vitro findings to possible cigarette smoke-induced depletions of respiratory tract lipophilic antioxidants remains to be clarified.
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PMID:Destruction of tocopherols, carotenoids, and retinol in human plasma by cigarette smoke. 859 20

The vitamin and mineral nutritional status of 34 elderly (mean age 77.6 +/- 4.7 years) and 39 younger subjects (mean age 41.7 +/- 7.5 years) from Crevalcore and Montegiorgio (the two rural areas of The Seven Countries Study) was studied. Comparisons have been made between centres, between age groups, and with data obtained from similar surveys performed in 1960 and 1970. Levels of thiamin and riboflavin nutritional status were higher in 1991 than in 1970. Plasma retinol values were above levels of deficiency, but vitamin E and beta-carotene tended to be low. The zinc status of the populations, as assessed by leucocyte zinc concentrations, was generally low. A decline in copper intake during the past ten years may be responsible for the low leucocyte copper concentration which was more apparent in the younger subjects. Serum cholesterol was above, and HDL cholesterol below, the European Atherosclerosis Society recommendations.
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PMID:Vitamin and mineral nutritional status and other biochemical data assessed in groups of men from Crevalcore and Montegiorgio (Italy). 882 99

The atherogenicity of low density lipoproteins (LDL) may be modulated by its serum levels, structure and affinity for components of the intima, all properties that can be altered by diet. Linoleic acid-rich diets (n-G, 18:2) reduce the levels of LDL whereas those rich in oleic (n-9,18:1) are considered 'neutral'. However, LDL enriched in linoleic acid have been reported to be more vulnerable to free radical-mediated oxidation than those enriched in oleic, a potentially atherogenic property. The effect of dietary fats on other properties of LDL that may also modulate atherogenesis, such as size and capacity to interact with intima components, are not well established. We explored here how a change from an olive oil-rich diet (OO) to a sunflower oil-rich one (SFO) affects these parameters in a community with a traditional Mediterranean diet. Eighteen free-living volunteers were placed for 3 weeks on a diet with 31% of caloric intake as sunflower oil and then shifted for an additional 3 weeks to a diet in which OO provided 30.5% of the calories. The LDL after SFO had a fatty acids ratio of (18:2 + 18:3 + 20:4) to (16:0 + 16:1 + 18:0 + 18:1) of 1.06 +/- 0.11 compared to 0.73 +/- 0.06 after the OO period. Serum LDL was significantly lower after SFO than after OO. Unexpectedly, copper-catalyzed oxidation of LDL from the SFO period was significantly less than that of the particles from the OO period. The resistance to oxidation of LDL of the SFO and OO period related to alterations in content of the antioxidants alpha-tocopherol, beta-carotene and retinol, in addition to changes in size and fatty acids composition. In vitro binding of LDL to human arterial proteoglycans was also significantly lower for the SFO-LDL than the OO-LDL, a result that can also be attributed to the larger size of the SFO-LDL. Therefore, three properties of LDL: circulating levels, oxidizability, and affinity with intima proteoglycans, that may modulate its atherogenicity, were shifted in a favorable direction by diets rich in linoleic acid and natural antioxidants.
Atherosclerosis 1996 Sep 06
PMID:Effect of olive and sunflower oils on low density lipoprotein level, composition, size, oxidation and interaction with arterial proteoglycans. 884 55

Oxidative modification of plasma lipoproteins increases their atherogenicity. Nutritive antioxidants, including carotenoids, can prevent such lipoperoxidation and may protect against atherosclerosis. Plasma retinol, ascorbate, alpha-tocopherol and four carotenoids (lutein, lycopene, alpha-carotene and beta-carotene) were measured using HPLC in 45 patients with chronic renal failure (CRF) and in 21 controls. Plasma retinol was significantly increased in patients with CRF (conservative therapy mean of 3.7 mumol/l vs. 1.9 mumol/l; p < 0.001). Plasma lycopene was significantly lower in patients with CRF (healthy mean 0.44 mumol/l vs. conservative therapy mean 0.27 mumol/l and haemodialysis mean of 0.17 mumol/l; p < 0.001), a finding that persisted even after adjusting for plasma cholesterol. Low circulating antioxidant lycopene levels may contribute to an already impaired antioxidant defence system in patients with CRF. The process of haemodialysis further compromises antioxidant defences, principally by removing water-soluble ascorbate and urate, but does not appear to affect circulating carotenoid concentrations.
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PMID:Abnormal antioxidant vitamin and carotenoid status in chronic renal failure. 894 32

Oxidative modification of LDL is believed to be a crucial step in atherosclerosis. Thus, antioxidant vitamins may have a role in the prevention of coronary disease. We examined the cross-sectional association of serum vitamin levels, the susceptibility of LDL to hemin-induced oxidation (lag phase to conjugated diene formation), and the malondialdehyde-LDL (MDA-LDL) to native LDL radioactivity binding ratio with carotid intima-media thickness (IMT), a measure of asymptomatic early atherosclerosis. The participants in this observational study were 231 asymptomatic age-, sex-, race-, and field center-matched case-control pairs selected from the Atherosclerosis Risk in Communities (ARIC) study cohort on the basis of B-mode carotid artery ultrasonograms obtained from 1986 through 1989. Cases exceeded the 90th percentile of IMT, and control subjects were below the 75th percentile of IMT for all arterial segments. Biochemical analyses were performed on fasting frozen (-70 degrees C) serum specimens collected from 1990 through 1992. In conditional logistic regression adjusting for age, blood storage time, total cholesterol, and log-triglyceride concentrations, serum beta-cryptoxanthin and lutein plus zeaxanthin levels were inversely related to the extent of atherosclerosis (odds ratio [OR] per 1-SD increase: 0.75, 95% confidence interval [CI]: 0.59-0.94; and OR per 1-SD increase: 0.76, 95% CI: 0.59-0.95, respectively). Increases in alpha-carotene and lycopene were associated with nonsignificantly lower odds of being a case, whereas beta-carotene, retinol, and alpha-tocopherol were unrelated to IMT. Although not reaching statistical significance, the lag phase and autoantibodies against MDA-LDL were positively associated with asymptomatic atherosclerosis. After adjustment for potential confounders, only the inverse association of lutein plus zeaxanthin with asymptomatic atherosclerosis was maintained. This study supports a modest inverse association between circulating levels of some carotenoids, particularly lutein plus zeaxanthin, and carotid IMT. These findings suggest that these carotenoid compounds (regarded as biomarkers of fruit and vegetable intake) may be important in early stages of atherosclerosis.
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PMID:Association of serum vitamin levels, LDL susceptibility to oxidation, and autoantibodies against MDA-LDL with carotid atherosclerosis. A case-control study. The ARIC Study Investigators. Atherosclerosis Risk in Communities. 919 70


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