Serum Lipid Fatty Acid Research Articles

Interrelationships among hair mercury levels, fish-eating habits and fatty acid composition of serum lipids

Scalp hair and blood samples were collected from 151 persons who were living in several places in Kagoshima-prefecture and supposedly had no abnormal exposures to mercury compounds. Hair was analysed for total mercury and blood was analysed for serum lipid fatty acids. The study subjects were also individually questioned on the amounts of average fish intake in a day. Results obtained were as follows:1) Hair mercury levels were significantly higher in males than in females, the average values being 11.95±9.15ppm with a maximum of 45.5ppm for males and 7.05±5.36ppm with a maximum of 25.8ppm for females. The hair mercury levels increased with increases in the amount of daily fish consumption for both sexes with an indication that such increases might be attributable to the fish consumption.2) Serum concentrations of eicosapentaenoic acid (20:5, EPA) and docosahexaenoic acid (22:6, DHA) both of which belong to the ω-3 series of polyunsaturated fatty acid, and the value of EPA/AA (a ratio of 20:5 for arachidonic acid) also increased with an increase of daily fish consumption for both sexes, indicating that these values can give quite valuable information in the assessment of individual fish consumption.3) When comparison was made taking into account of the amount of daily fish consumption, however, there were no significant differences of hair mercury levels between the sexes, particularly for those having a low intake of fish.4) There were no significant differences between the sexes for the serum concentrations of eicosapentaenoic acid and docosahexaenoic acid but the value of EPA/AA was significantly higher in males than in females, suggesting that males have a partiality for a fish diet as compared with females.5) When the serm concentration of eicosapentaenoic acid or docosahexaenoic acid was used as an indicator for evaluation of the amount of fish consumption, the hair mercury levels showed a tendency to increase along with the values of these indicators for both males and females. However, the hair mercury levels were significantly higher in males than in females even when the comparison was made taking into account of the values of these indicators, which could not be explained only by the amount of fish consumption.

Effect of supplementing medium chain triglycerides with linoleic acid-rich monoglycerides on severely disturbed serum lipid fatty acid patterns in patients with cystic fibrosis.

7 patients with cystic fibrosis, having serum lipids with fatty acid compositions (FACs) skewed in the direction of essential fatty acid deficiency, were given a mixture of medium chain triglycerides (MCTs) with linoleic acid-rich monoglycerides (LAMs) as food fat (about 1-1.25 g/kg body weight/day). Blood was sampled before and after a short period (4-11 days) of experimental fat feeding. The FACs of the serum triglycerides (TGs), cholesterol esters (CEs) and phospholipids (PLs) were determined before and after dietary treatment. Dietary treatment resulted in a significant increase of the previously reduced fraction of linoleic acid in all lipid classes. In TGs, the increase in the fraction of linoleic acid was accompanied by a reduction of the previously increased fraction of palmitoleic acid to normal values, by a reduction in the fraction of oleic acid to subnormal values and by an increase in the fraction of stearic acid which, however, remained normal. In PLs, the increase in the fraction of linoleic acid was accompanied by an increase in the fraction of dihomogammalinoleic acid which remained normal, however. In CEs, concomitant with the increase of the previously reduced linoleic acid fraction, there was a reduction of previously elevated palmitoleic and oleic fractions, the latter to a normal value. Thus, supplementing a MCT-containing diet with LAMs in cystic fibrosis patients results in a considerable amelioration of the previously disturbed FACs of the major serum lipid classes.

Changes of polyunsaturated fatty acids in serum lipids of spontaneously hypertensive rats during the onset of high blood pressure

The fatty acid pattern of serum triglycerides and cholesterol esters has been estimated in spontaneously hypertensive rats (SHR) and normotensive Wistar rats (WR) at 4,5 6 ,7, and 8 weeks of age. The percentage of linoleic acid (LA~ was lower in SHR when compared with 1AR, but increased with age in both strains. Arachidonic acid (AA) showed an abrupt fall in SHR and NR at 5 weeks of age in comparison to 4 week old rats. The fall was more pronounced in serum triglycerides of the former and in cholesterol esters of the latter. The changes in AA occured prior to the onset of hypertension in SHR. From the data it can be concluded that the formation of AA from LA might be dependent on age being quantitatively different in SHR and WR. Furthermore, eicosapentaenoic acid (EPA) appeared leaver in SHR than in age-related WR. Docosapentaenoic and docosahexaenoic acids also revealed a marked decrease in rats between 4 and 5 weeks of age indicating that individual polyunsaturated fatty acids (PUPA) change in a different manner which might be relevant to the development of high blood pressure in SHR.

Serum selenium concentration related to myocardial infarction and fatty acid content of serum lipids.

A longitudinal case-control study of 33 patients with one or more risk factors for coronary heart disease and 64 controls showed that the serum selenium concentration (range 0.63-1.33 mumol/l (50-105 micrograms/l] was not associated with development of clinical manifestations of coronary heart disease during a follow up of five to seven years. The content of polyunsaturated fatty acids, especially eicosapentaenoic acid, in serum cholesterol esters and phospholipids was positively correlated with selenium concentration. As a low content of polyunsaturated fatty acids in serum lipids was an independent risk factor for coronary heart disease in these subjects it may be hypothesised that the high coronary risk in subjects with a very low serum selenium concentration (less than 0.57 mumol/l (less than 45 micrograms/l] might be due not to selenium deficiency but to the coexisting low concentrations of polyunsaturated fatty acids in serum.

Effect of sex and age on fatty acid composition of human serum lipids

Serum was obtained from approximately 10 individuals of each sex from each decade of life from 0 to 90 years of age. Most of the serum samples were obtained from the excess remaining after diagnostic procedures performed for hospitalized patients. The individuals were screened according to tentative diagnosis, and overt cases of diseases known to have effects upon essential fatty acid (EFA) metabolism were eliminated. Serum lipids were separated into phospho- lipids, cholesteryl esters, triglycerides, and free fatty acids. These lipid classes and a sample of the total lipids were subjected to fatty acid analysis by gas chromatography. The data produced were arranged by computer to compare the effects of age upon each fatty acid present and upon each parameter calculated from fatty acid composition for each lipid group and each sex. No significant difference between sexes was found for any individual fatty acid in any lipid, but the average total unsaturation of all lipid classes was significantly higher for males than for females at both 0 and 90 years of age. In cholesteryl esters, and to a lesser extent in phospholipids, the total polyunsaturated fatty acids, the total co6 acids and the sum 18:2e�6 + 20:4w6 - 20:3w9 declined more rapidly with age in females than in males, suggesting a trend toward EFA deficiency, although the ratio 20:3w9/ 20:4�6 did not change significantly. The age and sex differences observed and the SD encountered were much smaller than the changes observed in EFA deficiency, indicating that this population has utility in comparisons with suggested cases of EFA deficiency. The triene/tetraene ratio, 20: 3w9/20:4w6, was found to be 0.1 ± 0.08 for male and female populations, indicating that a ratio above 0.2 should be considered the upper limit of normalcy. Between 0 and 4 months of age, a profound change took place in the patterns of fatty acids in serum lipids. At birth, phosphohipids were low in l8:2c,6 but 20:&,6 and 20:3co9 were elevated. The ratio of 20:3�,9/20:4w6 was 0.16 at birth and decreased progressively during infancy. Some of these observations suggest that at birth the infant has marginal reserves of EFA. The drastic change in composition of serum lipid shortly after birth probably reflects a change in supply of EFA from one rich in 20:4w6 and poor in 18:2�,6 to one high in 18:2�6 and low in 20:4�6. This may have significance in the nutrition of premature or very young infants. Am. J. Clin. Nuir. 32: 2390-2399, 1979.

Serum lipid pattern in beta-thalassaemia.

Serum lipids, phospholipid fractions and the composition of serum lipid fatty acids were studied in 20 children presenting beta-thalassaemia major, 20 heterozygous children and 20 normal controls. Total serum phospholipids, their fractions and cholesterol were significantly lower in patients with thalassaemia major. These changes were referred to hepatic damage and to severe anaemia, respectively. Some serum lipid polyunsaturated fatty acids were significantly decreased in patients with thalassaemia major as compared to heterozygotes and normal controls. Since these alterations are a sign of lipid oxidation, the causes of this phenomenon are discussed.

ESSENTIAL FATTY ACIDS IN SERUM LIPIDS OF YOUNG MALE RURAL GUATEMALANS AND URBAN NORTH AMERICANS.

ESSENTIAL FATTY ACIDS IN SERUM LIPIDS OF YOUNG MALE RURAL GUATEMALANS AND URBAN NORTH AMERICANS.

Correlation of Diet and Serum Cholesterol Level with Serum Lipid Fatty Acid Composition.

SummaryThe findings suggest that the level of linoleic acid in the diet, age, and possibly other factors may influence the serum cholesterol level and fatty acid composition of the serum lipid fractions. The significance of these findings is discussed.

Dietary Fat and Hypercholesteremia in the Cebus Monkey: III. Serum Polyunsaturated Fatty Acids

The effect of dietary factors on the concentration of polyunsaturated fatty acids in serum lipids and in subfractions of serum lipids was studied in the Cebus monkey. When cholesterol was included in the diet the polyunsaturated fatty acid content of sera was reduced. The level of dietary polyunsaturated fatty acids influenced the level of polyunsaturated fatty acids esterified with cholesterol in serum. When Cebus monkeys were placed on diets essentially free of dietary fat, they developed certain hair and skin changes. The polyunsaturated fatty acid levels in the total serum lipids and in the serum cholesterol ester fractions of these monkeys was markedly depressed. The dienoic acids were the principal group affected.