Long chain polyunsaturated fatty acids may account for higher low-density lipoprotein oxidation susceptibility in Lithuanian compared to Swedish men.

OBJECTIVES: Mortality in coronary heart disease among middle-aged men is four times higher in Lithuania than in Sweden. Traditional risk factors cannot account for this difference. We earlier reported that low-density lipoprotein (LDL) in Lithuanian men showed a lower resistance to oxidation, measured as LDL lag time during copper oxidation, than that in Swedish men. Serum concentrations of several fat-soluble antioxidant vitamins were lower among Lithuanian men. The aim of this study was to investigate whether differences in LDL fatty acid composition could account for the difference in LDL oxidation susceptibility between men in the two countries. METHODS: This cross-sectional study included randomly selected healthy 50-year-old men from Vilnius, Lithuania (n=50) and Linköping, Sweden (n=50). Main outcome measures were fatty acids in LDL, phospholipid (PL) and cholesterol ester (CE) fractions of LDL and LDL oxidation susceptibility. RESULTS: The mean proportions of PL 20:5n3 (eicosapentaenoic acid, EPA) were higher in Vilnius men (2.09 +/- 1.05 vs. 1.53 +/- 0.58%, p= 0.004). LDL lag time was shorter in Vilnius men, mean +/- SD (75.4 +/- 13.6 vs. 89.5 +/- 13.1 mins, p<0.0001) than in Linköping men. Mean serum gamma-tocopherol was lower in Vilnius men (0.07 +/- 0.05 vs. 0.12 +/- 0.04 microg/mmol, p<0.0001) but alpha-tocopherol did not differ. In a multiple regression analysis controlled for city, high PL-EPA, low alpha-tocopherol, and high plasma triglycerides significantly contributed to a short LDL lag time, r2=0.53. CONCLUSIONS: Fat quality, i.e. poly unsaturated fatty acids, especially LDL-EPA, plasma triglycerides and antioxidative vitamins may partly account for the increased LDL oxidation susceptibility found in Vilnius men compared with Linköping men.

Adipose tissue fatty acids in men from two populations with different cardiovascular risk: the LiVicordia study.

The LiVicordia study was set up to investigate possible causes for coronary heart disease mortality in middle-aged Lithuanian men being four times higher than in Swedish men. In a previous part of this study we found lower total and low density lipoprotein (LDL) cholesterol in the Lithuanian men in spite of them having a higher fat intake than in the Swedish men. Their LDL was also more susceptible to oxidation in vitro than was that of the Swedish men. Fat quality can influence LDL oxidation. In order to obtain data on long-term fat quality intake we measured the fatty acid composition of abdominal wall adipose tissue by gas chromatography in men aged 50 years from Vilnius, Lithuania (n=50) and Linköping, Sweden (n=50). Men from Vilnius had a significantly higher percentage of adipose tissue long chain polyunsaturated fatty acids (PUFA) (20:4n6, 20:5n3, 22:5n5, 22:6n3) and lower percentage of saturated fatty acids, especially myristic acid (14:0), 3.4+/-0.7 versus 4.6+/-0.8, p<0.0001. The percentage content of adipose tissue linoleic acid (18:2n6) was 11.5+/-2.1 versus 11.0+/-1.4 (n.s.) and of linolenic acid (18:3n3) 0.7+/-0.3 versus 0.6+/-0.2 (n.s.) in men from Vilnius and Linköping, respectively. It is concluded that the adipose tissue content of essential fatty acids is similar in men from Vilnius and men from Linköping and therefore the intake is also likely to be similar. The higher contents of long chain highly unsaturated fatty acids in men from Vilnius may be of importance in the oxidation process of LDL.

Increased plasma 7 beta-hydroxycholesterol concentrations in a population with a high risk for cardiovascular disease.

The mortality in coronary heart disease among 50- to 54-year-old men is 4 times higher in Lithuania than in Sweden. It was recently suggested that traditional risk factors could not explain this mortality difference. LDL of Lithuanian men showed, however, a lower resistance to oxidation than that of Swedish men. In addition, the plasma concentration of gamma-tocopherol, lycopene, and beta-carotene were lower in Lithuanian men. In the present investigation, we determined plasma oxysterols in men from Lithuania and Sweden and found that the plasma concentration of 7 beta-hydroxycholesterol was higher in Lithuanian men, 12+/-5 versus 9+/-8 (SD) ng/mL (P=0.0011). This oxysterol is a cholesterol autoxidation product and there is no indication that it should have an enzymatic origin. Mean LDL oxidation lag time was shorter in Lithuanian men (75+/-14 versus 90+/-13 minutes, P<0.0001) and the concentration of LDL linoleic acid was lower (249+/-56 versus 292+/-54 microgram/mg of LDL protein, P<0.0001). Lipid corrected gamma-tocopherol was 0.07+/-0.02 mg/mL in Vilnius men and 0.12+/-0. 04 mg/mL (P<0.0001) in Linköping men. There was a negative correlation between the concentration of 7 beta-hydroxycholesterol and lag time (R=-0.31, P=0.0023). It is suggested that the higher 7 beta-hydroxycholesterol concentration in Lithuanian men is an indication of an increased in vivo lipid peroxidation.

[The effect of linseed oil on the fatty acid composition of blood plasma low- and very low-density lipoproteins and cholesterol in diabetics]. / Vliianie l'nianogo masla na zhirno-kislotnyi sostav lipoproteidov nizkoi i ochen' nizkoi plotnosti i kholesterin plazmy krovi u bol'nykh sakharnym diabetom.

Twenty patients with compensated diabetes mellitus of 10-15-year duration took polyunsaturated fatty acids omega-3 (30 g of flax oil a day) in addition to their routine food. This led to an insignificant lowering in total cholesterol and elevation of cholesterol in high density lipoproteins. A significant rise in the level of omega-3 polyunsaturated fatty acids in lipoproteins occurred in 6 patients only. Minor effect of the diet oil may be due to low delta-6-desaturic activity in the majority of the examinees. The findings point to necessity to use other sources of omega-3 acids in diet therapy of diabetics, fish oil, in particular.

[The stability of the properties of electroradiographic plates for medical x-ray diagnosis]. / O stabil'nosti svoistv élektroradiograficheskikh plastin dlia meditsinskoi rentgenodiagnostiki.

The properties of selenium electrocardiographic plates used for the purposes of medical diagnosis are under discussion. The plates are observed to reveal no noticeable traces of fatigue and to retain constant sensitivity to radiation and radiography in the case of the 5 to 10 minutes' interval between obtaining electroradiograms (ERG) during working hours (7 hours). After the technical resource which is equal to 2000 ERG is over, the radiation sensitivity decreases to 10% and defectiveness does not exceed 25%. The actual expiration date of the plates is between 7 and 9 years without worsening of their properties. The quality of the plates stored for a longer time might deteriorate due to the defect which is attributed to crystallization of the selenium layer.

[Effect of linseed oil on fatty acid composition of low- and very low density lipoproteins, cholesterol and its fractions in the blood serum of albino rats]. / Vliianie l'nianogo masla na zhirnokislotnyi sostav lipo- proteidov nizkoi i ochen' nizkoi plotnostei, urovnii kholesterina i ego fraktsii v plazme krovi belykh krys.

The authors studied the influence of linseed oil, and mixtures of linseed and sunflower oils, in varying ratios, on the levels of cholesterol, low- and very low-density lipoproteins, high-density cholesterol, free and esterified cholesterol, and on the fatty-acid composition of low- and very low-density lipoproteins. In experiments on Wistar white rats linseed oil decreased cholesterol concentration, and the levels of low- and very low-density lipoproteins, as well as affected the fatty-acid composition of lipoproteins.