Objective: To investigate possible risk factors and mechanisms behind the four times higher and diverging mortality from coronary heart disease in Lithuanian compared with Swedish middle aged men.

Abstract-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 ␥-tocopherol, lycopene, and ␤-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␤-hydroxycholesterol was higher in Lithuanian men, 12Ϯ5 versus 9Ϯ8 (SD) ng/mL (Pϭ0.0011). 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 (75Ϯ14 versus 90Ϯ13 minutes, PϽ0.0001) and the concentration of LDL linoleic acid was lower (249Ϯ56 versus 292Ϯ54 g/mg of LDL protein, PϽ0.0001). Lipid corrected ␥-tocopherol was 0.07Ϯ0.02 mg/mL in Vilnius men and 0.12Ϯ0.04 mg/mL (PϽ0.0001) in Linköping men. There was a negative correlation between the concentration of 7␤-hydroxycholesterol and lag time (RϭϪ0.31, Pϭ0.0023). It is suggested that the higher 7␤-hydroxycholesterol concentration in Lithuanian men is an indication of an increased in vivo lipid peroxidation. (Arterioscler Thromb Vasc Biol. 1999;19:967-971.)Key Words: oxysterols Ⅲ LDL oxidation Ⅲ vitamins Ⅲ fatty acids Ⅲ cross-sectional study C oronary heart disease (CHD) incidence and mortality is rising in the East European countries, in contrast to the decreasing trend in Western Europe and in the United States. [1][2][3] For example, the mortality in CHD among 50-to 54-year-old men was 4 times higher in Lithuania than in Sweden in 1994. In LiVicordia I, a cross-sectional population study, we investigated the prevalence of ultrasound-detected subclinical atherosclerosis and possible causes for these diverging coronary mortality trends in the 2 countries. 4 Lithuanian men had more carotid atherosclerosis. Although traditional risk factors could not explain the difference in CHD mortality, we found that Lithuanian men had a higher LDL susceptibility to oxidation and lower concentrations of the plasma antioxidant vitamins ␥-tocopherol, ␤-carotene, and lycopene than Swedish men. There is a high correlation between the plasma concentrations of these vitamins and the corresponding vitamin content in LDL. 5 The increased susceptibility to oxidation and lower concentrations of LDLassociated vitamins in the Lithuanian population may be caused by dietary factors or an increased in vivo oxidation of LDL. We have recently shown that cholesterol oxidation products (oxysterols) are good markers of LDL oxidation in vitro. 6 In addition, the oxysterol 7␤-hydroxycholesterol, together with an increased oxidation susceptibility of VLDLϩLDL, were the strongest predictors of progression of carotid atherosclerosis in Finnish men. 7 We therefore decided to determine oxysterols in plasma from the 2 p...

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01994720.

No abstract

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.