POLAND AND UNITED-STATES COLLABORATIVE STUDY ON CARDIOVASCULAR EPIDEMIOLOGY - A COMPARISON OF HDL CHOLESTEROL AND ITS SUBFRACTIONS IN POPULATIONS COVERED BY THE UNITED-STATES ATHEROSCLEROSIS RISK IN COMMUNITIES STUDY AND THE POL-MONICA PROJECT

HDL cholesterol (HDL-C) levels are inversely related to coronary heart disease (CHD) risk; and HDL-C distributions vary among countries. Pol and is one of the few developed countries in which CHD rates are incre asing at the same time that US rates have been falling, but whether th ese differences are explained by differences in risk factors such as H DL-C has not been determined. To examine this possibility, levels of H DL-C and its subfractions were compared in US and Polish urban and rur al men and women aged 45 to 64 years. Age-adjusted HDL-C means were 0. 20 mmol/L higher in urban Polish men and 0.37 mmol/L higher in rural P olish men than in their US counterparts (P<.0001); means in urban Poli sh women were 0.06 mmol/L higher (P<.05) and in rural Polish women 0.0 9 mmol/L higher (P<.001) than in their US counterparts. Adjustment for age, education, alcohol intake, smoking, BMI, heart rate, and menopau se status (in women) had little effect on differences. Means of HDL(2) and HDL(3) levels showed similar between-country differences, althoug h differences were minimal for HDL(2) in urban men and women, and HDL( 3) means did nor differ between rural women. BMI was inversely related to HDL-C and both subfractions in all gender-country-site strata (P<. 001), and alcohol was directly related to HDL-C (P<.001) in all strata except Polish women. Cigarette smoking was negatively related to HDL- C and both subfractions in all US samples except HDL(2) in urban men, whereas in Polish samples, significant associations were found only in urban women for HDL-C and in rural and urban women for HDL(3). Age, h eart rate, and education showed inconsistent or no association with HD L-C and its subfractions in either country. This profile of HDL-C and its subfractions in Polish samples contrasts sharply with the opposite trend in CHD mortality rates, which suggests either that other risk f actors may account for the trends or that the relationship between HDL -C and CHD may differ between the two countries.