This volume is the proceedings of the 4th International Congress on 'Arterio­ sclerosis; Etiopathogenesis, Clinical Evaluation and Therapy', held in Bologna. In the pages of this book you will find a record of all the themes developed by the various speakers at the Congress and closely studied by the many scientists who attended and who were concerned to learn about recent research develop­ ments in the arteriosclerosis field. In the sections that follow, the various trends in the different countries can be seen. The emphasis throughout is on clinical aspects of arteriosclerosis, and not merely on experimental laboratory studies. This is particularly important at a time when the technology is improving and so sometimes seems to command more attention than actual clinical observations. A careful researcher of arteriosclerosis will be able to see from the results of epidemiological, experimental, nutritional and clinical surveys (addressed more towards controlling physiological behaviour through life habits than through drugs) the best course to take in defining and controlling­ with maximum precision - the progression of arteriosclerosis disease. Professor Sergio Lenzi Professor Giancarlo Descovich xix SECTION 1 Atherosclerosis risk factors and their influence on cardiovascular diseases BACKGROUND PAPER 1 Atherosclerosis today A. M. COTTO, Jr. RISK FACTORS The three major risk factors for coronary artery disease are hypercholesterol­ aemia, hypertension and cigarette smoking. I will focus on lipids and lipo­ proteins but would also like to make a few comments about other risk factors.