Prevalence of cardiovascular disorders and risk factors in two 75-year-old birth cohorts examined in 1976-1977 and 2005-2006

Background and aims The number of older people are increasing worldwide, and cardiovascular diseases are the major causes of death in western societies. This study examines birth cohort differences in cardiovascular disorders and risk factors in Swedish elderly. Methods Representative samples of 75-year-olds living in Gothenburg, Sweden, examined in 1976-1977 and in 2005-2006. Blood pressure, s-cholesterol, s-triglycerides, height, body weight, body mass index, history of myocardial infarction, angina pectoris and stroke/TIA, and diabetes mellitus were measured. Results The prevalence of total cardiovascular disorders, hypertension and hypercholesterolemia decreased, and the prevalence of stroke increased in both genders. The prevalence of cardiovascular disorders was higher in women than in men in 1976-1977, and higher in men than in women in 2005-2006. The decrease in blood pressure occurred independently of antihypertensive treatment. The prevalence of current smokers decreased in men and increased in women. The prevalence of life-time smokers and diabetes mellitus increased only in women. The proportion on antihypertensive treatment and overweight and obesity increased only in men. Hypertension, overweight and obesity were more common in women in 1976-1977. These sex differences were not observed in 2005-2006. Conclusions The overall prevalence of cardiovascular disorders decreased, and sex differences reversed between the 1970s and 2000s among Swedish septuagenarians. Our findings emphasize the importance of environmental factors, not only for the prevalence of cardiovascular disorders, but also as explanations for sex differences. Reasons for changes could be increased survival in those with disorders and risk factors, changes in lifestyle and diet, and better preventive strategies, such as treatment of hypercholesterolemia and hypertension.